Lecture Notes: Forest Insects
ENT/PLPATH/FWE500
Insects and Disease in Forest Resource Management
Kenneth F. Raffa
Dept. Entomology
345 Russell Laboratories
University of Wisconsin
Madison, WI 53706
262-1125
http:entomology.wisc.edu/~ raffa
TABLE OF CONTENTS
Role of Insects in Forest Ecosystems ..............................................4
Introduction to Entomology ..............................................6Classification and Diversity of Insects ..............................................6Insect Structure & Function ..............................................6Growth & Development ..............................................7Major Insect Orders ..............................................7Insect Behavior ..............................................10
Population Dynamics ..............................................11Role in Forest Entomology ..............................................11Population Processes ..............................................11Population Models ..............................................11Life Tables ..............................................14Population Distribution ..............................................15Insect Population Sampling Techniques .......................................... 15
Principles of Integrated Pest Management. ............................................. 16Economic Injury Levels ..............................................16Available tactics of Forest Pest Control.............................................. 16Integrated Pest Management ..............................................17
Root Insects ..............................................18Introduction ..............................................18Impact on Stand ..............................................18Management ..............................................19Conifer Root Weevils ..............................................19Bark beetles, White grubs, Invasive weevils, Lepidoptera, Homoptera 21
Stem Colonizing Bark Beetles ..............................................22Introduction ..............................................22Biology ..............................................22Major Species ..............................................22Management of Bark Beetles ..............................................24
Wood Borers ..............................................26Introduction ..............................................26Native Species ..............................................26
Metallic Borers, Long-horned Beetles ..............……............ 26Horntails, Lepidoptera ..............................................27Ambrosia Beetles ..............................................28
Invasive Species ..............................................29Emerald Ash Borer .............................................. 29Asian Longhorned Beetle ..............................................29Pine Sawyer / pine wilt nematode ......................................... 29Horntail: Sirex noctilio ..............................................30
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Tree Response to Defoliation ..............................................31Introduction ..............................................31Physiology of Defoliation ..............................................31Relation of Control Options to Life History of Defoliating Insects ....32
Hardwood Defoliators ..............................................33Lepidoptera ..............................................33Coleoptera ..............................................36Diptera ..............................................36Orthoptera and Phasmodea ..............................................36Thysanoptera ..............................................37Diptera, Hymenoptera ..............................................37
Conifer Defoliators ..............................................38Budworms ..............................................38Tussock Moths ..............................................39Caseworms and Bagworms ............................................. 40Conifer Sawflies ..............................................40Regionally important defoliators ….......................................... 41
Fluid Feeding Insects ..............................................42Introduction ..............................................42Homoptera ..............................................42Mites: Acarina ..............................................44Other ..............................................44
Shoot and Tip Insects ..............................................45Introduction ..............................................45Weevils ..............................................45Shoot Moths ..............................................46Bark Beetles ..............................................47
Cone and Seed Insects ..............................................48Cone Moths ..............................................48Seed Moths ..............................................48Cone Beetles ..............................................48
Gall Insects ..............................................49
Appendix 1: Insect Population Sampling TechniquesAppendix 2: Major Categories of Insecticides; Mechanisms of Insecticide Resistance
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ROLE OF INSECTS IN FOREST ECOSYSTEMS
I. Herbivory (=Phytophagy)
A. Host Range: Mono-, oligo-, poly- phagousImplications to pest management
B. Plant parts (highly specialized)Microsite
C. Impact1. Can range from marginally beneficial to lethal
2. Implications to Management: Stand level losses in forestsIndividual losses in ornamentals
3. Beneficial: Bio Control of weeds (Alder) & Fungi
4. Ecological: Affects competition between plantsCan influence succession, forest structure, gaps, fire
5. Vector plant pathogens
Insect mouthparts
Sometimes mechanical, sometimes quite specialized
6. Must consider at multiple levels
Plant part: Tree may compensate: Diversion of energy, abscission
Stand level:Increase of light, moisture, release from competitionRelease of bound biomass
II. Predation & Parasitism
A. Host range
B. Specialize on insect stages: Eggs, Larvae, Pupae, Adults
C. Sophisticated prey searching mechanismsOdor - Plant wounds, insect
D. Management: BioControl
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Ecology: Can enhance diversity of ecosystem; Not allow any one herbivore to reach high densities
III. Food For other Animals
A. Food webs
B. Antipredator mechanisms
CamouflageMimicry: Toxic insects, wasps, etc.Chemical Defenses
Implications to Management: SamplingBiological Control
IV. Saprophagy
Importance
Context of pest: Termites, Carpet beetles
V. Pollination
2/3 of flowering plantsForestry - mostly hardwoods
VI. Pest Actions of Insects.
Only “pest” because they interfere with human objectives
Major pests include both introduced and native
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INTRODUCTION TO ENTOMOLOGY
I. CLASSIFICATION AND DIVERSITY OF INSECTS
A. Arthropods
Phylum Arthropoda: Key CharacteristicsExoskeleton Open circulatory system Segmented body parts Ventral nerve cord (decentralized)Paired appendages Open respiratory system
Crustacea - Aquatic - 2 prs antennae - 2 body parts (cephalothorax, abdomen)
Millipedes - more than 1 pr/segm, scavengers
Centipedes - 1 pr/segm, predators
Arachnids - Spiders (pred), Ticks, Mites (Some are important pests) no antennae, 4 prs legs,
B. Insects
Class Insecta: Key Characteristics - 3 distinct body parts 2 pr wings3 prs legs 1 pr antennae
Most diverse of all groups - 1 - 3 million species - @90% of all animals, over half of all life forms
C. Useful Field Guides to Forest Insects and Their Damage
Drooz: Eastern Forest Insects, USDA Misc. Publ. 1426, 1985Furniss & Carolin: Western Forest Insects, USDA Misc. Publ. 1139, 1977
II. INSECT STRUCTURE AND FUNCTION
A. Exoskeleton
B. Major Body Regions
C. Nervous System
D. Circulatory System
E. Respiratory System
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F. Digestive System
G. Reproductive System
III. GROWTH AND DEVELOPMENT
A. Types of Development 1. Hemimetabolous ‘Incomplete metamorphosis’2. Holometabolous ‘Complete metamorphosis’
B. Moulting
C. Endocrine control1. Ecdysone2. Juvenile Hormone
D. Life History Stages1. Diapause2. Dormancy:, Aestivation3. Diurnal Rhytms4. Migration
IV. MAJOR INSECT ORDERS
IntroductionPhylogenetic Order28 orders; 8 orders contain >95% of species
A. Orthoptera (Grasshoppers); Related orders include Phasmatodea (walking sticks) and Mantodea (mantids)
1. Chewing mouthparts2. Incomplete metamorphosis3. Leathery forewings, Membranous hindwings
Most not very important in forestry Some important groups:
Walking sticks on oak in US; Eucalyptus in New ZealandGrasshoppers on oak
B. Blattodea (formerly Isoptera) - termites
1. Chewing mouthparts2. Incomplete metamorphosis3. Highly social
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Very common in forests; feed on cellulose (Indigestible - require protozoa and bacteria - basis of their social systems)
Beneficial - nutrient cyclingDamaging - wood products, sometimes trees
Blattodea - roaches
C. Thysanoptera - Thrips
1. Extremely small - Feathery wings2. Highly modified mouthparts:
Intermediate between chewing & suckingPiercing & sucking
Asymmetric3. Intermediate metamorphosis
Several important species in forestry but not many
D. Hemiptera - Bugs
1. Sucking mouthparts2. Incomplete metamorphosis
3. Subordersa. Heteroptera
Some plant pests, many predators, some human pests
b. Homoptera - Aphids, Scale insects, Spittle bugs, cicadas Plant feedersSometimes quite complex developmentImportant ectors of plant pathogens
E. Coleoptera
1. Largest insect order (@300,000): Most important pest group in forestry2. Chewing mouthparts3. Complete metamorphosis4. Elytra (Thick & horny; Cover hindwings in flight)
Highly Diverse: Plant feeders, predatorsImmatures - Grublike, Some free living
F. Diptera - flies – Fourth large orderest
1. Sucking mouthparts - adults2. Complete metamorphosis
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3. Adults - 2nd Pair of wings highly reduced "Haltere" – Stabilizing organs4. Larvae - maggot like
Not major pest of forests Important vectors of pathogens causing Human Disease
Parasitic flies - TachinidaeLook like houseflies - hairyFemale attaches egg to larva (mostly Lep) or leaf
Predacious flies - Asilidae (Robber flies); Dolichopodidae
G. Lepidoptera
1. Third largest insect order: Second important pest group in forestry2. Sucking mouthparts3. Complete metamorphosis4. Adults - Scaly wings5. Less diversity than Beetles: Almost all are plant feeders as larvae.
Most feed on nectar as adults (some do not feed)6. Larvae are damaging stage "caterpillars" - 3 pairs of true legs
4 - 5 pairs fleshy prolegs7. Types of feeding
Defoliation, Mine leaves, stems, buds
H. Hymenoptera - Wasps, Bees, Ants, Sawflies, Woodwasps, Parasitic wasps
1. Second largest insect order; Most beneficial group in forestry2. Chewing mouthparts - Modified3. Complete metamorphosis4. Adults - Membranous wings;5. Ovipositor - Highly specialized - Defense, Insertion into plants or insects6. Three Important Ecological Groups
a. Plant - feeders: Sawflies, woodwasps, galls: Pestsb. Parasites - Ichneumonidae & Braconidae: Benefitc. Social Insects - bees, ants, wasps - pollination, predation:
7. Larvae a. Caterpillar like (Sawflies > 5 prs prolegs) b. Grublike
V. INSECT BEHAVIOR
A. Introduction: "Observable Physiology"
B. Feeding Behavior
1. Types of feeding
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2. Host range
3. Specialization on plant parts
4. Host location
C. Reproductive Behavior
1. Mate location
2. Mating frequency
3. Oviposition
D. Orientation
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POPULATION DYNAMICS
I. ROLE IN FOREST ENTOMOLOGY
A. Prediction
B. Management
B. Characteristics of Populations
II. POPULATION PROCESSES
A. Birth, Death, Immigration, Emigration
III. POPULATION MODELS
A. Exponential Growth
dn/dt = rN
Nt = N0ert
B. Sigmoid Growth
Carrying Capacity K
dn/dt = rN {(K-N)/K}
Nt= K/ (1+B-rt)
C. Competition
D. Predation
E. Density Independent and Density Dependent Factors
Density Independent Factors: The proportionate effect on population processes (Birth, death, reproduction, movement) is not related to population density.
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1. Example: Early frosts in 1995, 1999, & 2007 caused high mortality to a budworm. But the proportionate mortality is not related to population density
Population Yr. Before frost After frost Mortality % Mortality 2002 1000 500 500 502003 800 No frost2004 50000 No frost2005 75000 37500 37500 502006 100 No frost2007 200 100 100 50
2. Example: Mortality and % mortality vary; Proportionate mortality related to precipitation, but not density.
PopulationYear Precipitation May 1 June 1 Mortality % Mortality 2003 7 500 100 400 802004 4 2000 1000 1000 502005 5 1500 600 900 602006 3 1000 600 400 402007 6 2500 800 1750 70
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F. Density Dependent Factors: The proportionate effect on population processes (Birth, death, reproduction, movement) is related to population density.
1. Example:
Population rates and mortality due to disease are listed below. As the population increases, both the absolute mortality and the % mortality increase
Yr. Population Mortality % Mortality2002 1000 10 12003 5000 500 102004 100000 90000 902005 800 8 12006 10000 2000 202007 50000 25000 50
Types of density-dependent forces
1. Competition
a. Starvation
b. Can sometimes be have Non-lethal Effects:
Examples: Delayed Development, Reduced Fecundity
2. Predation and Parasitism: Both Numerical and Functional Responses
a. Numerical response: Predator population increases when prey abundant
b. Functional response: Consumption / predator increases when prey abundant
3. Disease
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4. Density Dependence Can Sometimes be Positive
a. Allee Effects: Significance to invasive species
5. Some environmental effects can have a density-dependent component
C. Carrying Capacity, Sigmoid Growth and Equilibrium Behavior
1. Effect on Population and Per Capita Growth Rates
2. Time delays
3. Integrating Density-Dependent and Density Independent factors
D. Genetic Change
IV. LIFE TABLES
Life tables present the number of surviving individuals from an initial cohort, at a series of time intervals. They are used to predict future population densities, both between and within generations.
A. Age-Specific death rate: percentage that dies during a particular stage.
B. Cumulative death rate: percentage of original cohort that dies before a particular life stage is reached.
Example:
Stage No. SurvivingAge - Specific
Death RateCumulativeDeath Rate
Egg 1000 50% --Larva - 1 500 60% 50%
- 2 200 50% 80% - 3 100 40% 90% - 4 60 58% 94%
Pupa 25 20% 97.5%Adult 20 -- 98%
C. Key Factors
Source of Stage-specific mortality that best predicts year to year fluctuation
Not necessarily the highest mortality factor
How is it computed? a) calculate the age specific mortality rates; b) determine what factor is most responsible for mortality during each stage; c) determine which stage-
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specific mortality is most correlated with generation to generation change ; d) What is the agent that causes this mortality?
V. POPULATION DISTRIBUTION
A. Space
Random, Clustered, Even
B. Time
1. Seasonal abundance
2. Outbreak behavior
C. Space * Time Interactions
VI. INSECT SAMPLING
A. Sampling vs. Collecting
B. Absolute vs. Relative Methods
C. Appendix 1
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PRINCIPLES OF INTEGRATED PEST MANAGEMENT
I. ECONOMIC INJURY
A. Relationship of Population Density to Yield Loss
B. Sampling
C. Decisions to Employ Control Measures
II. AVAILABLE TACTICS OF FOREST PEST CONTROL
A. Biological Control
1. Natural Components
2. Introduced Species
3. Enhancement of Native Control Agents
4. Biotic Insecticides
5. Advantages, Disadvantages
B. Silviculture
1. Species Composition and Planting Schedules
2. Thinning
3. Harvesting Schedules
4. Advantages, Disadvantages
C. Resistance Breeding
1. Genetic Variation
2. Operational Considerations
3. Biotechnology
4. Advantages, Disadvantages
D. Exclusion and Eradication
1. Quarantine
2. Relating Exclusion to Other Control Measures and Insect Biology
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E. Chemical Control
1. Insecticides (Appendix 2)
a. Types
b. Advantages and Disadvantages
c. LD values
d. Systemic
2. Pheromones
3. Insect Growth Regulators
4. Antifeedants
III. INTEGRATED PEST MANAGEMENT
A. Optimum Combination
B. Applying General Principles To Specific Situations
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ROOT INSECTS
I. INTRODUCTION
A. Increased importance
B. Taxonomy of major groups
C. General features of root insects
1. Slow development time
2. Oligophagous
3. Orientation to host odors
4. Clustered distributions
5. Low fecundity
6. Close symbiotic relationships with fungi
D. High Level of Niche Partitioning
1. Host age and condition
2. Microhabitat
3. Behavior
II. IMPACT ON STAND
A. Direct
1. Larval feeding
2. Adult feeding
B. Indirect
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III. MANAGEMENT
A. Sampling
B. Control
1. Chemical
2. Biological
3. Silvicultural
4. Tree breeding
IV. CONIFER ROOT WEEVILS
A. INTRODUCTION
1. Types of Damage
2. Weevils: Curculionidae
a. Identification
b. Description
3. Relationships With Other Insects and Fungi
4. Increased Importance
B. MAJOR CONIFER ROOT WEEVILS:
1. Pine Root Collar Weevil: Hylobius radicis
a. Hosts
b. Distribution
c. Life cycle
d. Damage
e. Stand factors
f. Control and Management
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2. Pine Root Tip Weevil: Hylobius rhizophagus (H. assimilis)
a. Hosts
b. Distribution
c. Life cycle
d. Damage
e. Control and management
3. Pales Weevil: Hylobius pales
a. Hosts
b. Distribution
c. Life cycle
d. Damage
e. Control and management
4. Pitch-eating Weevil: Pachylobius picivorus
5. Other Conifer Root Weevils
a. Warren's Collar Weevil
b. Strawberry Root Weevil
c. Eastern Pine Weevil: Pissodes nemorensis
d. Hylobius abietis: Europe
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V. BARK BEETLES (COLEOPTERA: SCOLYTIDAE)
A. Hylastes
1. Pests of western Douglas fir plantations, vectors of
Black Root Stain disease
B. Pseudohylesinus
VI. WHITE GRUBS (COLEOPTERA: SCARABAEIDAE)
A. Biology
B. Plantation Pests, Alternate Hosts
C. Control
VII. INVASIVE ROOT WEEVILS OF NORTHERN HARDWOOD FORESTS
A. General Biology and significance
B. Phyllobius oblongus
C. Polydrusus sericeus
D. Sciaphilus asperatus
VIII. LEPIDOPTERA
A. Conifer swift moth
IX. HOMOPTERA
A. Aphids
B. Cicadas
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STEM COLONIZING BARK BEETLES
I. INTRODUCTION
A. Taxonomy: Coleoptera: Curculionidae: Scolytinae (formerly Scolytidae)
1. Bark beetles
2. Ambrosia beetles
B. Economic Importance
C. Distribution
D. Classification By Vigor of Hosts Selected
II. BIOLOGY
A. Life History
B. Host Resistance
C. Pheromones
1. Aggregation
2. Anti-aggregation
D. Microorganisms
1. Blue Stain Fungi: Ophiostoma, Ceratocystis
2. Digestion
E. Relationship of Life Stages to Control Tactics
F. Factors Predisposing Trees to Attack
III. MAJOR SPECIES
A. Mountain Pine Beetle: Dendroctonus ponderosae
1. Northwest and Rocky Mountains
2. Lodgepole Pine, Ponderosa Pine, Sugar Pine, White Pine
3. Grosmannia clavigerum formerly O. clavigera
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4. Responses to climate change: Changes in voltinism, habitats, geographic
range
B. Western Pine Beetle: Dendroctonus brevicomis
1. California and southwestern Rocky Mountains
2. Ponderosa pine
C. Southern Pine Beetle: Dendroctonus frontalis
1. Southern states
2. Loblolly, Virginia, Short Leaf Pine
3. O. minus; Basidiomycetes; Mites
D. Spruce beetle: Dendroctonus rufipennis
1. Alaska, British Col., Rocky Mtn states, North Central states, New
England
2. White spruce, Sitka Spruce, Lutz spruce
3 Variations in population behavior: Region; Population phase
E. Pine Engraver: Ips pini
1. Transcontinental
2. All pines, some spruces
3. Major Lake States bark beetle
4. O. ips
F. European Spruce Bark Beetle: Ips typographus
1. Europe
2. C. polonica
G. Turpentine Beetles: Attack Base of Weakened Trees; Vector Leptographium fungi
1. Red Turpentine Beetle: Dendroctonus valens
a. Transcontinental
b. Introduced into China in mid 1980’s.
2. Black Turpentine Beetle: Dendroctonus terebrans
a. Southern States
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3. Dendroctonus murrayanae in western Canada, high elevations of US Rocky Mts
4. Dendroctonus micans in Europe
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H. Other Conifer Bark Beetles - Moderately Aggressive. Capable of outbreaks under
stress conditions
1. Southern States
a. Eastern 5 Spined Pine Engraver: Ips grandicollis
b. Small Southern Pine Engraver: Ips avulsus
2. Western States
a. Douglas Fir Beetle: Dendroctonus pseudotsugae
b. Fir Engraver: Scolytus ventralis
3. Eastern and Lake States
a. Eastern Larch Beetle: Dendroctonus simplex
I. Dutch Elm Disease
1. Imported Pest Complex
2. Smaller European elm bark beetle: Scolytus multistriatus, C. ulmi
Native elm bark beetle: Hylurgopinus rufipes
3. Biology of beetle, vectoring of fungus, and transmission across root grafts
4. Control
J. Other Bark Beetles Colonizing Angiosperms
1. Hickory Bark Beetle
IV. MANAGEMENT OF BARK BEETLES
A. Impacts
1. Forest Products
2. High Values Trees
a. Recreation, Watershed
b. Private
3. Wilderness
a. Old Growth
b. Endangered Species
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c. Dispersal
B. Chemical
1. Insecticides
2. Pheromones
C. Biological
1. Natural Enemy Complex
a. Predators - Beetles, Flies, Mites, Woodpeckers
b. Parasites - Wasps, Flies, Nematodes
c. Disease Agents
2. Utilizing Biological Control
a. Problems
b. Role in Sanitation
D. Silviculture
1. Augmentation of Host Resistance
a. Thinning
b. Site Selection
c. Harvesting Schedule
2. Reduce Food Base
a. Age mosaic
b. Removal of large trees
c. Timing of operations
3. Population Removal
a. Removal of Infested Trees
b. Destruction of Slash
E. Survey Methods and Population Prediction
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WOOD BORERS
I. INTRODUCTION
A. General Biology
B. Host Location
C. Ecological Role
D. Economic Impacts
Native Species
I. "METALLIC BORERS," "FLAT-HEADED BORERS"
A. Coleoptera: Buprestidae
B. Life Cycle
1. Adult characteristics
2. Larval characteristics
3. Larval mines
C. Ornamental and Forest Pests
1. Bronze Birch Borer: Agrilus anxius
a. Resistant Varieties: Japanese White Birch--"Whitespire"
2. Two-lined Chestnut Borer Agrilus bilineatus
3. Control
D. Plantations
1. Poplar root girdler: Agrilus horni
2. Turpentine borer: Buprestis
E. Lumber Yards
1. Golden buprestid: Buprestis
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II. "LONG-HORNED BEETLES," "ROUND-HEADED BORERS"
A. Coleoptera: Cerambycidae
B. Life Cycle
1. Adult characteristics
2. Larval characteristics
3. Larval mines
C. Host relationships
1. Living trees
a. Sugar Maple Borer
b. Red Oak Borer
c. Locust Borer
d. Poplar Borers:
1. Saperda spp: association with Hypoxylon cankers
e. Management
2. Recently felled trees
3. Old moist wood
4. Dry seasoned wood
5. Twig and stem girdlers
III. "HORNTAILS"
A. Hymenoptera: Siricidae
1. Description
2. Life Cycle
3. Control
V. LEPIDOPTERA: Cossidae
A. Oak carpenterworm
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VI. AMBROSIA BEETLES
A. Coleoptera: Scolytidae (and related families)
1. Biology
2. Economic impact
3. Trypodendron
B. Management
1. Cutting Operations
a. Removal of brood trees and logs
b. Rapid removal of felled trees
2. Storage
a. Distance from sources of beetles
b. Maintain minimum inventories
c. Water Misting
d. Pheromones
VI. Termites
VII. Other
A. Carpenter Ants: Formicidae
B. Coleoptera: Bostrichidae, Curculionidae
C. Diptera: Agromyzidae
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Invasive Species
A. Emerald ash Borer1. Host range, Biology
2. Geographic range
3. Means of spread
4. Control
B. Asian Long-Horned Beetle
1. Introduced into NY in 1996; Chicago 1998.
2. Native range: China, Japan, Korea
3. Hosts
a Primary: Maple, poplar, willow
b. Other: Birch, elm, horsechestnut
4. Life history
a. @ 30 eggs/female; hatch in 10 days
b. Camrial Region: L1-L3; Sapwood: L4-L5.
c. Pupate in tree
4. Control: Sanitation, chemical
C. Pine Sawyer--Vector of Pine Wood Nematode
1. Japan, Portugal
a. Causal agents
1. Native beetle: Monochamus
2. North American nematode: Bursaphelencus
b. Host--Japanese red pine
2. Biology
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3. Impact on host: Death of ray and axial paranchyma cells surrounding duct
epithelium, wilt
4. Control
a. Insecticides
b. Sanitation
c. Introduced entomophagous nematode
D. Sirex noctilio in Australia, New Zealand, S. Africa
1. Introduced Insect/Fungal Complex, Introduced Tree
a. Amylastereum spp & Stereum spp
b. Pinus radiata (Monterey Pine)
2. Life Cycle
a. Adults attracted to stressed trees (Monoterpenes)
b. Insert egg in first drill
Insert fungal arthrospores & mucus in second drill
c. Host responds by accumulating resins & polyphenols
d. Fungi & mucus impede host response
e. Multiple attacks
3. Wilt Symptoms & Tree Death
4. Control
a. Biological
1. Nematode: Deladenus spp
b. Sanitation
c. Resistance Breeding
5. Introduction and Establishment in US
E. Other
1. Poplar & Willow borer: Cryptorhynchus-hybrid poplars
2. Formosan Termite
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TREE RESPONSE TO DEFOLIATION
I. INTRODUCTION
A. Types of Yield Loss
1. Direct
a. Mortality
b. Radial increment loss
c. Altered physiological allocation
2. Indirect
a. Predisposition to subsequent attack
b. Susceptibility to environment
c. Lowered competitive ability
B. Types of Feeding Behavior
C. Insect Groups
II. Physiology of Defoliation
A. Factors Affecting Response
1. Hardwoods vs. conifers
2. Early season vs. late season
3. Environmental effects
4. Degrees of and repetitive defoliation
5. Tissue location and age
B. Reflushing
C. The Role of Stress
1. Effect on plant resistance
2. Effect on tolerance
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3. Population level effects
D. Changes in host suitability for subsequent attack
1. Short vs. long-term effects
2. Types of changes
a. Allelochemicals
b. Nutrients
c. Storage patterns
d. Phenology
3. Effects on different feeding guilds
a. Folivores
b. Root pathogens
c. Bark beetles
III. Relation of Various Control Options to Life History of Defoliating Insects
A. Biological
B. Chemical
C. Silvicultural
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HARDWOOD DEFOLIATORS
I. LEPIDOPTERA
A. Tussock Moths: Lymantriidae
1. Gypsy Moth: Lymantria dispar
a. History, current distribution
b. Life cycle and recognition
c. Host range and preferences
d. Population behavior
1. Weather
2. Host Plant Quality
a. Species Preference
b. Defensive Chemicals: Tannins
3. Natural Enemies
a. Generalist Predators
b. Specialist Parasitoids
c. Viruses
4. Interactions Between Host Plants and Natural Enemies
a. Predators
b. Parasites
c. Virus
d. Btk
e. Sampling
1. Pheromones
2. Egg Mass Survey
3. Larval Banding
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f. Control
1. Biological
a. Major natural enemies
Egg: Ooencyrtus kuvanae (Encyrtidae)
Larva: Cotesia melanoscela (Braconidae)
Blepharipa intermedia (Tachinidae)
Compsilura concinnata (Tachindae)
NPHV
Entomophaga maimaiga
Pupa:White footed deer mice
Calosoma sycophanta (Carabidae)
Brachymeria intermedia (Cholcididae)
b. Microbial control
1. Btk
2. NPHV
3. Entomophaga maimaiga
2. Chemical
a. Insecticides - Sevin
b. Pheromones - "Disparlure," "Gyplure"
c. Insect growth regulators-Dimilin
3. Silvicultural
4. Mechanical
g. Exclusion
h. Interagency cooperation
i. Asian gypsy moth: Introductions; Flight in females
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2. White-marked tussock moth: Orgyia leucostigma
a. Host range
b. Distribution
c. Biology and recognition
3. Satin moth: Stilpnotia salicis
Brown-Tail Moth, Nygmia phaeorrhoea
B. Tent Caterpillars and Webworms
1. Tent Caterpillars: Lasiocampidae: Malacosoma
a. Forest Tent Caterpillar: M. disstria
b. Eastern Tent Caterpillar: M. americanum
c. Western Tent Caterpillar: M. californicum
2. Webworms: Arctiidae
a. Fall Webworm: Hyphantria cunea
C. Other Arctiidae
1. Halisidota - "Tussock Moths"
a. Hickory TM - H. caryae
b. Spotted TM - H. maculata
c. Pale TM - H. tessellaris
d. Sycamore TM - H. harrisii
D. Inchworms: Geometridae
1. Inchworms: Geometridae
2. Fall Cankerworm: Alsophila pometaria
a. distribution
b. host range
c. biology
3. Spring Cankerworm: Paleacrita vernata
4. Bruce Spanworm: Operopthera bruceata
5. Winter Moth: Operopthera brumata
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E. Notodontidae
1. Yellow-necked Caterpillar: Datana ministra
2. Walnut Caterpillar D. integerrima
F. Royal Moths: Citheroniidae
1. Hickory Horned Devil: Citheronia regalis
2. Orange-Striped Oakworm: Anisota senatoria
3. Green-Striped Mapleworm: Dryocampa rubicunda
G. Leaf Roller Moths, Leaf tiers, Leaf Miners
II. COLEOPTERA
A. Leaf Beetles: Chrysomelidae
1. Elm Leaf Beetle: Pyrrhalta luteola
2. Cottonwood Leaf Beetle: Chrysomela scripta
3. Willow Leaf Beetle: Plagiorda versicolora
4. Leaf miners
B. Scarabaeidae
III. ORTHOPTERA and PHASMATODEA
A. Grasshoppers: Acrididae
1. Red-Legged Grasshopper: Melanoplus femurrubrum
B. Walkingsticks: Diapheromera femorata
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IV. THYSANOPTERA - THRIPS
A. Introducted Basswood Thrips: Thrips calcaratus
B. Pear Thrips: Taeniothrips inconsequens
V. DIPTERA
A. Leaf Miner Flies: Agromyzidae
1. Holly Leaf Miner: Phytomyza ilicicola
VI. HYMENOPTERA (SAWFLIES)
A. Leaf Miners: Birch, Elm, Alder
B. Defoliators: Slug Oak Sawfly: Caliroa quercus coccineae
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CONIFER DEFOLIATORS
I. BUDWORMS - LEPIDOPTERA: TORTRICIDAE
A. Eastern Spruce Budworm: Choristoneura fumiferana
1. Importance, range
2. Biology
a. hosts
b. life cycle
3. Natural Enemies
a. Predators - Birds
b. Parasites
1. Eggs - Trichogramma minutum (Chalcidae)
2. Early laravae - Apanteles fumiferanae (Braconidae)
3. Late larvae - Actia interrupta (Tachinidae)
Meteorus thrichynotus (Braconidae)
4. Pupal - Itoplectus conquistidor (Ichueumonidae)
c. Diseases
1. NPHV
2. Protozoa - Nosema
3 Fungi
4. Population dynamics, sampling
a. cycles
b. key factors
c. sampling
5. Impact
a. tree
b. stand
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6. Management
a. silviculture, risk rating
b. insecticides, IGR's
c. microbial control
d. natural enemy enhancement
e. pheromones
B. Western Spruce Budworm: Choristoneura occidentalis
1. Importance, range
2. Biology
3. Control
C. Jack Pine Budworm: Choristoneura pinus
1. Biology & Host Range
2. Damage
3. Control
II. TUSSOCK MOTHS - LEPIDOPTERA:LYMANTRIIDAE
A. Douglas fir tussock moth: Orgyia pseudotsugata
1. Importance, range
2. Biology
a. hosts
b. life cycle
3. Population dynamics
a. cycles
b. factors
c. sampling
4. Impact
a. tree
b. stand
40
5. Management
a. silviculture, risk rating
i. corrective measures
ii. preventative measures
b. insecticides, IGR's
c. microbial control
d. natural enemy enhancement
e. pheromones
B. Pine Tussock Moth: Dasychira plagiata
1. Biology
2. Host range
3. Site conditions
III. CASEBEARERS AND BAGWORMS
A. Casebearers (Lepidoptera: Coleophoridae)
1. Larch Casebearer, Coleophora laricella
a. Biology
b. Damage
c. Control
B. Bagworms (Lepidoptera: Psychidae)
1. Thyridopteryx ephemeraeformis
IV. CONIFER SAWFLIES - HYMENOPTERA: DIPRIONIDAE, TENTHREDINIDAE
A. General
B. Importance of Lake States
C. Redheaded Pine Sawfly - Neodiprion lecontei
1. Importance
2. Host range
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3. Biology
4. Control
D. European Pine Sawfly - N. sertifer
1. Host range
2. Biology
E. Introduced Pine Sawfly - Diprion similis
1. Host range
2. Biology
F. European Spruce Sawfly - D. hercyniae
G. Larch Sawfly - Pristophora erichsonii
1. Host range
2. Biology
V. REGIONALLY IMPORTANT DEFOLIATORS
A. Needleminers (Lepidoptera: saturniidae)
1. Lodgepole needleminer - Coleotechnites milleri
B. Silkworm Moths (Lepidoptera: Saturniidae)
1. Pandora Moth - Coloradia pandora
C. Inchworms (Lepidoptera: Geometridae)
1. Western Hemlock Looper - Lambdina fiscellaria
D. Sulfur Butterflies - Lepidoptera: Pieridae
1. Pine Butterfly (Neophasia menapia)
E. Scarab Beetles (Coleoptera: Scarabaeidae)
1. Foliar damage
a. Pine chafer - Anomala oblivia
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FLUID-FEEDING INSECTS
I. INTRODUCTION
A. Nature of Feeding
B. Nature of Damage
1. Nutrient loss
2. Pathogen transmission
3. Phytotoxins
II. HEMIPTERA: HOMOPTERA
A. Adelgids and Aphids
1. Balsam Woolly Adelgid--Adelges picea
a. Introduced pest
b. Host range
c. Geographic range
d. Damage
e. Survey and detection
f. Control
2. Hemlock Wooly Adelgid, Adelges tsugae
a. Host range
b. Impact
3. Cooley Spruce Gall Aphid - Adelges cooleyi
a. complex life cycle, alternate hosts
b. importance
4. Pine Bark Aphid - Pineus strobi
a. Introduced
5. Gall Aphids
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B. SCALE INSECTS
1. General
2. Pine Tortoise Scale - Toumeyella parvicornis
3. Red-pine scale - Matsucoccus resinosae
4. Beech scale - Cryptococcus fagi
a. Infection court for Nectria coccinea (Fungus)
b. Association with lichens
C. SPITTLEBUGS
1. Biology
2. Saratoga Spittlebugs - Aphrophora saratogensis
a. Biology
b. Damage
c. Control
3. Pine Spittlebug - Aphrophora parallela
a. Hosts
1. Preferred - Scotch
2. Most pines, also Spruce, Fir, Larch, Hemlock
3. All ages and sizes
b. Infection counts for Diplodia pini fungus
1. Flagging
c. Control
1. Thinning: increases vigor
2. Entomophaga fungus
D. LEAFHOPPERS: Cicadellidae
1. White-banded elm leafhopper - Scaphoideus luteolus
a. Elm yellows: Phytoplasma
E. CICADAS
1. Ovipositional damage
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III. MITES: CLASS ACARINA
A. Spruce Spider Mite, Oligonychus ununguis
1. Symptoms
2. Occurrence following pyrethroid application
IV. OTHER FORMS OF FLUID-FEEDING BY ARTHROPODS
A. Predation: Hemiptera (true bugs), spiders
B. Ectoparasitism: Ticks, mites, biting flies
C. Nectar: Adult moths, bees, flies, etc.
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SHOOT AND TIP INSECTS
I. INTRODUCTION
A. Types of Damage
B. Interactions with other groups
II. WEEVILS (COLEOPTERA: CURCULIONIDAE)
A. White Pine Weevil, Pissodes strobi
1. Geographic range: Transcontinental
a. Wisconsin hazard zones
2. Host range
a. Northeast and Lake states: White Pine
b. Pacific Northwest: Sitka Spruce
c. All pines
3. Biology
a. Adult feeding and oviposition
b. Larval girdling of shoots
4. Damage
a. Deformed terminals
5. Control
a. Prevention
1. Hardwood cover
b. Treatment
1. Pruning
2. Removal
c. Resistance Breeding
B. Other Weevils
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III. SHOOT MOTHS
A. European Pine Shoot Moth, Rhyacionia buoliana
1. Geographic range
a. Northeastern U.S. and Southern Canada
b. Lake States, S.E. Wisconsin
c. Pacific Northwest
2. Host range: All pines, especially Red Pine, <15' tall
3. Life Cycle
a. Adults emerge in spring; oviposition at base of buds, needles fascicles,
twig tips.
b. Larvae
1. Early Larvae spin webbing; mine needles
2. Mid Larvae (mid summer): Bore into new buds & overwinter
3. Late Larvae (spring): Bore into new buds: most damaging
phase.
4. Temperature: Cannot tolerate < -29% C.
B. Red Pine Shoot Moth, Dioryctria resinosella
1. Central Wisconsin
2. 30-40 year old trees
3. Shoots and Cones
C. Nantucket Pine Tip Moth, Rhyacionia frustrana
1. Geographic distribution: Eastern, Central and Southern States
2. Host range: All pines except longleaf and white
a. South: Loblolly, Shortleaf
b. Mid-Atlantic: Pitch, Virginia, Scotch
c. Central: Red
3. Plantation problems
D. Zimmerman pine moth, Dioryctria zimmermani
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E. White-Pine Shoot Borer, Eucosma gloriola
1. Geographic Range: Northeastern and Lake States
2. Host Range: White, Jack, Red, Scotch Pines
F. Western Pine Shoot Borer, Eucosma sonomana
IV. BARK BEETLES (Curculionidae: Scolytinae) (Formerly Scolytidae)
A. Pine Shoot Beetle Tomicus piniperda
1. Native and North American distribution
2. Life history
3. Impact
4. Management
B. Pitch Canker
1. Fusarium subglutinans f. sp. pini, vectored by Pityophthorus twig beetles.
2. Monterey pine in California.
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CONE AND SEED INSECTS
I. CONE AND SEED INSECTS
A. Introduction
1. Importance
2. Ecology
B. Cone Moths (Lepidoptera)
1. Red Pine Coneworm, Dioryctria disclusa
2. Fir Coneworm, Dioryctria abietivorella
a. True firs, Douglas fir
3. Spruce Coneworm, Dioryctria reniculelloides
4. Southern Pine Coneworm
C. Seed Moths
1. Spruce Seed Moth, Laspeyresia youngana
2. Filbertworm
3. Valentinia
D. Cone Beetles (Coleoptera)
1. Bark Beetles (Curculionidae: Scolytinae) (Formerly Scolytidae)
a. Red Pine Cone Beetle, Conophthorus resinosae
1. Importance
2. Hosts
3. Life cycle
b. White Pine Cone Beetle, Conophthorus coniperda
1. Importance
2. Hosts
3. Life cycle
c. Western species of Conophthorus
2. Weevils (Curculionidae): Curculio
49
a. Pecan Weevil
b. Chestnut Weevil
E. Cone Flies (Diptera)
1. Spruce Cone Maggot
2. Walnut Husk Fly
F. Bugs ( Heteroptera: Hemiptera)
1. Seed bugs Coreidae - Platycoreia luridans
2. Pentatomidae - Shieldbacked Pine Seed Bug, Tetyra bipunctata
(north),
T. corculus (south)
G. Gall Wasps (Hymenoptera: Cynipidae)
GALL INSECTS
I. Major Groups
A. Aphids
B. Midges: Cecidomyidae
1. Balsam Gall Midge
2. Protection by fungal endophytes
C. Sawflies - Deciduous: Tenthredinidae
D. Gall Wasps: Cynipidae
E. Zimmerman Pine Moth\
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APPENDIX 1: INSECT POPULATION SAMPLING TECHNIQUES
I. Absolute Population Estimates -- expressed as a density (numbers) per unit areaA. Absolute population estimates using marking techniques
1. Methods of marking animalsa. paints and dye solutionsb. labelsc. fluorescent substances (powder)d. mutilatione. marking internally by injectionf. marking by feeding with dyesg. genes, mutant and normalh. radioactive isotopes
2. Capture-recapture methods: Lincoln IndexB. Absolute population estimates by sampling a unit of habitat - air, plants,
1. Sampling from the aira. exposed cone type of suction trapb. enclosed cone types of suction trapc. rotary and other traps
2. Sampling from plantsa. direct countingb. the separation of exposed small animals from the foliage on which they are
living(1) knockdown by chemicals, jarring and heat(2) brushing(3) washing(4) imprinting
c. the expulsion of insects from trees or shrubs(1) jarring or beating(2) chemical knockdown
d. the extraction of insects from herbage and debris(1) suction apparatus(2) cylinder or covering method(3) tents for sampling strongly phototactic insects(4) extraction by heat and drying
e. methods for insects (eggs) in plant tissues(1) dissection(2) bleaching and/or selective staining(3) X-rays
C. Absolute population estimates by sampling a unit of habitat - soil and litter1. Mechanical methods of extraction
a. dry sievingb. soil washing (or wet sieving)c. soil washing and flotationd. flotatione. separation of plant and animal matter by differential wettingf. centrifugationg. sedimentation
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h. elutriation2. Behavioral or dynamic methodsa. dry extractors
(1) large Berlese funnel(2) horizontal extractor(3) multiple canister extractor(4) Kempson bowl extractor
b. wet extractors(1) Baermann funnel(2) hot water extractors(3) sand extractors(4) cold water extractor
c. chemical extractiond. electrical extraction
D. Absolute population estimates by sampling a unit of habitat -freshwater habitats
II. Relative Methods of Population Estimation -- the population is measured in unknown units -- allow only comparisons in space and time; especially useful in extensive workA. Catch per unit effort
1. Visual observation2. Flushing3. Collecting with net or similar device
B. Trapping1. Interception traps
a. air - flight trapsb. water - aquatic trapsc. land - pitfall and other traps
2. Flight traps combining interception and attractiona. sticky trapsb. water traps
3. Light and other visual trapsa. shelter trapsb. trap host plantsc. use of vertebrate hosts or substitutes as bait
(1) moving baits(2) stationary baits
d. bait traps utilizing non-living materials(1) carbon dioxide and "scents" of animals(2) carrion and dung(3) fruits and other attractants
e. sound traps
III. Estimates based on products and effects of insects (population indices). The insects themselves are not counted, but their products (e.g., frass, webs, exuviae, nests, etc.,) or effects (e.g., plant damage) are counted.A. Products
1. Exuviae2. Frass3. Other products
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B. Effects1. Economic damage2. Yield3. Amount of plant consumed
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APPENDIX 2: MAJOR CATEGORIES OF INSECTICIDES
I. PYRETHROIDSA. Mode of Action - Axon poisonB. Attributes - Moderately broad acting
Highly effective; very low doses needed Moderately persistent in environment Low mammalian toxicity High fish toxicity
May release mite outbreaksC. Examples - PydrinD. Comments - Expensive
Derived from Chrysanthemum
II. ORGANOPHOSPHATESA. Mode of Action - Acetylcholinesterase inhibitorB. Attributes - Very broad acting
Less persistent in environment High mammalian toxicity Some miticidal activity
C. Examples - Malathion, orthene, lorsban, cygonD. Comments - Inexpensive; commonly used
III. CARBAMATESA. Mode of Action - Acetylcholinesterase inhibitorB. Attributes - Moderately broad acting
Less persistent in environmentModerate mammalian toxicity (sometimes high)
Sometimes high bee (and earthworm) toxicityC. Examples - Carbaryl "Sevin," Temik, VydateD. Comments - Sevin is widely used
IV. NEONICOTINOIDSA. Mode of Action - Postsynaptic inhibitorB. Attributes - Moderately broad acting
Less persistent in environmentUsually low mammalian toxicityWidely used against sucking insects, boring insects because of systemic activity
C. Examples - Imidacloprid very widely usedD. Comments - Derived from nicotine
V. MICROBIAL PESTICIDESA. Bacillus thuringiensis
1. Different subspecies used on Lepidoptera, Coleoptera, Diptera2. Attributes - Moderately broad acting
Less persistent in environment
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No known mammalian toxicityWidely used
3. Examples - DipelB. Viruses
1. Attributes Species specific Less persistent in environment
No known mammalian toxicityExpensive, sometimes slow acting
3. Examples - Gypchek
VI. INSECT GROWTH REGULATORS
VII. ORGANOCHLORINESA. Mode of Action - Axon poisonB. Attributes - Very broad acting
Highly persistent in environmentLongterm controlEnvironmental Contamination; BiomagnificationBird egg shell thinningVariable toxicity, carcinogenicity & mutagenicity
May releases mite outbreaksC. Examples - DDT, lindane, chlordaneD. Comments - Most are banned for most uses
INSECTICIDE TERMINOLOGY
Systemic - Will be taken up by plantLD50 - The dose required to kill 50% of the population; the lower the LD50, the higher the
toxicityLT50 - The time required to kill 50% of the population
MECHANISMS OF INSECTICIDE RESISTANCE
Reduced penetrationExcretionSequestrationDetoxificationTarget Site Insensitivity
For resistance management, see recommendations by IRAC
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