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. Insect Pest Management
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. Pest status depends on population levels economic factors &
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?
Measures of 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) Table Sugar 29,700
Baking Soda
3,500
Malathion
1,375
Aspirin*
1,000 (about 100 tablets)
Table Salt
400
Caffeine*
192 (about 100 strong cups of coffee)
Gasoline
150
Nicotine 53
Vitamin D (pure)
9.5
* 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 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
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

51. Advantages of Biological Control
Control is self-perpetuating
Control is selective and density dependent
Does not create new problems - normally

52. Disadvantages of Biological Control
Not effective against Direct Pests
where any damage is unacceptable
Some level of damage occurs and must be acceptable
Must be implemented over large areas
May take years to become effective

53. Other Approaches to Insect Control:
Host Resistance--
Preference/non-preference –
Antibiosis –
Tolerance -

54. Other Approaches to Insect Control:
Legislative Control:
Laws made to prevent entry or spread of pests. Quarantine against pine shoot borer.

55. Integrated Forest Pest Management
“The combination of all suitable
techniques to reduce or manipulate
pest populations so that they remain
below economically important levels”

57. Questions to for Principals of Forest Insect Management:
1) What are the basic differences in management philosophy between those in Federal forestry and the private forestry companies?
2) Why is control of seed orchard pests so important? Why is the approach used in seed orchards said to be similar to pest management in agriculture?
3) What are the basic approaches to pest management used in forestry?
4) What are the basic characteristics of commonly used insecticides?
5) What is the LD 50 of a pesticide?
6) What is the basic mode of action of the organophosphate and carbamate insecticides?
7) What are semiochemicals and how can they be used in forest pest management?
8) What is the difference between density dependent and density independent pest control?
9) What type of biological agent was used in the control program of the larch casebearer? Would you characterize this as a program of introduction, conservation or enhancement?
10) Why is Bacillus thuringensis used so often in control of forest Lepidoptera?
11) What are the basic types of viruses used in control of forest pests?
12) Explain why biological control agents are not effective at eradicating a pest species.