The sarcophagid fauna of Japan was published by Kano et al. (1967) including that of the Ryukyus. They reported 2 subfamilies, 18 genera and 70 species, but besides their report, 2 species, Blaesoxipha filipjevi and Pierretia olsoufjevi, have reported by Kurahashi (1964) and Buei (1965) respectively. In the present paper, the authors described and illustrated 3 new species of sarcophagid flies, Heteronychia nipponensis, Blaesoxipha ampliforceps and Blaesoxipha amamiensis, from the main island of Japan and Amami-oshima Island.

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In this paper manifesting the seasonal prevalence and natural infection of the vector mosquitoes of Japanese encephalitis virus in the Fukuoka area in 1966, the results obtained from Uchihashi and Ae, Kasuya-gun, and Mitsuzawa, Mii-gun, were compared each other and additionally with the result obtained from Kanatake, Fukuoka City, in the same year (Yamamoto et al., 1968b). Furthermore, the correlation between mosquito factors and the size of epidemics was preliminarily discussed. With some exceptions, there was an approximate similarity in time and pattern of mosquito infection among the different study sites. A prior infection of the vector mosquitoes was evidenced at Ae but not at the other study sites. Despite of the fact that the epidemic of Japanese encephalitis was far larger in size in 1966 than in other years, the mosquito infection encountered in 1966 was similar in essential pattern and in the proportion of infected to total populations to those in other years. The annual difference of mosquito infection was recognized only in the time of occurrence. This fact probably suggests that the annual variation in the density of infected populations of the vector mosquitoes was mainly attributable to the difference in time of infection but not to that in infection rate. Thus, the annual variation in the time of mosquito infection would attach a great importance to the epidemiology of Japanese encephalitis.

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Segregation of the siphonal hair types in the type 4-3 population of Culex pipiens molestus was observed from F_1 through F_<10>. The occurrence frequency of the type 4-4 larvae decreased and those of the type 4-3 and 3-3 larvae increased as the selection progressed. However, the occurrence of the type 4-4 larvae will not be expected to reach to zero, even though the selection is continued further. The fertile egg raft ratio, number of larvae produced per egg raft and mortality during larval period under the experimental conditions were observed, which did not show an apparent change during the selection experiment.

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Laboratory observations were carried out with a colony of Norway rat, Rattus norvegicus, on the amount of consumption of various forms and compositions of dry baits to be used as the base of rodenticides. The animals used were a laboratory colony which had been bred and maintained by us from commensal rats. The feeding preference was tested by comparing the amount of consumption of two different kinds of baits set at the same time in a cage, and the position of baits were frequently changed alternatively so as to eliminate the effects of place preference. As the results, it was demonstrated that the rats preferred wheat flour to corn meal; the addition of fish meal at a rate of 1% or less as well as that of rice bran to 5% or less to the bait did not cause significant differences in the amount of food consumption; baits incorporated with 3 to 6% of vegetable oil were highly preferred by the rats, while liquid paraffine had no such effect; the addition of a synthetic sweetener sodium cyclohexylsulfamate also did not enhance the food consumption. As to the forms of the dry baits, cylinder type was preferred to biscuit type, and cylinder type baits of 0.4 to 0.5g in weight was found to be best preferred.

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