Download Bug Basics - University of Arizona

Bug Basics
Peter Warren
County Extension Director
Urban Horticulture Extension Agent
Pima County Cooperative Extension
University of Arizona
Overview
The Big Picture
 Identification
 Diagnosing Plant Damage
 Identification Tools
 Common & Invasive Pests
 Benefits
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From “Evolution of the Insects”
(Grimaldi & Engel 2005)
Identifying Arthropods
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Animals
Segmented body
Exoskeleton
Paired jointed
appendages
Bilateral symmetry
Arthropod Groups
Crustacea >> Water fleas, shrimps, lobsters, crayfish,
crabs, sowbugs (pillbugs)
 Diplopoda >> Millipedes
 Chilopoda >> Centipedes
 Symphylans >> Symphyla
 Xiphosura >> Horseshoe Crabs
 Arachnida >> spiders, scorpions,
harvestmen, mites, ticks
 Insecta >> insects
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Insect Classification
Kingdom - Animal
Phylum - Arthropoda
Class - Insecta
Order - Hemiptera
Family - Pentatomidae
Genus - Nezara
Species - viridula
Author - Linnaeus
Insect Orders
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Approximately 31 Orders
Divided primarily on
– type of metamorphosis
– structure of wings
– structure of mouthparts
Mantophasmatodea
Insect Development
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Metamorphosis
– Meta = change
– Morph = form
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Two types of Metamorphosis
– Simple = gradual change
– Complete = profound change
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Molting
Evolutionarily advanced Orders
use complete metamorphosis
Immature versus Adult
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Many wormlike
Number of legs varies
Most soft and fleshy
No wings
Most slow moving
Examples
– Caterpillars, Maggots,
Grubs
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Three body segments
Six legs
Most crunchy
Most have wings
Most fast moving
Examples
– Butterflies, Flies,
Beetles
Key Immature Characteristics
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Where are they found?
What are they eating?
Do they have legs?
If so, how many?
Coloration?
Meet the Beetles
Key Adult Characteristics
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Exoskeleton
– protection
– support
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Head
– antennae
– eyes
– mouthparts
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Thorax
– legs
– wings
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Abdomen
– digestion
– respiration
Abdomen
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Internal organs
– For reproduction, digestion,
circulation, and respiration
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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
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Wing Variations
Coleoptera (Beetles)
 Elytra -- hard, sclerotized front wings that
serve as protective covers for membranous
hind wings
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Wing Variations
Hemiptera: (True Bugs)
 Hemelytra -- front wings that are leathery or
parchment-like at the base and membranous
near the tip
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Wing Variations
Orthoptera, Blattodea, and Mantodea
(grasshoppers, cockroaches, & mantids)
 Tegmina -- front wings that are completely
leathery or parchment-like in texture
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Wing Variations
Diptera (flies)
 Halteres -- small, club-like hind wings that
serve as gyroscopic stabilizers during flight
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Wing Variations
Thysanoptera (thrips)
 Fringed wings -- slender front and hind wings
with long fringes of hair
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Wing Variations
Lepidoptera (butterflies & moths)
 Scaly wings -- front and hind wings covered
with flattened setae (scales)
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Wing Variations
Many Orders (dragonflies, bees, etc.)
 Membranous wings -- front and hind wings
thin and more or less transparent
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Wing Venation
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Costa (C)
Subcosta (Sc)
Radius (R)
Media (M)
Cubitus (Cu)
Anal veins
(A1, A2, A3)
Times fun when your having flies
Mouthparts
Chewing
Sponging/Lapping
Piercing/Sucking
Siphoning/Sucking
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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
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Types of Insect Injury
Chewing >> beetles, caterpillars, grasshoppers, etc.
 Piercing sucking >> aphids, scale, leafhoppers, etc.
 Internal feeders >> leaf miners, borers, caterpillars, etc.
 Subterranean >> wireworms, root maggots, rootworms, etc.
 Egg laying >> cicadas, gall insects, etc.
 Nest material >> leaf cutter bees, etc.
 Disease vector >> aphids, leafhoppers, bees, beetles, etc.
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Effective Diagnosis
Recognition of symptoms
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Regular monitoring
Record keeping
Accurate identification
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Close examination
Consulting experts as needed
Knowledge of pest life cycle
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Identify susceptible life stages
Determine location for management
Distribution of pest population
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Are there enough of them to be a problem?
Are they wide spread or spreading?
Landscape CSI
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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
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Resources for diagnosis
– Coworkers
– Reference books, internet
– Extension Office
Determining Insect Pest Status
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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
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Publications
– Land-grant Universities
– OMRI.org
– BIRC.org
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Community Availability
– Survey Local Stores/Nurseries
– Cooperative Extension/MGs
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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
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Knowledge of Plants and Pests
– Potential pests and conditions likely associated
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Setting Goals for Protection
– Action thresholds and available control options available
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Site Maps
– Details the physical and environmental features
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Monitoring
– Weekly checks recommended
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Making Control Decisions
– Considering the data available
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Record Keeping
– Date, location, weather, activity
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Evaluation
Overview of IPM Options
Host resistance
 Biological control
 Chemical control
 Cultural control
 Mechanical control
 Do nothing
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Host Resistance
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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
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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
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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
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Type
– match chemical with
problem
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Time
– use chemical when most
effective
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Place
– use chemical where most
effective
Non-target Organisms
Mammals
 Birds
 Fish
 Bees
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Least Toxic Insecticides
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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
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– Site selection
– Soil preparation
– Plant selection
Diversity
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Avoid large plantings of one type
– less attractive from the start
– can slow the spread of pests
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Include farmscaping plants if
diversity is not realistic
Use native and well adapted species
Use disease and insect resistant
varieties
Mechanical and Physical Control
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Direct or indirect measures that either
destroy pests outright or make the
environment unsuitable
Removing pests
– by hand, with traps
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Preventing access to plants
– screens, ditches, row covers
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Sanitation
– remove shelter, food sources, moisture,
attractive odors
Three Cardinal Rules of IPM
Know your ecosystem
 Scout regularly
 Keep good records
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Invasive Insects
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Mostly accidental introductions
– Notable exceptions include gypsy moth
– Humans are excellent vectors
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Success
– No natural enemies
– Similar food plants
– Similar climate
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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
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$19 billion
+ $300 million
+ ???
+ ???
+ ???
> $20 billion
Encouragement
Diversity
 Food plants
 Native species
 Minimize insecticide use
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– least toxic first
– spot treat
Questions?