Entomology Review

Entomology Review
or
What’s that Bug?
Lady
Beetle
larvae
pillbugs (crustaceans)
spiders, ticks, and
snails (molluscs)
Not all “bugs” are
insects.
spiders (arachnids)
mites (arachnids)
centipedes (chilopods)
millipedes (diplopods)
Remember this?
Phylum:
Arthropoda
Arthropoda
Class:
Insecta
Arachnida
Order:
Diptera
Araneae
Family:
Muscidae
Theridiidae
Genus:
Musca
Latrodectus
Species:
domestica
hesperus
Common name:
house fly
black widow
Arachnids: spiders, ticks, scorpions, mites
two main body regions -
cephalothorax
(head and thorax fused together)
abdomen
four pairs of jointed legs
no antennae
simple eyes
no wings
Arachnids
• Spiders and their Kin
Spiders
Ticks
Scorpions
Mites
• Spiders are mostly beneficial
Insect Characteristics
Three Distinct Body Regions: Head, Thorax, Abdomen
Antennae - One Pair
Jointed Legs - Three Pairs
Wings - None, One or Two Pairs
Undergoes Metamorphosis
piercing-sucking mouthparts
chewing mouthparts
siphoning
Common Insect Orders
Orthoptera - crickets, grasshoppers
Hemiptera - true bugs
Homoptera - aphids, scale, hoppers
Lepidoptera - butterflies, moths
Coleoptera - beetles, weevils
Diptera - flies, mosquitoes
Hymenoptera - bees, ants
Characterized by:
Mouthparts
Type of legs, wings, antenna
Metamorphosis
ORTHOPTERA - grasshoppers, locusts, crickets, mantids, cockroaches
Gradual metamorphosis, chewing mouth
parts
Moderate to large, hard-bodied
adults with two pairs of wings.
Front wings are hard, leathery
Nymphs resemble adults, except for
being wingless. Both adults &
nymphs cause damage.
HEMIPTERA - true bugs
Recognized by
triangle on back
Gradual metamorphosis, Piercing-sucking
mouthparts in nymphs (immatures) and
adults
Harlequin Bug
HOMOPTERA -aphids, scales, leafhoppers, cicadas, whiteflies, mealybugs
Gradual metamorphosis, piercingsucking mouthparts in nymphs
(immatures) and adults
Small, soft-bodied insects,
except for cicadas
Aphids
HOMOPTERA
Mealybugs are considered a type
of scale. They are oval,
segmented, and covered with wax.
Scales may be small, round or footballshaped, and armored (California red scale)
or soft-bodied (cottony cushion scale).
HOMOPTERA -aphids,
scales, leafhoppers,
cicadas, whiteflies, mealybugs
Whitefles are tiny sap-suckers found in
vegetables, ornamentals, and citrus trees.
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
Complete metamorphosis
Larvae - chewing
Mouthparts
Adults - siphoning
Adults are soft-bodied with two
pairs of membranous wings
covered with small scales.
Larvae are worm-like,
voracious feeders with prolegs
on abdomen and thorax.
LEPIDOPTERA - butterflies, moths
Leaf-eating caterpillars (tomato hornworm, armyworms,
loopers) chew irregular holes. Many small caterpillars
roll leaves to form shelters.
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
Lady beetles (ladybugs) are beneficials
Flea beetles, wireworms (click beetle larvae), cucumber
beetles, vegetable weevils, and green fruit beetles are
common pests in California home vegetable gardens
Flies & Mosquitoes - Diptera
Only 2 wings (1 pair)
Mouth parts adapted for sucking
or piercing & sucking
Complete metamorphsis
DIPTERA - flies, mosquitoes, gnats, midges
Important garden and agricultural pests include the
cabbage maggot, onion maggot, apple maggot, walnut
husk fly, fruit flies, and leafminers
apple maggot
walnut husk fly
onion maggot
cabbage maggot
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
HYMENOPTERA - bees, wasps, ants, sawflies
Pear sawfly larvae
Leafcutter wasp
Rose sawfly damage
Raspberry horntail
WHAT IF YOU DON’T SEE A BUG?
Symptoms or signs of insect attack: Chewed foliage or fruit
Symptoms or signs of insect attack: bleached, stippled or mined leaves
Grape leafhopper
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
frass
sooty mold
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