Abstract
The spermatheca is an organ that stores and maintains viability of sperm until fertilization. It has an important role in copulation and oviposition, and it is highly informative in species delimitation. Here, we present a comparative study of the spermathecal morphology in the coleopteran family Megalopodidae. The spermathecae of 34 species, representing 13 genera and all three subfamilies, were studied. Illustrations are newly provided for all species, except in 14 cases in which illustrations were reproduced from previously published literature. Our results show that each subfamily of Megalopodidae can be effectively differentiated based on the particular spermathecal anatomy. In addition, the spermathecal anatomy presents a range of variation within each subfamily, useful for diagnosing species and, in some cases, identifying groups of genera. For instance, the "American group" is thus recognized in this study.