Go big or go home: A model-based assessment of general strategies to slow the spread of forest pests via infested firewood

Abstract

Invasive pests, such as emerald ash borer or Asian longhorn beetle, have been responsible for unprecedented ecological and economic damage in eastern North America. These and other wood-boring invasive insects can spread to new areas through human transport of untreated firewood. Behaviour, such as transport of firewood, is affected not only by immediate material benefits and costs, but also by social forces. Potential approaches to reduce the spread of wood-boring pests through firewood include raising awareness of the problem and increasing the social costs of the damages incurred by transporting firewood. In order to evaluate the efficacy of these measures, we create a coupled social-ecological model of firewood transport, pest spread, and social dynamics, on a geographical network of camper travel between recreational destinations. We also evaluate interventions aimed to slow the spread of invasive pests with untreated firewood, such as inspections at checkpoints to stop the movement of transported firewood and quarantine of high-risk locations. We find that public information and awareness programs can be effective only if the rate of spread of the pest between and within forested areas is slow. Direct intervention via inspections at checkpoints can only be successful if a high proportion of the infested firewood is intercepted. Patch quarantine is only effective if sufficiently many locations can be included in the quarantine and if the quarantine begins early. Our results indicate that the current, relatively low levels of public outreach activities and lack of adequate funding are likely to render inspections, quarantine and public outreach efforts ineffective.

Optimal emerald ash borer (Agrilus planipennis) control across the United States

“…Despite the uncertainties surrounding biological control, relying on the past quarantine measures and adherence levels did not limit EAB expansion to the extent desired by state and federal agencies. Jentsch et al (2020) found that only extremely high management effectiveness would reduce EAB spread rates with recreational travelers, whether this took the form of a high compliance, large quarantine zone, or high rates of firewood interception at highway checkpoints. The authors pointed to low levels of public outreach and low quarantine budgets as the source of current underperforming control measures.…”

“…Conventional strategies based on these models tend to target the pest invasion front (or leading edge, (Sharov et al, 2002)), without considering the ability of major cities to act as hubs of long-distance pest transport via the road network (Chivers & Leung, 2012;Hudgins et al, 2017;Yemshabov et al, 2015). While these strategies have been demonstrably effective for species whose landscape-scale spread is dominated by natural dispersal (Sharov et al, 2002), EAB spread is known to be driven by anthropogenic transport (Jentsch et al, 2020;Ward et al, 2020), and several models exist that account for human population density as an attractor of EAB propagules (Ward et al, 2020;. Indeed, from 2012 to 2021, the domestic quarantine effort undertaken by the US Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) to control EAB only regulated outbound movement from a fairly contiguous suite of infested areas (McCullough, 2020;APHIS, 2018;.…”

Modelling coupled human–environment complexity for the future of the biosphere: strengths, gaps and promising directions

“…Social media data has also been used to reconstruct user networks based on interactions and examine homophily within these networks [ 148 ], which can inform CHES network models. Empirical trade and transport networks can provide important insights into the spatial CHES coupling as well as human metapopulation models [ 151 ], having already been applied to CHES models for invasive species [ 152 , 153 ] and land use via global food trade [ 92 , 154 ].…”

Optimal emerald ash borer (Agrilus planipennis) control across the United States

“…Despite the uncertainties surrounding biological control, relying on the past quarantine measures and adherence levels has been insufficient to limit EAB expansion. Jentsch et al [50] found that only extremely high management effectiveness would reduce EAB spread rates with recreational travelers, whether this took the form of a high compliance, large quarantine zone, or high rates of firewood interception at highway checkpoints. The authors pointed to low levels of public outreach and low quarantine budgets as the source of current ineffective control measures.…”