Sensitivity of Developing Hymenolepis diminuta Larvae to High Temperature Stress

Abstract

The purpose of the studies reported here was to determine if differences in sensitivity to high temperature exist at different stages in the larval development of the cestode Hymenolepis diminuta. Voge and Heyneman (1958) have described structural abnormalities which occur in these larvae when grown in confused flour beetles at supraoptimal temperatures of 38.5 and 40? C. Voge and Turner (1956) showed that cysticercoid development of H. diminuta may proceed normally at temperatures as high as 37? C. In all the above studies, larvae were kept at 37? C or higher for their total period of development and growth. It was therefore of interest to establish as precisely as possible: 1) The period of exposure to supraoptimal temperature which would cause abnormal development, 2) The stage or stages during larval development most sensitive to such exposure, 3) The relation between length of exposure during the developmental period and incidence of abnormalities, and 4) The effect, if any, of relatively brief exposure on infectivity of cysticercoids to the final host. Furthermore, it was thought desirable to compare the results obtained from such studies with information available on high temperature sensitivity during development of some free-living invertebrates.