Effects of sublethal fumigation with phosphine on the reproductive capacity of Liposcelis entomophila (End.) (Psocoptera: Liposcelididae)

AbstractThe goal of our study was to determine if phosphine exposure changed the fecundity of the surviving Liposcelis entomophila, and the fitness of resulting offspring. Two strains of L. entomophila, were tested. One (F0) that had not been exposed to phosphine in the laboratory, and a second (F4) that had been exposed to the LC50 dose of phosphine for 4 successive generations. The daily egg production, rate of growth, hatching rate, sex ratio, and adult emergence rate were measured after exposures to phosphine at the LC20 and LC50 doses. LC20 fumigation did not affect peak oviposition and fumigation at LC50 dose delayed peak oviposition peak in F0. Females fumigated at LC20 dose had higher fecundity in the first oviposition peaks from 3rd day. The accumulated egg production of F4 fumigated at LC20 and LC50 was significantly higher than that of F0 in the first and second weeks. All the results indicated that long term fumigation with sublethal LC20 could stimulate the surviving females to lay more eggs....