A Prototype Insecticide Applicator and Quality Control Monitoring for Plague Management on Prairie Dog Colonies

Abstract

ABSTRACTPlague causes declines in native wildlife populations including those of prairie dogs (Cynomys sp.) and endangered black‐footed ferrets (Mustela nigripes). The infusion of insecticides into prairie dog burrows is a vector control method regularly used to suppress or prevent plague transmission by fleas. Detailed methods on how insecticide application equipment (dusters) is calibrated or how the quality of application is monitored are not regularly reported. We describe a new prototype duster and compare its performance to commercially available equipment using quality‐control monitoring procedures. We infused 0.05% deltamethrin (dust) into burrows of Gunnison's and black‐tailed prairie dogs (C. gunnisoni, C. ludovicianus) in Colorado in 2014–2017. The prototype and commercial dusters distributed a similar amount of dust ( = 5.39 and 5.29 g/burrow, respectively; t(797) = −0.83, P = 0.4). However, the prototype dusters required less operation time to dispense dust than the commercial dusters ( = 1.0 sec vs. 7.69 sec/burrow; t(481) = 49.2, P ≤ 0.001). If we applied a standard operating time of 5 sec to all commercially available units, 60% (20 of 34) would fail to dispense ≥4 g of dust. The prototype dusters were more consistent in their dust output, with all units (12 of 12) dispensing ≥4 g of dust with an operation time of only 1 sec. Controlled and accurate application of insecticide is difficult to achieve if quality‐control monitoring and equipment calibration are not conducted. The efficacy of vector control is likely only as effective as the quality and precision of the application of the insecticide itself. When evaluating plague management outcomes, it is important to consider if some observed limitations of efficacy are caused by the failure of the management tool or the failure of managers to effectively use the tool. Future work to calibrate the prototype dusters to dispense larger target doses and performance testing with other insecticide formulations is needed. Additional modifications to adapt the prototype dusters for use on ATV‐mounted platforms may increase the utility of the equipment. © 2021 The Wildlife Society.