The Excretion of Ammonia and Uric Acid During The Larval Life of Certain Muscoid Flies

Abstract

In the early years of this century Weinland (1906) conclusively showed that ammonia constitutes the bulk of the nitrogenous excreta of larvae of the blow-fly, Calliphora vomitoria. This was a remarkable observation in a subphylum that was, and still is, considered essentially uricotelic. Pupae and imagines of this species excrete uric acid; Weinland was therefore led to postulate that pupation was basically a physiological change, the change from ammonia to uric acid as the protein catabolite. Twenty-five years later Delaunay (1931), reviewing protein catabolism in invertebrates, quotes Weinland’s work and states that “les larves de Calliphora…n’excrètent pas d’acide urique”.