The author studied on the bionomics of Oriental moth. Cnidocampa flavescens WALKER, damaging to the persimmon tree n the southern part of Korea from 1964 to 1965. The results can be summarized as follows, 1. Emergence peak period of Oriental moth was mid-June in Taegu district and eggs are deposited on the opposite side of persimmon tree leaf. Specially most of eggs are deposited on the terminal part of opposite side and peak period s also mid-June. 2. Hatched Percentage of eggs was in 1964 while in 1965 at the rearing room. Mean egg Period was in 1964 while days in 1965. Thus during two years, the egg period was about 6 days. 3. In the growth ratio of Oriental moth fed on various host plants persimmon tree, Acer negund, Hazel-wood and Platanus, the best growth ratio was shown on the leaf of Hazel-wood from 1st till 3rd instar, but, on the contrary, persimmon tree was the best from 4th till the last instar. The growth ratio of head width was also the same tendency as the body length above mentioned. Individuals fed on the leaf of platanus were dead after 20 days. 4. Oriental moth has one generation a year and molts 6 times. The first molting occurred in 5 hours after hatched, and the other moltings were done at f days intervals. After 3 days since the last molting, larvae made the non for over-winter in it. 5. As the bristles on the process of larval body are different from each position and instar, judgement of instars are possible by the counting of bristles on the body according to the Table 8. Specially the bristle of L. 2., D. 2, 3 ,8. 10. and L. 1, 3, 4, 5, 6, 7, are perfectly different from each instar. From these bristles, instars can be recognized easily. 6. Pupation of larvae in the over-wintered cocoon on the stem of persimmon tree was done in mid-May and continued will early June when emergence will take place. 7. Mean number of eggs in the ovary was

Many of the chlorophenol derivatives are widely used as insecticides, herbicides and plant growth regulators. The function and use of these chemicals would be different according to the number of chlorine and their chemical structures. It was reported in this article that 1) Bis(trichlorophenoxy) ethane was synthesized with 2 mol-trichlorophenol and 1 moi-dibromoethane in 2 moi-Sodium hydroxide alcohol solution, and 3) the insecticidal activity of Bis(trichlorophenoxy) ethane was compared with Phenkapton, Tedion V-18, BHC, and DDT, on Citrus red mite, Bombix mori (Silk worm), and Daikon leaf beetle(Phaedon brassicae) 3) The toxicity of Bis(2, 4, 5-trichlorophenoxy) ethane and Bis(2, 4, 5-trichlorophenoxy) ethane was studied on mice. The following results were obtained. 1) Yield of Bis(2, 4, 5-trichlorophenoxy) ethane, , m.p. , and yield of Bis(2,4, 6-trichlorophenoxy) ethane, , m.p. . 2) Insecticidal activity of Bis(2, 4, 5-trichlorophenoxy) ethane to Citrus red mite is stronger than that of Tedion V-18, and weaker than that of Phenkapton. 3) Insecticidal activity of Bis(2, 4, 5-trichlorophenoxy) ethane to Bombix mori is weaker than those of BHC and DDT. 4) Insecticidal activity of Bis(2. 4, 5-trichlorophenoxy) ethane to Daikon leaf beetle proved to be ineffective. 5) Five rams of Bis(2, 4, 5-trichlorophenoxy) ethane and Bis(2, 4, 6-trichlorophenoxy) ethane pet kg of body weight respectively were given to mice orally, and none of the mouse was killed by it after a period of 72 hours. Therefore it seems that there is almost no toxicity.

• 沈載昱