Submitted to: Journal of Pest Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/9/2016
Publication Date: 11/30/2016
Citation: Short, B.D., Khrimian, A., Leskey, T.C. 2016. Pheromone-based decision support tools for management of Halyomorpha halys in apple orchards: development of a trap-based treatment threshold. Journal of Pest Science. doi: 10.1007/s10340-016-0812-1.
Interpretive Summary: The invasive brown marmorated stink bug (BMSB) has become a serious pest in mid-Atlantic apple orchards. We conducted a study to determine if the number of BMSB adults captured in traps baited with pheromone and a pheromone synergist could be used to make management decisions in experimental apple orchards. In this study, experimental apple orchards were treated with an insecticide for BMSB control only when a pre-determined cumulative threshold of either one, 10 or 20 adults per trap was reached. These three treatments were compared with plots treated with weekly insecticide applications and plots never treated. Fruit were sampled at harvest from each treatment plot and evaluated for the presence of BMSB injury. At harvest, significantly less fruit injury was observed when treated weekly or using a threshold of one or 10 BMSB adults per trap to trigger insecticide applications. There was no difference in fruit injury in the 20 adults per trap or control plots. Also, insecticide sprays were reduced by 40% in the 10 BMSB adults per trap threshold compared with the weekly interval spraying. Our results suggest that baited pheromone traps can be used as a tool to trigger insecticide applications for management of BMSB in apple orchards.
Technical Abstract: The invasive brown marmorated stink bug, Halyomorpha halys (Stål), has become a serious pest in mid-Atlantic apple orchards. Because no decision support tools exist for H. halys management, calendar-based insecticide applications have been the only successful technique for mitigating H. halys injury in orchards. Following the identification of the two component aggregation pheromone of H. halys, a 3.5: 1 mixture of (3S,6S,7R,10S)-10,11-epoxy-1-bisabolen-3-ol and (3R,6S,7R,10S)-10,11-epoxy-1-bisabolen-3-ol, and pheromone synergist methyl (2E,4E,6Z)-decatrienoate, we conducted a study to determine if biological information generated by traps baited with this pheromone and pheromone synergist could be used to make management decisions. In this study, experimental apple orchards were treated with a H. halys-targeted insecticide only when a pre-determined cumulative threshold of either one, 10 or 20 adults per trap was reached. Once threshold was reached, two alternate row middle sprays one week apart were triggered and the threshold was reset. For comparison, some orchards were also subjected to a weekly alternate row middle spray or left untreated as controls. At harvest, significantly less fruit injury was observed when treated weekly or using a threshold of one or 10 H. halys adults per trap to trigger insecticide applications. Orchards treated using a cumulative threshold of 20 adults per trap or when left unsprayed had significantly higher fruit injury. In addition, insecticide applications were reduced by 40% using a threshold of 10 adults per trap but only by 8% using a threshold of one adult per trap compared with a weekly insecticide application. Our results suggest that baited pheromone traps can be used as decision support tools to trigger insecticide applications when needed to mitigate risk and effectively manage H. halys in apple orchards.