Hessian Fly Hessian Fly ID/Management ID/Management

in Wheatin WheatJack BaldwinJack Baldwin

Fangneng Fangneng HuangHuang

Rogers LeonardRogers Leonard

Steve HarrisonSteve Harrison

Ed TwidwellEd Twidwell

Adults

Hessian fly Mayetiola destructor

•There are 4-6 generations each year.

•A generation takes about 35 days at 75 º F, longer at cooler temperatures.

•Development occurs between 40-80 º F

Hessian fly eggs

Hessian fly larvae 2nd stage (L) and 3 stage (R)

Hessian fly puparia

puparia

Larvae R. Ratcliffe Photo

Hessian fly puparia

1 2-3 3-4

Hessian Fly In Wheat

Fly damaged plants and/or tillers

More dead tillers, thin stand

Toxins in saliva cause stunting, plant death, yield and quality losses

A thin stand of stunted plants (right) is a classic symptom of Hessian fly infestation

Hessian Fly In Wheat

Fly damaged plants and/or tillers

John Van Duyn - NC State Randy Weisz – NC State

Hessian fly damage looks different, depending on when the wheat was infested

sometimes a wide leaf blade is a symptom. Often the wide blade has a blue-green hue.

Hessian fly damage looks different, depending on when the wheat was infested

early infestation results in stunting so leaf blades only partially emerge from the ground

Infested tillers often die, particularly when subjected to cold stress in winter

Hessian fly puparia

infested in winter?

infested in spring

Hessian fly yield loss in winter wheat

• Seedling early tiller stage: – 1 larva completely stunts

and kills tiller– Cold injury

• Jointing / Heading / grain fill stage: – Multiple larva per stems at

joints– Stunts stem– Weaken stem cause

lodging.– Reduces grain filling / test

weight.

↓

Hessian fly yield loss in winter wheat

• Seedling early tiller stage: – 5% - 8% infested tillers

• Heading / grain fill stage: – 15% - 20% infested

stems– 10% @ $7.00+/bu

Ryegrass /winter wheat are common for food plots in southern “green fields”.

1998 440-83K acres

2007 613-228K acres

Winter Wheat Acreage and Losses to Hessian Fly in Georgia (1972-2007)

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1972

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x1

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$ L

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Acreage $ Losses

Hessian fly outbreak years

$28M

Wheat Hessian Fly Management Summary

for Georgia

David BuntinDept. of EntomologyUGA – Griffin Campus

2008

Hessian ‘fly-free’ planting dates to avoid fall damage

Effect of Spring Tillage on Hessian Fly Emergence from Wheat Stubble(From Chapin et al. 1992. J. Entomol. Sci. 27:293)

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Hes

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No-till Burn Disk Burn &Disk

Plow

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Hessian fly Suppression (Wheat Stubble Management)

• Plant as far away from previous year’s wheat stubble as possible.

• Bury stubble to prevent emergence.• No-till = burn alone > disking > plow.• Burning stubble will not kill pupae.• Plant resistant varieties in previous years field.

Control Volunteer Wheat

Only important alternate host in GA is little barley, Hordeum pusillum

No-till Soybeans with volunteer wheat

DO NOT use susceptible wheat for wildlife plots or as a cover crop

Hessian Fly Parasitism in Winter Wheat in Georgia – 1986/1987

Sample

Period

Parasitoid

Species

% Parasitism

North GA South GA

October P. hiemalis 9 0

January P. hiemalis 27 4

March P. hiemalis 57 4

May H. destructor

E. allynii

23 5

Plant Resistance for Hessian Fly Control

When a population of Hessian flies overcomes the host plant resistance, it is called a biotype.

Numerous plant resistance genes have been identified for Hessian flies. As they are deployed, new biotypes emerge.

It is important to know what biotypes are present in order to choose the right Hessian fly "resistant" variety

Hessian Fly Biotype Composition in Southern Georgia (1986-2000)

0%10%20%30%40%50%60%70%80%90%

100%

1986 1989 1991 1996 2000 2008

EGMOLOther

Sources: R. Ratcliffe et al., USDA-ARS, Purdue Univ.

?

Other

Biotype L

Biotype O

Percent:

Poplarville 1996L, D, J

Roger Ratcliffe, now retired from the USDA Hessian fly lab

Hessian fly biotypes 1996-2001

Insecticides for Hessian Fly

• Gaucho 600– 0.8 to 2.4 fl. oz. / 100 lb

• Gaucho XT– 3.4 oz/100 lbs seed– Raxil & Apron fungicides– Rate too low for HF

• Gaucho XT + Gaucho 600 @ 1 oz/100 lb seed

• Commercial seed treater– Seed conditioner, dealer

• Cruiser 5FS (Wheat-Pak)– 1 oz/100 lb seed– Contains 3 fungicides– Rate too low for HF– Max. 1.33 oz/100 lb seed

• Karate Z (1.92 oz/A) – @ 2-4 leaf stage. – @ full tiller (early to mid March)– Suppression; Timing difficult

Di-Syston 15G and Thimet/Phorate 20G are no long labeled for use on wheat.

Hessian Fly Control by Insecticide Treatments (Plains, GA)

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1994/1995 1995/1996 1996/1997

% I

nfes

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Til

lers

Untreated DiSyston 15G Gaucho 600 @0.8Gaucho 600 @ 1.2 Gaucho 600 @ 1.6 Warrior @ 30DAP

**

*

**

*

*Significantly different from Untreated, P = 0.05.

Early spring Hessian fly control with insecticide in fall infested

wheat

Early spring Hessian fly control with insecticide in fall infested

wheat

Treatments* Eggs/10 leaves** HF/5 plants*** Bu/acre

• Warrior@2.6 oz 12.3 c 41.2 c 48.2 a

• Warrior@ 3.8 oz 5.0 c 23.3 c 56.7 a

• Warrior@2.6 oz 2X 8.0 c 16.2 c 58.1 a

• Untreated 32.3 b 131.8 a 17.7 b * Sprayed 3/13; ** on 3/20; *** on 4/6

JVD

Hessian Fly Management Tactics

• Rotate wheat if possible. • Control volunteer wheat. • Do not use susceptible wheat as cover crops/wildlife plantings.• Conventional tillage (fall and spring).• Plant at recommended times.• Variety selection.

– Plant resistant varieties (if possible).– Plant susceptible varieties ‘only’ in new fields.

• Insecticides use strategies– Seed treatments – Lambda cyhalothrin - scouting for late winter suppression.

For Grazing: only oats, rye, ryegrass.

Questions?