The common vole (Microtus arvalis) is a major rodent pest in European agroecosystems, causing periodic outbreaks that result in substantial crop losses and pose potential public health risks. Rodenticides remain the most widely used method for population control; however, current phosphide-based formulations present challenges related to environmental safety and non-target species exposure. This study evaluated the palatability and efficacy of novel alpha-chloralose bait variations for common voles. Laboratory trials were conducted in three phases: (i) screening of non-toxic cereal carriers to identify highly palatable formulations, (ii) comparison of alpha-chloralose from two manufacturers to select the optimal active ingredient, and (iii) enhancement of palatability and attractiveness through incorporation of several attractants. Choice and no-choice feeding tests revealed that alpha-chloralose efficacy is strongly influenced by bait formulation and pellet size, with small pellets (3 mm) ensuring that a single pellet provides a lethal dose for an individual vole. In laboratory conditions, the highest mortality rate, 50% (n = 12), was observed in the bait containing the milkvetch attractant. Subsequent small-scale field trials demonstrated that this bait achieved efficacy (85%) comparable to commercial zinc phosphide bait (90%). The study confirms that alpha-chloralose, when incorporated into optimized bait matrices, could be a viable rodenticide that combines rapid, humane action with a reduced risk of secondary poisoning, making it a promising tool for integrated pest management strategies.
Aulický et al. (Mon,) studied this question.