Transcript Immature Insects

Immature Insects
Rick Story, Department of Entomology
Types of Insect Development
1) Incomplete (egg nymph or larva adult)
2) Complete (egg larva pupa adult)
Insect Growth
-external skeleton
-grows with successive molts
-each stage is an instar
-typically 5-7 instars for larval growth
Insect Metamorphosis
-change in body form from immature
to adult stage
Incomplete Metamorphosis
Immatures look like adults except:
1) Smaller
2) Lack wings
3) Lack genitalia
Incomplete Metamorphosis
Immatures look like adults:
1) Same mouthparts
2) Feed on same plants
3) Occur together with adults
4) Have compound eyes
Complete Metamorphosis
-immatures do not look like adults
-have an inactive pupal stage for
transformation
Complete Metamorphosis
Immatures unlike adults:
1) Different mouthparts
2) Different host plants
3) Do not typically occur together
4) Lack compound eyes
Identification of Immatures
Incomplete development orders – characters
similar for nymphs and adults
Complete development orders- characters
completely different
Main orders with complete development
Neuroptera : green + brown lacewings
Lepidoptera : caterpillars (moths)
Hymenoptera : sawfly larvae, ants, bees, wasps
Diptera : maggots (flies)
Coleoptera : white grubs, weevils,
wireworms (beetles)
Neuroptera
-Larvae are predators, with well developed legs
and an elongated body
-sickle shaped mandibles with blood groove
diagnostic character
Lepidoptera
-Larvae (caterpillars) are plant feeding and
have chewing mouthparts
-caterpillar body form diagnostic (cylindrical
body, thoracic legs well developed, abdominal
prolegs present)
Diptera
-Larvae with variable feeding habits and
chewing mouthparts
-body with head capsule partially to completely
reduced, no thoracic legs, soft bodied, white,
often occur in damp habitats.
Coleoptera
-Larvae with chewing mouthparts, plant feeding
or predators
-Have well developed head capsule, thoracic
legs present (usually), and lack abdominal
legs
Hymenoptera
-sawflies: caterpillar body form (prolegs lack
hooks), feed on foliage
-bees, wasps, ants: grub-like body form with
well developed head capsule and no thoracic
legs.
Author: Rick Story
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[email protected]