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

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.