Use of orally administered chitin inhibitor (lufenuron) to control flea vectors of plague on ground squirrels in California.

The efficacy of orally administered lufenuron, a chitin inhibitor, to control fleas on California ground squirrels, Spermophilus beecheyi (Richardson), was evaluated during a 2-yr study in Santa Barbara County, CA. Results demonstrated that use of a host-targeted feed cube containing lufenuron was effective in significantly reducing the burden of Oropsylla montana (Baker) and Hoplopsyllus anomalus (Baker) fleas on ground squirrels. A flea index that indicated a mean number of fleas per squirrel of 10.0 decreased to 1.3 after 2 treatments in season 1, and to 0.7 and 0.2 after the 3rd and 4th treatments, respectively, in season 2. A cost comparison of this new method compared with a traditional reactive, emergency, insecticide-based plague control program demonstrated a cost reduction of approximately 90%. The results of this study indicated that a lufenuron feed cube was an effective, cost-saving, and proactive technique for controlling fleas on California ground squirrels, and thus reducing the risk of disease transmission in plague endemic regions.