|Marshall, Steve - UNIV OF GUELPH, ONTARIO|
|Petersson, Erik - UPPSALA UNIV., SWEDEN|
Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 5, 1999
Publication Date: N/A
Interpretive Summary: Flies, including species of agricultural pests, often form mating aggregations and perform complex courtships. An understanding of how females are distributed, and ultimately where males search for mates, is important in predicting fly behavior. Flies that are closely associated with larger arthropods, and seem superficially similar in other ways as well, sometimes have very different sexual behaviors. Comparisons made by scientists at the Center for Medical, Agricultural and Veterinary Entomology of different environmental and life history characteristics in these various flies can identify factors, such as abundance relative to hosts and copulation frequency, that have influenced the evolution of their mating systems. When combined with studies on still other types of flies, this information will generate a general theory that accounts for when, where, and how flies of all different types meet and mate. Such a theory would be an important guide to research in agricultural problems; e.g., where and why do Mediterranean fruit flies form mating aggregations, and do sterile males behave in ways that allow them to locate females and copulate?
Technical Abstract: Spiders, dung-feeding scarabs, social, and prey-storing insects provide predictable and concentrated sources of food for a variety of thief flies (kleptoparasites) and their larvae. Whenever waiting in the vicinity of the "host" for an opportunity to exploit its resources is more energy efficient and less dangerous than foraging among hosts, a number of intimate relationships between the fly and host may evolve. In extreme cases, flies may become long-term phoretic associates that travel with hosts even while the latter is in flight. The behaviors and ecologies of kleptoparasitic Diptera are reviewed with special attention paid to the adaptations of Sphaeroceridae phoretic upon Scarabaeidae. The mating systems of kleptoparasitic flies are influenced by the type of resource that is stolen; flies associated with predators are mostly female, while those found on scarabs are of both sexes. These differences are discussed in terms of mate location, sperm competition, and mate choice.