Many adult Chrysoperla comanche (Stephens) green lacewings were caught in traps baited with live yeast cultures during tests designed to catch olive fruit flies. All 13 yeast species tested were more attractive than the industry-standard dried torula yeast (Cyberlindnera jadinii; syn. Candida utilis). Live C. jadinii culture attracted significantly more lacewings than the inactive dried-pellet form of the same yeast species, demonstrating that volatiles from live yeast cultures attract adults of this lacewing. Odor profiles for two of the highly active yeasts tested herein (Lachancea thermotolerans and Solicoccozyma terrea) were similar to that for Metschnikowia pulcherrima, a yeast species isolated earlier from the gut diverticulum of Chrysoperla rufilabris. A new Metschnikowia species (M. chrysoperlae), along with two new Candida spp. that were recently realigned to one of the Metschnikowia clades (M. picachoensis and M. pimensis), were also identified from the diverticulum of C. comanche. Thus, one clade of Metschnikowia yeasts that commonly occur in floral nectar appears to exhibit mutualistic symbioses with Chrysoperla green lacewings. Both male and female C. comanche adults were attracted in the present study, and we speculate that males have exploited this symbiosis by offering Metschnikowia-laden regurgitant, including attractive volatiles, to females ('mating trophallaxis') as a nuptial gift.
Keywords: Attraction; Metschnikowia; Mutualism; Reproduction; Symbiosis; Torula; Trophallaxis.