Prey capture by a generalist predator on flowering and nonflowering ambush sites: Are infloreseences higher quality hunting sites?

Flowers are sites of frequent visitation by pollinators and numerous other insect groups and thus could potentially represent high-quality resource patches for generalist predators that are able to exploit these aggregations of prey. In northeastern old-fields, the sit-and-wait predator Phymata pennnsylvanica Handlirsch (Heteroptera: Phymatidae) occupies ambush sites on both inflorescences and nonflowering green plants. In 1998, a study was conducted to test the hypothesis that flowers are higher-quality hunting sites than nonflowering plants for these predators, Prey capture events were directly observed during daily and hourly checks on fifth-instar bugs placed on flowering or nonflowering ambush sites in the field. Prey capture rate, prey size, and food consumption rate did not differ significantly between the two site types. However, the taxonomic composition of the prey caught on the two site types was strongly divergent, with adult Diptera dominating on flowering sites and sap-feeding Homoptera dominating on nonflowering sites. These results indicate that there are times when flowering and nonflowering sites can be largely functionally equivalent for a predator in terms of prey capture success and suggest that nonflowering sites may be more important in the foraging ecology of P. pennsylvanica and other old-field ambush predators than has previously been realized. However, one implication of the existence of distinct prey communities on the two site types is that the relative quality of flowering versus nonflowering sites could potentially vary unpredictably among different locations or years depending on the particular dynamics of the dominant prey groups on each site type.