Abstract
The first stage larvae of Philometroides carassii(ISHII, 1931) NAKAJIMA et EGUSA, 1977 which were released from the gravid females had very delicate bodies with adhesive sharp pointed tails. They extended and constracted actively in live but were always bent into a siclke-shape when died. They survived in water for seven days at 15°C, five days at 25°C, four days at 2-5°C and several hours at 37°C.
Drying, freezing, heating and irradiating of ultraviolet rays were very effective to kill them. The larvae were killed instantly when water was evapolated or freezed. Heated larvae died within 18-20 minutes at 40°C, 8-9 minutes at 45°C and a minute at 50°C, and larvae were killed, within 6-8 minutes by irradiation of 2, 000μW/cm2, 14-16 minutes by 1, 000μW/cm2, 43-45 minutes by 400μW/cm2. Larvicidal effect of several disinfectants and anthelmintics were examined in vitro. One ppm of Acrinol, Benzetonium chloride and Sodium dichloroisocyanurate and 10 ppm of Bithionol and Dithiazanine iodide was demonstrated to kill larvae within three days.
