An Overview of Recent Ground Squirrel Bait Registration Research Supported By the California Bait Surcharge Program

The California Department of Food and Agriculture Rodent Bait Surcharge Program is actively funding studies to develop and register safe, effective and practical ground squirrel baits. Under this program, Genesis Laboratories has conducted eight studies since 1994 designed to fulfill registration requirements for existing baits and to develop new baits. Areas of research include field efficacy, application methods and rates, non-target hazards, and residue loads in animal and plant tissues. Existing diphacinone and chlorophacinone treated oat groat baits have proven to be effective in controlling the California ground squirrel. Applications of these baits to alfalfa crops did not result in quantifiable residue loads. Preliminary studies found bromethalin treated oats may be effective against the California ground squirrel. Chlorophacinone treated cabbage bait was not effective against Belding's ground squirrel.