THE EFFECTS OF TEMPERATURE ON THE SURVIVAL AND DEVELOPMENT OF THE FREE-LIVING STAGES OF TRICHOSTRONGYLUS RETORTAEFORMIS ZEDER (NEMATODA)

Abstract

The effects of temperature on the survival and development of the free-living stages of Trichostrongylus retortaeformis have been studied using agar cultures inoculated with pure cultures of Escherichia coli. The ova hatched and infective larvae developed at temperatures ranging from 5 °C to 30 °C, but 35 °C was lethal in 24 hours. The time of development of the larvae to the infective stage was inversely proportional to the ambient temperature between the limits of 10 °C and 30 °C. The longevity in water of third-stage larvae previously cultured at 20 °C, 25 °C, and 30 °C was studied at temperatures ranging from 5 °C to 40 °C.