Parental host species affects behavior and parasitism by the pentatomid egg parasitoid Trissolcus japonicus (Hymenoptera: scelionidae)

Authors: BOYLE, SEAN - University Of Delaware; Weber, Donald; HOUGH-GOLDSTEIN, JUDITH - University Of Delaware; Hoelmer, Kim

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/29/2020
Publication Date: 5/30/2020
Citation: Boyle S, Weber D., Hough-Goldstein J, Hoelmer KA. Parental host species affects behavior and parasitism by the pentatomid egg parasitoid Trissolcus japonicus (Hymenoptera: Scelionidae). Biological Control 149: 104324. 2020. https://doi.org/10.1016/j.biocontrol.2020.104324
DOI: https://doi.org/10.1016/j.biocontrol.2020.104324

Interpretive Summary: The brown marmorated stink bug is a serious invasive agricultural and nuisance pest across North America and Europe. One of the most promising methods of long-term control is importation of natural enemies from its native range, including egg parasitoids that attack then hatch out from the pest's eggs. Field and laboratory evaluations determined the egg parasitoid Trissolcus japonicus (“samurai wasp”) as the primary candidate biocontrol agent for the stink bug. Laboratory host range evaluations are necessary to determine the host range among stink bugs, some of which are beneficial predator species. Laboratory no-choice evaluations only show the potential host range of natural enemies and do not account for behavioral choices made by natural enemies in response to different environmental cues. This study was designed to test the behavior of samurai wasps that emerged from brown marmorated stink bug eggs and from eggs of the spined soldier bug, a North American native predator. Although wasps emerging from the predator eggs shows some changes in host preference, the females were smaller than those from brown marmorated eggs, and were less active and less fecund. Our study suggests that behavioral and reproductive studies may be used to further evaluate the host specificity of samurai wasp and can be an invaluable supplement to traditional no-choice biocontrol host range testing.

Technical Abstract: The brown marmorated stink bug (Halyomorpha halys) is a serious invasive agricultural and nuisance pest across North America and Europe. One of the most promising methods of long-term control is importation of egg parasitiods from its native rangein Asia. Field studies in Asia, as well as laboratory evaluations in quarantine, determined the egg parasitoid Trissolcus japonicus (“samurai wasp”) as the primary candidate biocontrol agent. Laboratory host range evaluations are necessary to determine the host range among stink bugs, some of which are beneficial predator species. Laboratory no-choice evaluations only showed that the samurai wasp's physiological host range includes several other species of native stink bugs. But such no-choice tests do not account for behavioral choices made by natural enemies in response to different environmental cues. This study was designed to test the behavior of samurai wasps that emerged from brown marmorated stink bug eggs and from eggs of the spined soldier bug (Podisus maculiventris), a North American native predator. Although wasps emerging from the predator eggs shows some changes in host preference, the females were significantly smaller than those from brown marmorated eggs, and were less active and less fecund, suggesting that their oviposition in P. maculiventris will constitute a selective disadvantage. Our study suggests that behavioral and reproductive studies may be used to further evaluate the host specificity of samurai wasp and can be an invaluable supplement to traditional no-choice biocontrol host range testing.