Entomology Review or
What’s that Bug?
Lady
Beetle
larvae
spiders, ticks, and
centipedes (chilopods)
millipedes (diplopods)
snails (molluscs)
mites (arachnids)
spiders (arachnids)
pillbugs (crustaceans)
Not all “bugs” are
insects.
Phylum: Arthropoda Arthropoda
Class: Insecta Arachnida
Order: Diptera Araneae
Family: Muscidae Theridiidae
Genus: Musca Latrodectus
Species: domestica hesperus
Common name: house fly black widow
Remember this?
two main body regions - cephalothorax
(head and thorax fused together)
abdomen
Arachnids: spiders, ticks, scorpions, mites
no antennae
simple eyes
four pairs of jointed legs
no wings
Arachnids
• Spiders and their Kin
Spiders
Ticks
Scorpions
Mites
• Spiders are mostly beneficial
Wings - None, One or Two Pairs
Three Distinct Body Regions: Head, Thorax, Abdomen
Jointed Legs - Three Pairs Antennae - One Pair
Undergoes Metamorphosis
Insect Characteristics
chewing mouthparts
piercing-sucking mouthparts
siphoning
Orthoptera - crickets, grasshoppers
Hemiptera - true bugs
Homoptera - aphids, scale, hoppers
Lepidoptera - butterflies, moths
Coleoptera - beetles, weevils
Diptera - flies, mosquitoes
Hymenoptera - bees, ants
Common Insect Orders
Characterized by:
Mouthparts
Type of legs, wings, antenna
Metamorphosis
Nymphs resemble adults, except for
being wingless. Both adults &
nymphs cause damage.
Moderate to large, hard-bodied
adults with two pairs of wings.
Front wings are hard, leathery
ORTHOPTERA - grasshoppers, locusts, crickets, mantids, cockroaches
Gradual metamorphosis, chewing mouth
parts
HEMIPTERA - true bugs
Gradual metamorphosis, Piercing-sucking
mouthparts in nymphs (immatures) and
adults
Recognized by
triangle on back
Harlequin Bug
HOMOPTERA -aphids, scales, leafhoppers, cicadas, whiteflies, mealybugs
Gradual metamorphosis, piercing-
sucking mouthparts in nymphs
(immatures) and adults
Small, soft-bodied insects,
except for cicadas
Aphids
Mealybugs are considered a type
of scale. They are oval,
segmented, and covered with wax.
Scales may be small, round or football-
shaped, and armored (California red scale)
or soft-bodied (cottony cushion scale).
HOMOPTERA
Whitefles are tiny sap-suckers found in
vegetables, ornamentals, and citrus trees.
HOMOPTERA -aphids, scales, leafhoppers,
cicadas, whiteflies, mealybugs
Leafhoppers feed on undersides of
leaves, transmit virus diseases. Hosts
are: beans, cucurbits, potatoes,
eggplants, grapes, and apples
Butterflies & Moths: Lepidoptera
• Complete metamorphosis
• Larva are caterpillars
• 4 wings, often showy
• Adults are nectar feeders
Moth vs. Butterfly
Moth
• Antennae are feathery or wiry
• Wings at rest – out-stretched, folded or angled
• Day & night
Butterfly
• Antennae end in a club
• Wings at rest out-stretched or held vertically
• Day-time only
LEPIDOPTERA - butterflies, moths
Larvae - chewing
Adults - siphoning
Complete metamorphosis
Mouthparts
Larvae are worm-like,
voracious feeders with prolegs
on abdomen and thorax. Adults are soft-bodied with two
pairs of membranous wings
covered with small scales.
Leaf-eating caterpillars (tomato hornworm, armyworms,
loopers) chew irregular holes. Many small caterpillars
roll leaves to form shelters.
LEPIDOPTERA - butterflies, moths
Beetles = Coleoptera
• More Beetle species than all other animals
• Hard “shelled” forewing
• Vegetarians, predators, scavengers & parasites
COLEOPTERA - beetles, weevils
Complete metamorphosis
Chewing Mouthparts
(adults and larva)
Larvae (grubs, wireworms,
borers) have head capsule
COLEOPTERA - beetles, weevils
Adults have two pairs of wings.
Horny, leathery front wings (elytra)
cover membranous hind wings
underneath, used for flying.
COLEOPTERA - beetles, weevils
Flea beetles, wireworms (click beetle larvae), cucumber
beetles, vegetable weevils, and green fruit beetles are
common pests in California home vegetable gardens
Lady beetles (ladybugs) are beneficials
Flies & Mosquitoes - Diptera
Only 2 wings (1 pair)
Mouth parts adapted for sucking
or piercing & sucking
Complete metamorphsis
Important garden and agricultural pests include the
cabbage maggot, onion maggot, apple maggot, walnut
husk fly, fruit flies, and leafminers
DIPTERA - flies, mosquitoes, gnats, midges
cabbage maggot
onion maggot apple maggot
walnut husk fly
Hymenoptera: Ants, Wasps, Bees, Sawflies
• Narrow waists
• Chewing mouthparts
• Complete metamorphosis
• Can have up to 2 pairs of membranous wings
HYMENOPTERA - bees, wasps, ants, sawflies
Many species are beneficial,
are parasites, natural
enemies or biological control
agents of many pest insects
Raspberry horntail
Pear sawfly larvae Leafcutter wasp
Rose sawfly damage
HYMENOPTERA - bees, wasps, ants, sawflies
WHAT IF YOU DON’T SEE A BUG?
Symptoms or signs of insect attack: Chewed foliage or fruit
Grape leafhopper
Symptoms or signs of insect attack: bleached, stippled or mined leaves
Symptoms or signs of insect attack:
distortion (swelling, twisting, cupping) of
plant parts
Symptoms or signs of insect attack: Dieback of twigs, stems or plant
Peach tree borer
Symptoms or signs of insect attack: presence of insect-related debris
sooty mold
frass
So What’s that Bug?
Red-humped caterpillar
Bark Beetle
Spider mites – not visible to
the naked eye, look for
webbing, suck juices from
plants
Stink bugs attack stone fruits, broccoli,
cabbage, tomatoes. They give off an
offensive odor when disturbed.
Centipede: not an insect,
but a general predator of
insects
Curled, distorted leaves
and sticky honeydew
exudates on leaves are
strong signs of aphid
infestation.
Tomato Hornworm: voracious
muncher of leaves
Lygus bugs
attack beans,
strawberries and
orchard crops.
Assassin Bug: eats beetles,
caterpillars, hornworms & other
insects
Syrphid fly larvae are important
predators of aphids & scales
Earwig, chews flowers & fruit,
can also be beneficial predator
by eating insects & larvae
Walnut Husk Fly: 2 wings,
compound eyes
Codling Moth: larvae are
“worm” in the center of
apples & pears, look for
stings, remove overwintering
pupae
Lacewing: good bug, preys on
aphids and whiteflies
Cucumber beetle: bad
bug, eats crops &
foliage
Scales: suck plant juices
under their covering