Ovipositional characteristics of lacewings, Chrysoperla carnea (Stephans) and Chrysopa pallens (Rambur) (Neuroptera: Crysopidae) in field

Abstract

The oviposition characteristics of two species of lacewings, Chrysoperla carnea (Stephans) and Chrysopa pallens (Rambur), were investigated in pear, eggplant and cucumber fields as well as on locust trees at Saitama Horticultural Experiment Station (Kuki City) in 1996. The habitat and oviposition site of C. pallens adults showed a closer association to aphid populations than C. carnea. Consequently, many eggs of the former species were deposited where aphids were abundant in the eggplant and pear fields. On the other hand, the distribution pattern of C. carnea eggs in the eggplant field was a weakly aggregated distribution. The spatial association of eggs of C. carnea and C. pallens and their prey (aphids, spider mites and thrips) in the eggplant field was analyzed by interspecies mean crowding. The distribution of C. carnea eggs showed a weak correlation to aphids, whereas C. pallens eggs had a positive correlation with aphids. The developmental times and rate of C. carnea and C. pallens were observed on three prey species: Tetranychus urticae Koch (green-form), Aphis craccivora Koch, and Uroleucon nigrotuberculatum (Olive) to determine the food habits of their larvae. When spider mites were provided as prey, C. carnea survived and developed well, but C. pallens did not develop to adults.