Three adult corn rootworm sampling techniques were employed in 59 Iowa cornfields during August 1976 and 1977. Northern and western corn rootworm beetle counts were analyzed by Green's coefficient, Cx, and Iwao's regression method, m*=a+bm, to determine spatial dispersion patterns. Both indices indicated that most rootworm beetle populations sampled were characterized by aggregated dispersion. Spatial behavior in rootworm beetles tended to be density dependent. Some populations with large mean densities, however, did not differ significantly from randomness.