Seasonal abundance and spatial distribution of two sympatric leafhoppers (Homoptera: Cicadellidae) on eastern redbud trees

Two sympatric leafhopper species, Erythroneura aclys (McAtee) and E. bistrata (McAtee), occur together in some Kentucky settings in high numbers on eastern redbud trees, Cercis canadensis L. Seasonal and spatial distributions were examined to determine whether the species segregate within their habitat. Both leafhopper species undergo two generations per year, and population densities peaked within a week of each other in both generations. E. aclys was the more abundant of the two species. Leafhoppers partially subdivided tree canopies: E. aclys occurred significantly more frequently in the lower than in the upper canopy. E. bistrata showed less preference for either canopy level, but on average was encountered in greater numbers in the upper canopy. Both species preferred newer leaves along branches, but E. aclys showed significantly greater preference than E. bistrata, especially in the lower canopy. E. bistrata changed its resting or feeding position on individual leaves when it was in the presence of E. aclys. In general, differential distribution among and within trees increased as density increased, but only a change in position by E. bistrata within leaves when E. aclys was present was clearly the result of interspecific interactions