Flies of the genus Blepharoneura, found throughout South America, are highly diverse and highly specific to the plant species they infest. The flies are parasitized by wasps, called “parasitoids” because the wasps kill their hosts (the flies). If the wasps themselves exhibit high degrees of host specificity, they may have influenced the high degree of speciation exhibited by the fly species. Using data from specimens gathered from Peru in 2008, I sought to determine how host specific these newly discovered parasitoid wasp species are and to identify patterns of parasitism displayed by these newly discovered wasp species. The rate of parasitism of a few (3) fly species differed dramatically: the rate of parasitism in general was between 5%-60%, although most (9) fly species were parasitized at similar rates, generally between 20%-30%. I also sought to characterize how host specific these wasp species were. Of the ten wasp species studied, two species parasitized a single host species, four parasitized two host species, and four parasitized four or more host species. However, I also examined if this specificity differed when considering pupal specimens and live specimens separately. Strikingly, when considering only live wasp specimens, five wasp species appeared to be specific to a single host, four wasp species parasitized two host species, and only a single wasp species parasitized more than two host species. The difference between the pupal and adult samples suggests that most species of wasps survive to adulthood only when they infest a particular species of fly.
Andrew Roth, ’11
Majors: Economics and Business, Biology
Sponsor: Marty Condon