Behavioral Responses of Mediterranean Fruit Flies (Diptera: Tephritidae) to Trimedlure Baits: Can Leks Be Created Artificially?

Abstract

A field experiment investigated effects of trimedlure baits on the mating system of a wild population of Mediterranean fruit flies, Ceratitis capitata (Wiedemann), in a fruit orchard in Hawaii. Systematic censuses were conducted before, during the time, and after baits were in place, and the abundance of fruit flies and leks, incidence of male calling, and number of matings were compared among these three periods. In both replicates, numbers of lekking males and leks were significantly greater when baits were in place than when they were absent. In both replicates, these increases resulted directly from male attraction to the trimedlure baits, because both numbers of males seen in natural leks as well as numbers of natural leks were unaffected by the baits. Also, in one replicate, a marginally significant increase in number of calling males was noted when baits were in place. Trimedlure baits had no effect on female abundance in either replicate. Only 11 matings were recorded during the entire study, but one of these occurred in a lek formed near a trimedlure bait. Total number of males and number of calling males did not differ significantly between natural leks and those formed near baits, but female/male ratios were significantly higher at natural leks. The possible utility of “artificial leks” as a control technique is discussed.