Survival of adults and development stages of Sarcoptes scabiei var. canis when off the host.

All life-stages of Sarcoptes scabiei var. canis survive in the hosts' environment for several days to several weeks depending on r.h. and temperature. Survival of larvae was comparable to males; survival of nymphs was comparable to females. Females and nymphs generally survived longer than larvae and males. Low temperature (10-15 degrees) and high r.h. prolonged survival of all life stages. At 10-15 degrees C, females and nymphs survived 1-3 weeks at 97% r.h., 1-2 weeks at 75% r.h. and 5-8 days at 45% r.h. At 20-25 degrees C, survival was significantly reduced but all life-stages survived at least 2 days at 25% r.h. and 5-6 days at 75-100% r.h. Long survival off the host coupled with host-seeking behavior of these mites make it likely that environmental contamination is a source of scabies in domestic and wild mammals, and in humans.