Ovipositional preference and larval–early adult performance of two generalist lacewing predators of aphids in pecans

Abstract

Abstract We examined the ovipositional preference and larval to early adult performance of two generalist, predatory green lacewing species Chrysoperla comanche (Banks) and Chrysopa nigricornis Burmeister. Both of these predators are abundant in pecan trees (Carya illinoensis (Wagenh) K. Kock) in southern Arizona where two specialist aphids Monellia caryella (Fitch) and Melanocallis caryaefoliae (Davis) are found. Ovipositional preference was tested in a three-way choice experiment with pecan seedlings infested with one of the two aphid species or without aphids. Females of both green lacewing species showed a significant preference for ovipositing on plants bearing aphids, but only C. comanche distinguished between the two aphid species. Both aphid species were suitable for larval development and developmental time was not affected by aphid treatment. C. nigricornis pupae were significantly heavier when larvae were fed only M. caryaefoliae, but no difference in pupal weight was found for C. comanche. The pre-oviposition period was significantly longer for C. nigricornis females that were fed a mixture of the two aphid species during larval development compared with each aphid species alone. However, aphid diet did not affect the number of eggs laid by either species during the first five days of oviposition.