Non-target impact assessment of the introduced green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) on the indigenous sibling species, C. nipponensis (Okamoto) through interspecific predation

Abstract

As a part of a risk assessment of the non-target effect of the introduced green lacewing on native ecosystem, we performed a laboratory experiment to characterize the symmetry of the interspecific predation between the introduced green lacewing, Chrysoperla carnea and the native sibling species, C. nipponensis among different stages. The elder and larger larvae always ate the younger and smaller individuals, regardless of species. When the same instar and similar sized larvae were paired, almost equal predation rates between the two species was observed. Our results suggest that size was the most important factor to determine the symmetry of the interspecific predation between C. carnea and C. nipponensis. Populations of C. nipponensis will not be decreased by interspecific predation with C. carnea without extreme mass releases of C. carnea in a small arena.