Abstract
The convergent lady beetle (Hippodamia convergens) is a generalist natural enemy that is utilized extensively in augmentative biological control across the United States. Recent studies have pointed to both genetic and phenotypic differences in Western (California) versus Eastern (Kansas) populations of the species. Here we investigate phenotypic differences in their utilization of pea aphids in (a) Eastern versus Western populations, (b) Hybrid Eastern and Western populations versus their progenitor populations, and (c) within population competition rates in Eastern, Western, and Hybrid populations. Across eight replicate treatments, we find no phenotypic differences (P > 0.2), contradicting previous genetic and behavioral studies. Hybrid F1 populations however show an overall greater percentage weight gain, potentially indicative of a hybrid vigor effect, and greater fitness of augmented populations of the species.
