Meeting Abstract
P1.115 Jan. 4 Plasticity in Lek Spatial Dynamics in Gryllotalpa major Saussure (Orthoptera: Gryllotalpidae): The Influence of Above-ground Botanical Biomass and Grass Height on Male Spacing. HOWARD, D.R.; University of Tulsa, Oklahoma daniel-howard@utulsa.edu
The prairie mole cricket (Gryllotalpa major Saussure) is a threatened orthopteran insect of the tallgrass prairie ecosystem of the south central United States. Remnant populations occupy fragmented prairie sites in Oklahoma, Arkansas, Kansas and Missouri, including The Nature Conservancy�s Tallgrass Prairie Preserve and White Oak Prairie in northeastern Oklahoma. Advertising male prairie mole crickets are known to aggregate spatially in leks, but the high degree of observed spatial variance in these leks remains unexplained. We hypothesize that increased prairie grass height (Hg) and above-ground botanical biomass (Ba) correlate with increased spatial extent of the lek. Populations were surveyed at the two Nature Conservancy sites during the spring of 2005 and 2006, using the male cricket�s acoustic call to locate advertising aggregations. During this period, eleven leks consisting of three-hundred advertising males were located. The geographic coordinates of each male�s burrow within the lek were documented using GPS technology, and six spatial parameters for each leksite were calculated using GIS software. Additionally, Hg and Ba samples were collected and analyzed from each of the leks. The data indicate a significant positive correlation between Hg and Ba, between Hg and mean inter-burrow distance, and between Ba and mean nearest neighbor distance, mean furthest neighbor, and mean inter-burrow distance. This suggests that as grass heights and biomass increase in a prairie, individual male prairie mole crickets space themselves further apart. This behavior may allow searching females to more easily locate mates in an acoustic environment made more complex by above-ground botanical factors.
