The role of honeydew in ladybug (Coleoptera: Coccinellidae) attraction to Melanaphis sorghi

The sorghum aphid, Melanaphis sorghi, is a key pest of sorghum in the United States. Predators—particularly coccinellids—are an important component of M. sorghi control, as their densities influence aphid densities. Recent studies have shown that natural enemies’ preference and performance may be mediated by bacteria present in their hosts’ honeydew. The seven-spot ladybug, Coccinella septempunctata, is an abundant M. sorghi predator in Texas. This beetle is known to be attracted to other aphid species’ honeydew. In this talk, I report on whether C. septempunctata is attracted to M. sorghi honeydew, and whether microorganisms mediate that attraction. My results will inform the feasibility of improving biocontrol by inoculating microorganisms in sorghum to recruit natural enemies before M. sorghi populations build up, as well as increase our knowledge of the role of microorganisms in prey/host location.