1. The subelytral chamber is an air space between the elytra and the dorsum of the abdomen of some Tenebrionid beetles. Postulated functions for the subelytral chamber have been a reduction of transpiratory water loss and a thermal buffer for heat flow from the elytra to the abdomen.
2. We show that there is a significant correlation between water loss and the depth of the subelytral chamber.
3. This implies that the chamber may be a structure that permits the rapid expansion of the abdomen, providing the beetles with a mechanism by which they can quickly drink large quantities of water from an ephemeral source such as a rain puddle. As the beetles drink, the abdomen greatly expands, and the chamber shrinks.
Slobodchikoff, C. N., & WISMANN, K. (1981). A function of the subelytral chamber of tenebrionid beetles. Journal of Experimental Biology, 90(1), 109-114.