Control of Common Vole (Microtus arvalis) in Alfalfa Crops Using Reduced Content of Anticoagulants

Abstract

The common vole, Microtus arvalis, which is prone to cyclic overpopulation, poses a significant threat to sustainable alfalfa production by either chewing shoots periodically or gnawing and damaging roots permanently. In areas with established vole colonies, the density of alfalfa plants was shown to decrease 55.3–63.4%. Simultaneously, the number of alfalfa shoots decreased by 60.9–71.7%. These experiments were conducted in compliance with an EPPO standard method in alfalfa fields at three geographically remote sites. The experiment tested the efficacy of the most widely used acute rodenticide zinc phosphide (2%), and anticoagulants applied at significantly reduced doses of active ingredients, i.e., bromadiolone (25 ppm) and brodifacoum (25 ppm), as well as a combination of these active ingredients at a low concentration (10 + 10 ppm). Three weeks after treatment, zinc phosphide and brodifacoum achieved the highest average efficacy, at 98.5% and 92.05%, respectively, while the average efficacy of the anticoagulant combination and bromadiolone was 87.2% and 75.5%, respectively. The achieved efficacy of baits based on brodifacoum and the combination of brodifacoum and bromadiolone in controlling common voles indicates their possible utilization in the field. Baits with 25 ppm of brodifacoum and the combination of bromadiolone and brodifacoum (10 + 10 ppm) showed satisfactory results and their introduction could significantly improve pest management programs for rodent control. At the same time, the use of anticoagulant rodenticides with reduced contents of active ingredients would significantly reduce their exposure to non-target animals, especially predators and vultures. By further improving the palatability of tested baits for target rodent species, their efficacy and safety of application would be significantly improved.

Analysis of some trends of the pharmaceutical market of rodenticides in Ukraine and the peculiarities of their use for deratization

“…Розрізняють родентициди гострої та хронічної дії. Jokic & Blazic (2022) порівнювали ефективність найпоширенішого гострого родентициду фосфіду цинку (2 %) та антикоагулянтів у значно знижених дозах діючих речовин (бромадіолону (25 ppm), бродифакуму (25 ppm) та їх комбінації у низькій концентрації (10 + 10 ppm). Найвища середня ефективність спостерігалася через 3 тижні, зокрема за застосування фосфіду цинку та бродифакуму 98,5 % та 92,05 % відповідно, за комбінації антикоагулянтів та бромадіолону -87,2 % і 75,5 % відповідно.…”

Management of the Common Vole in the Czech Lands: Historical and Current Perspectives

“…Because of their persistency in the environment and non-negligible risk of primary and secondary nontarget intoxication (e.g., [123,124]), anticoagulants have been restricted for plant-protection application over time. Currently, although some of these active substances are still approved for use against field rodents (common voles) in the EU and other European countries (e.g., Serbia [125][126][127]), most national authorities have banned the use of anticoagulant products for these purposes [6].…”

Background food influences rate of encounter and efficacy of rodenticides in wild house mice

“…2002; Jacob et al . 2010; Jokić and Blažić 2022) meaning wild mice have to locate the toxic grains in the complex crop environment during foraging activity where non-toxic grains may be abundant. In this situation, we might expect that the probability of an animal encountering and consuming a toxic grain bait will depend on the availability of the similar background food, either maturing seeds/grain on the crop or as grain on the ground due to pre- and post-harvest loss.…”

“…Toxic baits, such as rodenticides, are often coated on wheat grains (a familiar food type for granivorous rodent pests such as house mice and voles) for use in agricultural settings. The toxic grains are distributed by air or ground onto crops including cereals, canola, lentils, and alfalfa Jacob et al 2010;Jokić and Blažić 2022) meaning wild mice have to locate the toxic grains in the complex crop environment during foraging activity where non-toxic grains may be abundant. In this situation, we might expect that the probability of an animal encountering and consuming a toxic grain bait will depend on the availability of the similar background food, either maturing seeds/grain on the crop or as grain on the ground due to pre-and post-harvest loss.…”