Petiole (insect anatomy)

In entomology, petiole is the technical term for the narrow waist of some hymenopteran insects, especially ants, bees, and wasps in the suborder Apocrita.

The petiole can consist of either one or two segments, a characteristic that separates major subfamilies of ants.

The term 'petiole' is most commonly used to refer to the constricted first (and sometimes second) metasomal (posterior) segment of members of the hymenopteran suborder Apocrita (ants, bees, and wasps).

It is sometimes also used to refer to other insects with similar body shapes, where the metasomal base is constricted.

The plump portion of the abdomen posterior to the petiole (and postpetiole in the Myrmicinae) is called the gaster.