Competition among threadleaf sundews for limited insect resources

Here, I report evidence demonstrating intraspecific competition for insect resources in a carnivorous plant species, the threadleaf sundew, Drosera filiformis Raf. tracyi MacFarlane. I present critical evidence showing that insects represent an important resource for this plant. Previous demonstrations of the importance of insect prey have been conducted in the laboratory, not in the field, with the exception of those of Thum (1988, 1989). I also demonstrate that density-dependent competition for this resource can reduce the growth rates of whole plants. This provides an unusual case study in which both the process and the consequences of competition have been observed directly.