Biology Slide 1 of 44 Copyright Pearson Prentice Hall End Show 28–3 Insects Slide 2 of 44 Copyright Pearson Prentice Hall End Show 28–3 Insects Insects Class Insecta contains more species than any other group of animals. Slide 3 of 44 Copyright Pearson Prentice Hall End Show 28–3 Insects What Is an Insect? Unlike spiders who have two body parts 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 Slide 4 of 44 Copyright Pearson Prentice Hall End Show 28–3 Insects 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 Slide 5 of 44 Copyright Pearson Prentice Hall End Show 28–3 Insects 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. Slide 6 of 44 Copyright Pearson Prentice Hall End Show 28–3 Insects 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. Slide 7 of 44 Copyright Pearson Prentice Hall End Show 28–3 Insects What Is an Insect? Specialized Mouthparts Mandibles used to saw and grind food Ant Copyright Pearson Prentice Hall Slide 8 of 44 End Show 28–3 Insects What Is an Insect? Specialized Mouthparts Tubelike mouthpart used to suck nectar Moth Copyright Pearson Prentice Hall Slide 9 of 44 End Show 28–3 Insects What Is an Insect? Specialized Mouthparts Spongelike mouthpart used to lap up food Fly Copyright Pearson Prentice Hall Slide 10 of 44 End Show 28–3 Insects What Is an Insect? Movement and Flight Insects have three pairs of legs, which are used for walking, jumping, or capturing and holding prey. Slide 11 of 44 Copyright Pearson Prentice Hall End Show 28–3 Insects 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. Slide 12 of 44 Copyright Pearson Prentice Hall End Show 28–3 Insects What Is an Insect? Metamorphosis The growth and development of insects usually involves metamorphosis, which is a process of changing shape and form. Insects undergo either incomplete metamorphosis or complete metamorphosis. Slide 13 of 44 Copyright Pearson Prentice Hall End Show 28–3 Insects What Is an Insect? Immature insects that undergo incomplete metamorphosis look very much like the adults. These immature forms are called nymphs. Slide 14 of 44 Copyright Pearson Prentice Hall End Show 28–3 Insects What Is an Insect? Adult Adult Eggs Incomplete Metamorphosis Nymph Nymph Nymph Copyright Pearson Prentice Hall Slide 15 of 44 End Show 28–3 Insects 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. Slide 16 of 44 Copyright Pearson Prentice Hall End Show 28–3 Insects What Is an Insect? pupa Adult Eggs Complete metamorphosis Adult Larva Larva Pupa Copyright Pearson Prentice Hall Slide 17 of 44 End Show 28–3 Insects Insect Communication Insect Communication Insects communicate using sound, visual, chemical, and other types of signals. Much of their communication involves finding a mate. Slide 18 of 44 Copyright Pearson Prentice Hall End Show 28–3 Insects Insect Societies 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. Slide 19 of 44 Copyright Pearson Prentice Hall End Show 28–3 Insects 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. Slide 20 of 44 Copyright Pearson Prentice Hall End Show 28–3 Insects Insect Societies The round dance indicates that food is fairly close to the hive. Slide 21 of 44 Copyright Pearson Prentice Hall End Show 28–3 Insects Insect Societies The waggle dance indicates that food is farther away from the hive. It also indicates the direction of the food. Slide 22 of 44 Copyright Pearson Prentice Hall End Show 28–3 Click to Launch: Continue to: - or - Slide 23 of 44 End Show Copyright Pearson Prentice Hall 28–3 How many body parts do insects have? a. two b. three c. four d. five Slide 24 of 44 End Show Copyright Pearson Prentice Hall 28–3 Which group contains the most species? a. vertebrates b. nonvertebrate invertebrates c. noninsect arthropods d. insects Slide 25 of 44 End Show 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. Slide 26 of 44 End Show 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. Slide 27 of 44 End Show Copyright Pearson Prentice Hall 28–3 Which of the following species form complex societies? a. butterflies b. ants c. locusts d. flies Slide 28 of 44 End Show Copyright Pearson Prentice Hall END OF SECTION