Influence of trap location in the tree canopy on captures of adventive Trissolcus japonicus (Hymenoptera: Scelionidae)

Authors: DYER, JARED - Virginia Tech; TALAMAS, ELIJAH - Florida Department Of Agriculture And Consumer Services; Leskey, Tracy; BERGH, J. CHRISTOPHER - Virginia Tech

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/3/2022
Publication Date: 4/7/2022
Citation: Dyer, J., Talamas, E., Leskey, T.C., Bergh, J. 2022. Influence of trap location in the tree canopy on captures of adventive Trissolcus japonicus (Hymenoptera: Scelionidae). Journal of Economic Entomology. 115(3):904-908. https://doi.org/10.1093/jee/toac039.
DOI: https://doi.org/10.1093/jee/toac039

Interpretive Summary: The Samurai wasp, Trissolcus japonicus, is an important egg parasitoid of the brown marmorated stink bug (BMSB) in the native range in Asia. In 2014, the Samurai wasp was detected in Maryland. Since then, it has been reported in 15 states, District of Columbia, and two Canadian provinces. To optimize monitoring tools for the Samurai wasp, we compared mid- and lower-canopy deployment locations of yellow sticky cards (YSCs) in a favored BMSB host tree, tree of heaven. These YSCs have been proven to be a sensitive tool for monitoring Samurai wasp presence at mid-canopy previously, but this deployment location (based on increased BMSB activity at mid-canopy) requires additional labor efforts. Data collected in 2021 and 2022 revealed no significant differences in captures of the Samurai wasp on YSC in mid- or lower-canopy, indicating that a more convenient, less labor intensive lower-canopy location can be used for YSC deployments for Samurai wasp biosurveillance efforts.

Technical Abstract: Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae) is an egg parasitoid of the invasive Asian pest, brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae). Also native to Asia, adventive T. japonicus populations have been detected in North America since 2014 and are currently reported from 15 US states, the District of Columbia, and two Canadian provinces. Yellow sticky cards (YSCs) have proven effective for monitoring the presence, seasonal abundance, and distribution of these adventive populations. Our research has utilized YSCs deployed in the mid-canopy of H. halys host trees, following a study in which all leaves on felled tree of heaven, Ailanthus altissima (Mill.) Swingle, were inspected for H. halys egg masses, yielding eggs parasitized by T. japonicus only from mid- and upper-canopy leaves. However, given that other investigators have captured T. japonicus using YSCs deployed in the lower-canopy and that the effect of YSC placement in trees on T. japonicus captures had not been examined, captures of T. japonicus in YSCs in the mid- and lower-canopy of individual A. altissima were compared. Traps were replaced weekly for five weeks and assessed for Scelionidae species. In 2020 and 2021, T. japonicus represented =53% of all Scelionidae captured, and there was not a significant effect of YSC location in the canopy on its captures. Deploying YSCs at either canopy height was effective for measuring the relative abundance of T. japonicus, but sampling from the lower canopy substantially improved the efficiency and convenience of T. japonicus surveillance.