SOIL COMPACTION EFFECT ON CORN-ROOTWORM POPULATIONS IN MAIZE ARTIFICIALLY INFESTED WITH EGGS OF WESTERN CORN-ROOTWORM (COLEOPTERA, CHRYSOMELIDAE)

Controlled infestation with eggs of western corn rootworms, Diabrotica virgifera virgifera LeConte, was used in a 2-yr study on the effects of wheel traffic-induced soil compaction on com rootworm establishment , survival, and larval injury to the roots of maize, Zea mays L. Root injury ratings and cumulative emergence of adults of western corn root worms, as taken from emergence cages, were lowest in plots where eggs had been infested into compacted interrows. Measurements of soil bulk density, air-filled porosity, and air permeability were taken on core samples to characterize soil physical properties in relation to soil c ompaction. Lowest rootworm survival and injury coincided with higher b ulk density, lower air-filled porosity, and lower air permeability val ues characteristic of soil from the compacted interrow plots. Survival and establishment of western corn rootworm larvae were associated wit h greater soil pore continuity in uncompacted plots. Soil compaction i nduced by controlled wheel traffic may have potential as a management strategy for reducing larval corn rootworm movement into strip intercr opped maize adjacent to areas previously planted to maize and rotated into a crop that is not a host for corn rootworms.