Functional Response of Three Species of Chrysoperla Preying on Melanaphis sacchari

The sugarcane aphid, Melanaphis sacchari, is a worldwide pest that significantly affects sorghum (Sorghum bicolor (L.) Moench. In the USA this pest can cause up to 100% yield losses, mainly when no action is taken to control this pest. In this study, the potential of three species of Chrysoperla for biological control of M. sacchari was assessed by comparing predation capacity and functional responses of the three species. Individuals of Chrysoperla carnea were collected in a crop of wheat (Triticum aestivum L.) in the State of Guanajuato, Mexico, while C. externa and C. comanche were obtained from a laboratory colony reared on cereal moth, Sitotroga cerealella (Olivier), and from a commercial planting of pecan, Carya illinoensis (Wangenh), respectively. Our results suggested that C. carnea is a good option for an augmentative biological control program against M. sacchari in sorghum because the species had a mean predation capacity of 119.4 nymphs in 24 hours, and a type II functional response; they were able to locate and consume 80% of their prey even at the low prey density of 64. C. carnea had a high coefficient of attack (0.10) and a short handling time (0.10 hour) compared to the other Chrysoperla species.