A total of 419 specimens, 25 species, and eight families of Neuroptera were collected from 81 light trap sites in Fairfax County, Virginia, during 2005. Eighty percent of the species (20 of 25) belong to the families Chrysopidae, Coniopterygidae, and Hemerobiidae. The most commonly collected species was the green lacewing, Chrysoperla rufilabris (Burmeister), with 29% of the specimens. First records for the state of Virginia are noted for Hemerobius pinidumus Fitch and Hemerobius stigma Stephens. These data provide a baseline for monitoring future climate change in the metropolitan Washington, D.C. area. Neuroptera are among our most beneficial insects. Larvae are predators of other insects and can consume a wide variety of insect eggs, nymphs, larvae, and adults (Tjeder 1966) in a variety of habitats and ecological niches. Many move actively over the foliage feeding on almost any insect of the appropriate size. Neuropterans are released in agricultural lands to augment naturally occur-ring field populations, and are reared for release more than any other group of beneficial insects (Tauber, M.J. et al. 2000). Larvae of antlions are sedentary predators living in tree holes, on the soil surface, and in specialized pits that they create in loose soil (Stange 2004). Larvae of mantis-flies are mostly predators on spider egg sacs (Redborg 1998). Berothid larvae live in termite nests and feed on the termites (Tauber, C.A., and M.J. Tauber 1968). The only aquatic family of neuropterans in North America, the Sisyridae, feed on freshwater sponges as larvae (Parfin and Gurney 1956). Neuropterans are plentiful in the urban environment. Adults are nocturnal and chrysopids and hemerobiids can frequently be seen at window panes and store fronts at night. In the eastern United States their adult taxonomy, geographical distributions, and diapause mechanisms are fairly well understood (Penny et al. 1997; Tauber, M.J., and C.A. Tauber 1976), yet relatively few studies have been carried out on seasonal activity patterns. With the growing evidence that humans are impact-ing the environment and are a major contributor to climate change (Hansen and Lacis 1990; Walther et al. 2002), we need to understand baseline patterns of seasonal variation in insect populations. To investigate seasonal patterns of neuropterans in the Mid-Atlantic States, we analyzed collections from a series small light traps set up at 81 sites in Fairfax County, Virginia, in 2005. The light traps were used to monitor mosquito populations and throughout the warmer seasons were also utilized to monitor adult neuropteran presence.