In its natural environment, the Colorado potato beetle,Leptinotarsa decemlineata(Say), colonizes plants that are distributed in patches. In such conditions, females must select oviposition sites that will provide sufficient resources for the survival of their offspring. The presence of conspecific eggs on the plant reduces the amount of resources available, so the density of conspecific eggs must be evaluated. In the laboratory, most females laid their eggs on the terminal leaflet of the highest of 3 leaves available to them. Feeding damage did not seem to modify the process of oviposition, and the presence of eggs did not change feeding patterns. In choice tests, egg clutches, hexane-washed eggs, yellow paper, and green paper reduced deposition of eggs on the treated leaflet, whereas hexane, white paper, and egg extract did not. Conspecific egg perception using visual cues, and possibly other stimuli, was demonstrated.