Tall grass, small wasps: measuring the biodiversity of braconid wasps (Hymenoptera: Ichneumonoidea) in two warm season grasslands

North American prairies, a hotbed of endemic and grassland-dependent insect diversity, once occupied ~350 million hectares in America north of Mexico. However, fragmentation due to increased demand for agricultural landscapes and rapidly expanding urban areas has resulted in prairies becoming one of the most endangered ecosystems in North America. For example, <3% of the original 97.1 million hectares of tallgrass prairie remain. Conservation and management of prairie ecosystems are dependent in part upon understanding the dynamics of their microfauna. Here, we examined two warm-season grasslands, 8-hectare and 36-hectare fragments with each receiving different management strategies, to establish estimates of biodiversity for the parasitoid wasp family Braconidae. Sampling was conducted using SLAM traps that operated March 31–November 8, 2014 and resulted in 99 samples. Early season samples (through June 30) yielded 575 specimens sorted into 104 morphospecies representing 48 genera. Singletons made up 72% of the total species richness between the two sites. While no significant difference was found in the mean number of braconid species collected at each site, species diversity between the sites was drastically dissimilar (Morisita-Horn = 0.294). These patterns are expected to hold through the latter half of the season. Together, these results suggest considerable ecosystem variation that could be due to factors such as differential fragment size, management plan, patterns of colonization based on historical species distributions, and/or presence of host species.