Reducing sodium fluoroacetate and fluoroacetamide concentrations in field rodent baits.

Laboratory trials were carried out in order to establish the minimum active ingredient (a.i.) concentration of sodium fluoroacetate (1080) and of fluoroacetamide (1081) in wheat baits employed against Microtus guentheri, the Levant vole, and Meriones tristrami, Tristram's jird, without interfering with the toxicants' efficacy. Using a mixture of treated and untreated grain enabled a greater reduction in the a.i. concentration compared with that which could be achieved when all the grains offered contained a lower a.i. concentration of the toxicants. For M. tristrami the lowest efficient final a.i. concentration in the bait was 0.0125% for 1080 mixed bait (1:4 mixture of 0.05% poison grains with filler grains) and 0.01% for 1081 mixed bait (1:10 mixture of 0.1% poison grains with filler grains); and for M. guentheri - 0.005% mixed bait of 1080 or 1081 (1:10 mixture of 0.05% poison grains with filler grains). This leads to a reduction of the hazards involved in the use of prepared baits of these toxicants in the field. [ABSTRACT FROM AUTHOR]