1. Insecticides
A Brief Overview of a Complex Subject

2. Modes of Entrance into Insect
Contact - dermal – through the skin
Stomach - oral – through the mouth
Respiration - inhalation through the nose or gills
Systemic - combination of above

3. Toxicity to humans or nontarget 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 - LD – 5,000 mg/kg
Nontoxic - LD50 <5,000 mg/kg

4. Toxicity to insects natural enemies
Most insecticides have the potential to affect populations of beneficial insects.

5. Toxicity to insects natural enemies
Highly toxic - Pest populations recover much faster than enemy populations in nature

6. Toxicity to insects natural enemies
Moderately toxic – Pest populations recover somewhat faster than enemy populations in treated environment

7. Toxicity to insects natural enemies
Low toxicity – Natural enemies are maintained to a degree & quickly attack recovering pest populations

8. Toxicity to insects natural enemies
Nontoxic – Normal enemy population levels are maintained which quickly attack recovering pest populations

9. Environmental hazard
Environmental hazard of insecticides is generally evaluated as a function of persistence often compared to effectiveness

10. Environmental hazard
High – Environmental persistence far greater than period of effectiveness (> 5 months and often > a year)

11. Environmental hazard
Intermediate – Persists beyond effectiveness (3-5 month half-life)

12. Environmental hazard
Low – Persists about the period of effectiveness (up to about 3 months) and then degrades completely over several months

13. Environmental hazard
Very low – Persists for short periods (>45 days) and degrades completely

14. Resistance/Resurgence Hazard
The hazard of populations developing resistance and resurging is evaluated for most insecticides

15. Resistance/Resurgence Hazard
High – Strong potential to develop resistance and resurge

16. Resistance/Resurgence Hazard
Intermediate – Moderate potential to develop resistance in treated environments

17. Resistance/Resurgence Hazard
Low – Minimal potential to develop resistance

18. Resistance/Resurgence Hazard
None – No resistance developed, no resurgence after many treatments

19. Insecticides

20. Organochlorines 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

21. Organochlorines Several were used in forestry DDT Lindane
Dicofol (Kelthane)
Endosulfan (Thiodan)

22. Organophosphates 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

23. Organophosphates
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)

24. Organosulfurs Small group of sulfur containing insecticides
Low insect toxicity, but with good miticidal characteristics

25. Carbamates 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

26. Carbamates Very few used in forestry Carbaryl (Sevin) Aldicarb (Temik)
Methomyl (Lannate)

27. Botanicals 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)

28. Botanicals
Some are chemically modified after extraction to enhance their insecticidal properties

29. Botanicals
Pyrethrins
Retenone
Ryaia

30. Botanicals
Pyrethrins
Very toxic to cooled blooded animals, some peoples and cats.
Very effective on most insects.
it rapidly breaks down in sunlight, air and water.

31. Botanicals
Retenone
Derived from the roots of over 68 plant species and is very toxic to fish, pigs, and cool blooded animals
Used to control leaf eating caterpillars and beetles
Direct contact may cause skin and mucus membranes irritation.

32. Botanicals
Ryaia
Botanical insecticides made from the ground stem of Ryana speciosa
Is highly toxic to the fruit moths, and citrus thrips

33. 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.

34. Nicotine
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.

35. Essential oils
Some plants also produce essential oils in specialized gland cells:-
Peppermint oil( (زيت روح النعناعcontrol of household pests such as cockroaches and ants.
Clove oil((كبش قرنفلinhibit soil born fungal disease.
Citrus oil control of flea, aphid and mites
Lavender oil insect repellent.
Thyme oil
Rosemary oil
Cedar oil--

36. Microbial 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

37. Microbial Pathogens Bacillus thuringiensisBacillus Sphaericus
Baculovirus

38. Repellants 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

39. Repellants Repellent for foliage feeders
(مواد طاردة للحشرات التي تتغذى على الاوراق النباتية)
Such as:-
bordeaux mixture
(copper sulfate, hydrate lime, water)
Repelles of beetles and grasshoppers
Copper ions affect enzymes in the fungal spores in such a way as to prevent germination.

40. Repellants Repellents for crawling insect
المواد الطاردة للحشرات الزاحفة
Such as:-
Cresol ( organic compound, used as disinfectants)
Trichlorobenzene (effect for along time, repelled white ants)
Repellents to fabric eating insects
المواد الطاردة للحشرات التي تتغذى على المواد المصنعة

41. Repellants repellents to blood sucking insects Such 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)

42. الشروط الواجب توافرها في المواد الطاردة
1- ان لاتسبب حساسية لجلد الانسان و الحيوان
2- الا ينتج عن استعمالها رائحة غير مقبولة و ان لا يكون لها تاثير على الملابس
3- ان تعطي حماية لمدة طويلة بتركيزات منخفضة
4- ان تكون رخيصة الثمن و يمكن الحصول عليها بسهولة
5- الا يكون لها تأثير سام على الانسان و الحيوان
6- ان يبقى مفعولها لمدة طويلة
7- يجب ان يكون لها تاثير طارد لانواع عديدة من الحشرات
8-يجب ان لا يفقد مفعولها بسرعة بواسطة عرق الانسان

43. Fumigants
Fumigants generally contain a halogen (chlorine, bromine, fluorine, etc.) in their molecules
Small molecules which vaporize at relatively low temperatures

44. Fumigants
Methyl bromide
Dichloropropene
Chloropicrin
Metam-sodium

45. Transgenic Crops with Insecticidal Properties
Plants genetically engineered to enhance insecticidal properties

46. Pheromones Pheromones (chemical used for communication within species)
Chemical signal that triggers a natural response in another member of the same species Behavioral chemicals = semiochemicals
Sex Pheromones
Are released by either one( mainly the female) or both genders for the purpose of mate attraction
Aggregation pheromones
Function 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)

47. Pheromones Trail pheromones
Are 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

48. 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 الافات الى مصائد تحتوي على مواد سامة.