Artificial adult diet for <i>Chrysopa oculata</i> (Neuroptera: Chrysopidae) to overcome the barriers to rearing predatory adult green lacewings

The green lacewing Chrysopa oculata Say is a crucial natural enemy contributing to arthropod pest management in crop production. Chrysopa spp. are unique because both larvae and adults are predatory. In contrast, only the larvae of Chrysoperla spp. are predatory, and their adults consume nectar and pollen. Although an established artificial diet exists for Chrysoperla adults, limited information on suitable artificial diets for Chrysopa adults limits their broader use in research and commercial biological control programs. Thus, the objective of this study was to identify a suitable diet for Chrysopa oculata adults. Five protein supplements: cricket powder, fly fish food, goldfish food, aphids, and Ephestia kuehniella Zeller eggs added separately to the Chrysoperla carnea (Stephens) adult diet were evaluated as C. oculata adult diet treatments. We provided the treatments to paired C. oculata adults for 6 consecutive generations and evaluated egg hatch, larval survival, developmental time, adult longevity, and sex ratio. Chrysopa oculata in the goldfish and fly fish food treatments had higher egg-to-adult survival compared to those in the E. kuehniella treatment in the second generation. However, the later generations showed significant effects of the treatments, with no adults eclosed from the fly fish food treatment, and significantly fewer adults eclosed under the goldfish food treatment in the fifth generation. Additionally, none of the eggs hatched in the cricket powder treatment in the seventh generation. The E. kuehniella treatment supported a higher number of generations, indicating E. kuehniella as the most suitable protein supplement for C. oculata adults.