The importance of sampling intensity for documenting braconid wasp diversity

Konza Prairie Biological Station (KPBS) is a 3,487-hectare tallgrass prairie preserve located near Manhattan, Kansas. The prairie is divided into 60 watersheds subjected to various combinations of prescribed burning and grazing. A long-term sampling program focused on parasitoid wasps was conducted at KPBS from 2001–2006. Objectives were to (1) survey species composition and abundance for economically important wasp groups and (2) compare wasp diversity at sites subjected to different combinations of burning and grazing. Braconids were sampled using Malaise traps that operated continuously, on average, for 187 days/year in 11 watersheds representing gallery forest, non-gallery forest woodland, and prairie habitats. Preliminary results based on sampling carried out in 2001 yielded ~14,589 specimens of Braconidae representing 22 subfamilies. Of the ~14,589 specimens collected, ~9,900 were Microgastrinae, a taxonomically difficult group that contains cryptic species. The remaining ~4,689 specimens represent 109 genera; one, three, and 35 of those genera were first records for the Nearctic Region, contiguous U.S., and Kansas, respectively. Unprecedented levels of diversity for braconids in tallgrass prairies were observed for Doryctinae, Cardiochilinae, Ichneutinae, and Rogadinae. Samples from 2001 yielded eight genera and 31 morphospecies of Rogadinae; a previous survey at KPBS yielded only one genus and four species of Rogadinae. Species richness for rogadines collected in gallery forest, non-gallery forest woodland, and prairie habitats in 2001 was 14, 16, and 20, respectively.