Evaluating chemical cues associated with Halyomorpha halys toward enhanced sensitivity of surveillance for Trissolcus japonicus

Authors: DYER, JARED - Virginia Tech; Talamas, Elijah; Leskey, Tracy; J. CHRIS, BERGH - Virginia Tech

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/25/2022
Publication Date: 7/14/2022
Citation: Dyer, J.E., Talamas, E.J., Leskey, T.C., J. Chris, B. 2022. Evaluating chemical cues associated with Halyomorpha halys toward enhanced sensitivity of surveillance for Trissolcus japonicus. Environmental Entomology. https://doi.org/10.1093/ee/nvac045.
DOI: https://doi.org/10.1093/ee/nvac045

Interpretive Summary: In Asia, the samurai wasp is one of the most important egg parasitoids of brown marmorated stink bug (BMSB). While the samurai wasp has been present in North America since 2014, there are no established attractants that can be used in association with yellow sticky card (YSC) traps or sentinel egg masses(BMSB) to increase sensitivity of biosurveillance programs. Here, we evaluated potential olfactory stimuli (BMSB aggregation pheromone and pheromone synergist lures and n-Tridecane lures) to determine if they increased captures on YSC, increased parasitism of sentinel egg masses, or increased the numbers of eggs laid by BMSB in baited trees. None of these stimuli increased samurai wasp captures on YSC or parasitism of sentinel egg masses, and trees baited with the BMSB aggregation pheromone and pheromone synergist lures did not result in increased BMSB egg masses. Thus, sensitivity of YSC and sentinel egg masses cannot be enhanced with these olfactory stimuli. Therefore, in all likelihood, more YSC or sentinel egg masses will need to be deployed to ensure reliable samurai wasp detection.

Technical Abstract: In Asia, Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae) is the predominant egg parasitoid of brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae). Detections of adventive T. japonicus populations in North America since 2014, where invasive H. halys populations have impacted various specialty crops, spurred surveillance efforts to track T. japonicus, and yellow sticky cards (YSC) deployed in H. halys host trees have proven effective for this purpose. While T. japonicus exhibits positive behavioral responses to several olfactory stimuli associated with H. halys under laboratory conditions, these have not been evaluated for their potential utility to enhance surveillance of T. japonicus in the field. In northwestern Virginia, where both H. halys and T. japonicus are well-established, we examined the effect of baiting tree of heaven, Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae) with lures containing the H. halys aggregation pheromone and pheromone synergist on the abundance of H. halys egg masses and captures of T. japonicus in YSC. We also assessed the effect of baiting YSC with newly-laid H. halys egg masses or n-tridecane, a component of H. halys tarsal prints, on T. japonicus captures. Destructive sampling of pheromone-baited and non-baited trees revealed no significant differences in H. halys egg mass abundance on foliage. Similarly, YSC deployed in pheromone-baited and non-baited trees showed no significant differences in T. japonicus captures. Moreover, YSC augmented with H. halys egg masses or n-tridecane showed no increase in T. japonicus captures compared with non-baited controls. The implications for surveillance of adventive T. japonicus are discussed.