STUDIES ON THE CONTROL OF PLAGUE IN THE WESTERN UNITED-STATES - LABORATORY TRIALS OF 6 INSECTICIDE DUST FORMULATIONS APPLIED TO SOIL FOR THE CONTROL OF THE PLAGUE VECTOR OROPSYLLA-MONTANA (SIPHONAPTERA, CERATOPHYLLIDAE)

In this study, six insecticide dust formulations were laboratory-tested in soil mixtures ranging in concentration from 40 to 1,280 parts per million (ppm) against a proven vector of bubonic plague, Oropsylla montana (Baker). Pulicidal effects of the six insecticides, which included three organophosphates, two carbamates, and a pyrethroid, were compared by LD50 values at both ambient and 75% RH. Permethrin (Pyraperm 455 dust), a pyrethroid with a LD50 < 40 ppm, demonstrated the most effective pulicidal action for the 13-wk trial period, followed in order by chlorpyrifos, bendiocarb, propetamphos, diazinon, and carbaryl.