Morphology of the Three Anterior Pairs of Spiracles of Laccotrephes Maculatus Fabr. (Aquatic Heteroptera)

Abstract

The three anterior pairs of spiracles of Laccotrephes maculatus F., have been described and depicted. In submerged condition L. maculatus derives oxygen from the air stores communicating with the spiracles. The first pair of spiracles lies in the inter-segmental membrane between the prothorax and mesothorax. The second and third pairs of spiracles are located in the mesothorax and metathorax respectively. All the three pairs of spiracles possess a cuticular sieve plate with a network of trabeculae. The mesothoracic and metathoracic sieve plates have a tough inner membrane which limits permeability. The sieve plate of the third spiracle in contrast lacks the inner membrane. The first abdominal spiracle therefore, is important in the exchange of gases.