Petiole (insect anatomy)

The sand wasp Ammophila sabulosa has an exceptionally long petiole.
The petiole of this ant consists of two segments

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

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

Structure

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 petiole is occasionally called a pedicel, but, in entomology, that term is more correctly reserved for the second segment of the antenna.[1][2]

The plump portion of the abdomen posterior to the petiole (and postpetiole in Myrmicinae) is called the gaster.[3]

The structure of the petiole is an easy way to visually classify ants, because the major subfamilies of Formicidae have structural differences: some ants have two-segment petioles, while others have a single-segment petiole.[4]

Other uses

'Petiole' may also be used in the context of wing veins, where a wing cell that is ordinarily four-sided is reduced to a triangle with a stalk (the cell thus being petiolate).

The stalk at the base of paper wasp nests is also called a petiole.

References

  1. ↑ "Glossary". University of Florida. Retrieved 4 January 2014.
  2. ↑ Zombori, L. (1999). Dictionary of Insect Morphology. Walter de Gruyter. p. 173.
  3. ↑ Zombori, L. (1999). Dictionary of Insect Morphology. Walter de Gruyter. p. 79.
  4. ↑ Gordon, Deborah (2010). Ant Encounters. Princeton University Press.