The main morphological characteristics of insects are as follows:
- Segmented body divided into three sections: head, thorax, abdomen.
- Mouth including mandibles.
- Three pairs of legs attached to the thorax.
- One pair of antennae.
- External skeleton (exoskeleton)
- Usually, one or two pairs of wings attached to the thorax
Larvae of some holometabolous insects (with complete metamorphosis), such as the Lepidoptera
- Body with a highly sclerotized (hardened) head and 13 segments, the last two of which are fused together.
- Thoracic segments with three pairs of articulated legs.
- Some abdominal segments with pairs of prolegs bearing hooks that allow the larvae to cling to objects.
- The larva has a cuticle, a special membrane, as part of its external skeletal structure.
- Mouth parts with glands for the secretion of silk.