Technical Abstract: First dataset of cDNA library for genes isolated from the brown citrus aphid, BrCA, Toxoptera citricida (Say). The BrCA is considered the main vector of citrus tristeza virus, an economically important disease of citrus. Scientist at the U.S. Horticultural Research Laboratory in Ft. Pierce, Florida, used expressed sequence tags (ESTs), to scan for, and tag active genes within alate aphids, which is the aphid stage, which disperses and spreads Citrus tristeza virus. The BrCA cDNA library has provided important information to allow scientist to address important scientific questions related to aphid biology. This information will rapidly advance research on these insects. This database will also act as a direct model for hundreds of thousands of closely related aphid species. Databases such as these help scientists to identify genes critical to aphid biology, to understand the molecular basis of aphid growth and development, and to address fundamental questions concerning BrCA, cell biology and pathology, thus providing a driving force for the development of new methods of pest management.