ABSTRACT
The influence of temperature on the development and embryonation of Ascaris suum eggs was studied using coarse sand medium in an environmental chamber with 50% humidity. The time required for development and embryonation of eggs was examined under 3 different temperature conditions, 5degrees C, 25degrees C, and 35degrees C. A. suum eggs did not develop over 1 month at the temperature of 5degrees C. However, other temperature conditions, 25degrees C and 35degrees C, induced egg development to the 8-cell-stage at days 5-6 after incubation. All eggs examined developed to the 8-cell stage at day 6 after incubation in the sand medium at 25degrees C. The higher temperature, 35degrees C, slightly accelerated the A. suum egg development compared to 25degrees C, and the development to the 8-cell stage occurred within day 5 after incubation. The formation of larvae in A. suum eggs at temperatures of 35degrees C and 25degrees C appeared at days 17 and 19 after incubation, respectively. These findings show that 35degrees C condition shortens the time for the development of A. suum eggs to the 8-cell-stage in comparison to 25degrees C, and suggest the possibility of accelerated transmission of this parasite, resulting from global warming and ecosystem changes.