A Marking Study of the Black Blister Beetle, Epicauta pensylvanica (Degeer) (Coleoptera: Meloidae), Demonstrates a Preference for a Restored Tallgrass Prairie

ABSTRACT: Blister beetles (Coleoptera: Meloidae) have a long history in human culture, are detrimental to human health, and considered an agricultural pest. However, little is known about the ecology of many of these beetle species in natural systems. The black blister beetle, Epicauta pensylvanica (Degeer), is a common fall species that regularly feeds on goldenrod (Solidago spp.) flowers. Previous ecological research used mass releases to explore movement patterns and habitat use. For a more natural investigation, a marking study was conducted to quantify the population size, movement patterns, and habitat use in a restored tallgrass prairie and adjacent degraded grassland. We uniquely marked a total of 914 individuals, recapturing 22.2% over 16 surveys (16 August to 11 October 2018). A maximum daily count of 286 individuals was recorded on 11 September, corresponding to a population size estimate of 2,011 (1,258– 4,139 95% CI). Several times, adult numbers increased one to two days following rain events, and ultimately dropped substantially following mowing of the degraded grassland. Beetles were capable of moving throughout the study site based on one individual traveling at least 599 m over the course of the study. However, most detected movements were short and there was no preference in movement directionality, suggesting that beetles would most often move to adjacent flowering goldenrod patches. Despite the lack of directionality, the restored tallgrass prairie portion of the study site retained significantly more beetles than the degraded grassland. While further describing the ecology of the black blister beetle, this study also supports the effectiveness of the habitat restoration efforts.