By Neal Wallace
Reading Time: 2 minutes
A new pest control compound being developed by a Canterbury University scientist sterilises pests by inducing the early onset of menopause.
Rudi Marquez-Mazlin, a professor at the School of Physical and Chemical Sciences, said the base compound in his product, dubbed Ratbegone, is delivered by bait and acts only on females, which become sterile.
The secret compound acts on specific traits in the gut of target species, with the initial focus on rats and possums.
The active ingredient in Ratbegone was originally discovered by chance when Marquez-Mazlin was involved in cancer research in Scotland.
He was giving it to rats that were being bred for the project, and found they were inadvertently becoming sterile.
Because it was irrelevant to his cancer research, the compound was set aside until Marquez-Mazlin moved to Christchurch.
鈥淚t was a case of unintended consequences, having a product from an earlier project that has turned out to be quite useful.鈥
Hunter friends told him about 1080, the biodegradable poison primarily used for controlling introduced predators. While appreciating its role, he knew he potentially had a better, more humane solution.
Its development has reached a point where Marquez-Mazlin hopes to start field trials by Christmas.
鈥淲e鈥檙e really confident that it will help, that it will stop fertility and create sterilisation in possums and rats.鈥
Operating on the specific metabolisable gut environment of targeted species, it is innocuous to humans, ruminants, birds and fish, even if it is consumed.
Possums and rats find it appealing to eat.
It will be delivered via bait and Marquez-Mazlin said the uneaten compound quickly decomposes in the natural environment.
In trials, none of the rats treated with high doses of Ratbegone could become pregnant. Some of those given lower doses had offspring, but all died within 12 hours.
Marquez-Mazlin attributed those deaths to developmental issues during pregnancy caused by the compound.
Other than being unable to get pregnant, treated animals do not show any side effects and live out their lives as usual.
鈥淭hey display normal behaviour. There are no changes in their demeanour.鈥
Disrupting fertility to control pest species has been explored previously but the approaches relied on what he called over-complicated delivery vectors and on toxic and non-sustainable biological or chemically active ingredients.
Marquez-Mazlin said next he will turn his attention to developing a compound for wild cats, stoats and ferrets.
Most domestic cats are sterilised by their owners so the impact will be minimal, but reducing the feral cat, ferret and stoat population will have a significant benefits for biodiversity.
The challenge with using wild animals in research is the lack of knowledge of their history or background and difficulty getting them to reproduce in captivity.