ARS | Publication request: Ornaments in the Diptera

Submitted to: Florida Entomologist Society Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: March 26, 1997
Publication Date: N/A

Interpretive Summary: Understanding the sexual behavior of flies is a critical component of control and monitoring techniques that use attractants and sterile males. Such information dictates when, where and how pheromones and host odors can be collected and eventually duplicated and placed in traps. Mate-searching behaviors and courtships need to be understood in order to insure that mass-reared flies can locate females and then compete with wild sexual rivals for mates. Flies with particularly elaborate sexual behaviors and signaling structures (ornaments such as enlarged eyes and projections from the legs) may allow us to more easily determine what kinds of qualities males are advertising when they communicate with potential mates or display aggressively to other males. This survey of ornamented flies and its discussion of what their ornaments might "mean" to other flies will help entomologists design research into the behaviors of flies, including the economically important tephritid fruit flies.

Technical Abstract: Occasionally, flies bear sexually dimorphic structures (ornaments) that are used, or are presumed to be used, in courtships or in aggressive interactions with sexual rivals. These are reviewed, beginning with projections from the head, continuing through elaborations of the legs and finishing with gigantism of the genitalia. Several functions for ornaments are considered, including advertisement of genetic properties, subversion of female mate choice and "runaway" sexual selection. Neither the type of ornament nor the degree of elaboration necessarily indicates which of the above processes is responsible for a particular ornament. Resource distribution and the resulting possibilities for resource defense and mate choice explain the occurrence of ornaments in some species. The phyletic distribution of ornaments may reflect foraging behaviors and the type of substrates upon which courtships occur.