Bacillus velezensis LP16S-a Potential Entomopathogen for Southern Green Stink Bug, Nezara viridula (L.)¹

Strains of Bacillus velezensis have been successful biological control agents for various plant diseases. A novel strain - Bacillus velezensis LP16S - was recently shown to inhibit mycelial growth and spore germination in four major pathogens of sorghum, Sorghum bicolor (L.) Moench. Southern green stink bug, Nezara viridula (L.), infests sorghum and has beneficial endosymbiotic bacteria in the insect gut. Because B. velezensis LP16S was detrimental to propagation of certain fungi, we hypothesized that B. velezensis LP16S might affect internal microbiota, thereby affecting survival and longevity of N. viridula. Adult male and female N. viridula were fed for 2 days green bean sections that were either sterile or contaminated with a derivative strain of B. velezensis LP16S (i.e., B. velezensis LP16SR). Diet significantly affected survival of the stink bugs. Mean survival of adults fed B. velezensis LP16SR (15.79 days) was significantly less than adults fed sterile beans (18.58 days). Interaction of Diet by Sex was significant, indicating that females fed B. velezensis LP16SR had significantly shorter mean survival (approximately 15 days) than did females fed sterile beans (approximately 21 days). Also, the former group had maximum longevity at 72 days while the latter group had maximum longevity of 92 days. From observed differences in mean survival and longevity, implications and future research should consider B. velezensis LP16S as a potential entomopathogen to control N. viridula.