Impact of prescribed burning on endophytic insect communities of prairie perennials (Asteraceae: Silphium spp.)

Prescribed burning currently is used to preserve endemicity of plant communities in remnant tallgrass prairies. Although some types of arthropods benefit from changes in plant communities brought about by burning, other species that are endemic to prairies may be threatened. Because they inhabit the 'fuel layer' of prairies, endophytic insects would seem particularly susceptible to this management tactic. In this paper, we assess the impact of prescribed burning on endophytic insect communities inhabiting stems of Silphium laciniatum L. and S. terebinthinaceum Jacquin (Asteraceae), endemic prairie plants. Populations of these insects were decimated by burning, with mortality approaching 100% in most cases. Their populations nevertheless began to rebound within a single growing season, with densities moderately but significantly reduced 1 year after the burn. Even when a prairie remnant was completely incinerated, plant stems were recolonized by insects within one growing season. Our findings suggest that sufficient numbers of endophytic insects survive burns in remains of Silphium to recolonize burned areas the following year.[PUBLICATION ABSTRACT]