Interspecific interaction rates and space use were observed for P. lydia at 3 ponds in north-central Texas from June to August 2007. Aggressive interactions of marked individuals were tallied for each interacting sp. by which individual was the aggressor or target and which sp. won or lost. The space used was also mapped. These data were also collected for one individual each of the libellulids Pachydiplax longipennis and Tramea lacerata and compared to P. lydia. Interaction rates were different depending on the category of interacting odon. (perching or flying), supporting the hypothesis that the thermoregulatory categories of perching and flying aid in habitat partitioning among spp.