Selected central Iowa confields were sampled for corn rootworm larvae in 1978 and 1979, using core and cube sample units. Dispersion patterns were examined by field for each year with the variance-to-mean ratio. Spatial dispersion across fields was estimated from the 1979 sample counts by using s2/m and Taylor's power law. Most populations of corn rootworm larvae exhibited aggregated dispersion patterns. A discussion of possible reasons for aggregation is presented.