18

Chapter-II

KHAPRA BEETLE AND ESTIMATION OF LOSSES

2.1 INTRODUCTION

Khapra beetle Trogoderma granarium Everts and other beetles of the Dermestidae

family are considered to be the most destructive stored product pests. The pest had been

given status as an A2 quarantine organism for EPPO (OEPP/EPPO, 2007). Besides it is

considered as a pest of quarantine concern for CPPC, COSAVE, JUNAC, NAPPO and

OIRSA.

The continued occurrence of T. granarium on produce imported from countries where it

is native, and the potential for spread due to increasing trade and transportation of

cereals, made it a persistent threat to EPPO countries. The WTO committee on SPS had

also prohibited the importation of wheat, maize, rice, sorghum, chickpeas, beans,

sunflower seeds, sesamum seeds, soybeans, ground nuts, linseed and similar grains and

seeds and the flours and meals thereof in order to protect domestic production and to

prevent the introduction and spread of this notorious pest. This restriction is applicable to

products originating in or consigned from various countries including Austria, Serbia,

Spain, Switzerland; Afghanistan, Bangladesh, Chinese Taipei, Cyprus, India, Iran, Iraq,

Israel, Korea, Lebanon, Pakistan, Saudi Arabia, Sri Lanka, Syria, Turkey, Yemen,

Angola, Algeria, Egypt, Gambia, Libya, Mali, Mauritania, Morocco, Mozambique,

Niger, Nigeria, Senegal, Somalia, Sudan, Tunisia, Zimbabwe, Indonesia, Malaysia and

all other countries in which the Khapra beetle has been reported (EPPO, 1981).

The import restrictions are supported by the facts that feeding by Khapra beetle larvae

reduces the quality, grade and weight of grain. In India, average damage levels ranged

from 6-33 percent of grain in a single storage season, with maximum damage of 73

percent (Rahman et al., 1945). Loss of weight in wheat ranged from 2.2 to 5.5 percent.

Under optimal conditions of 36 °C, 15 percent infestation level caused 2.6 percent loss in

weight and 24 percent in viability of wheat grains in few months of storage (Prasad et al.,

1977). The weight loss of grain and cost of necessary treatment may result in less profit

for the wholesalers. Severe infestations of grain by Khapra beetle may make it

unpalatable or un-marketable. Grain quality may decrease due to depletion of specific

nutrients. Infestation levels of 75 percent in wheat, maize, and sorghum grains results in

19

significant decreases in crude fat, total carbohydrates, sugars and true protein contents;

and increases in moisture, crude fiber and total protein contents (Jood and Kapoor, 1993;

Jood et al., 1993, 1996a). Besides, substantial loss of vitamins e.g. thiamin, riboflavin

and niacin occurs due to the infestation (Jood and Kapoor, 1994). Significant increases or

health hazardous non-protein nitrogen, total nitrogen and total protein have also been

recorded (Jood and Kapoor, 1993). Whereas level of uric acid exceeds the acceptable

limits due to T. granarium and other insect pest’s infestations. Total lipids,

phospholipids, galactolipids, and polar and non-polar lipids have also been reported to

decline significantly at infestation levels of 50 percent and 75 percent (Jood et al.,

1996b). On the other hand, antinutrient polyphenol and phytic acid have been reported to

increase significantly (Jood et al., 1995). Morison (1925) suggested that barbed hairs of

larvae that rub off and remain in the grain may present a serious health hazard if

swallowed. Cast skins may cause dermatitis in people handling heavily infested grains

(Pruthi and Singh, 1950).

Theses quality deteriorating characteristics of T. granarium have assigned the pest a

status of a noxious pest and a technical barrier to trade. Keeping the destructive nature

and its significance for the global food security and safety in view, the present

investigations were carried out with the following objectives.

Objectives:

1. Estimation of quantitative losses caused by the infestation of T. granarium larvae.

2. Evaluation of qualitative losses with special reference to crude protein, fiber and fat

contents.

3. Varietal preference of T. granarium toward different major varieties.

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Chapter-II 2.2 REVIEW OF LITERATURE

The Khapra beetle Trogoderma granarium Everts, particularly in its larval stage of

development, is the world's most destructive pest of stored grain and stored vegetable

products. Numerous research reports corresponding to extent of damage have proved that

T. granarium is one of the serious threats to food security of the countries, which are

already facing food shortages. Larvae of this pest feed and contaminate the food grains

through their cast skins, urine, excreta rendering the commodities unsuitable for human

consumption; ultimately causing critical food security and safety problems. In adverse

conditions, the pupae can survive in dormant phase for at least three years and so can

easily spread during foodstuff handling and transport. Work of some notable researchers

is summarized as under.

2.2.1 Quantitative Losses Caused by Khapra Beetle

The Khapra Beetle is one of the world’s most damaging pests of whole and ground

cereals, oilseeds, dry fruits, copra and other stored products. Its immense economic

significance is due to its potential to cause huge loss in stored grains through voracious

feeding and heating of grains, in larval ability to withstand starvation for up to 3 years as

well as in its ability to live on food with very low moisture content.

El-Lakwah et al., (1989) observed that T. granarium flourishes in unheated premises in

most countries of Africa, the Middle East and southern Asia. It normally occurs at places

where temperature is relatively high. That is why Khapra beetle is considered as the most

serious pests in hot and dry areas including Sahel region of Africa and parts of the Indian

sub-continent (Banks, 1978; Haines, 1981). Studies have further revealed that the pest is

extremely cold-hardy and tolerant of both high temperature and extremely low relative

humidity.

Rees (1998) reported that larvae as well as adults of T. granarium are similar in

appearance to T. variabile but T. granarium is better able to survive and breed on cereals

and other stored products. Devastating infestations can occur, especially in bagged grains

and seed stores with a loss ranging 2-70 %. The larval stages of the pest are more tolerant

to contact insecticides and fumigants. Pruthi and Singh (1950) maintained that Khapra

21

beetle larvae typically attack the embryo point or a weak place in the pericarp of grain or

seed, but in case of higher infestation they feed other parts too. Young larvae feed on

damaged seeds, while the older larvae are capable to feed on whole grains. Howe (1952)

revealed that larvae wander in and out of sacked material, weakening the sacks, which

may ultimately tear resulting in spillage and spoilage of grains. Rahman et al., (1945)

observed that feeding by Khapra larvae reduce weight and grade of grain. They reported

severe damage caused by larval feeding to the tune of 6 to 33 percent in a single storage

season, with maximum damage of 73 percent. Hafiz and Hussain (1961) recorded 10-18

percent losses due to insects, rats and mold in Pakistan. Girish et al., (1975) recorded an

average weight loss of 7 to 22 percent caused by T. granarium, T. castaneum, R.

dominica, S. oryzae, Sitotroga cerealella and Ephestia cautella during six months of

storage. Bains et al., (1976) described distribution and pest status of T. granarium and

other stored product pests in wheat grain stores in the Indian Punjab, on the basis of a

survey conducted during 1971-72. They reported grain damage ranging 9 to 14.4 percent

and the weight loss ranging 1 to 3 percent. The incidence was higher in bulk-stored

wheat than in bags. Bhardwaj et al., (1977) collected 180 samples of wheat from all 12

districts of the Indian Punjab, during December 1975 and January 1976. They found that

the samples were commonly infested with T. granarium, T. castaneum, S. oryzae, R.

dominica, S. cerealella and O. surinamensis. Laboratory investigations of the samples

revealed that the moisture content of the grain averaged 11 percent, germination 82.5

percent, infested grains 5.1 percent, germ eaten 2.6 percent and weight loss 2.5 percent

after about 8-10 months' storage. Prasad et al., (1977) also found that khapra larvae

caused 2.2 to 5.5 percent weight loss in stored wheat. They found that 15 % infestation

level caused 2.6 % weight loss coupled with 24 percent loss in viability under optimum

condition at f 36 °C.

Such significant quantitative losses and cost of control negatively affect profitability for

grain dealers, flour millers and wholesalers. T. granarium normally attacks as a major

pest except in arid climates where other primary pests are inhibited by the dryness

(Proctor, 1994). Khan and Cheema (1978) determined 2.3 percent storage loss of wheat

in some parts of the Punjab province of Pakistan. Kraszpulski (1985) reported that T.

granarium feeds mainly on products of plant origin. Optimum growth and development

of the pest takes place at temperatures ranging 32 to 35 °C. He further reported that

larvae of Khapra beetle are much resistant to insecticides than other stored product pests.

Ahmed (1988) during his investigation reported 10-15 percent loss of wheat grains due to

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the attack of Khapra beetles, lesser grain borers, rice weevils and granary in cereal

storage sector of Pakistan.

Hemed et al., (1992) worked on population buildup and losses caused by different

combinations of T. granarium, S. cerealella and R. dominica to maize grains under

laboratory conditions. They found that S. cerealella was more successful grain feeder

than T. granarium and R. dominica. Seifelnasr (1992) used baited insect traps to survey

and identify stored grain insects in the main grain production and storage area in central

Sudan. T. granarium, R. dominica, O. surinamensis, O. mercator, T. castaneum,

T. confusum, S. oryzae, Cryptolestes ferrugineus, S. cerealella and Tenebroides

mauritanicus were collected in the traps. T. granarium and R. dominica ranked 1st and

2nd in abundance, respectively at all sites. The percentage losses of sorghum were

strongly related with the mean numbers of insects trapped at different sites and ranged

between 2.5 and 7.6 percent. Khan and Kulachi, 2002, collected 220 samples of wheat

grains from different locations of D.I. Khan. They recorded average losses to the tune of

3.4 and 6.5 percent by C&W and TGM methods, respectively within five months storage.

They also observed black pointed grains, broken/shriveled grains and green/immature

grains, which were counted as 0.6, 3.1 and 0.7 percent, respectively. While an average

amount of foreign matter was found 30.3 percent. On an average 1.93 percent grains

were found infested with T. granarium, R. dominica and Tribolium spp.

Aheer and Ahmed (1993) evaluated feeding preference of khapra larvae and lesser grain

borer for twelve wheat varieties / lines including 85054, 86175, Shalimar-88, 85205,

86371, 85276-2, 84021, 86299, Punjab-85, 83035, 86369 and 84133-6. They observed

significant differences in number of bored grain and grain weight loss caused by

T. granarium and R. dominica among the varieties. A wheat variety, 86175 proved less

susceptible to R. dominica and exhibited minimum damaged grains (0.6 percent) and loss

in weight (0.34 percent). In case of T. granarium, a variety 86299 was found relatively

more resistant. It showed minimum loss in weight (0.58 percent). Rao et al., (2004)

screened twenty-eight wheat cultivars for their resistance to T. granarium. In these

investigations mean number of progeny beetles per 20 grams of different cultivars ranged

10.0 to 36.9. The wheat varieties Kalyansona, HS 240, WTN 50 and UAS 2023 were

found as the most resistant, while MACS 2846, Sonalika, Raj 6062, DT 46 and GW 1188

proved to be the most susceptible. Correlation studies between various grain

characteristics and progeny beetle emergence revealed that grain size and hardness

23

played an important role in resistance and susceptibility of wheat grain to Khapra beetle.

The maximum percentage loss in weight was recorded in MACS 2846 (63.6) and

minimum in Kalyansona (19.6).

2.2.2 Qualitative Losses of Wheat, Food Safety and the Khapra Beetle

Morison (1925) disclosed that barbed hairs of khapra larvae that rub off and remain in

the grain may prove a serious hazard to human heath if swallowed. Pruthi and Singh

(1950) concluded that cast skins may cause dermatitis in people handling heavily infested

grains. Diekmann (1996) stated that out of 20 species of storage pests, T. granarium has

been declared as a quarantine pest in most of the countries of the world due to its food

safety concerns. Perez et al., (2003) also reported that insect fragments in wheat flour are

major concerns of the milling industry because consumers demand high quality and

wholesome products. Due to the reason FDA has established a defect action level of 75

insect fragments per 50 g of flour. Today flour millers of the United States regularly test

their flour to comply with this federal requirement and to deliver sound flour to their

consumers. Parashar (2006) reported that T. granarium larvae are one of the most serious

stored grain pests but the adults are harmless. The larvae start feeding from embryo point

and later consume the entire kernel/seed, which makes the grain hollow and only the

husk remains. In case of severe infestations, infested grains are filled with frass, cast

skins and excreta, which badly deteriorates quality of the grains. Hence, there is an

increasing trend among grain buyers towards zero-tolerance to these contaminants.

Countries such as Canada have a legally defined zero tolerance for stored-grain insects

(Canada Grain Act, 1975). The larvae are often found on edges of jute stacks and make

the infested store unhygienic. Khare et al., (1974) reported that insect infestation in

stored wheat grain reduce germination and produce unpleasant odors, dirty appearance

and abhorrent taste due to contamination with insect fragments and excrement. They

reported that commonly found stored product insect pests include T. granarium,

T. castaneum, S. oryzae, R. dominica, S. cerealella, O. surinamensis, Cryptolestes

pusillus and Laemophloeus minutus.

Yadav (1980) conducted an experiment to study the effect of temperature and humidity

changes on the protection of stored wheat against insect infestation. He observed that 9.5

percent moisture facilitates the development of S. oryzae. That is why majority of wheat

samples taken were infested by this pest. R. dominica was found in 8.2 percent of

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samples and T. granarium for which high levels of humidity are known to be

unfavourable, was present in only 2.8 percent of samples. Raju (1984) reviewed the

biotic and abiotic factors that cause approximately 20 percent losses of stored foodstuffs

and stored grains in India as compared with 5 percent in Europe. It was found that

T. granarium, T. castaneum, S. oryzae, S. cerealella, R. dominica and Laemophloeus

minutus were the most common species found in food stuffs. He reported that the grain

with > 0.5 percent kernel infestation was unfit for milling, and the wheat flour containing

over 10 mg uric acid/100 g was unacceptable to consumers. Ramzan and Chahal (1985)

conducted laboratory studies with three levels of initial infestation (1, 2 and 3 pairs) of T.

granarium, T. castaneum and S. oryzae. Their results enunciated significant increases in

kernel damage and loss in seed viability with the proportional increase in infestation

level and storage period.

Yadav and Singh (1985) evaluated host-suitability of lentil flour for the development of

eight stored product insects; out of which T. granarium took four times longer in lentil

flour as compared to wheat flour. Similarly, T. castaneum, L. serricorne, and Stegobium

paniceum developed about twice as slowly on lentil flour as compared to wheat.

Warchalewski et al., (1993) studied varietal preference of S. granarius, T. confusum and

E. kuehniella towards 9 wheat varieties. It was found that kernel hardness, falling

number, non-protein nitrogen content and protein quality instead of quantity appears to

contribute towards increased wheat grain resistance. Gharib (2004) carried out studies on

the susceptibility of thirteen Egyptian wheat varieties to infestation by the Khapra beetle

and lesser grain borer. Their results revealed significant differences in growth index,

percent weight loss, damage and germination (%). among the tested varieties. Hala et al.,

(2005) confirmed results of Gharib, 2004 and Samir et al., (2005) by reporting food

preference of T. granarium and S. oryzae towards different wheat and maize varieties.

Their results showed that mean number of eggs/female as well as mean numbers of the

emerged individuals increased when the insects were allowed to feed on their preferred

food grains. Wheat varieties generally proved as more preferred food to the both insects

either in non-choice or free choice methods. Wheat variety Sakha 8 followed by Sakha

93 and maize variety Tri-H 322 were reported as the best preferred for the both insects,

while Giza 168 and Okrani were the least preferred. Poplawska et al., (2001) also carried

out investigations on feeding preferences of Khapra beetle towards grain of four barley

cultivars: Their results revealed that the development of T. granarium larvae on barley

grain and malt took longer as compared to wheat grain. Samir et al., (2005) reported

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T. granarium and S. oryzae as serious primary insect pests of the stored wheat and maize

grains. They reared the both insect pests on five varieties of wheat and maize and

reported significant differences in larval, pupal stages, oviposition period and female

longevity as well as number of eggs/ female. As far food preference is concerned,

T. granarium preferred wheat and maize nearly at the same rate, but S. oryzae preferred

wheat over maize grains. Pingale et al., (2006) subjected soft wheat to artificial

infestation by T. granarium C. oryzae L. and Ephestia cautella W. They reported that

weevils caused heavy reduction in weight of the grain. But the moth, which feeds only on

the germ portion, caused more reduction in viability. Analysis of results exhibited

significant increase in the acidity of fat and a decrease in the thiamine content due to

insect damage; but the effect on other constituents of the grain, such as total nitrogen and

reducing sugars was not significant. Some workers had reported that dietary preferences

of T. granarium vary not only from commodity to commodity but also within different

varieties of the same commodity. Sayed et al., (2006) performed experiments to

determine varietal resistance of wheat against T. granarium and R. dominica. For this

purpose they used twelve wheat varieties viz., Pak-70, Tandojam-83, Mehran-89, TJ-

0787, Sarsabz, Soghat, Sonalika, AZS-4, Zardana, Yekora, Abadgar and Anmol. Their

results revealed that population build up in both insect treatments was the lowest in

variety Mehran-89, whereas the highest population was recorded in case of TJ-0787. On

the basis of percent grain weight loss, the most resistant variety to both insect species

was found to be Mehran-89, while the least resistant varieties recorded were TJ-0787 and

Sarsabz against T. granarium and R. dominica, respectively. The remaining varieties

were considered as moderately resistant to susceptible. It was finally concluded that the

moisture content play a highly significant role in population growth, percent weight loss

and percent grain damage.

Krzymanska and Golebiowska (1987) investigated the effects of feeding by 6 species of

stored products beetles on the chemical composition of wheat grains. It was found that all

the pests exhausted the starch content. However feeding by the adults and larvae of

S. granarius and S. oryzae and the larvae of T. confusum and T. granarium caused an

increase in protein content, whereas larvae of O. surinamensis, T. granarium and T.

confusum reduced lipid content. In case of fatty acids, feeding by Sitophilus spp. reduced

palmitic and oleic acids but increased linoleic and linolenic acids; R. dominica,

T. confusum and T. granarium caused an insignificant increase in linoleic acid. All

species except Sitophilus damaged the germ. Sinha and Sinha (1990) collected fifty

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wheat samples including 25 free from infestation and the remaining 25 infested by stored

product insects. Aspergillus flavus infection was found common (87 percent) in insect

damaged samples; whereas 25 percent in insect-free samples. Of the four major pests

recorded, S. oryzae was the dominant insect species, followed by T. castaneum,

R. dominica and T. granarium. Lopes et al., (1991) subjected grains of Maize variety

BR-300 to infestation level of 5, 20, 30 or 50 percent with S. zeamais. Results did not

reveal significant differences in dry matter digestibility or nitrogen absorption among the

different infested meals but Nitrogen retention was significantly greater for the 5 percent

infested maize (33.77 %) than recorded for the other 3 infestation levels.

Ahmed et al., (1992) conducted a survey to assess the quality characteristics of wheat

grains and compared it with the existing Fair Average Quality (FAQ) standards. A total

of 824 samples were collected and their physical characteristics and insect infestation

were determined. They recorded significant differences among different samples in

relation to presence of foreign matter, moisture content, insect-damaged grain and broken

grain percentages. The incidence of live or dead T. granarium, T. castaneum, S. oryzae

Sitotroga cerealella and R. dominica was recorded in about 7 percent of samples. The

results proved that the current FAQ standards do not describe the quality of wheat

produced. Hence, need for a new grading system was suggested. Sinha and Sinha (1992)

found S. oryzae and T. castaneum as the dominant species found in maize samples when

stored for 4-12 months. Other species included O. surinamensis, R. dominica, T.

granarium and S. cerealella. They found that incidence of Aspergillus flavus as well as

the level of aflatoxins was comparatively higher in insect damaged maize samples than

undamaged samples. Toxigenic strains of A. flavus were isolated from both S. oryzae and

T. castaneum. Jood and Kapoor (1992a) evaluated protein quality of wheat grains having

25, 50 and 75 percent infestation caused by mixed populations of T. granarium and R.

dominica by feeding the infested grains to rats and studying their growth and nitrogen

balance. They found that feeding rats fed on grain with 50 and 75 % resulted in marked

decreases of food intake, body weight gain, food efficiency ratio, protein efficiency ratio,

nitrogen absorption, net protein utilization and dry matter digestibility. These parameters

showed negative association with infestation levels. However 25 percent level of grain

infestation did not affect the parameters significantly. In other experiments Jood et al.,

(1992a, 1993a) used maize and sorghum instead of wheat and reached the same

conclusion as drawn earlier. Jood and Kapoor (1992b) conducted an experiment wherein

they reported that protein and starch digestibility of wheat, maize and sorghum are

27

affected significantly (P<0.05) and adversely at 25, 50 and 75 percent grain infestation

caused by T. granarium and R. dominica individually as well as in mixed form. They

observed that T. granarium, primarily a germ feeder, reduces protein digestibility of

wheat and maize more than R. dominica or a mixed population of the both insect species.

The reduction in digestibility was found dependent on the distribution of proteins and

starch in seed components as well as feeding preferences of insects. Similarly substantial

changes in the contents of calcium, phosphorus, zinc, iron, copper and manganese were

observed when wheat, maize and sorghum grains were subjected to artificial infestation

by T. granarium and R. dominica (Jood et al., 1992b). In case of R. dominica they

observed significant increases in the mineral contents of wheat and maize at 75 %

infestation level, but these increases were not significant in case of T. granarium. On the

other hand, R. dominica did not significantly change the mineral content of maize.

However a significant reduction was noticed in case of T. granarium. Mixed populations

of both species showed intermediate changes in the mineral contents of the three cereal

grains. Storage of un-infested grains up to 4 months did not induce any appreciable

changes in the levels of the six minerals. In another experiment, Jood et al., (1993b) used

T. granarium and R. dominica to investigate the effect of insect infestation on

organoleptic characteristics of stored cereals. ‘Chapattis’ made from infested and

uninfested grain flours were evaluated for color, taste, texture, aroma and appearance by

a panel of semi-trained judges. Their results revealed no significant differences in the

scores for color, appearance, aroma and texture at all infestation levels for the three

cereals and the scores even did not differ significantly from the uninfested grains.

However at 50 and 75 percent infestation levels, scores for the taste of Chapattis were

significantly lower than uninfested grains. Bitter taste also resulted in poor overall

acceptability of Chapattis prepared from flours infested at 50 and 75 percent levels.

While investigating changes in the levels of total nitrogen, total protein, non-protein

nitrogen and uric acid contents of wheat, maize and sorghum grains having 25, 50 and 75

percent infestation caused by T. granarium and R. dominica separately and in mixed

population Jood and Kapoor (1993c) recorded a significant increase these contents with

the increase in infestation.. But there was significant reduction in nitrogen and true

protein contents of three cereal grains at 75 percent infestation level though the decrease

was non-significant at the 25 and 50 percent levels of grain infestation as compared to

control. Both insect species produced uric acid contents above acceptable limits (10

mg/100 g) even at 50 percent infestation levels in the three cereal grains. Variations in

contents of nitrogenous compounds during storage (1, 2 and 4 months) were found

28

marginal. Further studies conducted by Jood et al., (1993d) on the effect of insect

infestation on total soluble sugar, reducing sugar, non-reducing sugar and starch contents

of wheat, maize and sorghum grains indicated that these parameters are adversely

affected at 25, 50 and 75 percent insect infestation caused by T. granarium and R.

dominica, separately as well as mixed population. R. dominica caused significant

reduction in available carbohydrates at 50 and 75 percent infestation levels whereas T.

granarium achieved similar effect only at 75 percent. Mixture of both insect species

caused intermediate losses. Storage of cereal grains up to 4 months resulted in substantial

increase in sugars and decrease in starch content, but storage for a shorter period did not

cause any significant changes in levels of carbohydrates. Warchalewski and Nawrot

(1993) carried out investigations on activity of total wheat extractable proteins of 2

spring and 4 winter wheat cultivars relative to alpha-amylase inhibition of S. granarius,

T. confusum and Ephestia kuehniella in vitro, and also on differences between these

cultivars relative to various other wheat grain properties. Results exhibited a positive

correlation between alpha-amylase inhibition in E. kuehniella and growth parameters,

while kernel hardness of wheat was a determinant in the development of S. granarius.

Increased levels of non-protein nitrogen had a negative effect on growth of all the 3

species. Charjan et al., (1994) studied certain physiological, mycological and

biochemical changes in stored wheat induced by the infestation of S. oryzae and R.

dominica. It was found that the incidence percentage of fungal flora, total nitrogen, uric

acid, nitrogen and free fatty acid of grains increased considerably at the end of the third

and fourth month of storage. The 100-grain weight, germinability, non-reducing sugars,

reducing sugars and total water soluble sugars decreased with an increase in insect

infestation as compared to the control. Jood and Kapoor (1994) again reported substantial

losses in thiamine, riboflavin and niacin contents of wheat, maize and sorghum grains at

25, 50 and 75 % infestation levels induced by T. granarium and R. dominica separately

and as mixed population. As far amino acids are concerned, Jood et al., (1995) also

observed a significant decrease in essential amino acids of wheat, maize and sorghum

due to grain infestation caused by mixed populations of T. granarium and R. dominica

(50:50). Non-essential amino acids were also adversely affected. Jood et al., (1995)

declared a great increase in anti-nutrient polyphenol contents at 75 percent infestation

level. However increase was meager in case of anti-nutrient phytic acid. In an other

experiment, Jood et al., (1996a) reported that infestation of wheat, maize and sorghum

grains caused by T. granarium and R. dominica individually or in mixed populations

resulted in substantial reductions in the contents of total lipids, phospholipids,

29

galactolipids, and polar and nonpolar lipids. Losses of lipids showed significantly

negative correlations with the levels of insect infestations. T. granarium was found

comparatively more destructive than R. dominica. Jood et al., (1996b) finally found that

severe infestations of grain by Khapra beetle may make it unpalatable or unmarketable.

Grain quality may decrease due to depletion of specific nutrients. Wakil et al., (2003)

studied the nutritional losses of wheat due to the attack of T. granarium, T. castaneum, S.

oryzae and R. dominica. Their results revealed more nutritional losses in laboratory

infested wheat grains as compared to the infested samples taken from the public stores.

They reported a positive correlation among the damaged wheat and protein & fat

contents, whereas, negative correlation was found between carbohydrate contents and

insect damage. Fogliazza and Pagani (2003) conducted experiments using Sitophilus spp.

R. dominica, Tribolium spp., Trogoderma spp., O. surinamensis, E. kuehniella and S.

cerealella. They found that the insects infesting kernels (i.e. Sitophilus. spp. and R.

dominica) negatively affected the rheological properties more than flour pests. Both

kernel and flour pests showed negative effects on baking quality.

2.3 Food Security and Storage Losses

Food security of the world is linked with production of food crops as well as minimizing

the factors which negatively influence the produce. There is no second opinion that

stored grains pests cause considerable economic losses to cereal grains each year all over

the world. The damage caused by insects is comparatively greater than those caused by

other pests because of their ability for rapid population increase. There are over 750,000

known species of insects out of which 100 species had been found infesting stored

products. Detailed investigations had further revealed that only 20 species (excluding

psocids) out of the 100 are of major importance with worldwide distribution (Andrew,

2004). Rahman et al., (1945) reported that an average loss sustained by the Indian grain

storage sector ranged 6-33 percent in a single storage season with a maximum damage at

73 percent. Whereas storage losses in Australia averaged 10 percent with an end result of

2 percent additional cost of control (Bengston, 1997). Girish et al., (1974) carried out

survey of storage losses caused by the stored product insect pests during 1973-74. Their

results revealed that significant losses of grain were caused due to infestation by T.

granarium, T. castaneum, S. oryzae, R. dominica, S. cerealella, O. surinamensis and E.

cautella. The loss in weight after storage for six months varied from 0.06 to 9.7 percent

and the loss in viability ranged from 7 to 22 percent. Significant differences in the

30

susceptibility to damage were also shown by different varieties of wheat. Golebiowska et

al., (1976) observed that stored product beetles including T. granarium, S. granarius , S.

oryzae, R. dominica, T. confusum and O. surinamensis cause significant reduction in

germination and nutritional composition of the infested grains as well as significant

increases in weight loss and the number of damaged grains thus posing a serious threat to

food security. Caliboso (1977) estimated 34 percent loss caused to corn stored for eight

months in government warehouses in Philippine. Golop and Hodges (1982) reported

losses of stored grains in Tanzania as high as 30 percent during 3 to 6 months storage

period due to the attack of insect pest. It is generally accepted that 5-15 percent of the

total weight of all cereals, oilseeds, and pulses is lost due to many factors including

insect attack during post harvest operations (Anonymous, 1989). Chelkowski (1991) also

reported that 10 to 30 percent of total world grain production is lost after harvest. The

losses are more pronounced in the developing countries with a common average of 10–

15 percent (Lucia & Assennato, 1994). Neethirajan et al., (2007) reported that storage

pests cause considerable quantitative as well as qualitative losses; ultimately deteriorate

nutritional contents and lower crop value. Heavily infested grains become unfit for seed

purposes and its products become unsuited for human consumption. Thus there is a

census among notable workers that the insect infestation during storage may make grains

totally inedible through associated microbial spoilage and contamination resulting in

heavy financial losses (White, 1993).

In Pakistan, first schematic survey of losses was conducted by Chaudhary (1980) who

reported an aggregate loss of 15.3 percent during various post-harvest operation of wheat

in the country. Jilani (1981) also observed 10 to 15 percent post harvest loss of food

grains in Pakistan, which were chiefly caused by the attack of insect pests. His report was

later on supported by findings of Ahmed (1984). In the same year Ahmad and Afzal

(1984) recorded 22.7 percent post harvest loss of wheat in Pakistan, out which 9.5

percent occurred during storage period and the remaining 13.2 percent during harvesting

and threshing practices. Farmanullah (1985) recorded 0.22 percent handling & spoilage

losses and 2-33 percent quality loss of stored wheat in public sector godowns at D. I.

Khan. On the basis of a country wide survey, storage loss of wheat in Pakistan was found

in the range of 3.5 to 25 percent (Irshad & Baloch, 1985). Mohammad (1986) reported

that losses of wheat grains stored for 4 months in house type godowns of Pakistan were

2.03, 8.18 and 1.35 percent determined by S.V.W, T.G.M. and G.M. methods of loss

assessment, respectively. The corresponding figures for 7 months storage period were

31

recorded as 3.02, 9.41 and 2.06 percent, respectively. Whereas six months wheat storage

resulted in average weight loss of 1.99, 6.33 and 2.01 percent, determined by S.V.W,

T.G.M. and G.M. methods, respectively (Khan, 1986). Baloch (1986) recorded 4 and 7

percent annual storage losses at farm level and in the public sector, respectively

depending upon ecological conditions, biological factor (insects, molds, rodents and

birds), storage type, storage management, etc. Among the stored grain insect pests,

T. granarium, T. castaneum, R. dominica, S. oryzae and Sitotroga cerealella had been

found most destructive causing a minimum of 5-10 percent loss annually (Baloch et al.,

1994). These findings are sufficient to establish that stored grain insect pests are serious

threat to the global food security.

32

Chapter-II

2.4 MATERIALS AND METHODS

The present investigations were carried out in Stored Grain Research Laboratory of

Entomology Department of Pir Mehr Ali Shah, Arid Agriculture University Rawalpindi

during 2004-2008. Main objectives of the experiment were to determine quantitative and

qualitative losses caused by artificial infestation by Trogoderma granarium Everts and

relative resistance of wheat varieties against feeding by the pest. The materials and

methods employed in this study are briefed as under:

2.4.1 Collection of Insects

Mixed age cultures of the T. granarium were collected from farm houses as well as

stores of the Punjab Food department located at various places in Rawalpindi district.

The cultures were reared on healthy wheat grains apparently free from insect infestation.

To further ensure exclusion of any undetected population of insects, the wheat samples

were subjected to phosphine fumigation before using the grains as rearing medium (Jood

et al., 1992b). The fumigated grains were put in three glass jars (20 ×15 cm) each

containing one kg wheat. The jars were covered with muslin cloth with the help of rubber

bands and were placed in the laboratory at 30±2 °C and 65±5 % R.H. for conditioning.

After a fortnight, when moisture level of the grains ranged from 10-12 %, which is

suitable for insect growth and development (Pingale and Girish, 1967), the grains were

used as rearing medium.

2.4.2 Mass Rearing of Insects

From the mixed age cultures collected from various destinations, Khapra beetle were

separated at the pupal stage and the pupae were then reared in an incubator at 32± 2 °C

and 65±5 % R.H. The newly emerged adults (24-48 hrs after emergence) were used for

mass rearing. For this purpose, ten pairs (10 males+10 females) of adults were introduced

in the jars having cleaned, healthy and fumigated wheat with 12 % moisture contents.

The cultures were maintained in the incubator at 32±1 °C and 65±5 % relative humidity

for a period of three months for mass rearing. Later on uniform size larvae of the insect

were used in the experiment.

33

2.4.3 Collection of Wheat Varieties

Nine wheat varieties commonly grown in Pakistan vis-à-vis BWP-97, Manthar, Bhakkar-

2000, BWP-2000, GA-2002, Inqlab-91, DWR-97 Panjnad, and Wafaq-2001 were

collected from the Regional Agricultural Research Institute, Bahawalpur, Punjab,

Pakistan. One kg sample from each variety was taken and fumigated with Aluminium

phosphide tablets to nullify the possibility of previous infestation if any. The samples

were then cleaned by sieving through 3/8, 3/16, 1/8 and 1/12 inch mesh sieves. From this

cleaned wheat, working samples weighing 25 grams from each variety were drawn

(Proctor, 1994) and subjected to analyses for determination of moisture contents, insect

damaged, broken and healthy grains. Similarly 50 grams samples from each variety were

also drawn for analyses of crude protein, crude fat, crude fiber and ash contents.

2.4.4 Inoculation of Wheat Samples

200 gram wheat grain sample from each variety was taken in 250 ml glass jars and

twenty uniform size larvae of about 1-2 weeks old were taken from the culture and

introduced in each jar as triplicates. All the jars were then covered with muslin cloth with

the help of rubber bands. The jars were later on placed in an incubator under semi-

warehouse environment at 25± 2°C, 55±5 % R.H. and 12:12 hrs continuous light:dark

conditions for a period of six months to realize the filed conditions. Doors of the

incubator were opened for a period of 30 minutes on alternate days to ensure proper

aeration and to avoid accumulation of carbon dioxide produced as a result of biotic

respiration. After a period of 6 months, the jars were taken out and further analyses were

made for progeny development as well as physical and biochemical changes induced by

the insect infestation.

2.4.5 Determination of Moisture contents

Moisture of the grain was determined to investigate the correlation among moisture

content of the grain and levels of T. granarium infestation, progeny development, weight

loss, weight of frass, crude protein, crude fat, crude fibre, ash contents, insect damaged,

broken and healthy grains etc. For this purpose, a U.S. made grain moisture tester

(Farmex-MT3) was used.

34

2.5 Progeny Development

After weighing, the entire grain sample taken from each variety was sieved through

sieves of different mesh sizes ranging 1/8, 1/12, 3/16 and 3/8 inches. Live as well as dead

larvae, pupae and adults were counted for each replication of the corresponding wheat

variety under the laboratory magnifying glass 10³.

2.5.1 Weight Loss

Using sieve set, the infested grain in each jar was subjected to sieving to separate insect

skin debris, grain dust and other excretion added due to T. granarium infestation. A

sample weighing 25 gram was drawn from the cleaned wheat for assessment of percent

weight loss. For this purpose number and weight of damaged and undamaged grain was

recorded and put in the following equation for determination of weight loss (Gwinner et

al., 1996).

Percent Weight Loss = (Wµ × Nd) – (Wd × Nµ) × 100

Wµ × (Nd + Nµ)

Wµ = weight of undamaged grains

Nµ = number of undamaged grains

Wd = weight of damaged grains

Nd = number of damaged grains

2.5.2 Weight of Frass

While determination of weight loss, weight of exuviae, dead as well as live adult and

immature stages of Khapra beetle, flour dust and other excretion produced during the

larval infestation was recorded for each variety.

2.6 Comparative Resistance of Wheat Varieties

Progeny development, percent infested grains and weight loss was selected as criteria for

determination of comparative resistance of wheat varieties against T. granarium

infestation.

35

2.7 Insect Damaged, Broken and Healthy Grain Count

After removing the frass, samples of cleaned grain each weighing 25 gram was drawn

from each replication of the respective wheat variety. The grains were segregated and

counted for insect damaged, broken and healthy grains by using the following equations.

Percent Insect damaged grains = No. of insect damaged grains × 100 Total number of grains in the sample

Percent Broken grains = No. of broken grains × 100 Total number of grains in the sample

Percent Healthy grains = No. of healthy grains × 100 Total number of grains in the sample

2.8 Biochemical Analyses of Wheat Samples

Nutritional changes of the infested grains induced by infestation of T. granarium larvae

were studied for crude protein, crude fat, crude fiber and ash contents using ICC and

AOAC methods (Helrich, 1990). For this purpose, infested wheat samples were cleaned

and sieved to remove insect body parts. Later on 50 gm grains in triplicate were taken for

determination of crude protein, fat, carbohydrates, fiber and ash contents.

2.8.1 Determination of Crude Protein

Crude protein is a conventional expression for the total content of nitrogenous

compounds of the analyzed product, calculated by multiplying the corresponding total

nitrogen content by factor of 5.7 for wheat. Whereas nitrogenous compounds were

determined by oxidizing the organic matter of the sample with concentrated sulfuric acid

in the presence of a catalyst: the product of the reaction (NH4)2SO4 was treated by alkali;

free ammonia was distilled and titrated (AOAC Method No. 979.09).

2.8.2 Determination of Crude Fiber

Wheat samples were gelatinized in the presence of heat stable alpha amylase, and then

enzymatically digested with protease and amyloglucosidase to remove digestible protein

and starch. Four volumes of ethanol were added to precipitate soluble dietary fiber. Total

residue was filtered off and washed with ethanol and acetone. The residue was weighed

after drying. The remaining material was analyzed for protein and ash content,

36

respectively. Subtracting the amounts measured for protein, ash and a blank control from

the dry weight of the filtered residue yielded a value for total dietary fiber content (ICC

Standard No.156, 1994).

2.8.3 Determination of Ash

A five gram well mixed sample was weighed into a shallow, relatively broad dish that

had been ignited, cooled in a desiccator and weighed soon after reaching at room

temperature. The sample was later on ignited in a furnace at 550 °C (dull read ) until the

light gray ash resulted, which was cooled in a desiccator and weighed after reaching at

room temperature (AOAC Method No. 923.03).

2.8.4 Determination of Crude Fat

AOAC method No. 920.39 was followed for determination of crude fat contents

2.8.5 Determination of Carbohydrates

The starch content is the portion of the sample that can be determined as glucose after

enzymatic decomposition with amyloglucosidase. AOAC method No. 979.10 was used

for determination of carbohydrates.

37

Chapter-II

2.9 RESULTS AND DISCUSSION

2.9.1 Moisture Contents Analysis of variance depicted significant differences between moisture content of grain

before and after infestation (Appendix-4). The moisture recorded before infestation

revealed that there was no statistical difference in moisture contents of DWR-97, Panjnad

and Wafaq-2001 with mc values of 8.44, 8.34 and 8.08 percent, respectively. Similarly

there was fond no statistical difference between moisture content of wheat varieties

BWP-97 and Manthar, which depicted mc values of 10.47 and 10.41 percent,

respectively. Moisture content in case of Inqlab-91, GA-2002 was though statistically

similar with each other as well as with BWP-2000 but was found higher than those of

DWR-97, Panjnad and Wafaq-2001. Wheat variety Bhakkar-2000 exhibited a distinct

moisture content of 9.87, lower than those of BWP-97 and Manthar, but higher than

moisture contents of the remaining wheat varieties (Table-1). There was found a

significant increase in moisture content of all the wheat varieties after subjecting them to

artificial infestation of T. granarium larvae for a period of March 2006-August 2006. As

is evident from the Table-1, variety Wafaq-2001 showed minimum increase in moisture

content from 8.08 to 8.41 percent after infestation. The varieties Inqlab-91, DWR-97 and

Panjnad statistically proved similar with each other in respect of increase in moisture

content but ranked lower than those of BWP-97, Manthar, Bhakkar-2000 and BWP-

2000. Maximum moisture content was recorded in case of Bhakkar-2000 with 2.09

percent increase after infestation. Similarly Jood et al., (1996) also observed that 75

percent infestation level of T. granarium and R. dominica cause a significant (P < 0.05)

increase in moisture contents of the infested grains as compared to control and lower

levels of infestation. The results are also in line with the findings of Ravan et al., (1987),

Jood and Kapoor (1993) and Jood et al., (1993). The increase in moisture contents over

time may be due to the absorbance of atmospheric moisture by the grain, biotic

respiration as well insect excretion.

2.9.2 Progeny Development, Weight Loss and Weight of Frass

It is evident from the Table-2 that maximum progeny development was observed in

wheat variety BWP-97 showing 792.7 larvae per 200 gram wheat. Progeny development

38

Table 1 Moisture Content of Wheat Varieties before and after infestation.

Moisture content (%) Wheat Varieties Before infestation After infestation

BWP-97 10.47a 11.79 a MANTHAR 10.41a 11.32 ab BHAKKAR-2000 9.87 b 11.96 a BWP-2000 9.00 c 10.37 cd GA-2002 8.59 cd 10.67 bc INQLAB-91 8.55 cd 9.693 de DWR-97 8.44 d 9.633 e PANJNAD 8.34 d 9.487 e WAFAQ-2001 8.08 d 8.41 f

Means followed by the same letter in each column are not significantly different by

Duncan's multiple range test (P = 0.01)

Table 2 Progeny development, Weight loss and Weight of frass of Wheat

Varieties after infestation.

WHEAT VARIETIES Progeny Development (No.)

Weight Loss (%)

Weight of Frass

(g) BWP-97 792.70 a 20.25 a 24.47 a MANTHAR 752.00 a 19.53 a 23.21 a BHAKKAR-2000 668.70 b 18.27 ab 20.64 b BWP-2000 624.0 b 16.24 bc 19.25 b GA-2002 551.70 c 15.47 bc 17.03 c INQLAB-91 440.00 d 15.37 bc 13.58 d DWR-97 472.00 d 14.10 c 14.57 d PANJNAD 280.70 e 13.81 c 8.663 e WAFAQ-2001 189.70 f 6.223 d 5.857 f

Mean 530.16 15.47 16.36

Means followed by the same letter in each column are not significantly different by Duncan's Multiple Range Test (P = 0.01)

39

in case of Manthar-2000 was though statistically similar to that recorded in BWP-97 but

was lower having 752 larvae per 200 gram wheat. The varieties Bhakkar-2000 and BWP-

2000 were also found statistically similar in respect of progeny development with 668.7

and 624 larvae. Minimum progeny development of 189.7 was recorded in case of Wafaq-

2001.

Whereas weight loss caused after 6 months of artificial infestation by T. granarium

larvae revealed BWP-97 as one of the most susceptible wheat varieties with mean loss of

20.25 percent. Other varieties vis-à-vis Manthar, Bhakkar-2000, BWP-2000, GA-2000,

Inqlab-91, DWR-97, Panjnad and Wafaq-2001 followed BWP-97 with an average weight

loss of 19.53, 18.27, 16.24, 15.47, 15.37, 14.1, 13.81 and 6.2 percent, respectively. Data

pertaining to the weight of frass also depicted approximately similar ranking except that

weight of frass recorded in case of DWR-97 was higher as compared to that recorded in

case of Inqalab-91. There was found a positive correlation among progeny development

and infestation percentage, weight loss as well as weight of frass. The results are in

conformity with the previous findings reported by Ahmed et al., (1976) and Navarro et

al., (1978) who observed a high degree of positive correlation among the progeny

development and the infestation level, grain damage and weight loss of the infested

grains. Bhardwaj et al., (1977) observed 2.5 percent weight loss against 5.1 percent

infestation. Khattak et al., (2000) while working on the effect of T. granarium infestation

on twelve rainfed wheat lines also found that correlation among progeny development,

damaged grains and weight loss was positive and highly significant (P < 0.01). Grain is

living entity, which is affected by biotic and a biotic factors resulting in qualitative and

quantitative loss (Ahmed, 1995; Singh et al., (1997). Khan and Kulachi (2002) also

reported a positive correlation between the progeny development of T. granarium,

T. castaneum and R. dominica and the losses caused by them in terms of grain weight

loss. Our results are also in line with those of Syed et al., (2006) who correlated T.

granarium and R. dominica infestation with significant weight loss of different wheat

varieties.

2.9.3 Insect Damaged, Broken and Healthy Grains Recorded after Infestation.

The results pertaining to percent damage to wheat grains caused by T. granarium larvae

in different wheat varieties under natural storage conditions are presented in Table-3.

Mean values did not reveal statistically significant differences among various varieties of

40

Table 3 Insect damaged, Broken and Healthy grains Recorded after infestation.

Insect damaged grains %

Broken Grains (%)

Healthy Grains (%)

WHEAT VARITIES

Before infestation

After infestation

Before infestation

After infestation

Before infestation

After infestation

BWP-97 2.00 a 43.37 a 2.66 a 16.72 a 95.34 a 39.91 f MANTHAR 0.66 bc 42.87 a 2.00 a 15.02 ab 97.33 a 42.10 f BHAKKAR-2000 0.00 c 38.44 b 4.00 a 13.65 b 96.00 a 47.91 e BWP-2000 0.00 c 34.21 c 1.66 a 11.27 c 98.34 a 54.52 d GA-2002 1.33 ab 34.45 c 1.66 a 11.17 c 97.00 a 54.38 d INQLAB-91 1.66 a 30.27 d 2.66 a 10.43 c 95.68 a 59.30 c DWR-97 1.66 a 35.94 bc 3.33 a 6.913 d 95.00 a 57.15 cd PANJNAD 0.00 c 24.67 e 2.00 a 5.237 d 98.00 a 70.10 b WAFAQ-2001 0.00 c 19.97 f 3.33 a 4.973 d 96.67 a 75.06 a

Mean 0.81 33.79 2.59 10.6 96.59 55.6

Means followed by the same letter in each column are not significantly different by Duncan's Multiple Range Test (P = 0.01)

Fig. 3 Anatomy of a Wheat grain Fig. 4 Nutritional Composition of kernel

Source: AWB, 2006.

41

wheat in respect of broken and healthy grains before infestation. However, there were

found significant differences among the wheat varieties in respect of insect damaged

grains before subjecting to the artificial infestation. Maximum number of damaged grains

was recorded in variety BWP-97 with 2 percent infestation followed by Inqlab-91,

DWR-97, GA-2002 and Manthar with 1.66, 1.66, 1.33 and 0.66 percent infestation,

respectively. The remaining four varieties did not show any sign of grain damage.

Comparison of mean values before and after infestation showed highly significant

variations among different wheat varieties in respect of damaged, broken and healthy

grains. As is evident from the Table 3, maximum damaged grain was found in BWP-97

with 43.37 percent, statistically resembling to Manthar with 42.87 percent insect

damaged grains. Minimum insect damaged grain was found in Wafaq-2001 with 19.97

percent. Same trend existed in insect broken grains and vice versa with the healthy

grains. These findings are in consistent with those of Pingale (1964), Badawy and Hassan

(1965), Shah (1969), Azeem et al., (1976), Hameed et al., (1984), Irshad and Baluch

(1985), Ahmad et al., (1986), Irshad et al,. (1988), and Khattak et al., (2000) who

observed a positive correlation between infestation caused by T. granarium and te

damage caused to wheat grains. Lately Syed et al., (2006) carried out investigation to

evaluate the comparative resistance of wheat varieties against infestation of T. granarium

and R. dominica. Their results revealed that grain damage and weight loss percentage

was mainly dependent upon the progeny development, which was also dependent on the

varietal preference of the pests used in the investigations.

2.9.4 Biochemical Changes Caused by T. granarium Infestation

Analysis of variance presented in Appendix-5 exhibited highly significant differences

among different biochemical parameters before and after infestation of T. granarium

larvae. However no visible effects of feeding by different larval strains were observed in

respect of protein, fat, carbohydrate, ash and fiber contents of wheat grains after the

infestation. Generally the feeding preference of the larvae toward different varieties was

found definitely diverse. It is worth mentioning that there was found a positive

correlation between larval infestation and protein, fat, fiber and ash contents irrespective

of wheat varieties. On the contrary there was found a negative correlation between

carbohydrate and infestation caused to stored grains irrespective of wheat varieties.

Quality of flour made from the infested wheat may depend upon the nature and feeding

behaviors of pests attacking the grain. If we look at wheat grains they appear as seeds,

42

but closer examination shows them to be true fruit. Wheat grains when milled produce

fine powdery flour. A single grain makes about 20,000 particles of flour.

While making whole meal flour all components of kernel are included, but in extracting

white flour the seed coats and the germ are not used. In fact, they are crushed but taken

out as small flakes, by sieving through nylon or silk mesh. The outer part of the kernel is

composed of different layers of intercrossing cellulose (Fig. 3). Chemically a wheat grain

is composed of cellulose, minerals (bran) and protein with a high biological value.

However, due to low sifting rates of the flour, the protein is almost lost (Fig. 4). The

peripheral part of the wheat caryopsis is chiefly composed of indigestible and irritating

parts (cellulose and lignin) as well as minerals (ashes) that can interact, creating

undesirable compositions during the technological production processes of both dried

and fresh pasta. From a technological standpoint, the low sifting of the flour and the

semolina determines a "rational" sacrifice of the biodynamic components present in the

external layers of the caryopsis (the protein in the aleuronic layer). A good percentage of

these components are, however, present in more highly sifted flour (and semolina). In

modern mills (high milling) the sifting rate determines the type of flour and semolina.

The relationship between the principal chemical characteristics of the flour and the

sifting rate are very close, even if these characteristics always depend on the intrinsic

characteristics of the grains that are milled. That is, with a 50 percent sifting rate, the

parts farthest from the floury kernel or the layers nearest to the cortical part of the grain

are excluded from the flour. More over, for the flours subjected to a 72 percent or 80

percent sifting rate, the percentage of the parts closest to the external layers of the

caryopsis is obviously greater. To clarify this basic but important concept, the cross-

section of the wheat caryopsis indicates the concentration of the chemical elements that

most interest the flour and the semolina intended for use in making pasta. In short it is

the type of insect pest i.e. germ feeder, endosperm feeder, grain borer or external feeder

which decide deficiency of some nutritional components, which they eat out. The flour

that comes out from the grain of wheat is used in making chapatti, Nan, bread, biscuits,

cakes, confectionery, pudding and pies. Normally, the wheaten flour is rich in

carbohydrates (for energy), protein (for growth and development), the essential B

vitamins (for good health, good nerves and good digestion) and important minerals like

iron (for healthy blood) and calcium (for strong bones and teeth). General composition of

a 100 percent whole wheat bread is given in Fig. 5.

43

2.9.4.1 Crude Fiber

It is evident from that Table-4 that fiber contents generally increased after infestation on

over all weight bases. A maximum increase of 1.4 percent was observed in the variety

BWP-97 followed by Manthar, Inqlab-91, Bakhar-2000, GA-2002, DWR-97, BWP-

2000, Wafaq-2001 and Panjnad with 1.36, 0.92, 0.84, 0.86, 0.587, 0.56, 0.25 and 0.21

percent, respectively. The difference observed in level of fiber contents may be attributed

to the feeding behaviour of the T. granarium larvae (Jood et al., 1992). It has been

reported that T. granarium larvae primarily prefer to feed on germ portion as compared

to bran or endosperm. That is why bran portion is least effected under the normal course

of infestation resulting in an increase in fiber contents on over all weight basis (Salunkhe

et al., 1985). The results are also in line with the work of Hameed et al.,1984; Jood and

Kapoor 1993, Jood et al., 1993, 1996a) who observed an increase in fiber contents of

wheat grains after subjecting to T. granarium infestation. They also found an inverse

correlation among susceptibility of the stored grains to insect pests and the fat, protein,

fiber and ash contents. Our findings are in consistence to the previous work as Wafaq-

2001 with the highest fiber contents of 1.953 proved to be the most resistant wheat

variety with only 6.2 percent weight loss. The results are also in line with findings of

Samuels and Modgil (2003) who concluded that with the increase in infestation and the

storage period; moisture, ash, crude proteins, crude fiber, non-protein nitrogen and uric

acid contents of wheat grains are significantly increased at (P<0.05).

2.9.4.2 Crude Protein

The results pertaining to protein enunciated highly significant differences between the

crude protein contents of wheat grains before and after infestation by the T. granarium

larvae. Maximum increase of 2.83 % was observed in case of BWP-97 and Manthar

followed by GA-2002, Panjnad, Inqalab-91, Bhakkar-2000, Wafaq-2001 and BWP-2000

with 1.65, 1.64, 1.11, 1.10, 0.57 and 0.01 percent, respectively (Table-4). In case of

Panjnad, no change in content of crude protein was observed. Increase in the content of

crude protein apparently seems illogical as larvae of T. granarium preferably eat on grain

germ, which contains protein. Hence there should have been an inverse relationship

between infestation level and the protein content of the wheat grain. But we found a

positive correlation between the two parameters against the hypothesis. A survey of

literature revealed apparently contradicting results. Some showed increase in protein

contents under the influence of T. granarium infestation. While other indicated reduction

44

Fig. 5 The Nutritional Value of 100 % Whole Wheat Bread

Table 4 Biochemical Changes Induced in Wheat Varsities by T. granarium

Infestation

CRUDE

PROTEIN CRUDE FAT CRUDE FIBER ASH CONTENT CARBOHYDRATE WHEAT

VARITIES Before After Before After Before After Before After Before After

BWP-97 9.2 g 12.03 d 1.36 e 2.76 a 2.14 b 3.45 b 0.80 g 1.53 bcd 81.04 a 74.4 b

MANTHAR 9.2 g 12.03 d 1.51 d 2.87 a 2.36 a 3.79 a 0.86 f 1.41 e 77.69 c 73.3 bc

BHAKKAR-2000 9.84 f 10.94 e 1.66 bc 2.50 b 2.14 b 3.43 b 0.98 d 1.39 e 75.79 d 72.20 c

BWP-2000 10.93 e 10.94 e 1.59 cd 2.15 c 1.99 c 3.20 c 1.00 d 1.49 d 79.85 b 74.97 b

GA-2002 11.48 d 13.13 c 1.50 d 2.18 c 2.15 b 3.46 b 0.91 e 1.50 cd 73.76 e 68.50 d

INQLAB-91 12.03 c 13.14 c 1.947 a 2.87 a 2.24 ab 2.94 d 1.53 ab 1.66 a 80.7 ab 78.05 a

DWR-97 12.03 c 12.03 d 1.713 b 2.30 bc 1.74 d 2.63 e 1.44 c 1.56bcd 68.07 g 65.93 e

PANJNAD 12.58 b 14.22 a 1.983 a 2.19 c 1.58 e 2.23 f 1.50 b 1.58 bc 69.97 f 67.3 de

WAFAQ-2001 13.10 a 13.67 b 1.953 a 2.21 c 2.11 bc 2.27 f 1.55 a 1.59 ab 69.97 f 67.2 de

Means 11.15 12.45 1.69 2.44 2.05 3.04 1.17 1.52 75.21 71.32

Means followed by the same letter in each column are not significantly different by Duncan's multiple range test (P = 0.01)

38 percent Water 38 percent Digestible Carbohydrates8 percent Fiber

10 percent Protein

4 percent Fat

2 percent Vitamin

45

in the protein contents. For example, Jood and Kapoor (1992a) carried out investigations

on protein and starch digestibility of wheat, maize and sorghum grains affected by

T. granarium and R. dominica. They observed that T. granarium, primarily a germ

feeder, reduce protein digestibility of wheat and maize more than do R. dominica or a

mixed population of both insect species. In the same year they evaluated protein quality

of wheat grains having 25, 50 and 75 percent infestation caused by mixed populations of

T. granarium and R. dominica by rat growth and nitrogen balance studies. They observed

that feeding of a diet containing insect-infested wheat grain (50 and 75 %) results in

marked decreases of food intake, body weight gain, food efficiency ratio, protein

efficiency ratio, nitrogen absorption, biological value, net protein utilization and dry

matter digestibility. These parameters showed negative association with infestation levels

(Jood and Kapoor, 1992b). Further experiments carried out by Jood and Kapoor (1993)

exhibited contradicting results wherein they recorded a significant increase in the levels

of total nitrogen, total protein, non-protein nitrogen and uric acid contents of wheat,

maize and sorghum grains having 25, 50 and 75 percent infestation caused by

T. granarium and R. dominica separately and in mixed population. They also observed a

significant reduction in protein nitrogen and true protein contents of the three cereal

grains at 75 percent infestation level. The picture became clearer by the findings of

Samuels and Modgil (2003), who stated that an increase in insect infestation and storage

period though significantly increase crude proteins, moisture, ash, crude fiber, non-

protein nitrogen and uric acid contents; yet, true proteins, crude fat, calorific value,

weight and density of wheat grains are significantly reduced at (P<0.05). That is why Aja

et al., (2004) suggested that while determining the effect of insect infestation on protein

contents of stored grains, gluten index should be measured as an index of protein quality.

Later studies revealed that increase in contents of crude protein in the infested grains is

actually due to production of non beneficial rather harmful proteins such as cast skins,

exuviates, dead insects, wings, legs and other body parts of the insects that come along

with the infested grain samples. On the other hand true protein or beneficial proteins are

factually reduced. Besides the increase in protein percentage may also be due to

significant depletion of carbohydrates that constitute major part of a wheat grain.

2.9.4.3 Carbohydrates

Findings of the present investigations enunciated a negative effect of T. granarium

infestation on the carbohydrate contents of wheat grains. Maximum reduction to the tune

46

of 6.59 percent carbohydrate was observed in BWP-97 having maximum progeny

development and weight loss; followed by GA-2002 (5.26), BWP-2000 (4.88), Manthar

(4.36), Bhakkar-2000 (3.59), Wafaq-2001 (2.78), Inqalab-91 (2.71), Panjnad (2.67) and

DWR-97 (2.14 %), respectively (Table-4). These results showed a positive value of the

correlation coefficient between progeny development and carbohydrate contents valuing

0.678 with the infested grains. It is obvious from the values of correlation co-efficient

that reduction in carbohydrate was not solely dependent upon the progeny development.

There are some other factors, which might have contributed toward reduction in

carbohydrate contents. Such factors are varietals resistance as well as insect preferences

toward specific wheat varieties. The results are in conformity with the findings of Jood

and Kapoor (1992a) who carried out investigations on the effect of storage and insect

infestation on starch and protein digestibility of cereal grains. They found that T.

granarium significantly reduce starch digestibility of wheat and maize. Further studies

carried out by them also revealed a significant reduction in carbohydrate contents of

wheat, maize and sorghum when artificially infested with T. granarium and R. dominica.

The results are also in line with the findings of previous workers such as Hemeed et al.,

(1984) who observed a significant decrease in carbohydrate contents of wheat grains due

to attack of T. granarium larvae. These results were later on confirmed by Jood et al.,

(1996).

2.9.4.4 Crude Fat Contents

It is evident from the Table-4 that maximum increase in crude fat was observed in case of

BWP-97; whereas it was found minimum in case of Panjnad. There was found a highly

positive correlation (0.89) between increase in fat percentage and weight of frass after the

infestation. The phenomenon is contradictory to the facts that T. granarium primarily

feeds on germ of the wheat grain, which is store house for protein and lipids (Fig. 4).

Under these circumstances higher infestation should have been resulted in reduction of

fat content of the wheat grains. But the present findings have revealed opposite results,

which are in conformity with those observed by Hameed et al., (1984). Later studies

revealed opposite results indicating significant decrease in crude fat contents with

increase in the infestation level. In an experiment, infestation levels of 75 percent in

wheat, maize, and sorghum grains caused by T. granarium and R. dominica resulted in

significant decreases in crude fat, total carbohydrates, sugars, protein nitrogen, and true

protein contents and increases in moisture, crude fiber, and total protein (Jood and

47

Kapoor 1993, Jood et al., 1993; 1996a). Samuels and Modgil (2003) also reported

significant decreases in crude fat, weight, density, calorific value and true proteins with

increase in the insect infestation and storage period. In case of present investigations

increase in fat is simply a percent increase resulting from depletion of carbohydrates etc

due to infestation and hence is not an actual increase in fat content.

2.9.4.5 Ash Contents

The results have revealed significant increase in ash contents of the infested grains. A

maximum of 0.73 percent increase was observed in wheat variety BWP-97 followed by

GA-2002, Manthar, BWP-2000, Bhakkar-2000, Inqalab-91, DWR-97, Panjnad and

Wafaq-2001 with 0.59, 0.55, 0.49, 0.41, 0.13, 0.12, 0.08 and 0.04 percent, respectively.

Increase in ash content is commonsensical because of feeding preference of T. granarium

larvae that bore into germ and prefer to eat germ as compared to the bran portion, which

is chief store house of minerals in case of wheat grains (Salunkhe et al., (1985). Our

findings are in line with those of Hameed et al., (1984) who recorded significant increase

in ash contents in wheat grains attacked by the T. granarium larvae. Later on Jood et al.,

(1992b) also concluded that T. granarium primarily a germ feeder appears to eat a

portion of bran, thus offsetting the increase in mineral composition of wheat grains,

which stores minerals mostly in its bran portion. Our results are also in conformity with

those of Samuels and Modgil (2003) who found a significant increase in ash, moisture,

crude proteins, crude fiber, non-protein nitrogen and uric acid with increase in infestation

and storage period.

2.9.5 Conclusions

Results of the present investigations have revealed more or less similar feeding behavior

of all the test strains of T. granarium. The larvae fed on both germ as well as endosperm

of the grains. In most of the cases, entire grain was consumed and partially eaten husk

was only remaining of the healthy grain. In some grains larvae were found camouflaging

themselves inside the shell. A huge quantity of larval exuviates was an indication of the

infestation severity among different varieties used in the present investigation. Flour dust

was also visible on lower part of the jars. Some live and dead adults of T. granarium

were also observed among the grains. Apparently, there was found a varying quantity of

exuviates, flour dust, live & dead adults and cast skins on different wheat samples

indicating different levels of susceptibility or resistance. Color change as well as foul

48

odor was also observed in severely infested samples. Statistical analyses of the data

showing various physical, quantitative, qualitative and nutritional characteristics of

different wheat varieties influenced by the artificial infestation of T. granarium larvae for

6 month storage period under normal condition is presented in Appendix-4 & 5 and

Tables 1, 2, 3 & 4. Overall correlation among different parameters has been presented in

Table-5.

Literature has revealed that the insect resistance mechanisms of cereal grains are

complex and depend on physico-chemical and biochemical properties of the grain and on

the subsequent biochemical and physical adaptation of post-harvest insects to these

properties (Baker, 1986; Warchalewski et al., 1989; Dobie, 1991; Warchalewski and

Nawrot, 1993; Warchalewski et al., 1993). Stored grains may have high resistance to

insect pests because of the lack of vital nutrients or the presence of compounds that

adversely affect insect development (Taylor and Medici, 1966; Medici and Taylor, 1966;

Yetter et al., 1979; Nawrot et al., 1985; Gatehouse et al., 1986; Dobie, 1991; Baker et

al., 1991; Huesing et al., 1991; Warchalewski and Nawrot, 1993; Pueyo et al., 1995;

Zhang et al., 1997; Piasecka-Kwiatkowska, 1999; Piasecka-Kwiatkowska and

Warchalewski, 2000a, b). In general, insects tend to develop more slowly on resistant

grain varieties. Various studies on wheat grain resistance had been condcuted, but there

were few attempts to determine the particular factors that govern resistance (Dobie,

1991). The present studies aimed to evaluate the relative resistance of the commoly

grown wheat varities of Pakistan as well as effect of T. granarium infestation on physico-

chemical and biochemical chracteristics of the stored wheat revealed Wafaq-2001 as the

most resistant variety against T. granarium.

49

Table 5 Correlation Matrix showing relationship of different Physical and Biochemical changes of Wheat grains Induced by Larval

Infestation of Khapra beetle T. granarium.

Parameters Progeny development

Progeny development 1.000

Moisture content

Moisture content 0.900 1.000Weight of

Frass

Weight of Frass 1.000 0.900 1.000Weight

Loss

Weight Loss 0.920 0.835 0.920 1.000Weevilled

Grains

Weeviled grains 0.968 0.864 0.968 0.911 1.000Broken Grains

Broken Grains 0.954 0.920 0.954 0.876 0.888 1.000Healthy Grains

Healthy Grains -0.989 -0.907 -0.989 -0.923 -0.986 -0.952 1.000Crude Protein

Crude Protein 0.962 -0.981 0.962 -0.887 -0.921 -0.954 0.957 1.000Crude

Fat

Crude Fat 0.892 -0.749 0.893 -0.724 -0.868 -0.823 0.875 0.826 1.000Crude Fiber

Crude Fiber 0.494 0.524 0.494 0.310 0.408 0.667 -0.512 -0.530 -0.408 1.000Crude Ash

Crude Ash -0.901 -0.813 0.494 -0.767 -0.821 -0.877 0.863 0.885 0.940 -0.492 1.000Carbo- hydrate

Carbohydrate 0.678 0.621 0.678 0.658 -0.821 0.794 -0.642 -0.645 -0.466 0.644 -0.553 1.000

50

Chapter-II

LITERATURE CITED Aheer, G.M. and R. Ahmad. 1993. Response of wheat to Trogoderma granarium

(Everts.) and Rhizopertha dominica (F.B.). J. Agric. Res., 31: 319-322.

Ahmad, H. 1984. Storage of wheat in Pakistan. Prog. Farm., 4: 36-44.

Ahmad, M. 1995. Grain Storage Management News Letter, Univ. Agri. Faisalabad, 2: 1.

Ahmad, S. I. and M. Afzal. 1984. Harvest and Post harvest losses in wheat. Prog. Farm.,

4: 31-35.

Ahmad, M., M. R. Khan, A. Iqbal and M. Hassan. 1986. Farm Level Storage Loss of

Wheat by Insect pests in Samundri Tehsil. Pak. Entomol. 8:41-44.

Ahmed, H. 1984. Losses incurred in stored food grain by insect pests: A review.

Directorate of Scientific Information, P.A.R.C., Islamabad.

Ahmed, M, S. S. Shaukat and A. Ahmed. 1992. A comparison of quality characteristics

of Pakistan wheat with the existing FAQ specifications: a proposal for a new

grading system. Tropical-Science, 32:11-20.

Aja, S., G. Perez and C. M. Rosell. 2004. Wheat damage by Aelia spp. and Erygaster

spp.: Effects on gluten and water-soluble compounds released by gluten

hydrolysis. Seed Sci. & Technol., 32:159-169.

Andrew, J. H. 2004. The major insect pests of stored cereals and pulse grains in Somalia;

and their control. Ref. manual. UNA IPM. Nairobi 75776-00200.

Anonymous. 1989. Proceedings of the 18th International Course on Plant Protection.

International Agricultural Centre, Wageningen, The Netherlands.

AWB. 2006. Cereal Consumption in Australia. In: Cereals and Diets. AWB Limited, 380

La Trobe Street, Melbourne 3000, Victoria, Australia.

Azeem, M.I., M. Ahmad and M. Haq. 1976. Relative susceptibility of some varieties of

wheat to Khapra beetle and brown grain beetle during storage. Pak. J. Agric.

Sci., 13: 36-66.

Badawy, A. and H. M. Hassan. 1965. Studies on a natural infestation of Khapra beetle, T.

granarium (Everts) in Sudan. Bull. Entomol., Egypt, 48:273-280.

Bains, S.S., G.S. Battu and A.S. Atwal. 1976. Distribution of T. granarium Everts and

other stored grain insect pests in Punjab and losses caused by them. Bull.

GrainTechnol.,14:18-29.

51

Baker, J. E., S.M. Woo, J.E. Throne and P.L. Finney. 1991. Correlation of α-amylase

inhibitor content in Eastern soft wheats with development parameters of the

rice weevil (Coleoptera: Curculionidae). Envirom. Entomol., 20:53–60.

Baloch, U. K., 1986. Post harvest research in food grains in Pakistan 1986. Pak. Agric.

Res. Council, Islamabad, 45.

Baloch, U. K., M. Irshad and M. Ahmed. 1994. Loss assessment and loss prevention in

wheat and storage-technology development and transfer in Pakistan. Proc.

Intern. Working Conf. Stored Prod. Protec., 2: 902-905.

Banks, H.J. 1978. Distribution and establishment of Trogoderma granarium Everts

(Coleoptera: Dermestidae): climatic and other influences. J. Stored Prod.

Res., 13:183–202.

Battu, G.S., S.S. Bains, and A.S. Atwal. 1975. The lethal effect of high temperature on

the survival of the larvae of Trogoderma granarium Everts. Indian J. Ecol. 1:

98-102.

Bengston, M. 1997. Pests of stored products BIOTROP Special Publication, 59:53-60.

Bhardwaj, A.K., P.K. Srivastava, G. K. Girish. 1977. Assessment of storage losses in

wheat due to insect damage in Punjab. Bull. Grain-Technol., 15:126-129.

Caliboso, F.M. 1977. Studies on the losses of stored grains due to insect infestation.

Presented at the "Action Oriented Field Workshop for Prevention of Post

Harvest Rice lop Losses". Malaysia.

Canada Grain Act. 1975. Canada Grain Regulations, Canada Gazette, part II-109,

14:1708–1839.

Chahal, B.S. and M. Ramzan. 1991. Multiplication of Khapra beetle on wheat fumigated

with phosphine. Indian J. Ecol. 18: 86-87.

Charjan, S.K.U., J.L. Tarar and P.N. Raut. 1994. Studies on the quality of wheat grain

influenced by the infestation of stored grain pests during storage. J. Phytol.

Res., 7: 195-198

Chaudhary, M. A. 1980. Food grain losses at farm level in Pakistan. Vol. 1. Deptt. Agric.

Marketing, Univ. Agric., Faisalabad.

Chelkowski, J. 1991. Cereal grain mycotoxins, fungi and quality in drying and storage.

Elsevier Science Publishers B.V., The Netherlands.

Collins, P. J., G. J. Daglish, H. Pavic, T. M. Lambkin and R. Kopittke. 2001. Combating

strong resistance to phosphine in stored grain pests in Australia. Proc.

Australian Postharvest Technical Conf. Adelaide, Australia. Aug. 1-4, 2000.

52

Diekmann, M. 1996. Storage pests and their control. In A.J.G. van Gastel, M.A. Pagnotta

& E. Porceddu (Eds.). Seed Science and Technology. Proc. Train-the-

Trainers Workshop Sponsored by Med-campus Programme (EEC), 24 Apr.-9

May 1993, Amman. Aleppo, Syria, ICARDA.

Dobie, P. 1991. Host-plant resistance to insects in stored cereals and legumes. In:

Ecology and Management of Food-Industry Pests. Ed. by GORHAM, J. R.

Arlington, VA: AOAC, pp. 373–383.

El-Lakwah, F.A., R. Wohlgemuth and M.M. Khattab. 1989. Efficiency of phosphine and

combinations of phosphine with carbon dioxide against Khapra Beetle larvae

Trogoderma granarium Everts. (Col., Dermestidae). J. Pest Sci. 62: 85-88.

FAO. 1994. Insect pests of stored grains in hot climates. In: D.L. Proctor (ed) Grain

storage techniques Evolution and trends in developing countries. FAO

Agricultural services Bull. No. 109. FAO, UN., Viale delle Terme di

Caracalla, 00100 Rome, Italy.

Farmanullah. 1985. Qualitative and quantitative loss assessment of wheat grains in food

Deptt. Stores at D. I. Khan (Pakistan). M.Sc. (Hons) Thesis, Deptt. Ent.

Peshawar, 68p.

Fleurat-Lessard, F. 1985. Les traitements thermiques de desinfestation des cereales et des

produits cerealiers: possibilite d'utilisation pratique et domaine d'application.

Bull. OEPP/EPPO 15:109-118.

Fogliazza, D. and M. Pagani. 2003. Stored product pests affecting wheat and flour

quality; Insetti delle derrate e qualita' delle farine [frumento]. Meeting on pest

control in food industry and food protection], Piacenza (Italy), 18-20 Sep

2002, 54: 897-903.

Gatehouse, A. M. R.., K.A. Fenton, I. Jepson and D.J. Pavey. 1986. The effects of α-

amylase inhibitors on insect storage pests: inhibition of α-amylase in vitro and

effects on development in vivo. J. Sci. Food Agric., 37:727–734.

Gharib, M.S.A. 2004. Screening susceptibility/ resistance of some wheat grain varieties

to Rhizopertha dominica (F.) and Trogoderma granarium (Everts) infestation.

Egypt. J. Agric. Res., 82:139-140.

Girish, G.K., B. P. Tripathi, R.P.S. Tomer and K. Krishnamurthy. 1974. Studies on the

assessment of losses. IV. Conventional grain storage practices and losses in

rural areas in Uttar Pradesh. Bull. Grain-Technol., 12:199-210.

53

Girish, G. K., A. Kumar and S. K. Jain. 1975. Assessment of the quality loss in wheat

damaged by Trogoderma granarium Everts during storage. Bull. Grain Tech.

13:26-31.

Golebiowska, Z., J. Nawrot and A. Pradzynska. 1976. Researches on the injuriousness of

some beetle species feeding on cereal grain. Prace Nauk. Inst. Ochr. Roslin,

18:49-87.

Golob, P. and R. Hedges. 1982. Study of an outbreak of Prostephanus truncates (Horn)

in Tanzania. Tropical Product Institute, London, England16, pp.23.

Gwinner, J., R. Harnisch and O. Muck. 1996. Manual of the prevention of post-harvest

grain losses. Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ)

GmbH. 338pp.

Hafiz, A. and H. Hussain. 1961. Good Seed Storage reduces losses and increase

production. Agric. Pak, XII (3): 368-385.

Haines, C.P. 1981. Insects and arachnids from stored products: a report on specimens

received by the Tropical Stored Products Centre 1973–77. Report L54,

Tropical Products Institute, London, UK, 73pp. Banks H.J. and Cavanaugh

J.A. (1985) Toxicity of phosphine to Trogoderma variabile Ballion (Col.:

Dermestidae). J. Aust. Entomol. Soc. , 24: 179–186.

Hala, A. El-Syrafi, N. F. Abdel-Baky, S. S. Awadalla, M. S. Gharib and A. Y. El-Said.

2005. Varietal Preference of Sitophilus oryzae (L.) And Trogoderma

Granarium Everts on Some Grain Varieties of Wheat and Maize. The Third

International Conference on IPM Role in Integrated Crop management and

Impacts on Environment and Agricultural Products. 26-29 Nov. 2005, Giza,

Egypt.

Hameed, A., H.A. Qayyum and A. Ali. 1984. Biochemical factors affecting susceptibility

of flour wheat varieties to Trogoderma granarium Everts. Pak. Entomol. 6:

57-64.

Hamed, M., K. Rasul and N. Hussain. 1992. Combined infestations and losses by three

storage insects to maize. J. Agric. Res., 30: 283-289.

Helrich, K. 1990. Official Methods of Analysis. Association of Official Analytical

Chemists, Inc. Suite 400. 2200 Wilson Boulevard, Arlington, Virginia 22201,

USA. pp.1298.

Howe, R.W. 1952. Entomological problems of food storage in northern Nigeria. Bull.

Entomol. Res., 43: 111-144.

54

Huesing, J. E.; R.E. Shade, M.J. Chrispeels and L.L. Murdock. 1991. α-amylase

inhibitor, not phytohemagglutinin, explains resistance of common bean seeds

to cowpea weevil. Plant Physiol., 96:993–996.

Irshad, M. and U.K. Baloch. 1985. Losses in wheat during storage and their prevention.

Prog. Farm., 5: 17-19.

Irshad, M.A., U.K. Baloch, M. Irshad and A.Khan. 1988. Losses in wheat in public

sector storage in Rawalpindi region during 1984-85. Pak. J. Agric. Res., 9:

136-140.

Ismail, A.Y., S.H. Abid and N.A. Mawlood. 1988. Effect of high temperature on the

mortality of the red flour beetle Tribolium confusum and khapra beetle

Trogoderma granarium. Zanco, 1: 35-42.

Jilani, G. 1981. Post-harvest protection of food grain with natural insect repellents. Prog.

Farm., 1: 66-29.

Jood, S. and A. C. Kapoor. 1992a. Biological evaluation of protein quality of wheat as

affected by insect infestation. Food Chem., 45: 169-174.

Jood, S. and A.C. Kapoor. 1992b. Effect of storage and insect infestation on protein and

starch digestibility of cereal grains. Food Chem., 44:209-212.

Jood, S. and A.C. Kapoor. 1993c. Protein and uric acid contents of cereal grains as

affected by insect infestation. Food Chem., 46:143-146.

Jood, S. and A.C. Kapoor. 1994. Vitamin contents of cereal grains as affected by storage

and insect infestation. Plant Foods Hum. Nutr., 46: 237-243.

Jood, S., A.C. Kapoor and R. Singh. 1992a. Biological evaluation of protein quality of

maize as affected by insect infestation. J. Agric. & Food Chem., 40: 2439-

2442.

Jood, S., A.C. Kapoor and R. Singh. 1992b. Mineral contents of cereal grains as affected

by storage and insect infestation. J. Stored Prod. Res., 28: 147-151.

Jood, S., A.C. Kapoor and R. Singh. 1993a. Biological evaluation of protein quality of

sorghum as affected by insect infestation. Plant Foods Hum. Nutr., 43: 105-

114.

Jood, S., A.C. Kapoor and R. Singh. 1993b. Effect of insect infestation on the

organoleptic characteristics of stored cereals. Postharvest Biol. & Technol., 2:

341-348.

Jood, S., A. C. Kapoor and R. Singh. 1993d. Available carbohydrates of cereal grains as

affected by storage and insect infestation. Plant Foods Hum. Nutr., 43:45-54.

55

Jood, S., A.C. Kapoor and R. Singh. 1995. Amino acid composition and chemical

evaluation of protein quality of cereals as affected by insect infestation. Plant

Foods Hum. Nutr., 48: 159-167.

Jood, S., A.C. Kapoor and R. Singh. 1996a. Effect of insect infestation and storage on

lipids of cereal grains. J. Agric. Food Chem., 44:1502-1506.

Jood, S., A.C. Kapoor and R. Singh. 1996b. Chemical composition of cereal grains as

affected by storage and insect infestation. Trop. Agric. 73:161-164.

Khan, D. A. and M. A. Cheema. 1978 farm products storage and storage losses in the

Punjab. Pub. No.166. Econ. Res. Inst. Lahore, 47 pp.

Khan, I. 1986. Assessment of wheat grains losses increasing in various type of food

Deptt. Stores at Peshawar .M.Sc. (Hons) Thesis Deptt. Ent. NWFP Agric.

Univ. Peshawar, 63 pp.

Khan, S.M. and I.R. Kulachi. 2002. Assessment of Post Harvest Wheat Losses in D. I.

Khan. Asian J. Plant Sci., 1:103-106.

Khare, B.P., K.N. Singh, R.N. Chaudhary, C.S. Sengar, R.K. Agrawal and P.N. Rai.

1974. Insect infestation and quality deterioration of grain-I. Germination,

odour and palatability in wheat. Ind. J. Entomol., 36:194-9.

Khattak, S.U., S. Kamal, K. Ullah, S. Ahmad, A.U. Khan and A. Jabbar. 2000. Appraisal

of rainfed wheat lines against Khapra beetle, Trogoderma granarium Everts.

Pak. J. Zool. 32:131-134.

Kraszpulski, P. 1985. Khapra bettle - a quarantine pest Trogoderma granarium Everts.

Och. Ros., 29: 8-9.

Krishnamurthy, K. 1975. Post-Harvest losses in food grains. Bull. Grain Tech., 13: 33-

49.

Krzymanska, J. and Z. Golebiowska. 1987. Biochemical composition of wheat grain as

influenced by some beetles feeding. Prace Nauk. Inst. Ochr. Rosl., 28: 87-

105.

Lopes, D.C., J.L. Donzele, J.C. Alvarenga, A.F. R-de and A.A. Vieira. 1991. Effect of

infestation level of maize on protein and energy digestibility for finishing

pigs. Revista da Sociedade Brasileira de Zootecnia, 20: 131-135.

Lucia, M. D. and D. Assennato. 1994. Agricultural engineering in development-post-

harvest operations and management of food grains, FAO Agricultural

Services Bulletin, FAO, Rome Italy.

Medici, J. C. and M.W. Taylor. 1966. Mineral requirements of the confused flour beetle

Tribolium confusum (Duval). J. Nutrition, 88:181–186.

56

Mohammad, R. 1986. Assessment of Storage losses of wheat grains in the food Deptt.

Stores of Hazara Division (NWFP)., Pakistan. M.Sc. (Hons) Thesis Deptt.

Entomol. NWFP Agric. Univ., Peshawar, 69 pp.

Morison, G. D. 1925. The Khapra beetle (Trogoderma granarium Everts). Proc. Royal

Physical Soc. Edinburgh, 21: 10-13.

Navarro, S., Y. Kashanchi, M. Green and H. Frandji. 1978. Causes of Loss in stored

grain in Israel. Sp. Pub. Minis. Agric. Isreal No. 105 XI. 11, 95-112 (Rev.

Appl. Entomol. (A) 67:1979.

Nawrot, J., J.R. Warchalewski, B. Stasinka and K. Nowakowska. 1985. The effect of

grain albumins, globulins and gliadins on larval development and longevity

and fecundity of some stored product pests. Entomol. Exp. Appl,. 37:187–

192.

Neethirajan, S., C. Karunakaran, D.S. Jayas and N.D.G. White. 2007. Detection

techniques for stored product insects in grain. Food Control, 18: 157-162.

OEPP/EPPO. 1981. Data sheets on quarantine organisms No. 121, Trogoderma

granarium. Bulletin OEPP/EPPO Bulletin 11 (1). 1-6.

OEPP/EPPO. 2007. EPPO Standards: EPPO A1 and A2 lists of pests recommended for

regulation as quarantine pests. PM 1/2(16). European and Mediterranean

Plant Protection Organization 1, rue Le Notre, 75016 Paris, France.

Parashar, M.P. 2006. Post harvest profile of black gram. Govt. India, Ministry of Agric.

Deptt. Agric. and Coop. Directorate of Marketing and Inspection, Nagpur-

440001.

Perez-Mendoza, J., J.E. Throne, F.E. Dowell and J.E. Baker. 2003. Detection of insect

fragments in wheat flour by near-infrared spectroscopy. J. Stored Prod. Res.,

39: 305-312.

Piasecka-Kwiatkowska, D. 1999. Rola rodzimych inhibitorow enzymow hydrolitycznych

w kształtowaniu odporno[sci ziarna zboz o zroznicowanej jakości na owadzie

szkodniki magazynowe. Ph.D. Thesis. Poznan, Poland. The Agric. Univ.,

Faculty of Food Technol.

Piasecka-Kwiatkowska, D. and J.R. Warchalewski. 2000a. The cereal protein inhibitors

of hydrolytic enzymes and their role. Part I. Protein inhibitors of α-amylase.

Zywnosc, 2:110–119.

Piasecka-Kwiatkowska, D. and J.R. Warchalewski. 2000b. The cereal protein inhibitors

of hydrolytic enzymes and their role. Part II. Protein inhibitors of proteinases.

Zywnosc, 3:33–38.

57

Pingale, S.V. and G.K. Girish. 1967. Effect of humidity on the development of storage

pests. Bull. Grain Technol., 5:101-108.

Pingale, S.V., M. N. Rao and M. Swaminathan. 2006. Effect of insect infestation on

stored grain. I. studies on soft wheat. J. Sci. Food Agric., 5: 51-54.

Poplawska, M., D. Ciepielewska and L. Fornal. 2001. Feeding of the khapra beetle on

barley, malt and buckwheat nutlets. J. Plant Protec. Res., 41: 216-222.

Prasad, H., P. Bhatia, and G. R. Sethi. 1977. Estimation of feeding losses by Trogoderma

granarium Everts in wheat. Ind. J. Entomol., 39: 377-378.

Proctor, D.L. 1994. Grain storage techniques: Evolution and trends in developing

countries. FAO Agricultural Services Bull. No. 109. FAO., Rome, Italy.

Pruthi, H.S. and M. Singh. 1950. Pests of stored grain and their control. Indian J. Agri.

Sci. 18: 1-88.

Pueyo, J. J., T.D. Morgan, N. Ameenuddin, C.H. Liang, G.R. Reeck, M.J. Chrispeels and

K.J. Kramer. 1995. Effects of bean and wheat α-amylase inhibitors on α-

amylase activity and growth of stored product insect pests. Entomol. Exp.

Appl. 75:237–244.

Rahman, K.A., G.S. Sohi and A.N. Sapra. 1945. Studies on stored grain pests in the

Punjab. VI. Biology of Trogoderma granarium Everts. Ind. J. Agri. Sci.

15:85-92.

Raju, P. 1984. The staggering storage losses - causes and extent. Pestic., 18:35-7.

Ramzan, M., B. S. Chahal. 1985. Effect of three levels of infestation of S. oryzae (Lin.),

T. granarium Everts and T. castaneum (Herbst.) on the kernel damage and

loss of germinability of wheat seed. J. Res. Punjab Agric. Univ. India, 22:

695-699.

Rao, N. S., K. Sharma, A. Samyal and S.M.S. Tomar. 2004. Wheat grain variability to

infestation by khapra beetle, Trogoderma granarium Everts. Ann. Plant Protec.

Sci., 12: 288-291.

Ravan, S., M. Ahmad, M. Hassan and M. R. Khan. 1987. Relative Susceptibility of

Milled and Polished Grains of Different varieties of Rice to Rice weevil. Pak.

Entomol. IX:5-8.

Rees, D. 1998. Pest trends in the Australian grain bulk handling system. Aust.

Postharvest Tech. Conf., pp. 39-42.

Rees, D.P. 1998. Psocids as pests of grain storages. In: Banks, H.J., Wright, E.J.,

Damcevski, K.A. (Eds.), Stored Grain in Australia. Proc. Aust. Postharvest

Tech. Conf., Canberra, Australia, 46–51.

58

Salunkhe, D.K., J.K. Chavan and S.S. Kadam. 1985. Postharvest Biotechnology of

Cereals. CRC Press, Boca Rato, Fl. pp.208.

Samir, S. Awadalla, N. F. Abdel-Baky, H. A. El-Syrafi , M. S. Gharib and A. Y. El-Said.

2005. Some Biological Aspects of Sitophilus oryzae (L.) And Trogoderma

granarium Everts On Different Grain Varieties of Wheat and Maize. The 3rd

Int. Conf. on IPM Role in Integrated Crop management and Impacts on

Environment and Agricultural Products. 26-29 November 2005, Giza, Egypt.

Samuels, R. and R. Modgil. 1999. Physico-Chemical Changes in Insect Infested Wheat

Stored in Different Storage Structures. J. Food Sci. Technol., 36: 479-482.

Samuels, R. and R. Modgil. 2003. Physico-Chemical Changes in Insect Infested Wheat

Stored in Different Storage Structures. Ind. J. Agric. Sci., 73:562-563.

Sayed, T.S., F.Y. Hirad and G.H. Abro. 2006. Resistance of Different Stored Wheat

Varieties to Khapra Beetle, Trogoderma granarium (Everest) and Lesser

Grain Borer, Rhizopertha dominica (Fabricus). Pak. J. Biol. Sci., 9: 1567-

1571.

Seifelnasr, Y. E. 1992. Stored grain insects found in sorghum stored in the central

production belt of Sudan and losses caused. Trop. Sci., 32:223-30.

Shah, M.A. 1969. Evaluation of stored wheat losses caused by T. granarium (Everts) and

R. dominica (F).In: Syed, T.S., F.Y. Hirad and G.H. Abro (Eds.).2006.

Resistance of Different Wheat Varieties to Khapra Beetle, Trogoderma

granarium (Everts) and lesser Grain Borer, Rhizopertha dominica (Fabricius).

Pak. J. Biol. Sci., 9:1567-1571.

Singh, H., V. Kumar, R. Kumarand and H.R. Rohilla. 1997. Neem in Sustainable

Agriculture. Scientific Publishers, Lodpur, 147-161.

Sinha A.K. and K. K. Sinha. 1990. Insect pests, Aspergillus flavus and aflatoxin

contamination in stored wheat: A survey at North Bihar (India). J. Stored

Prod. Res., 26:223-226.

Sinha, K.K. and A.K. Sinha. 1992. Impact of stored grain pests on seed deterioration and

aflatoxin contamination in maize. J. Stored Prod. Res., 28:211-9.

Syed, T.S., F.Y. Hirad and G.H.Abro. 2006. Resistance of Different Wheat Varieties to

Khapra Beetle, Trogoderma granarium (Everts) and lesser Grain Borer,

Rhizopertha dominica (Fabricius). Pak. J. Biol. Sci., 9:1567-1571.

Taylor, M. W. and J.C. Medici. 1966. Amino acid requirements of grain beetles. J. Nutr.

88,176–180.

59

Wakil, W., M. Hassan, A. Javed and S. Anwar. 2003. Comparison of nutritional losses of

insect infested wheat in laboratory and public storages. Pak. J. Arid Agric. 6:

1-6.

Warchalewski, J. R., D. Madaj and J. Skupin. 1989. The varietal differences in some

biological activities of proteins extracted from flours of wheat seeds harvested

in 1989. Nahrung Food, 33:805–821.

Warchalewski, J. R. and J. Nawrot. 1993. Insect infestation versus some properties of

wheat grain. Roczniki Nauk Rolniczych, Seria E. 23:85–92.

Warchalewski, J. R., D. Piasecka-Kwiatkowska, J. Nawrot and Z. Winiecki. 1993.

Naturalny system ochronny ziarna zbóż przed szkodnikami magazynowymi

mit czy rzeczywistosc Ochrona Roslin, 37:11–12.

Warchalewski, J.R and J. Nawrot. 1993. Insect infestation versus some properties of

wheat grain. Roczniki Nauk Rolniczych Seria E, Och. Ros., 23: 85-92.

Warchalewski, J.R., J. Nawrot and E.K. Kaminska. 1993. The growth of laboratory

populations of some stored product insects in nine wheat grain varieties.

Roczniki Nauk Rolniczych Seria-E, Och. Ros., 22: 31-37.

White, N.D.J. 1993. Annual costs related to stored-product pests in Canada (losses and

preventive measures), Agriculture Canada Research Branch, Winnipeg, MB.

Yadav, T.D. and K.K. Nathan. 1980. A study on the effect of ecological changes on the

safe storage of wheat in Delhi region. Ind. J. Entomol., 42:326-9.

Yadav, T.D. and S. Singh. 1985. Host-suitability of lentil for eight stored product insects

LENS Newsletter (ICARDA); Lentil Experimental News Service. 12: 27-28.

Yetter, M. A., R.M. Saunders and H.P. Boles. 1979. α-amylase inhibitors from wheat

kernels as factors in resistance to postharvest insects. Cereal Chem., 56:243-

244.

Zhang, N., B.L. Jones and P. Tao. 1997. Purification and characterisation of a new class

of insect α-amylase inhibitors from barley. Cereal Chem., 74:119–122.