Principles of Forest Insect Pest Management: Strategies and Control Methods

1. OBJECTIVES OF FOREST INSECT MANAGEMENT • At the end of this section students should be able to: • Have an understanding of the following ecological processes, concepts and pest management strategies. • The dynamic events associated with forest succession and the role of forest insects in the process. • The basic differences between forest insect management on federal forest lands versus on private lands. • The mortality quotient and the concept of economic damage. • The different insect pest management strategies including mechanical and physical control, chemical control, biological control, and some alternative methods of insect control. • The kinds of insecticides used in applied control and the different formulations of those chemicals. • The basic differences between density dependent and density independent control.

2. Principles of Forest Insect Pest Management

3. Hickory Horned Devil

4. Regal Moth - adult of Hickory Horned Devil

5. Philosophy of Forest Management 1) Federal/State/County Lands 2) Industrial and Private Forestry

6. Philosophy of Forest Management • Federal/State/Government Lands: • Focus on Ecosystem Preservation • Approaches: • Establish forest preserves • Long rotations • Encourage recreation use • Protect biodiversity • Protect endangered species

7. Philosophy of Forest Management • Industrial and Private Lands: • Focus on Intensive Forestry • Approaches: • Genetic Improvement • Short rotations • Thinning and pruning • New technology in wood utilization and harvesting

8. Long Range Forest Management Goals • Federal Forestry: • Maintaining Forest Health • Industrial and Private Forestry: • Protecting Investments

9. Ecological Roles of Insects: • Herbivores – Defoliators – Gypsy moth • Predators – Checker beetles – Mantids • Prey – Southern Pine Beetles, Aphids • Detritivores – termites, borers • Vectors – Elm beetles & DED • Pollinators

10. What is a pest? Pest status depends on population levels economic factors & objectives of stand. (It is not your younger sibling)

11. Some Review Terms: Equilibrium Position - The average population level of an insect species (EP). Economic Threshold - The population level at which management action should be taken to prevent the pest from reaching the economic injury level (ET). Economic Injury Level - The lowest number of insects that will cause economic damage (EIL). Economic Damage - The amount of pest-caused damage that justifies the cost of applying pest control measures(ED).

12. Some Insects are never economic pests - the Equilibrium position (EP) is below the economic threshold (ET) or Economic Injury level (EIL) Example:Eastern Tent caterpillar

13. Some insects are occasional pests and must be controlled at ET or they will reach EIL. Example: Spruce budworm, Douglas-fir Tussock Moth

14. Some insects are regular and serious pests – the Equilibrium position (EP) is above EIL all the time unless steps are taken to keep them low. Example: Seed and cone moths in seed orchards

15. Economic considerations in Pest • Management include: • Value of crop • 2) Cost of control • 3) Pest status - depends on point of view

16. Approaches to Pest Management: • Mechanical Control • Chemical Control • Biological Control • Integrated Pest Management

17. 1)Mechanical Control: Fly swatters

18. 1) Mechanical Control: • Fly swatters • Salvage logging • Sanitation • Water treatment of cut logs • Kiln drying of lumber

19. 2) Chemical Control: Effects on insects and humans

20. Pesticides are poisons! Characteristics of Pesticides: • Specificity – range of action • Persistence – how long does it last? • Toxicity – How dangerous? • Measuresof Toxicity • LD 50 – dose (mg/kg) lethal to • 50% of test population - Oral or Dermal

21. “Everyday Toxins” Acute oral LD 50’s (mg/kg) * For a 170 lb. male

22. Mode of Action of Pesticides: • Stomach Poisons – Bacillus thuringiensis • Contact Poisons - Malathion • Systemics - Temik • Fumigants – Methyl bromide • Repellents – N,N-diethyl-meta-toluamide • Attractants – fire ant baits

23. Insecticide Chemical Groups: a) Botanicals Nicotine – tobacco plants Pyrethrum - chrysanthemums Rotenone – tropical Derris plants • Characteristics: • Quick knock down • Short residual time • Expensive

24. b) Organochlorines - also called Chlorinated hydrocarbons DDT Methoxychlor Lindane Chlordane Aldrin, Dieldrin, Endrin • Characteristics: • Generally have long residue • Toxicity varies greatly

25. c) Organophosphates - Malathion, Parathion All are Cholinesterase Inhibitors • Characteristics: • Generally very effective • Toxicity varies greatly - (Oral • LD 50 Malathion 1375, • Parathion 2 mg/kg) • Short residual

26. Cholinesterase Inhibition

27. d) Carbamates: carbyaryl (Sevin) or carbofuran (furdan) *Cholinesterase Inhibitors • Characteristics: • Generally quite effective • Generally less toxic than OP • Carbofuran is exception - Oral LD 50 8 mg/kg • Residual limited, but longer than OP

28. e) Synthetic Pyrethroids Ambush, Warrior T, Pounce • Characteristics: • Much more effective than natural Pryrethrum • Used at very low rates • Relatively safe - LD50 about 250 mg/kg • Resistance by insects has become a serious problem

29. Formulation and Application of Insecticides: • Sprays • Dusts • Wettable Powders (WP) • Emulsifiable concentrates (EC) • Ultra low volume sprays (ULV)

31. Pesticide Safety • Keep away from children • Read the Label • Legal contract between the user, • the producer and the State and • Federal Governments • Remember – these are poisons!

33. Insect Growth Regulators: Development Juvenile Hormone (JH) Methoprene. Synthetic ecdysone interferes with normal development Cuticle formation - Diflubenzuron disrupts cuticle formation, inhibits molting process

34. Behavioral chemicals = semiochemicals • Pheromones = chemicals used for • communication within species • Sex Pheromones • Aggregation pheromones • Anti-aggregation pheromones

35. Behavioral chemicals = semiochemicals • Specific insect pheromones collected, analyzed and synthesized. • Synthetic pheromone impregnated into rubber septum. • Wendell Roel of (Cornell University) • did much of the pioneering work in this field.

36. Pheromone may be used in insect control and pest management: • 1. Detection and monitoring • 2. Trap outs – Protection • 3. Attracticides • 4. Confusants

37. 1. Detection and monitoring: Turf beetle

38. 2. Trap outs /Protection: German Bark beetles

39. 3. Attracticides: pheromone plus insecticide Insects are attracted to the material and killed. Many ants are killed in this manner; Amdro, etc.

40. 4. Confusants: German Grape berry Moth

42. Biological Control: • a)Action of natural enemies • b)Predators • c)Parasites (Parasitoids) • d)Pathogens

43. Biological Control: • Usually density dependent - the percentage of hosts killed increases with population density • In contrast, natural control factors (like weather) are density independent • Kill the same percentage of the pests regardless of population density

44. Native and Introduced biological control agents • Predators – • Preying mantids • Lady bird beetles (ladybugs) • Lacewing larvae and adults • Ground beetles

45. Preying mantid Lacewing adult

46. Lady bird beetle (ladybug) Larva eating aphids

47. Parasitoids – • Chalcid wasps • Cynipid wasps • Ichneumonid wasps • Numerous Diptera

48. Value of Parasitoids vs. Predators • Parasitoids • Generally very host specific • Well synchronized with host biology • Predators • Not host specific, can switch prey when food is scarce • Populations do not die out when one prey is gone

49. Pathogens • Bacteria – Bacillus thuringiensis, Bt Controls many insect pests • Fungi – Entomophthorales spp. Infects Gypsy Moth larva • Viruses NPV – Nuclear Polyhydrosis virus (Gypsy Moth & other larva). GV Granulosis Virus (Douglas-fir Tussock Moth) • Protoza – Nosema – Fall Webworm

50. Approaches to Biological Control • Importation from other countries • Conservation that protect habitats of any biocontrol agents that may be present • Enhancement: Artificial rearing of agent for release to increase or “enhance” existing biocontrol populations