As the debate over rodenticide palatability versus toxicity continues, Bayers Alan Morris makes a strong case for viewing palatability as a higher priority consideration, under genuine field conditions.
Rodenticide palatability is top priority
“Many manufacturers quote technical comparisons between today’s modern, advanced rodenticides,” says Bayer’s Alan Morris. “But, it is important to understand that the figures that are used are from laboratory trials, and the actual efficacy of products can vary dramatically when used in the field.
“It is widely known that the success and efficacy of modern rodent control is down to a combination of palatability and toxicity,” he continues, noting the number of ways to compare rodenticides.
“The level of active ingredient, its activity against rodents (LD50), toxicity to non-target organisms (e.g. pets, birds), and location in which it will be used are all factors. However, until it can be established that bait uptake can be achieved, the factors such as the LD50 statistic, potency rating and speed of control are less important.
“When considering the rodenticide itself, it’s absolutely essential that it will actually be eaten by the target pest,” he says.
Alan adds that high toxicity brings additional risks. “The more toxic a bait is, the less of it is required to control the target species. But the problem with having a more toxic active ingredient is the risk to non-target species, which has implications for product stewardship and secondary poisoning.”
He explains that a rodent will continue to feed on bait for some time after it has consumed a lethal dose, and this means that the levels of active ingredient builds within its body until the level could be sufficient to result in secondary poisoning of a non-target species.
Palatability has therefore been the key priority in the development of Rodilon, and Bayer has invested significantly in developing four formulations.
“It was clear, due to the differences in feeding habits and general behaviour of rats and mice, that tailored bait formulations were a must for Rodilon,” explains Alan. “It’s important to offer treatment flexibility and match the bait formulation to the type of feed sources that are dominant within the target treatment area.
“So it’s imperative to choose a bait formulation suitable to the treatment site. For example, baiting in a grain store would be an obvious sign to use a grain based bait – a square block formulation would instantly be seen as an oddity. And it’s these type of considerations that have influenced the development of the various bait formulations in the new Rodilon range, notes Alan.