During the spring of 1979, we conducted surveys of the pre-dispersal seed-eating insect guild of loco weeds, Astraglus nutallianus D.C. Two alluvial plains (bajadas) separated by approximately 25 km, were surveyed. The bajadas are on the Mt. Summerford watersheds on the New Mexico State University Experimental Range, 40 km NNE of Las Cruces, N.M. On each site we classified the loco weeds into 5 relative density classes based on distance to nearest neighbor of the same species. Distance classes in meters were 0-0.5, 0.5-1.0, 1.0-5.0, 5.0-10.0 and 10.0-20.0. At least 10 plants in each of the density class areas were up rooted, place in plastic bags and transported to the laboratory. We recorded the number of plants of other species within a 1.5 m radius of each plant collected. All pods were stripped from each plant, and the total number of pods and the number of pods damaged by seed-eating insects were counted. A subsample of insect damaged and undamaged pods were opened and the number of seeds present in each was recorded. Another subsample was placed in containers to rear the larvae present. The plant, devoid of pods, was oven dried and weighed.