Interspecific competition between Trissolcus japonicus and Trissolcus mitsukurii, the two most promising candidates for biocontrol of Halyomorpha halys

Authors: GIOVANNINI, LUCREZIA - Centro Di Ricerca Difesa E Certificazione (CREA – DC); SABBATINI-PEVERIERI, GIUSEPPINO - Centro Di Ricerca Difesa E Certificazione (CREA – DC); SIMONI, SAURO - Centro Di Ricerca Difesa E Certificazione (CREA – DC); CERVO, RITA - University Of Florence; Hoelmer, Kim; ROVERSI, PIO FEDERICO - Centro Di Ricerca Difesa E Certificazione (CREA – DC)

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/26/2022
Publication Date: 9/30/2022
Citation: Giovannini, L., Sabbatini-Peverieri, G., Simoni, S., Cervo, R., Hoelmer, K.A., Roversi, P. 2022. Interspecific competition between Trissolcus japonicus and Trissolcus mitsukurii, the two most promising candidates for biocontrol of Halyomorpha halys. Biological Control. 176(2022), 105068. https://doi.org/10.1016/j.biocontrol.2022.105068.
DOI: https://doi.org/10.1016/j.biocontrol.2022.105068

Interpretive Summary: The invasive brown marmorated stink bug is a severe agricultural pest of worldwide importance and biocontrol is a promising method for long-term management. The parasitoid wasps Trissolcus japonicus and Trissolcus mitsukurii are the most effective candidate biological control agents. We assessed the foraging behavior and the reproduction of these species under various competition scenarios. Both Trissolcus species were able to parasitize host eggs already attacked by the other species, even if successful reproduction favored the species that first attacked the host eggs. Where both species were present at the same time T. mitsukurii was more aggressive towards T. japonicus and spent more time defending the host eggs it had already parasitized. For biological control of H. halys, releasing a single species appears to be the best strategy, since multiparasitism by both species results in wasted search time and lower reproductive potential.

Technical Abstract: The invasive stink bug Halyomorpha halys, native to east Asia, is a severe agricultural pest of worldwide importance and biocontrol is a promising method for its long-term management. Trissolcus japonicus and Trissolcus mitsukurii are considered the most effective candidates as biological control agents. When considering options for single or multiple species releases of agents, interspecific competition should be a component of evaluations. In this study different experimental designs assessed the foraging behavior and the progeny production by females of each species under extrinsic direct and indirect competition scenarios. In direct extrinsic competition, females of each species were tested in arenas either simultaneously (synchronous release) or when half of the host egg mass had already been parasitized by the other species (asynchronous release). In another experiment, H. halys egg masses previously parasitized by the female of one species were offered to the competitor females after 0, 3, 5, or 7 days. Both Trissolcus species were able to parasitize host eggs already parasitized by the other species, even if the progeny production always favored the species that arrived first on the host egg mass. However, in the synchronous releases, T. mitsukurii displayed more aggressive behavior towards T. japonicus. When released simultaneously, T. mitsukurii spent more time defending the host egg mass, resulting in a higher progeny production. For biological control of H. halys, single species release appears to be the best strategy, since multiparasitism by both species results in wasted searching time and energy, and lower reproductive potential.