OBJECTIVES OF FOREST ENTOMOLOGY Chapters 17 18 At

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

Definition of Forest Entomology

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

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. 1830 -1850: “Die Foresteinsketen”

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

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

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

F. P. Keen

W. G. Wellington

Historical Aspects Development of forest entomology

Forest Entomology 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.

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

Insects Cause Damage: To trees Southern Pine Beetle Spot

Insects Cause Damage: To Seeds and Cones Southern Pine Coneworm

Damage of Southern Pine Coneworm

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

Pales Weevil and Damage on Pine Seedling

Insects Cause Damage: To Wood Products Termites Damage Wooden Structures

Carpenter Ant & Damage

Insects also Spread Disease Southern Pine Beetle and Blue Stain Fungus

Dutch Elm Disease – vectored by Bark Beetles

Oak wilt causes tree mortality spread by Picnic Beetles

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

Hover Flies Pollinate Many Flowers

Preying Mantid feeding on a katydid

Larva of Lady beetle feeding on aphids

Insects also provide fodder for Gary Larson and his cartoon humor

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

Eastern tent caterpillar & tent

Eastern Tent Caterpillar Larva

Coleoptera: The Beetles

Asian Longhorned Beetle Anoplophora glabripennis Family Cerambycidae

Hymenoptera: Bees, Wasps, Ants & Sawflies

Carpenter Bee Yellow Jacket Wasp Carpenter Ant Pine Sawfly Ovipositing

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

True bugs Leafhoppers Aphids

Orthoptera: Grasshoppers, Katydids, & Walking Sticks

Katydid Grasshopper Walking Stick

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

Isoptera: Termites Termite Reproductives swarming

Termite soldier and workers

Insects Cause Damage Many Ways: Feeding Nest Building Oviposition

Tree Mortality caused by feeding of Adelgids

Nest building damage by carpenter ants

Oviposition damage caused by 13 -Year Cicada

Twig Mortality caused by 13 -Year Cicada

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

Aphid lion (lacewing larva) and victim

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

Insecticide Application in Seed Orchard

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

Mechanical removal of gypsy moth egg masses

Buffer zone stops/slows southern pine beetle advance

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

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?