Int
- Their feeding habits are similarly varied; almost any substance that has nutritive value is eaten by some group of insects.
- Insects also show huge variety in shape and form. Almost the only condition their group does not attain is very large body size.
- A number of features, however, are shared by most kinds of living insects, these include:
- A body composed of three tagmata, a head, thorax, and abdomen;
roduction- With around one million named species and perhaps several times that number unnamed, insects account for a great majority of the species of animals on earth.
- They are a tremendously successful group. Insects can be found in almost all terrestrial and freshwater habitats, from the driest deserts to freshwater ponds, from the canopy of a tropical rainforest (where their diversity is unbelievably great) to the arctic wastes. A few species are even marine.
- A pair of relatively large compound eyes and usually three ocelli located on the head;
- A pair of antennae, also on the head;
- Mouthparts consisting of a labrum, a pair of mandibles, a pair of maxillae, a labium, and a tonguelike hypopharynx;
- Two pairs of wings, derived from outgrowths of the body wall (unlike any vertebrate wings);
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- Three pairs of walking legs.
Class Insecta Orders
There are 26 orders of insects, but the vast majority belong to only these eight.
1. Coleoptera (Beetles)
2. Lepidoptera (Moths & Butterflies) 3. Hymenoptera (Bees,Wasps & Ants) 4. Diptera(Flies,Mosquitoes & Gnats) 5. Orthoptera (Crickets,Grasshoppers & Locusts) 6. Odonata (Dragonflies & Damselflies) 7. Homoptera (Aphids,Cicadas & Leafhoppers ) 8. Hemiptera ( Bugs, Backswimmers & Water Striders)
Insects are incalculably valuable to humans.
- Usually, we think of them in a negative context. Insects eat our food, feed on our blood and skin, contaminate our dwellings, and transmit horrible diseases. But without them, we could not exist. They are a fundamental part of our ecosystem.
A brief and incomplete list of their positive roles would include
- The pollination of many, perhaps most higher plants
- The decomposition of organic materials
- Facilitating the recycling of carbon, nitrogen, and other essential nutrients
- The control of populations of harmful invertebrate species (including other insects)
- The direct production of certain foods (honey, for example)
- The manufacture of useful products such as silk and shellac.