Vertebrate Pest Conference Proceedings collection

 

Title

EFFICACY DATA FOR REGISTRATION OF STRYCHNINE GRAIN BAITS TO CONTROL POCKET GOPHERS (Thomomys spp.)

Document Type

Article

Date of this Version

March 1990

Laboratory tests, field telemetry trials, and actual use field efficacy evaluations showed that a 0.5% strychnine alkaloid steam-rolled oat-groat hand-bait formulation (EPA Reg. No. 56228-20) with molasses, salt, glycerine, and soda was effective in controlling northern pocket gophers (Thomomys talpoides). Baits retaining at least 0.5% strychnine (w/w) were as effective (>95% control) as baits with 0.75% and 1.0% strychnine in field telemetry hand-baiting trials as well as operational hand-baiting and burrow-builder baiting field tests in forest habitat. Data indicated that the 0.5% strychnine hand bait (molasses formulation) should be reregistered and would be a good substitute for the 0.5% strychnine-Rhoplex bait (EPA Reg. No. 56228- 12) currently registered for burrow builder use for pocket gopher control. Both the retention of strychnine on bait, and use of a highly palatable top quality bait carrier were two important factors affecting efficacy of the bait.