Ch. 37 Insects Most diverse and largest number of species of any class of organism. They were present on earth before the dinosaurs, over 300 million years ago. Differences from other arthropods 1. 3 body segments  head, thorax, abdomen 1. 3 body segments  head, thorax, abdomen Video

2. Head has 1 pair of antennae 2. Head has 1 pair of antennae 3. Thorax has 3 pairs of legs & 1 or 2 pair of wings. 3. Thorax has 3 pairs of legs & 1 or 2 pair of wings. 4. No wings or legs attached to the abdomen. 4. No wings or legs attached to the abdomen. Video

Kingdom: Animalia Phylum: Arthropoda Phylum: Arthropoda Class: Insecta (700,000 + species named) What makes insect so successful? Lots of them – adapt very well Lots of them – adapt very well Great diversity – several types Great diversity – several types Reproduce rapidly Reproduce rapidly Small size & ability to fly (most) Small size & ability to fly (most)

Benefit of insects? 1. Pollination – plants can’t reproduce without insects. We need plants to survive. 2. Food – for other animals. Several animals rely on insects as a source of food. 3. Industrial uses – silk & honey Video What is the study of insects called? (E.C) Entomology Entomology

Grasshopper  External Structures 3 Body Parts: 1. Head Labium – grasps the food ( bottom lip) Labium – grasps the food ( bottom lip) Mandible – chews the food (jaws) Mandible – chews the food (jaws) Labrum – holds the food (upper lip) Labrum – holds the food (upper lip) Maxilla – extra jaws Maxilla – extra jaws 2. Thorax 3 pairs of legs (6 total) 3 pairs of legs (6 total) 2 pair of wings usually 2 pair of wings usually

3 parts to the thorax 1. Prothorax – pair of walking legs 1. Prothorax – pair of walking legs 2. Mesothorax. – pair of walking legs 2. Mesothorax. – pair of walking legs 3. Metathorax – pair of jumping legs 3. Metathorax – pair of jumping legs Forewings are attached to the mesothorax Forewings are attached to the mesothorax Hindwings are attached to the metathorax Hindwings are attached to the metathorax

3. Abdomen Spiracle – for respiration Spiracle – for respiration Tympanum – for hearing (eardrum) Tympanum – for hearing (eardrum) Ovipositors – holds it eggs Ovipositors – holds it eggs

Grasshopper  Internal Structures Digestive System What do grasshoppers eat? What do grasshoppers eat? What are the mouth parts? What are the mouth parts? Food passage: esophagus  crop (storage)  gizzard (grind)  midgut (digested)  hindgut (rectum & colon)  out the anus Food passage: esophagus  crop (storage)  gizzard (grind)  midgut (digested)  hindgut (rectum & colon)  out the anus

Circulatory System Open Circulatory System Open Circulatory System An aorta is a large vessel that carries the blood on the dorsal side. An aorta is a large vessel that carries the blood on the dorsal side. 2 Hearts along the aorta 2 Hearts along the aorta

Respiratory System No lungs or gills No lungs or gills Use spiracles – openings along the abdomen Use spiracles – openings along the abdomen The spiracles lead to the trachea The spiracles lead to the trachea Nervous System Brain connected to a ventral nerve cord Brain connected to a ventral nerve cord Has simple and complex eyes Has simple and complex eyes

Have antennae Have antennae Tympanum for sensing sound Tympanum for sensing sound Reproductive System The male deposits sperm into the seminal receptacle, which stores the sperm. The male deposits sperm into the seminal receptacle, which stores the sperm. The female uses its ovipositors to deposit her eggs in the ground. The female uses its ovipositors to deposit her eggs in the ground.

Types of Metamorphosis Incomplete Metamorphosis 1. Egg 1. Egg 2. Nymph – immature form of an adult 2. Nymph – immature form of an adult 3. Adult – able to reproduce (wings) 3. Adult – able to reproduce (wings)

Complete Metamorphosis 1. Egg 1. Egg 2. Larvae – caterpillar stage 2. Larvae – caterpillar stage 3. Pupa – cocoon protects the pupa 3. Pupa – cocoon protects the pupa 4. Adult – emerges from the pupa (butterfly) 4. Adult – emerges from the pupa (butterfly)

Defenses of Insects What ways do insects use defenses? 1. Stinger or bite – bee, wasp, ants 2. Camouflage – blend into their surroundings. Ex. Grasshopper, praying mantis Ex. Grasshopper, praying mantis 3. Warning coloration – alert other animals that the insect might be poisonous. Video

Insect Behavior Division of Labor among Bees 1. Worker bee – female bees, most abundant. (8,000) - sterile 2. Drone – male bees (100) 3. Queen bee – the only fertile female CHARACTERISTICS OF EACH BEE

The worker bee produces royal jelly to feed the queen bee The worker also secretes wax to make the hive. The produces a pheromone called queen factor, which makes the other females sterile. Round Dance – tells the other bees food is within 50 meters Waggle Dance – tells the other bees food is greater than 50 meters. Video