Insects & Diseases
Remember the classification
scheme?
Kingdom
Phylum
Class
> Order
Family
Genus
Species
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Approximately 30 orders.
Most are insignificant and are only studied for
scientific purposes.
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Mites
Ticks
Spiders
Mollusks (also spelled mollusc)
◦ Snails
◦ Slugs
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Largest number of species – 1 in 5 living
creatures is a beetle!
Mostly CHEWING MOUTHPARTS
Complete Metamorphosis
Two pairs of wings
◦ Front pair thick, hard, meet in a line
◦ Back pair membranous, used for flight
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Some of our best known pest species
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Japanese beetle
white grub
weevils
rootworms
Spot ID
 Chewing
mouthparts
Spot ID
 Chewing
mouthparts
 Forewings (elytra)
form hard shell
covering
hindwings
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Variable size
Adults have 2 pairs of membranous wings
covered with scales
Antennae usually knobbed, thread-like, or
feathery
Complete metamorphosis
Mouthparts
◦ Adults – lapping or sucking
◦ Larvae – chewing
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Coiling-sucking
mouthparts
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Coiling-sucking mouthparts
Four wings covered with
scales
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Many familiar friends and foes in Lepidoptera:
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Caterpillars
Butterflies
Moths
Cutworms
Armyworms
Borers
Leafminers
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One pair of wings
Halteres in place of hindwings
Piercing, sucking, sponging mouthparts
Complete metamorphosis
Larvae known as maggots
◦ usually legless, many aquatic
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Important econ. pest, disease vectors
Mosquitos, flies
Mostly beneficials for hort. crops
Spot ID
 Two wings
Spot ID
 Two wings
◦ Hind wings
reduced to
halteres
Spot ID
 Two wings
◦ Hind wings
reduced to halteres
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Sponging-sucking
mouthparts
◦ Except mosquitoes
and some others
that pierce skin
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Two pairs of wings or wingless
Antennae with 10 or more segments
Mouthparts chewing/lapping
Complete metamorphosis
Female ovipositor may be modified into
stinger or saw-like structure
Many are colonial
Many harmful and beneficial species
◦ bees, wasps, ants, sawflies
Hooks not shown
Spot ID
 Chewing mouthparts
Spot ID
 Chewing mouthparts
 Four membranous
wings
Spot ID
 Chewing mouthparts
 Four membranous
wings
 Waist often constricted
Spot ID
 Chewing mouthparts
 Four membranous wings
 Waist often constricted
 Females with ovipositor
or stinger at end of
abdomen
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Two pairs of wings usually present; flat over
body when resting
Forewings with the basal portion thickened
and leathery and the wingtip membranous
Hindwings entirely membranous
Piercing, sucking beak
Simple metamorphosis – juveniles (nymphs)
resemble adults
◦ Chinch bugs
◦ Squash bugs
◦ Box elder bugs
Spot ID
 A beak: piercing-sucking
mouthparts
Spot ID
 A beak: piercing-sucking
mouthparts
 Forewings covering hindwings
◦ Wing half membrane, half thickened
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Some consider this a suborder of Hemiptera
May or may not have wings
Some with wings held tent-like
Many are plant feeders
Piercing/sucking beak
Simple metamorphosis
Some bear live offspring (viviparity)
Can be very small
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Many important ornamental and
greenhouse pests
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Aphids
Whitefly
Scale
Leafhoppers
Cicadas
Mealybugs
Diversity in Homoptera
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Class Insecta
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Order
Order
Order
Order
Dermaptera – earwigs
Thrysanthoptera – thrips
Neuroptera – lacewings, mantids, ect.
Orthoptera – crickets, grasshoppers, roaches
Class Diplopoda – Millipedes
Class Chilopoda – Centipedes
Class Archnida
◦ Order Acari
 Ticks
 Mites
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Phylum Mollusca
 Slugs
 Snails
Managed in same ways as insects
Spot ID
 Jumping hind legs
Spot ID
 Jumping hind legs
 Some with ovipositor at
hind end
Spot ID
 Long skin-like hindwings
folded under very short
forewings
Spot ID
 Long skin-like hindwings
folded under very short
forewings
 Pinchers off end of abdomen