1. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Diversity Ants, mosquitoes, gnats, flies, bees, crickets all belong to the arthropod subphylum, an enormous group of mostly terrestrial arthropods that have chewing mouthparts called (jaws). Uniramians consist of three classes: (insects), (millipedes), and (centipedes). The insects are by far the largest group of organisms on Earth, with more than 700,000 named Insects and Their Relatives Entomology = study of insects

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Insects and Their Relatives

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Insect Diversity, (the order - no wings) More than percent of insect species belong to one of the four orders shown in this table. Insects and Their Relatives

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Insects Some show mimicry – similar markings for different harmful organisms Some show mimicry – one of two similar looking organisms is harmful, the other is not Bombardier beetles spray hot stream of noxious chemical from their for defense. of ants are used to guide others to food. Pheromones of moths are secreted by females to attract males. Insects can be controlled biologically by bacteria or plant products or chemically by

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Insect Diversity, continued Insect Body Plan All insects share the same general made up of three body sections. 1. Located on an insect’s head are mandibles, specialized mouthparts, and one pair of antennae. 2.. The thorax is composed of three fused segments. 3.. The abdomen is composed of 9 to 11 segments. Insects and Their Relatives

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Insect Insects and Their Relatives

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Insect Diversity, continued Insect Life Cycle The life cycles of most insects are complex, and often several are required before the adult stage is reached. During the last molt, the young insect undergoes a dramatic physical change called Insects and Their Relatives

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Insect Diversity, continued Insect Life Cycle: Complete Metamorphosis Almost all insect species undergo “ ” metamorphosis. In complete metamorphosis, the wingless, wormlike larva encloses itself within a protective capsule called a chrysalis. Here, it passes through a stage, in which it changes into an A complete metamorphosis is a complex life cycle. The can, however, exploit different habitats and food sources than adults. Insects and Their Relatives

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Insects and Their Relatives

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Types of That Go Through Complete Metamorphosis Insects and Their Relatives

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Insect Diversity, continued Insect Life Cycle: Incomplete Metamorphosis A number of species develop into adults in a much less dramatic incomplete metamorphosis. In these species, the egg hatches into a juvenile, or, that looks like a small, wingless adult. After several, the nymph develops into an adult. Insects and Their Relatives

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Insects and Their Relatives

13. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Types of Insects That Go Through Incomplete Insects and Their Relatives

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Anatomy of a Insects and Their Relatives

15. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Anatomy of a Grasshopper Insects and Their Relatives

16. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Insect Diversity, continued An insect’s wings develop from saclike outgrowths of the body wall of the The wings of adult insects are composed entirely of, strengthened by a network of tubes called (which carry air, not blood). In most insects, the power stroke of the wing during flight is downward, and it is produced by strong flight Insects and Their Relatives Chapter 39

17. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Insect Diversity, continued Social Insects Two orders of insects, Hymenoptera (ants, bees, and wasps) and Isoptera (termites), have elaborate Within these insect, there is a marked division of labor, with different kinds of individuals performing specific functions. The role played by an individual in a colony is called its. Caste is determined by a combination of heredity; diet, especially as a larva; hormones; and pheromones, chemical substances used for Insects and Their Relatives Chapter 39

18. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Social Insects continued Insects use pheromones to communicate – chemicals that effect behavior or Some use – chirp of rubbing wings of crickets, buzz of mosquitoes attracts mates, firefly lights

19. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Honey Bees Behavior is (genetically programmed) Three types of honeybees: – sterile females, feed honey to others, make up most of the hive (about 80,000), secrete wax, build & repair hive, gather pollen, have special mouthparts Queen and youngest larvae are fed “royal” jelly (high in protein). – secretes pheromone (queen factor) that keeps others from developing into queens. She lays eggs. – live only to fertilize queen (each queen is only fertilized once in a lifetime). Drones are from unfertilized eggs.

20. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Honey Bees Bees – round dance = food is near waggle dance = food is far (they also show direction) They show behavior – will die for the good of the hive (die if they sting, not true of wasps) – protecting relatives so genes are passed on Barbed is a modified ovipositor When overcrowded, bees are

21. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Insect and Us More than species do to numbers, short reproductive times, flying, defenses, jointed appendages, small size, variety. They bite, sting, carry (fleas plague, mosquitoes malaria) They destroy They make, shellac, wax, silk, recycle. They pollinate

22. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Insect Diversity, continued Insect Centipedes and have similar bodies. Each has a head region followed by numerous similar segments. Centipedes have one pair of legs per segment and can have up to segments. Modern millipedes have from 11 to 100 or more body segments, and most millipede segments have two pairs of legs. While centipedes are carnivores, most millipedes are Insects and Their Relatives