|Williams, A - University Of Maryland|
|Hager, A - University Of Illinois|
|Tranel, P - University Of Illinois|
Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/25/2018
Publication Date: N/A
Interpretive Summary: Resistance of pests and pathogens to pesticides and antibiotics is an increasing global problem. The emergence and spread of resistance is a common-pool resource problem, where susceptibility to treatment of highly mobile target organisms is a shared resource. However, research has mostly overlooked the common-pool resource nature of resistance. Using herbicide resistance as a model, we developed a discrete-time landscape-scale simulation to: 1) investigate the impacts of farm-scale weed management strategies on the rate of herbicide resistance emergence, and 2) address the common-pool resource nature of herbicide resistance by aggregating management strategies at different spatial scales. Our findings highlight the potential importance of large-scale cooperative management strategies for combating herbicide resistance, and offer insight for confronting resistance-based common-pool resource problems in analogous systems.
Technical Abstract: Common-pool resources (CPRs) have long presented society with challenging environmental, social and policy dilemmas. CPRs are those for which 1) user access is difficult to exclude or limit, and 2) the resource is finite, i.e., once a quantity of the resource has been extracted, it is no longer available to others. Antibiotic and pesticide resistance represent pressing instances of CPR challenges, where the susceptibility to treatment of highly mobile target organisms is a shared resource. However, research has largely overlooked the CPR nature of resistance evolution, and progress on delaying the emergence and spread of resistant pests and pathogens has been limited. Using herbicide resistance as a model, we developed a discrete-time landscape-scale simulation to: 1) investigate the impacts of farm-scale weed management strategies on the rate of herbicide resistance emergence, and 2) address the common-pool resource nature of herbicide resistance by aggregating management strategies at different spatial scales. Our results reveal that confronting resistance-based CPR problems requires implementation of effective temporal scale management strategies over large spatial scales. Recent studies of antibiotic and herbicide resistance have observed greater efficacy of mixture strategies compared with rotation strategies for reducing resistance, because mixtures apply more heterogeneous selection pressures than rotations on a temporal scale relevant to resistance evolution in their respective target organisms. While our results support these findings, they highlight the importance of accounting for the mobility of target organisms, and thus their ability to disperse between management units. Where susceptibility of target organisms to an active ingredient, e.g., an antibiotic or herbicide, is a resource shared by all operators in a locality, and where target organisms are highly mobile, judicious management by a single operator will make little impact on resistance emergence in the broader landscape. Thus, the individual operator will still suffer the consequences of resistance as it spreads across management units. Our model demonstrates that cooperative management between operators of individual management units has potential to confront this problem and extend the lifespan of these critical CPRs.