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Bugs of the Bay. What is a bug?. Bugs come in many shapes and sizes Bugs have some similarities and differences There are three main categories of bugs: Insects Arachnids Myriapods. Insects,spiders , and myriapods have distinctive features that help us identify them.
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What is a bug? • Bugs come in many shapes and sizes • Bugs have some similarities and differences • There are three main categories of bugs: • Insects • Arachnids • Myriapods Insects,spiders, and myriapods have distinctive features that help us identify them. We’ll talk mostly about insects and arachnids today.
What are insects?? • Insects are animals that lack a backbone • All insects have • a hard exoskeleton • a three-part body (head, thorax, and abdomen) • three pairs of jointed legs • compound eyes • two antennae. • legs (and wings, if applicable) are attached to the thorax • Insects breathe through holes called spiracles • Insects hatch from eggs. • There are about a million different types of insects and many more that have not been discovered yet.
What are spiders? • Spiders belong to a group of animals called “arachnids” Scorpions, mites, and ticks are also part of the arachnid family • Spiders have: • two body segments, • eight legs, • no wings or antennae • are not able to chew • All spiders are predators and many will eat other spiders
What is the difference between insects and spiders? • How the spider differs from the insects: • How many legs does an insect have? Let’s count to see how many legs the spider has. • How many body parts does the spider have? How many body parts does an insect have? Which one has more?
Insect or Spider
What are the life cycles (metamorphosis) of bugs?? • Bugs change shapes by metamorphosis • Complete metamorphosis – young look very different from the adults (caterpillars are young that turn into butterflies) • Incomplete metamorphosis – only change is in size as the young molt (shed their exoskeleton) and grow a new one to accommodate their growing body
What do bugs eat? • Insects • Some eat other insects • Some eat plants • Some are parasites that eat off other bugs but don’t kill them • Some are scavengers • Some eat just about anything
What do bugs eat? • Spiders • They are predators – they catch and eat other animals, mostly insects • Some spiders are big enough to catch lizards, birds, tadpoles or fish
What good are bugs to us? • Some insects produce valuable products: bees produce honey, and silk worms (which are really moths) produce silk. • Farmers need insects because without the insects many crops would not produce fruits. The insects are needed to pollinate the crops. Insects such as bees, wasps and butterflies visit a flower to collect nectar. At the same time, they pick up some pollen and carry it with them to the next flower they visit. In this way they help to cross-pollinate the plant, which will then produce good fruits.. • There are many other insects that are useful to farmers because they help control pest insects.
What good are bugs to us? • In many countries, people use insects as food. Actually there are hundreds of species of insects that are edible and can be eaten by people. Some of these are collected from the wild, while others are produced on special insect farms. • Insects can be used as live food for many pet animals. Pet birds, lizards and chameleons love to eat mealworms, crickets or grasshoppers. Also for other terrarium animals and for aquarium fish we can use insects as a healthy food. • Insects can also be used as a fishing bait, because many types of fish love to eat insects. • Many insects live as scavengers and feed on dead animals. Others feed on dead plant materials. In this way they help recycling of biomass in nature. This recycling process helps to create fertile top soil in which new plants and trees can easily grow. • Examples of insects that are important in this biomass recycling are ants, termites, flies and cockroaches. Another example of this recycling process is the way dung beetles feed on feces. They help recycling the dung and at the same time return nutrients to the soil.
What good are bugs to us? • Insects are easy to rear and multiply in large numbers. That’s why researchers often use insects to do all kind of experiments. A very famous laboratory insects is the common fruit fly (or vinegar fly). This insect has been studied a lot by researchers interested in genetics. • The beauty of insects can be best enjoyed in nature. Especially butterflies and beetles can be very beautiful with a large variation of patterns and colors. Many poets are inspired by the beauty of insects and write poems about butterflies, fireflies and other insects.
What good are bugs to us? • Spiders do more good than harm to people. • In North America, at least, only two kinds of spiders are truly harmful to humans – the brown recluse and the black widow (and, by all means, get rid of them). • The rest actually just eat other insects we usually find pretty scary, including mosquitoes carrying malaria (the world’s #1 fatal disease) and flies carrying cholera. • The presence of spiders in your house is a sign that 2,000 fewer bugs per spider will be there every year. • In your garden, spiders eat those bugs that love to damage your plants! In fact, they’re used in organic cotton farming for exactly this reason. • .
Where do bugs live?Everywhere, even in Antarctica, except for at the North and South Poles
How do bugs communicate? • Have you ever heard an insect make a sound? Does a bee make a sound? What sound does a bee make? • Explain that different insects make sounds in different ways. • They communicate without talking • Some use special chemical odors (pheromones) to “talk” and find each other • Some use visual signals—like fireflies with flashing lights • Others use sound • They make noises (mosquitoes and bees beat their wings, crickets and grasshoppers rub parts of their bodies together, and cicadas contract muscles in their abdomens • Some sing to each other
