The thorax consists of three segments: the prothorax, mesothorax and metathorax.

In aptera, from front to back, each segment is larger than the preceding one.

In alates, the thorax is both more strongly developed and sclerotized, especially the mesothorax where the wing muscles are housed.
The exact form of the mesothorax differs depending on the wing position adopted at rest,
The wings are relatively large. At rest they are held above the abdomen, either:

  • vertically (the most frequent position – figure A)
  • horizontally (Phylloxeridae, Adelgidae, Thelaxinae – figure B)
A : wings held roof-like (Macrosiphum euphorbiae)
Macrosiphum euphorbiae : adulte ailé vert
B : wings held flat (Thelaxes dryophila)
Thelaxes dryophila : adulte ailé

Modification date: 14 June 2024 | Publication date: 09 November 2010 | By: Evelyne Turpeau, Maurice Hullé, Bernard Chaubet