Experiments on the Survival and Behaviour of the Itch Mite, Sarcoptes scabiei DeG. var. hominis

(1) Adult female Sarcoptes were killed by 49°C. (120°F.) in 10 minutes and by 47·5°C. (117·5°F.) in 30 minutes.

(2) At 28°C. (82°F.) no Sarcoptes survived for two days and the majority died in 24 hours.

(3) At 13°C. (55°F.) and 90 per cent. R.H. the majority of the mites died within a week, but a few survived longer, even up to 14 days.

(4) At temperatures below 13°C. (55°F.) the mites survived for a shorter time.

(5) Sarcoptes gives no reactions, positive or negative to unidirectional light.

(6) Below 15°C. (59°F.) Sarcoptes is in chill coma. Little movement occurs below 20°C. (68°F.).

(7) In temperature gradient mites seldom, if ever, go below 24°C. (75°F.). They will walk into high temperatures which prove rapidly lethal.