Chapter 37 Section 1 The Insect World
Chapter 37
Section 1
The Insect World
Characteristics• Phylum Arthropoda
• Subphylum Hexapoda
• Class Insecta
• Body divided into three segments: head, thorax, & abdomen
• Most are small, some are huge
African Goliath Beetle
Atlas Moth
Characteristics• Entomology- the study of insects
and other terrestrial arthropods
• Entomologist- person who studies insects
Success of Insects• Live everywhere in the world except
for saltwater
• Most have the ability to fly- how does this make them successful?
• Light but sturdy exoskeleton
• Short lifespan and produce large numbers of eggs
Insects & People• Insect pests- how do they affect
humans?• Fleas- transmit harmful bacteria-
plague• Tsetse fly- African Sleeping Sickness• Termites- destroy wood in buildings
Insects & Humans• Serve as food for numerous species
of animals
• Pollination
• Commercially valuable- honey, wax, silk, etc
• Termites help recycle nutrients back into the environment
Insect Development• Metamorphosis- developmental
change
• Incomplete
• Complete
Incomplete Metamorphosis• Incomplete metamorphosis- nymph
hatches from an egg and gradually develops into an adult
• Nymph- immature form of an insect that looks like the adult, but it is smaller, and its wings and reproductive organs are undeveloped
• EX: GRASSHOPPER
Complete Metamorphosis
• Complete metamorphosis- insect undergoes two stages of development between the egg and the adult
• Example: butterfly
Importance of Metamorphosis
• Larval and adult stages have different functions and don’t compete for food
• Helps survive harsh winters• Example: butterflies and moths
spend the winter as pupae encased in cocoons buried in soil
Insect Defense• Camouflage, venom• Bold, bright colors- poisonous =
warning coloration• Mullerian mimicry- dangerous species
mimic the warning colors of others
• Batesian mimicry- harmless species mimics dangerous species
REVIEW!!!• Why are insects successful?
• List two ways that insects are harmful to society and two ways they are beneficial.
• Describe two types of mimicry in insects.