bug basics peter warren county extension director urban horticulture extension agent pima county...
TRANSCRIPT
Bug Basics
Peter WarrenCounty Extension Director
Urban Horticulture Extension AgentPima County Cooperative Extension
University of Arizona
Overview
The Big Picture Identification Diagnosing Plant Damage Identification Tools Common & Invasive Pests Benefits
From “Evolution of the Insects”(Grimaldi & Engel 2005)
Identifying Arthropods
Animals Segmented body Exoskeleton Paired jointed
appendages Bilateral symmetry
Arthropod Groups
Crustacea Diplopoda Chilopoda Symphylans Xiphosura Arachnida Insecta
>> Water fleas, shrimps, lobsters, crayfish, crabs, sowbugs (pillbugs)>> Millipedes
>> Centipedes
>> Symphyla
>> Horseshoe Crabs
>> spiders, scorpions, harvestmen, mites, ticks
>> insects
Insect Classification
Kingdom - Animal
Phylum - Arthropoda
Class - Insecta
Order - Hemiptera
Family - Pentatomidae
Genus - Nezara
Species - viridula
Author - Linnaeus
Insect Orders
Approximately 31 Orders Divided primarily on
– type of metamorphosis – structure of wings– structure of mouthparts
Mantophasmatodea
Insect Development
Metamorphosis– Meta = change– Morph = form
Two types of Metamorphosis– Simple = gradual change– Complete = profound change
Molting Evolutionarily advanced Orders
use complete metamorphosis
Immature versus Adult
Many wormlike Number of legs varies Most soft and fleshy No wings Most slow moving Examples
– Caterpillars, Maggots, Grubs
Three body segments Six legs Most crunchy Most have wings Most fast moving Examples
– Butterflies, Flies, Beetles
Key Immature Characteristics Where are they found? What are they eating? Do they have legs? If so, how many? Coloration?
Meet the Beetles
Key Adult Characteristics Exoskeleton
– protection– support
Head– antennae– eyes– mouthparts
Thorax– legs– wings
Abdomen– digestion– respiration
Abdomen
Internal organs– For reproduction, digestion,
circulation, and respiration External structures
– Cerci: feeler-like appendages
– Ovipositor: egg laying device, sometimes modified for defense
– Spiracles: openings for respiration
Thorax
Wings
Present only in the adult stage (one exception)
At most two pairs found Many variations in form
Wing Variations
Coleoptera (Beetles) Elytra -- hard, sclerotized front wings that
serve as protective covers for membranous hind wings
Wing Variations
Hemiptera: (True Bugs) Hemelytra -- front wings that are leathery or
parchment-like at the base and membranous near the tip
Wing Variations
Orthoptera, Blattodea, and Mantodea (grasshoppers, cockroaches, & mantids)
Tegmina -- front wings that are completely leathery or parchment-like in texture
Wing Variations
Diptera (flies) Halteres -- small, club-like hind wings that
serve as gyroscopic stabilizers during flight
Wing Variations
Thysanoptera (thrips) Fringed wings -- slender front and hind wings
with long fringes of hair
Wing Variations
Lepidoptera (butterflies & moths) Scaly wings -- front and hind wings covered
with flattened setae (scales)
Wing Variations
Many Orders (dragonflies, bees, etc.) Membranous wings -- front and hind wings
thin and more or less transparent
Wing Venation
Costa (C) Subcosta (Sc) Radius (R) Media (M) Cubitus (Cu) Anal veins
(A1, A2, A3)
Times fun when your having flies
Mouthparts
Chewing Piercing/Sucking
Sponging/Lapping Siphoning/Sucking
Herbivorous & predacious bugs and mosquitoes
Mandibles and maxillae are formed into stylets enclosed by the labium
Once the stylets penetrate, a secretion is injected to dissolve tissue– act as a toxin in predacious
species– act as anticoagulant for
mosquitoes
Diagnosing Plant Damage
Chewed leaves or blossoms Discolored leaves or blossoms Distorted leaves, branches, or trunks Dieback of shoots, twigs, or branches Products of insects and mites
Types of Insect Injury
Chewing Piercing sucking Internal feeders Subterranean Egg laying Nest material Disease vector
>> beetles, caterpillars, grasshoppers, etc.
>> aphids, scale, leafhoppers, etc.
>> leaf miners, borers, caterpillars, etc.
>> wireworms, root maggots, rootworms, etc.
>> cicadas, gall insects, etc.
>> leaf cutter bees, etc.
>> aphids, leafhoppers, bees, beetles, etc.
Effective Diagnosis Recognition of symptoms
– Regular monitoring– Record keeping
Accurate identification– Close examination– Consulting experts as needed
Knowledge of pest life cycle– Identify susceptible life stages– Determine location for management
Distribution of pest population – Are there enough of them to be a problem?– Are they wide spread or spreading?
Landscape CSI
Success depends on early identification and diagnosis Clues for diagnosis
– Problem symptoms» Nuts drop early» Nuts without edible meat
– Problem signs» Worm-like critter or frass in shell» Holes in shell
– Host preference» Shagbark hickory
Resources for diagnosis– Coworkers– Reference books, internet– Extension Office
Determining Insect Pest Status
First goal: identify to Order level (such as bee, beetle, fly)– antennae, wings, mouthparts– shape, texture, size, color– life stage: egg, larva, pupa,
adult Then use other clues to
determine pest status– Host plant– Activity and/or damage
» feeding, flying, crawling, etc.
Diagnostic Tools
Sources of Information
Publications– Land-grant Universities– OMRI.org– BIRC.org
Community Availability– Survey Local Stores/Nurseries– Cooperative Extension/MGs
Dotcom Resources & Catalogs– Buyer beware– Check for products that have been
tested by reputable organizations– Ask for data and references
Components of an IPM Program Knowledge of Plants and Pests
– Potential pests and conditions likely associated Setting Goals for Protection
– Action thresholds and available control options available Site Maps
– Details the physical and environmental features Monitoring
– Weekly checks recommended Making Control Decisions
– Considering the data available Record Keeping
– Date, location, weather, activity Evaluation
Overview of IPM Options
Host resistance Biological control Chemical control Cultural control Mechanical control Do nothing
Host Resistance
Plants naturally evolve resistance to pests
Plant breeding is used to alter the process
Genetic engineering provides a new wrinkle
This must be the one with
insect resistance!
Biological Control
Predators, parasites or parasitoids, and pathogens Lower pest densities to innocuous levels and keep them there Attract beneficial insects by planting flowering nectar & pollen sources Release beneficial insects into environments where pests exist
Chemical Control
Avicides to control pest birds Bactericides to destroy bacteria Fungicides to destroy fungi Herbicides to kill weeds Insecticides to destroy insects Miticides to kill mites Molluscicides to kill snails and slugs Nematicides to kill nematodes Piscicides to control pest fish Predacides to control vertebrate pests Rodenticides to destroy rodents
Pesticide Effectiveness
Type– match chemical with
problem Time
– use chemical when most effective
Place– use chemical where most
effective
Non-target Organisms
Mammals Birds Fish Bees
Least Toxic Insecticides
Bacillus thuringiensis (Bt) for caterpillars, beetles, flies, etc. (making sure you buy the right one)
Insecticidal soap for aphid, mealybug, psyllid, spider mite, and whitefly control
Horticultural oils for sessile (or nearly so) pests such as hemlock wooly adelgid
Cultural Control
The deliberate alteration of the plant production system to reduce pest populations or avoid pest injury to plants
The key to successful IPM Three basic types
– Site selection– Soil preparation– Plant selection
Diversity
Avoid large plantings of one type– less attractive from the start– can slow the spread of pests
Include farmscaping plants if diversity is not realistic
Use native and well adapted species Use disease and insect resistant
varieties
Mechanical and Physical Control
Direct or indirect measures that either destroy pests outright or make the environment unsuitable
Removing pests– by hand, with traps
Preventing access to plants– screens, ditches, row covers
Sanitation– remove shelter, food sources, moisture,
attractive odors
Three Cardinal Rules of IPM
Know your ecosystem Scout regularly Keep good records
Invasive Insects Mostly accidental introductions
– Notable exceptions include gypsy moth– Humans are excellent vectors
Success– No natural enemies– Similar food plants– Similar climate
Management– Difficult to eradicate– Efforts to slow the spread– Always bet on the bug
brown marmorated stink bug
Emerald ash
borer
Asian Long-horned Beetle
Insects with Benefits
Pollination Commercial products Biological Pest Control Decomposition Food for other animals
$19 billion
+ $300 million
+ ???
+ ???
+ ???
> $20 billion
Encouragement
Diversity Food plants Native species Minimize insecticide use
– least toxic first– spot treat
Questions?