Kingdom Animalia:Insecta

The insects In terms of numbers, the insects are

the most successful group on theplanet. There are both more individualinsects and more species of insectsthan all the species of all otherAnimalia groups combined.

Insect bodystructure Insect bodies have three

regions: the head, thorax, andabdomen. They have six jointed legsand many have pairs of wings. Thewhole of the body is covered by atough exoskeleton made of a tough,fibrous material called chitin.

The head is well supplied with senseorgans, including compound eyes thatare capable of forming accurateimages. The antennae can detectvibrations, and some insects haveextremely sensitive chemical detectorsthat can smell things over hugedistances.

Insects do not possess lungs. Gaseousexchange takes place through holes inthe exoskeleton called spiracles.These communicate with a network oftubes running throughout the insectbody. Insects have no circulatorysystem and this, combined withthe absence of lungs, means thatthey cannot grow beyond acertain size or they will be unableto get oxygen to the innermost partsof their bodies.

Some insects (ants, bees) havecomplex social structures withintricate behavior patterns. These sortsof insects often live in largecommunities with a single queen,producing most of the young.

abdomenexoskeletonspiraclethorax

Key words

GrasshopperLateral view

Lateral view of head

Leg

headthoraxabdomen

forewing

spiracles

coxa

trochanter

femur

tibia

pretarsus

maxillarypalp

labium

labial palp

labrum

mandible

clypeus

frons

ocelli

antennamaxilla

gena

compound eye

legs

compoundeye

antenna

tarsus

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