Insecticides A Brief Overview of a Complex Subject.
-
Upload
geraldine-george -
Category
Documents
-
view
221 -
download
0
Transcript of Insecticides A Brief Overview of a Complex Subject.
![Page 1: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/1.jpg)
InsecticidesInsecticides
A Brief Overview of a Complex Subject
![Page 2: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/2.jpg)
Modes of Entrance into Modes of Entrance into InsectInsect
Contact - dermal – through the skin
Stomach - oral – through the mouth
Respiration - inhalation through the nose or gills
Systemic - combination of above
![Page 3: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/3.jpg)
Toxicity to humans or Toxicity to humans or nontarget organismsnontarget organisms
Most insecticides have the capacity to affect non-target organisms
Same as previously discussed Highly toxic – LD50 0 – 50 mg/kg
Moderately toxic - LD50 50 – 500 mg/kg
Low toxicity - LD50 500 – 5,000 mg/kg
Nontoxic - LD50 <5,000 mg/kg
![Page 4: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/4.jpg)
Toxicity to insects Toxicity to insects natural enemiesnatural enemies
Most insecticides have the potential to affect populations of beneficial insects.
![Page 5: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/5.jpg)
Toxicity to insects Toxicity to insects natural enemiesnatural enemies
Highly toxic - Pest populations recover much faster than enemy populations in nature
![Page 6: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/6.jpg)
Toxicity to insects Toxicity to insects natural enemiesnatural enemies
Moderately toxic – Pest populations recover somewhat faster than enemy populations in treated environment
![Page 7: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/7.jpg)
Toxicity to insects Toxicity to insects natural enemiesnatural enemies
Low toxicity – Natural enemies are maintained to a degree & quickly attack recovering pest populations
![Page 8: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/8.jpg)
Toxicity to insects Toxicity to insects natural enemiesnatural enemies
Nontoxic – Normal enemy population levels are maintained which quickly attack recovering pest populations
![Page 9: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/9.jpg)
Environmental hazardEnvironmental hazard
Environmental hazard of insecticides is generally evaluated as a function of persistence often compared to effectiveness
![Page 10: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/10.jpg)
Environmental hazardEnvironmental hazard
High – Environmental persistence far greater than period of effectiveness (> 5 months and often > a year)
![Page 11: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/11.jpg)
Environmental hazardEnvironmental hazard
Intermediate – Persists beyond effectiveness (3-5 month half-life)
![Page 12: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/12.jpg)
Environmental hazardEnvironmental hazard
Low – Persists about the period of effectiveness (up to about 3 months) and then degrades completely over several months
![Page 13: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/13.jpg)
Environmental hazardEnvironmental hazard
Very low – Persists for short periods (>45 days) and degrades completely
![Page 14: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/14.jpg)
Resistance/Resurgence Resistance/Resurgence HazardHazard
The hazard of populations developing resistance and resurging is evaluated for most insecticides
![Page 15: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/15.jpg)
Resistance/Resurgence Resistance/Resurgence HazardHazard
High – Strong potential to develop resistance and resurge
![Page 16: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/16.jpg)
Resistance/Resurgence Resistance/Resurgence HazardHazard
Intermediate – Moderate potential to develop resistance in treated environments
![Page 17: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/17.jpg)
Resistance/Resurgence Resistance/Resurgence HazardHazard
Low – Minimal potential to develop resistance
![Page 18: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/18.jpg)
Resistance/Resurgence Resistance/Resurgence HazardHazard
None – No resistance developed, no resurgence after many treatments
![Page 19: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/19.jpg)
InsecticidesInsecticides
![Page 20: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/20.jpg)
OrganochlorinesOrganochlorines
•Also called the chlorinated hydrocarbon insecticides•Characterized by containing chlorine and carbon atoms•Powerful nerve poisons•Most affect a broad spectrum of non-target organisms along with the target pests•Long persistence and residual activity
![Page 21: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/21.jpg)
OrganochlorinesOrganochlorines
Several were used in forestry DDT Lindane Dicofol (Kelthane) Endosulfan (Thiodan)
![Page 22: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/22.jpg)
OrganophosphatesOrganophosphates
•Also known as the Ops• Characterized by containing carbon and phosphorus atoms• Generally only short term persistence and limited residual activity• Unfortunately, often have broad spectrum activity against beneficial insects
![Page 23: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/23.jpg)
OrganophosphatesOrganophosphates
Several used in forestry or applied to forests for public health purposes
Malthion (Malathion and Cythion) Acephate (Orthene) Methyl parathion (Methyl parathion) Diazinon (Diazinon and Spectracide) Chlorpyrifos (Dursban and Lorsban) Azinphos methyl (Guthion)
![Page 24: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/24.jpg)
OrganosulfursOrganosulfurs
•Small group of sulfur containing insecticides•Low insect toxicity, but with good miticidal characteristics
![Page 25: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/25.jpg)
CarbamatesCarbamates
•Insecticides which are derivatives of carbamic acid•Non-target toxicity is chemical specific, ranging from low to very high• Generally only short term persistence and limited residual activity• Often with broad spectrum activity against beneficial insects
![Page 26: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/26.jpg)
CarbamatesCarbamates
Very few used in forestry Carbaryl (Sevin) Aldicarb (Temik) Methomyl (Lannate)
![Page 27: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/27.jpg)
BotanicalsBotanicals
•Chemicals extracted or derived from plants •May be present and subsequently extracted from the plant material (a constitutive chemical), or• May be activated in the plant as a response to insect activity (inducible chemicals)
![Page 28: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/28.jpg)
BotanicalsBotanicals
•Some are chemically modified after extraction to enhance their insecticidal properties
![Page 29: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/29.jpg)
BotanicalsBotanicals
Pyrethrins Retenone Ryaia
![Page 30: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/30.jpg)
BotanicalsBotanicals
Pyrethrins
1. Very toxic to cooled blooded animals, some peoples and cats.
2. Very effective on most insects.3. it rapidly breaks down in
sunlight, air and water.
![Page 31: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/31.jpg)
BotanicalsBotanicals
Retenone1. Derived from the roots of over 68
plant species and is very toxic to fish, pigs, and cool blooded animals
2. Used to control leaf eating caterpillars and beetles
3. Direct contact may cause skin and mucus membranes irritation.
![Page 32: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/32.jpg)
BotanicalsBotanicals
Ryaia1. Botanical insecticides made from
the ground stem of Ryana speciosa
2. Is highly toxic to the fruit moths, and citrus thrips
![Page 33: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/33.jpg)
Nicotine Nicotine
• Nicotine a plant defense alkaloid • Nicotine is a fast acting contact killer
for soft bodies but does not kill most chewing insects.
• Concentrate is very poisons if inhaled.• Highly toxic to warm blooded animals.• Pale yellow to dark brown liquid.
![Page 34: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/34.jpg)
NicotineNicotine
• The effectiveness is similar that of organophosphorous compounds
• Nicotine inhibits the function of acetylcholine receptors located at the neuromuscular junctions.
• Nicotine is highly lipophilic and can pass through dermal tissues as well as the blood brain barrier.
![Page 35: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/35.jpg)
Essential oilsEssential oils
Some plants also produce essential oils in specialized gland cells:-
1. Peppermint oil( (زيت روح النعناعcontrol of household pests such as cockroaches and ants.
2. Clove oil((كبش قرنفلinhibit soil born fungal disease.
3. Citrus oil control of flea, aphid and mites4. Lavender oil insect repellent.5. Thyme oil6. Rosemary oil 7. Cedar oil--
![Page 36: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/36.jpg)
Microbial PathogensMicrobial Pathogens
•Fungi, bacteria, viruses, etc. which can be used to cause disease in an insect population•Relatively narrow spectrum of activity, not broad spectrum insecticides•Several have been genetically engineered to kill target insects more rapidly
![Page 37: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/37.jpg)
Microbial PathogensMicrobial Pathogens
Bacillus thuringiensisBacillus SphaericusBaculovirus
![Page 38: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/38.jpg)
RepellantsRepellants
•Large group of unrelated chemicals•Many experimental chemicals – but to the present no truly effective forest protectant chemical•Mostly have found use for people or livestock protection
![Page 39: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/39.jpg)
RepellantsRepellants
Repellent for foliage feeders (مواد طاردة للحشرات التي تتغذى على االوراق النباتية)Such as:-• bordeaux mixture (copper sulfate, hydrate lime, water)Repelles of beetles and grasshoppersCopper ions affect enzymes in the fungal spores
in such a way as to prevent germination.
![Page 40: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/40.jpg)
RepellantsRepellants
Repellents for crawling insectالمواد الطاردة للحشرات الزاحفة Such as:- • Cresol ( organic compound, used as
disinfectants)• Trichlorobenzene (effect for along time, repelled
white ants)
Repellents to fabric eating insectsالمواد الطاردة للحشرات التي تتغذى على المواد
المصنعة
![Page 41: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/41.jpg)
RepellantsRepellants
repellents to blood sucking insectsSuch as:-• Dimethyl phthalate ( anopheles, aedes,
culex)• 2-Ethyl-1.3- hexonediol ( house fly,
mosquito, flea)• DEET( applied to skin and cloths and is used
to repel mosquitoes)• Citronella oil ( personal insect repellents
such as mosquito)• Oil of lemon Eucalyptus ( active against
mosquito)
![Page 42: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/42.jpg)
الشروط الواجب توافرها في المواد الطاردةالشروط الواجب توافرها في المواد الطاردة
ان التسبب حساسية لجلد االنسان و الحيوان -1اال ينتج عن استعمالها رائحة غير مقبولة و ان ال يكون لها -2
تاثير على المالبسان تعطي حماية لمدة طويلة بتركيزات منخفضة -3
ان تكون رخيصة الثمن و يمكن الحصول عليها بسهولة -4اال يكون لها تأثير سام على االنسان و الحيوان -5
ان يبقى مفعولها لمدة طويلة -6يجب ان يكون لها تاثير طارد النواع عديدة من الحشرات -7 يجب ان ال يفقد مفعولها بسرعة بواسطة عرق االنسان-8
![Page 43: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/43.jpg)
FumigantsFumigants
•Fumigants generally contain a halogen (chlorine, bromine, fluorine, etc.) in their molecules•Small molecules which vaporize at relatively low temperatures
![Page 44: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/44.jpg)
FumigantsFumigants
Methyl bromide Dichloropropene Chloropicrin Metam-sodium
![Page 45: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/45.jpg)
Transgenic Crops with Transgenic Crops with Insecticidal PropertiesInsecticidal Properties
Plants genetically engineered to enhance insecticidal properties
![Page 46: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/46.jpg)
Pheromones
Pheromones(chemical used for communication within species)
Chemical signal that triggers a natural response in another member of the same speciesBehavioral chemicals = semiochemicals
• Sex PheromonesAre released by either one( mainly the female) or both genders
for the purpose of mate attraction• Aggregation pheromonesFunction in defense against predator, mate selection
and overcoming host resistance by mass attack• Alarm phrmones Some species release a volatile substance when
attacked by predator that can trigger flight ( in aphid)
![Page 47: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/47.jpg)
Pheromones
• Trail pheromonesAre common in social, for example ants make their
paths with these pheromones which are non volatile hydrocarbones
• Releaser pheromones Are powerfull attraction molecules that some
insects may use to attract males from a distance of two miles or more
![Page 48: Insecticides A Brief Overview of a Complex Subject.](https://reader035.fdocuments.net/reader035/viewer/2022062800/56649de65503460f94adef31/html5/thumbnails/48.jpg)
Pheromones
بدا المختصون في استخدام الفرمونات و خاصة الجنسية منها للحد من اضرار الحشرات حيث
تم انتاج مركبات شبيهة بالفرمونات و قد نجحت بعض التطبيقات الحقلية باستخدام
الفرمونات المصنعة للتقليل من اضرار بعض الحشرات كدودة جوز القطن القرنفلية و يمكن
استخدام الفرمونات المصنعة او الطبية في مقاومة الحشرات بتوجيه افراد االفات الى
.مصائد تحتوي على مواد سامة