Ethyl formate dilution in carbon dioxide for fumigation control of the brown marmorated stinkbug Halyomorpha halys, Stål (Hemipitera: Pentatomidae)

Authors: Kawagoe, James; Abrams, Adelaine; LOURIE, A - University Of California, Davis; Walse, Spencer

Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/18/2022
Publication Date: 4/18/2022
Citation: Kawagoe, J.C., Abrams, A.E., Lourie, A.P., Walse, S.S. 2022. Ethyl formate dilution in carbon dioxide for fumigation control of the brown marmorated stinkbug Halyomorpha halys, Stål (Hemipitera: Pentatomidae). Pest Management Science. 78(7):3090-3097. https://doi.org/10.1002/ps.6935.
DOI: https://doi.org/10.1002/ps.6935

Interpretive Summary: Brown marmorated stinkbug (BMSB) is a recent invasive pest that causes considerable damage to certain crops grown in Eastern USA. Moreover, this pest causes urban disturbance in its preparation for overwintering, as it forms large groups in sheltered areas, including houses, garages, and vehicles. The US exports ~ 1 billion USD annually in vehicles to Australia and New Zealand, and these countries require that BMSB is controlled in these shipments. Postharvest fumigation provides a biological safeguard against insect and microbiological pests and, in many scenarios, is the only available tool for government and industry to guarantee pest-free security. This work addresses the need to develop a postharvest fumigation treatment to control this pest in vehicles and shipping containers, particularly US exports when undergoing on-arrival inspection in Australia and New Zealand the results describe how the fumigant, ethyl formate, can be used to control BMSB. Moreover, this research provides an alternative to methyl bromide fumigation, a critical need for the United States per the international regulatory requirements of the Montreal Protocol.

Technical Abstract: Brown marmorated stink bug (BMSB), Halyomorpha halys (Stål), is an insect pest of concern to certain countries that import vehicles and shipping containers from the USA. Adult BMSB contained in gas-permeable cages were fumigated with ethyl formate (EF) in laboratory-scale chambers at 10.0 ± 0.5 °C (mean ±2s), across a range of applied doses and treatment durations. EF exposures were calculated as concentration (C) × time (t) products (Ct), exposure-mortality regressions were modeled, and the relative contribution of C versus t toward treatment efficacy was evaluated at air temperature = 10.0 ± 0.5 °C (mean ±2s). The induction of diapause, to simulate overwintering physiology, resulted in a 2.8-fold increase in tolerance of adults toward EF for 8- and 12-h fumigation durations respectively, but tolerance was unchanged for the 4-h duration. Results of this study identify how the applied dose and/or treatment duration can be modulated (i.e., tuned) to ensure adequate toxicological efficacy toward adult BMSB following postharvest fumigation with EF, commercially formulated as a 16.7 wt.% EF blend in carbon dioxide. A fumigation schedule for operational implementation was proposed based on the assimilation of technical results with regulatory, environmental, and logistical considerations.