Smarter Pest Control Tools with Low-Residue and Humane Toxins

Abstract

Considerable effort has been put into retaining older vertebrate pesticides and improving the effectiveness and safety of pest control. Nevertheless, conventional control targeting single species is sometimes still associated with non-target impacts, bioaccumulation of toxins, fluctuating pest numbers, and unexpected ecological consequences. To counter this, we are developing multi-species bait types for sustained field use that are more palatable to vertebrate pest species. We are incorporating "low-residue" toxicants, namely zinc phosphide, cholecalciferol, diphacinone, and a combination of coumatetralyl and cholecalciferol, in new bait formulations. Looking to the future, we seek to increasingly combine "low-residue" characteristics with humaneness. New humane formulations of cyanide are being developed for a variety of pest species, and para-aminopropiophenone is being introduced for predator control in New Zealand as part of the product development and registration pipeline.

Bait aggregation to reduce cost and toxin use in aerial 1080 baiting of small mammal pests in New Zealand

“…In spite of a growing body of scientific evidence showing that the use of aerial 1080 has a net positive effect on native flora and fauna, and is critical to control possums for preventing the spread of Tb,5, 6 some members of the public are opposed to its widescale use. The main issues of concern are by‐kill of indigenous wildlife and recreational hunting species,7 residual toxicity in the environment8 and secondary poisoning of non‐target domestic species 9…”

A review of existing and potential New World and Australasian vertebrate pesticides with a rationale for linking use patterns to registration requirements

“…In the USA its use was reviewed and supported by additional research in the 1990s (US EPA 1998). Whilst in common use in Australia for mouse plagues (Brown et al 2002) it has not previously been used in New Zealand but is currently undergoing registration as an alternative to 1080 for possum and rodent control (Eason et al 2008). It found favour in the USA, Australia and New Zealand because of its lack of persistence and comparatively low risk of secondary poisoning following its field use when compared with strychnine or 1080.…”

“…There is some debate about the humaneness of 1080 (Sherley 2007). Whilst it is not as humane as PAPP (see later) or cyanide (Eason et al 2008), it is more humane than many other actives, including strychnine or anticoagulant poisons. And because of its importance for conservation and agriculture it will be retained in Australia and New Zealand until better alternatives are developed (ERMA 2007; APVMA 2008).…”

Alternatives to brodifacoum and 1080 for possum and rodent control—how and why?

“…In sub-lethally poisoned animals, elimination processes for cyanide and zinc phosphide are likely to be much quicker, with elimination half-life values likely to be less than 12 hours (Eason et al 2008) (Table 1). Compound 1080 is rapidly absorbed into the blood and distributed through the soft tissues and organs.…”

“…Phosphine is exhaled from the lungs, and other metabolites, including phosphoric acid and phosphate, are excreted in urine and faeces (WHO 1976). In Table 1 Summary of vertebrate pesticide half-lives and expectation for persistence of residues in sub-lethally exposed target or non-target species (adapted from Eason et al 2008).…”