1. End Show Slide 1 of 44 Copyright Pearson Prentice Hall Biology

2. End Show Slide 2 of 44 Copyright Pearson Prentice Hall 28–3 Insects

3. End Show 28–3 Insects Slide 3 of 44 Copyright Pearson Prentice Hall Insects Class Insecta contains more species than any other group of animals.

4. End Show 28–3 Insects Slide 4 of 44 Copyright Pearson Prentice Hall What Is an Insect? What are the distinguishing features of insects?

5. End Show 28–3 Insects Slide 5 of 44 Copyright Pearson Prentice Hall What Is an Insect? Insects have a body divided into three parts—head, thorax, and abdomen. Three pairs of legs are attached to the thorax. Head Thorax Abdomen

6. End Show 28–3 Insects Slide 6 of 44 Copyright Pearson Prentice Hall What Is an Insect? Insects have a segmented body, an exoskeleton, and jointed appendages. A typical insect also has: a pair of antennae a pair of compound eyes two pairs of wings on the thorax tracheal tubes that are used for respiration

7. End Show 28–3 Insects Slide 7 of 44 Copyright Pearson Prentice Hall What Is an Insect? Responses to Stimuli Compound eyes made up of many lenses detect minute changes in color and movement. The brain assembles information from the eye and directs the insect’s response.

8. End Show 28–3 Insects Slide 8 of 44 Copyright Pearson Prentice Hall What Is an Insect? Insects have chemical receptors for taste and smell on their mouthparts, antennae, and legs. Insects have sensory hairs that detect movements in the surrounding air or water. Many insects also have well-developed ears.

9. End Show 28–3 Insects Slide 9 of 44 Copyright Pearson Prentice Hall What Is an Insect? Adaptations for Feeding Insects have three pairs of appendages that are used as mouthparts, including a pair of mandibles. Insect mouthparts are specialized for feeding. Many insects produce saliva containing digestive enzymes that help break down food.

10. End Show 28–3 Insects Slide 10 of 44 Copyright Pearson Prentice Hall What Is an Insect? Specialized Mouthparts Mandibles used to saw and grind food Ant

11. End Show 28–3 Insects Slide 11 of 44 Copyright Pearson Prentice Hall What Is an Insect? Specialized Mouthparts Tubelike mouthpart used to suck nectar Moth

12. End Show 28–3 Insects Slide 12 of 44 Copyright Pearson Prentice Hall What Is an Insect? Specialized Mouthparts Spongelike mouthpart used to lap up food Fly

13. End Show 28–3 Insects Slide 13 of 44 Copyright Pearson Prentice Hall What Is an Insect? Movement and Flight Insects have three pairs of legs, which are used for walking, jumping, or capturing and holding prey. The legs of many insects have spines and hooks that are used for grasping and defense.

14. End Show 28–3 Insects Slide 14 of 44 Copyright Pearson Prentice Hall What Is an Insect? Flying insects typically have two pairs of wings made of chitin. Flight has allowed insects to disperse long distances and to colonize a wide variety of habitats.

15. End Show 28–3 Insects Slide 15 of 44 Copyright Pearson Prentice Hall What Is an Insect? What two types of development can insects undergo?

16. End Show 28–3 Insects Slide 16 of 44 Copyright Pearson Prentice Hall What Is an Insect? Metamorphosis The growth and development of insects usually involve metamorphosis, which is a process of changing shape and form. Insects undergo either incomplete metamorphosis or complete metamorphosis.

17. End Show 28–3 Insects Slide 17 of 44 Copyright Pearson Prentice Hall What Is an Insect? Immature insects that undergo incomplete metamorphosis look very much like the adults. These immature forms are called nymphs. Nymphs lack functional sexual organs and other adult structures, such as wings. Nymphs gradually acquire adult structures as they molt and grow.

18. End Show 28–3 Insects Slide 18 of 44 Copyright Pearson Prentice Hall What Is an Insect? Adult Nymph Eggs Adult Incomplete Metamorphosis

19. End Show 28–3 Insects Slide 19 of 44 Copyright Pearson Prentice Hall What Is an Insect? In complete metamorphosis, animals hatch into larvae that look and act nothing like their parents. They feed and grow rapidly and molt a few times. They undergo a final molt and change into a pupa— the stage in which an insect changes from larva to adult.

20. End Show 28–3 Insects Slide 20 of 44 Copyright Pearson Prentice Hall What Is an Insect? pupa Adult Larva Pupa Complete metamorphosis Adult Eggs

21. End Show 28–3 Insects Slide 21 of 44 Copyright Pearson Prentice Hall Insects and Humans Many insects are known for their negative effects. Termites destroy wood structures. Desert locusts cause billions of dollars in damage to livestock and crops. Mosquitoes can infect humans with microorganisms that cause disease.

22. End Show 28–3 Insects Slide 22 of 44 Copyright Pearson Prentice Hall Insects and Humans Insects also contribute to the richness of human life. One third of the food you eat depends on plants pollinated by animals and insects. Insects produce silk, wax, and honey. They are considered a food delicacy in certain countries of Africa and Asia.

23. End Show 28–3 Insects Slide 23 of 44 Copyright Pearson Prentice Hall Insect Communication Insects communicate using sound, visual, chemical, and other types of signals. Much of their communication involves finding a mate.

24. End Show 28–3 Insects Slide 24 of 44 Copyright Pearson Prentice Hall Insect Communication Visual Cues Male fireflies use visual cues to communicate with potential mates. A light-producing organ in the abdomen is used to produce a distinct series of flashes. When female fireflies see the signal, they flash back a signal of their own, inducing the males to fly to them.

25. End Show 28–3 Insects Slide 25 of 44 Copyright Pearson Prentice Hall Insect Communication Chemical Signals Many insects communicate using chemical signals. The chemicals are called pheromones. Pheromones are specific chemical messengers that affect the behavior or development of other individuals of the same species.

26. End Show 28–3 Insects Slide 26 of 44 Copyright Pearson Prentice Hall Insect Communication Some pheromones function to signal alarm or alert other insects to the death of a member of the colony. Other pheromones enable males and females to communicate during courtship and mating.

27. End Show 28–3 Insects Slide 27 of 44 Copyright Pearson Prentice Hall Insect Societies What types of insects form societies?

28. End Show 28–3 Insects Slide 28 of 44 Copyright Pearson Prentice Hall Insect Societies Ants, bees, termites, and some of their relatives form complex associations called societies. A society is a group of closely related animals of the same species that work together for the benefit of the whole group.

29. End Show 28–3 Insects Slide 29 of 44 Copyright Pearson Prentice Hall Insect Societies Castes Within an insect society, individuals may be specialized to perform particular tasks, or roles. These are performed by groups of individuals called castes. Each caste has a body form specialized for its role.

30. End Show 28–3 Insects Slide 30 of 44 Copyright Pearson Prentice Hall Insect Societies The basic castes are: reproductive females (queens) reproductive males workers Most insect societies have only one queen.

31. End Show 28–3 Insects Slide 31 of 44 Copyright Pearson Prentice Hall Insect Societies A tropical leaf-cutter ant colony is one example of an insect society. Individuals in the colony have specific tasks or roles.

32. End Show 28–3 Insects Slide 32 of 44 Copyright Pearson Prentice Hall Insect Societies Major workers gather leaf tissue to use as a food source for fungus. The fungus provides food for the colony. Smaller worker ants ride atop the leaf, keeping alert for potential threats. Major Workers

33. End Show 28–3 Insects Slide 33 of 44 Copyright Pearson Prentice Hall Insect Societies The queen’s sole purpose is to lay eggs. Most of the eggs become worker ants. Females that will become queens leave the nest to start a new colony. Queen

34. End Show 28–3 Insects Slide 34 of 44 Copyright Pearson Prentice Hall Insect Societies Minor worker ants chop the leaves into a fine paste, tend to the gardens, and harvest fungus for other members of the colony. Minor Workers

35. End Show 28–3 Insects Slide 35 of 44 Copyright Pearson Prentice Hall Insect Societies Soldier ants guard the nest from potential attackers. Soldiers

36. End Show 28–3 Insects Slide 36 of 44 Copyright Pearson Prentice Hall Insect Societies Communication in Societies Each species of social insect use visual, touch, sound, and chemical signals to communicate information among members of the colony. Honeybees communicate information about food through a series of complex movements.

37. End Show 28–3 Insects Slide 37 of 44 Copyright Pearson Prentice Hall Insect Societies The round dance indicates that food is fairly close to the hive.

38. End Show 28–3 Insects Slide 38 of 44 Copyright Pearson Prentice Hall Insect Societies The waggle dance indicates that food is farther away from the hive. It also indicates the direction of the food.

39. End Show - or - Continue to: Click to Launch: Slide 39 of 44 Copyright Pearson Prentice Hall 28–3

40. End Show Slide 40 of 44 Copyright Pearson Prentice Hall 28–3 How many body parts do insects have? a.two b.three c.four d.five

41. End Show Slide 41 of 44 Copyright Pearson Prentice Hall 28–3 Which group contains the most species? a.vertebrates b.nonvertebrate invertebrates c.noninsect arthropods d.insects

42. End Show Slide 42 of 44 Copyright Pearson Prentice Hall 28–3 Characteristics shared by typical insects include a.six walking legs and one pair of wings. b.six walking legs and two pairs of wings. c.eight walking legs and one pair of wings. d.eight walking legs and two pairs of wings.

43. End Show Slide 43 of 44 Copyright Pearson Prentice Hall 28–3 The immature form of an insect that undergoes incomplete metamorphosis is called a(n) a.larva. b.nymph. c.pupa. d.embryo.

44. End Show Slide 44 of 44 Copyright Pearson Prentice Hall 28–3 Which of the following species form complex societies? a.butterflies b.ants c.locusts d.flies

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