7.6 Morphological features of insects

The body of an insect is divided into three parts:

1. The head, which bears the eyes, the antennae and the mouthparts
2. the thorax, which consists of three segments (prothorax, mesothorax, metathorax) carries three pairs of legs and the wings or the elytra, respectively
3. the abdomen, where the reproductive and digestive organs are located.

In the case of beetles, the forewings (elytra) are thickened and hornlike and protect the abdomen.

Moths have two pairs of membranous wings densely covered with pigmented scales.

Beetle larvae have three pairs of legs. However, in some species which develop inside the grain (e.g. weevils) they are lacking.

Figure 83

Figure 84

Moth larvae have three pairs of thoracic legs and additionally four pairs of prolegs, located at the 3rd, 4th, 5th and 6th segment of the abdomen. The final segment of the abdomen has a further pair of prolegs.