The development of the free-living stages of Strongyloides papillosus. I. Effect of temperature on the development of the heterogonic and homogonic nematodes in faecal culture.

Temperature had a significant effect on the proportion of free-living females and infective larvae of Strongyloides papillosus developing from faecal culture. The number of free-living males recovered from cultures incubated at 20 degrees C and 30 degrees C was fairly constant. However, females were most numerous at 30 degrees C and infective larvae at 20 degrees C, with the sum of the two approximately the same at both temperatures. This indicates that infective larvae and females are developing from genetically identical eggs. The critical period by which the course of development has been fixed occurs between 4 and 5 h at 30 degrees C, but between 4 and 24 h at 20 degrees C.