Volatile release, mobility, and mortality of diapausing Halyomorpha halys during simulated shipping movements and temperature changes

Authors: NIXON, LAURA - Lincoln University - New Zealand; Tabb, Amy; Morrison, William - Rob; Rice, Kevin; BROCKERHOFF, ECKEHARD - New Zealand Forest Research Institute; Leskey, Tracy; VAN KOTEN, CHIKAKO - Agresearch; GOLDSON, STEPHEN - Lincoln University - New Zealand; ROSTAS, MICHAEL - Lincoln University - New Zealand

Submitted to: Journal of Pest Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/14/2019
Publication Date: 2/20/2019
Citation: Nixon, L.J., Tabb, A., Morrison III, W.R., Rice, K.B., Brockerhoff, E.G., Leskey, T.C., van Koten, C., Goldson, S., Rostas, M. 2019. Volatile release, mobility, and mortality of diapausing Halyomorpha halys during simulated shipping movements and temperature changes. Journal of Pest Science. Available: https://doi.org/10.1007/s10340-019-01084-x.
DOI: https://doi.org/10.1007/s10340-019-01084-x

Interpretive Summary: The brown marmorated stink bug, Halyomorpha halys, is an agricultural and urban pest that has become widely established as an invasive species of major concern throughout the world. Common shipping lines go from the Eastern US Coast to the southern hemisphere. We simulated the voyage of brown marmorated stink bug on a sea voyage from the northern to southern hemisphere in a cargo container, and evaluated whether there were any tell-tall odors emitted from bugs, examined their mobility during temperature changes, as well as their mortality over the length of such a sea journey. We did not find that stink bugs emit more volatiles when they experience sea-simulated movement compared to stationary individuals, though many more bugs were found moving as temperatures warmed. By the end of the experiment, there was high mortality of stink bugs, likely as a result of high temperatures and moisture conditions. Our work has biosecurity implications for this widespread invasive species, which we discuss.

Technical Abstract: The brown marmorated stink bug, Halyomorpha halys, is an agricultural and urban pest that has become widely established as an invasive species of major concern in the USA and throughout Europe. The insect forms large aggregations before entering diapause, and it is often these aggregations that are found by biosecurity officials conducting inspections of internationally shipped freight. Here, we aimed to gain insights into the potential volatile emissions, mobility, and mortality rates of the insects after undergoing a ship voyage across the equator (i.e., from northern hemisphere winter to southern hemisphere summer). Experiments were performed to simulate the effects on aggregations of diapausing H. halys of two variables associated with trans-Pacific voyages, i.e. ship and container movement and temperature changes within containers. Thus, H. halys aggregations were exposed to simulated shipping movement, using a 6-axis VS-6577G-B Denso robot arm, and emission of defence volatiles were measured repeatedly during the “voyage”. We also simulated temperature changes as they occur during a 26-day voyage from Baltimore, north-east USA, to Auckland, New Zealand, and assessed the effects on the mortality and mobility of the bugs. Aggregations that experienced movement were not found to be any more likely to release volatiles than stationary aggregations, and neither did it affect bug mobility. Temperature changes had a significant effect on mobility. However, towards the end of the temperature simulation, most H. halys had died, probably from a lack of food and moisture. These findings are highly relevant for border biosecurity risk assessment and pathway risk management.