Lek Mating System and Large Male Aggressive Advantage in a Gall‐forming Tephritid Fly (Diptera: Tephritidae)

Abstract

Abstract Field and laboratory studies revealed that the mating system of a tephritid fly, Procecidochares sp., meets even the most stringent definition of lekking behavior. Mark‐recapture and plant‐preference experiments confirmed that newly emerged adult Procecidochares sp. left their larval host plant ( Chrysothamnus nauseosus ) and flew to Atriplex canescens . The flies used A. canescens solely as a mate encounter site. Sex ratios of emerging flies did not differ from unity, but sex ratios at the leks were extremely male‐biased. An advantage for larger individuals in male‐male aggressive encounters was quantified and observations suggested that females might be choosing mates based on outcomes of fights. Lekking behavior, previously reported among polyphagic tephritids, is considered exceptional for a monophagous species. Factors favoring a lek mating system in this species are discussed.