Assessing the use of antimicrobials to sterilize brown marmorated stink bug egg masses and prevent symbiont acquisition

The brown marmorated stink bug, Halyomorpha halys (Stal), is dependent on a beneficial obligate symbiont for successful development, survival, and fecundity. The bacteria are deposited on the egg mass surface by the female, and first instar nymphs become inoculated with the bacteria by feeding on the egg chorions upon hatching. Targeting the bacteria exposed on the egg mass surface may prove to be a viable management strategy for the stink bug. Egg masses were surface-treated with several antimicrobials and surfactants to determine whether exposure to these products adversely affected the fitness of newly hatched nymphs and/or sterilized the egg mass surface to prevent nymphal acquisition of the symbiont. Laboratory results showed that egg hatch rate was significantly reduced by Agri-Mycin and Naiad, nymphal survival was significantly impacted by AzaGuard and Naiad, and symbiont acquisition was significantly disrupted by Naiad, AzaGuard, and Liquid Copper Fungicide. Under field conditions, there were no significant treatment effects on nymphal survival or symbiont acquisition, but egg hatch rate was reduced by Naiad and Triton-X. Products with both antimicrobial effects and the ability to penetrate the coating covering the bacteria provided the best chance for disrupting symbiont acquisition.