Annual Fire, Mowing and Fertilization Effects on Two Cicada Species (Homoptera: Cicadidae) in Tallgrass Prairie
In tallgrass prairie, cicadas emerge annually, are abundant and their emergence can be an important flux of energy and nutrients. However, factors influencing the distribution and abundance of these cicadas are virtually unknown. We examined cicada emergence in plots from a long-term (13 y) experimental manipulation involving common tallgrass prairie management practices. The plots were arranged in a factorial experimental design, incorporating annual burning, mowing and fertilization (10 g N m-2 and 1 g P m-2). One cicada species, Cicadeita calliope, responded positively to fire, but negatively to mowing, and was most abundant in plots that were burned, unmowed and fertilized. Increased density of C. calliope in this treatment combination is related, in part, to increased availability of oviposition sites aboveground. Furthermore, C. calliope females from fertilized plots were significantly larger in body size relative to females from unfertilized prairie. Another cicada species, Tibicen tiurifera, emerged only from unburned plots. The mechanism underlying this negative response to fire is unclear, but may be related to the presence of standing dead vegetation or improved quality (i.e., N content) of belowground plant tissue in unburned plots. In contrast to C. calliope, the density of T. aurifera was not affected by mowing or fertilization. However, like C. calliope, die body size of T. aurifera females was significantly greater in fertilized plots. Cicada emergence resulted in N flux ranging from 0.05-0.16 g N m-2 in unburned plots, but N flux (as cicada biomass) from annually burned plots was negligible.