The mesothorax and metathorax are rather intimately fused together.
The number of spiracles is greatly reduced; in the adult a pair is present on the mesothorax, sometimes also a pair on the metathorax, and there is always a pair on the first and another pair on the eighth abdominal segment.
On account of the great extension of the metathorax and the haunches of the large hindlegs, the first abdominal sternite is wanting, and the second is - the stylets.
The males are very small, free-flying insects with the prothorax, mesothorax and elytra greatly reduced, the latter appearing as little, twisted strips, while the metathorax is relatively large, with its wings broad and capable of longitudinal folding.
Metathorax: m, Scutum.
The union of the first abdominal segment with the metathorax has been 8 FIG.
The Embiidae are feeble, somewhat soft-skinned insects with the prothorax small and the mesothorax and metathorax elongate.
A remarkable feature is the frequent concrescence of mesothorax and metathorax and in some cases, even, their fusion with the anterior abdominal segments.
Two pairs of wings are present in the vast majority of insects, borne respectively on the mesothorax and metathorax.