GENE DIVERSITY IN NATURAL DIABROTICA-BARBERI SMITH AND LAWRENCE POPULATIONS (COLEOPTERA, CHRYSOMELIDAE)

A survey of electrophoretic loci in Diabrotica barberi Smith & Lawrenc e showed that 21 of 27 loci were polymorphic. Mean gene diversity at t he polymorphic loci was 0.274 +/- 0.051 and 0.213 +/- 0.041 among all 27 loci. Gene frequencies were heterogeneous among collections of adul t beetles from 14 farms in five counties in northwestern Iowa. About h alf the variance in gene frequencies was partitioned among farms in co unties and half among the counties. Wright's F statistics showed that most departures from random mating occurred within populations; depart ures from random mating among populations were insignificant. The data show much gene flow among D. barberi populations.