The effects of time and temperature of storage on the infectivity of third-stage larvae of Heligmosomoides polygyrus (= Nematospiroides dubius). 1. Effects on the development to the adult stage in mice.

The relationship between storage time and temperature on the infectivity of the third-stage larvae of Heligmosomoides polygyrus (= Nematospiroides dubius) was examined. Results showed that third-stage larvae lose their infectivity when they aged. This loss was steeper at 22 degrees C than at 4 degrees C. Results obtained at 15 degrees C seemed to be intermediate. Data also demonstrated that a maturation period was required for maximum infectivity. A longer maturation period was observed at + 4 degrees C than at 22 degrees C and the maximum was maintained for longer at 4 degrees C.