Transcript Introduction to Insects

Introduction to Insects
The Study of Insects
• Known as entomology
• Entomologists have described and
classified more than 900,000
insect species.
• Entomologists discover from 7,000
to 10,000 new species of insects
each year.
Insect Classification
• Kingdom: Animalia
• Phylum: Arthropoda
• Class: Insecta
• Orders (know these): Coleoptera,
Diptera, Hemiptera, Homoptera,
Hymenoptera, Lepidoptera, Orthoptera,
Odonata
Insect Anatomy
• A hard exoskeleton protects a soft
interior.
• Divided into head, thorax, abdomen
• Most have wings of some type
• No Lungs: breathes through
spiracles and trachea
• insect anatomy web page
Mouth Parts
• Chewing (beetles)
• Sucking (adult butterflies)
• Piercing (true bugs)
• Lapping (fly)
Insect Growth
• The exoskeleton limits the
potential size of insects, but
provides valuable protection.
• To grow and become an adult,
young insects shed or molt their
exoskeleton.
Molting
• A new, flexible exoskeleton forms
beneath the old exoskeleton.
• By taking in extra air, the insect
expands itself and splits the old
skin.
• The new, soft exoskeleton starts to
harden in minutes.
• Once an insect becomes an adult it
stops growing.
Life Cycles: Metamorphosis
• Complete Metamorphosis
– For butterflies, the caterpillar is very different from
the adult.
• Incomplete Metamorphosis
– In grasshoppers, the young resemble the adults.
The younger stages are called nymphs.
• No Metamorphosis
– The young are identical to adults, except for
gonads.
Complete Metamorphosis
egg
adult
larva
pupa
Incomplete Metamorphosis
egg
adult
nymph
bigger
nymph