Meeting Abstract

7.1  Sunday, Jan. 4  Do carnivorous plants and spiders partition resources? JENNINGS, D.E.*; ROHR, J.R.; University of South Florida; University of South Florida dejennin@mail.usf.edu

Competition is traditionally believed to be greatest in strength between closely related taxa, and as a consequence relatively little attention has been paid to competition between distantly related taxa. To assess the potential for competition between taxa from different Kingdoms, we examined resource partitioning between a carnivorous plant (the pink sundew, Drosera capillaris) and spiders (Araneae) in Odessa, FL. We sought to answer four questions regarding these taxa: 1) to what extent do the diets of D. capillaris and spiders overlap? 2) how selective are their diets?; 3) do these taxa segregate themselves spatially?; and 4) do these taxa affect one anothers phenotypic traits? Sampling was conducted from July to September 2008 using a combination of quadrats, pitfall-traps and sticky-traps. Preliminary analysis of the results indicated that the most abundant spider species in the area was Sosippus floridanus – a sheetweb-building Lycosid. The diets of both D. capillaris and S. floridanus predominantly consisted of springtails and ants, which were also the most abundant prey taxa found in their habitat. There was a positive spatial association between D. capillaris and S. floridanus. However, S. floridanus webs were generally located further away from D. capillaris as D. capillaris density increased. The quantified phenotypic traits such as leaf and web area did not seem to be affected by the presence of the other species. Our results suggest that there is the potential for competition between these two species, and that future work should include manipulative field studies.