General Characters of Insects Word insect is derived

General Characters of Insects Word ‘insect’ is derived from latin word ‘insectum’ which means divided body. The body of insect is clearly divided into three parts a) Head b) Thorax ( 3 segments: Prothorax, Mesothorax and Metathorax) c) Abdomen (7 -11 segments) A generalized insect has a) 3 pairs of legs b) 2 pairs of wings c) pair of compound eyes d) pair of antennae e) 3 ocelli or simple eyes

Continued……… Insects have Exoskeleton Insects also show phenomenon of metamorphosis (Holometabolans and Hemimetabolans). Sexual Dimorphism is present. They reproduce both sexually and asexually (parthenogenesis in honey bees).

Holometabolous Metamorphosis Hemimetabolous Metamorphosis

Economic Importance of Insects: • Beneficial Aspects • Harmful Aspects

Beneficial Aspects:

1). Pollinators: Insect are the biggest pollinators of the world e. g. Honey Bees, Butterflies, Moths etc Entomophilous plants : Insects for their pollination

2). Important member of food chain: Insects are the most abundant organisms on earth so they are an important part of many food chains and food webs.

3). Different Products: Insects produce different useful products that we use in our daily life. e. g. Honey bees gives honey and wax Silk insect gives silk Lac insect gives lac (resin).