1. OBJECTIVES OF FOREST ENTOMOLOGY Chapters 17-18
At the end of this section students should be able to:
1) Appreciate the damage caused by forest insects.
2) Understand the multifaceted role of forest entomology and some of the factors involved in protection of forests and urban trees and the role of insects in the ecosystem.
3) Describe the development of forest entomology in Europe and North America.
4) Describe the contributions of the pioneers of forest entomology.
5) Identify the major trends of the profession.
6) Know some of the major sources of information on forest insects.
7) Discuss the scientific contributions and current research of the U.S. Forest Service.
8) Outline the current role of forest entomology in private and public

2. Definition of Forest Entomology

3. Influence of Germans
J. C. Schaffer - Early studies of Gypsy Moth
J.T.C. Ratzeburg –
Father of Forest Entomology

4. J.T.C. Ratzeburg
The study of forest insects which have an influence on the health and the utility of those wood plants with which the forester is concerned. :
“Die Foresteinsketen”

5. Forest Entomology in U.S. and Canada
A. D. Hopkins - Considered Father of U.S. Forest Entomology: Bark Beetle Specialist

6. F.C. Craighead (left) and J.A. Beal - 1926

7. Why Insects are Important in the Forests
Their activities result in damage
In 1950, Craighead estimated annual losses to be:
Bark beetles $20 million
Defoliators $20 million
Forest Product pests $60 million
Shade and ornamental pests ----$100 million

8. F.P. Keen

9. W. G. Wellington

10. Historical Aspects
Development of forest entomology

11. Forest Entomology “Divergent” theories of population changes
1. Taxonomic/natural history phase
2. Divergent phase
“Divergent” theories of population changes
Density Independent factors
Density Dependent factors
3. Ecosystem analysis phase
Interrelationships of all environmental factors – Ecological webs, food chains, weather, etc
4. Predictive Modeling Phase
Models developed from divergent and ecosystem phases.

12. Economic Impact of Forest Insects
Mortality – reduce growing stock
Delay stocking levels – Reproduction
Seeds, cones, seedlings
Reduce radial/axial growth
Defoliation of leaves/killing of buds
Deterioration
Loss of product value

13. Insects Cause Damage: To trees
Southern Pine Beetle Spot

14. Insects Cause Damage:
To Seeds and Cones
Southern Pine
Coneworm

15. Damage of Southern Pine Coneworm

16. Insects Cause Damage:
To seedlings
White Grub Adult
White Grub Larva

19. Pales Weevil and Damage on Pine Seedling

20. Insects Cause Damage: To Wood Products
Termites Damage Wooden Structures

21. Carpenter Ant
& Damage

22. Insects also Spread Disease
Southern Pine Beetle
and
Blue Stain Fungus

23. Dutch Elm Disease – vectored by Bark Beetles

24. Oak wilt causes tree mortality spread by Picnic Beetles

25. Insects are Important in the Forest
Beneficial:
As plant pollinators in the forest
As natural enemies of pest insects

26. Hover Flies Pollinate Many Flowers

27. Preying Mantid feeding on a katydid

28. Larva of Lady beetle feeding on aphids

29. Insects also provide fodder for Gary Larson and his cartoon humor

30. Important Insect Groups in the Forest
Lepidoptera : The butterflies & Moths

31. Eastern tent caterpillar & tent

32. Eastern Tent Caterpillar Larva

33. Coleoptera: The Beetles

34. Asian Longhorned
Beetle
Anoplophora
glabripennis
Family Cerambycidae

35. Hymenoptera: Bees, Wasps, Ants & Sawflies

36. Carpenter Bee
Yellow Jacket Wasp
Carpenter Ant
Pine Sawfly Ovipositing

37. Homoptera-Hemiptera: Aphids, Adelgids, leafhoppers, & true bugs.

38. True bugs
Leafhoppers
Aphids

39. Orthoptera: Grasshoppers, Katydids, & Walking Sticks

40. Katydid
Grasshopper
Walking Stick

41. Diptera: Flies and Mosquitoes
Diptera: Cone gall midge and damage

42. Isoptera: Termites
Termite Reproductives swarming

43. Termite soldier and workers

44. Insects Cause Damage Many Ways:
Feeding
Nest Building
Oviposition

45. Tree Mortality caused by feeding of Adelgids

46. Nest building
damage by
carpenter ants

47. Oviposition
damage caused
by 13-Year
Cicada

48. Twig Mortality
caused by 13-Year
Cicada

49. Approaches to Insect Control
Natural Control Factors
Weather
Natural Enemies
Cultural Control
Resistance
Stand Management
Chemical Control
Mechanical Control

51. Aphid lion (lacewing larva) and victim

52. Longleaf Pine is resistant to many insect enemies including
Southern Pine Bark Beetles

53. Insecticide Application in Seed Orchard

54. Use of pheromone
“Repellent” verbenone to
prevent bark beetle
attacks

55. Mechanical removal
of gypsy moth egg
masses

56. Buffer zone stops/slows southern pine beetle advance

57. Forest Entomology – Applied Ecology
Detection
Identification
Forecast – what will happen?
Assessment – risk to forest
Analysis of outbreak
Recommendations/Management

58. Questions for Introduction to Forest Entomology:
1) Why did damage caused by forest insects in North America prompt development of forest entomology as an important discipline within silviculture?
2) Describe the evolution of forest entomology in Europe and later in North America.
3) What are the basic reasons insects are important in the forests?
4) In what ways do insects cause damage to forest trees?
5) What are the most important insect groups in the forests?
6) How does natural control differ from cultural control?
7) Why is chemical control not used more often to control forest pests?
8) Why will the future use of pesticides likely decline in the control of forests pests?
9) Describe how forest pest management will change in the future. What key biological or mathematical disciplines will be most important in pest management?