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ARS Home » Northeast Area » Newark, Delaware » Beneficial Insects Introduction Research Unit » Research » Publications at this Location » Publication #330637
Research Project: Classical Biological Control of Insect Pests of Crops, Emphasizing Brown Marmorated Stink Bug, Spotted Wing Drosophila and Tarnished Plant Bug

Location: Beneficial Insects Introduction Research Unit

Title: Cold tolerance of Trissolcus japonicus and T. cultratus, potential biological control agents of Halyomorpha halys, the brown marmorated stink bug

Author
item NYSTROM, ERICA - University Of Minnesota
item VENETTE, ROBERT - Us Forest Service (FS)
item DIECKHOFF, CHRISTINE - University Of Delaware
item Hoelmer, Kim
item KOCH, ROBERT - University Of Minnesota

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/12/2017
Publication Date: 1/16/2017
Citation: Nystrom, E., Venette, R., Dieckhoff, C., Hoelmer, K.A., Koch, R.L. 2017. Cold tolerance of Trissolcus japonicus and T. cultratus, potential biological control agents of Halyomorpha halys, the brown marmorated stink bug. Biological Control. 107:11-20. doi:10.1016/j.biocontrol.2017.01.004.

Interpretive Summary: Brown marmorated stink bug, a pest of many important crop plants and a serious urban nuisance pest, is native to Asia and has invaded the USA, including the north central states. Native natural enemies do not significantly suppress populations of this invasive species, therefore exploration was conducted in Asia to identify potential classical biological control agents for this pest. Several parasitoid wasps that attack the eggs of this stink bug in Asia are being evaluated for potential release in the USA. Since the stink bug has invaded regions which experience sub-zero winter temperatures, cold tolerance is an important aspect for evaluation of the wasps as prospective biological control agents. Our study compared the cold tolerance of geographically-distinct populations of two species of Asian parasitoid wasps that attack the stink bug. We determined the freezing point and lower lethal temperature for each wasp population and found that populations of both species froze and survived at colder temperatures than those reported for the stink bug. We also found that the cold tolerance of the wasps is inherent and does not depend on local environmental conditions to induce the tolerance.

Technical Abstract: Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is native to Asia and has invaded the USA, including the north central states. It is a pest of over 100 species of plants and is also a nuisance household invader. The ability of native arthropods to suppress populations of H. halys has been variable. Therefore, exploration was conducted in Asia to identify potential classical biological control agents for this pest. Trissolcus spp. (Hymenoptera: Scelionidae) have been identified parasitizing H. halys eggs in Asia and are being evaluated for potential release against H. halys in the United States. Since H. halys has invaded regions which experience sub-zero winter temperatures, cold tolerance is one important aspect for evaluation of the Trissolcus spp. as prospective biological control agents. Considering that T. japonicus has been recently detected in the wild in the United States, there is an urgent need to determine whether T. japonicus can survive cold winter temperatures. Our study compared the cold tolerance of geographically-distinct populations of T. japonicus and T. cultratus in order to assess relative suitability of the populations for release as biological control agents. We used thermocouple thermometry to determine the supercooling point and lower lethal temperature after brief exposure to cold temperature for each population. In addition, we subjected adult T. japonicus to a short photoperiod and low temperature regime which induces reproductive diapause in H. halys in order to observe whether these conditions induce a change in cold tolerance in the parasitoid. We found that populations of both species froze and survived at colder temperatures than those reported for H. halys. In addition, there were no ecologically relevant differences in the temperature at which freezing or survival occurred among populations of either species, indicating that the populations are equally cold tolerant and suitable for introduction. Finally, T. japonicus does not acclimate by increasing its cold tolerance in response to conditions that induce reproductive diapause in H. halys, suggesting that the above mentioned measures of cold tolerance are ecologically relevant.