The work here reported concerns Tabanids taken in catches made during the period 1953-55, mainly in Niigata Prefecture, Japan. Tabanidae collected are 5 species of Pangoniinae and 12 species of Tabaninae. Tabanus iyoensis Shiraki has been prevalent along the mountain streams, where the working men are frequently attacked by the swarm of this horse-fly during the summer. On the other hand, T. mandarinus Schiner is very common along the foot of hills and the most violent bloodsucker of cattle. Tabanus rufldens, T. chrysurus and T. sapporoensis have been widely found in the hilly countries, while T. horvathi recorded in the plains only. Biting collections of T. iyoensis have shown that its main biting activity begins before sunset and reaches a distinct peak at dusk, thereafter the number taken diminish rapidly.

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Since the outbreak of Tsutsugamushi disease among the American troops in the fall of 1948, Mt. Fuji Area has called attention of the scientists and a number of works have been made on the trombiculid fauna of this area. In the present paper, the authors present the results of a whole year study on the seasonal and host distributions of the mites at two different stations on the northern slope, where have so far been made under ecological and epidemiological points of view. As the results of the monthly collections from December, 1954 to December, 1955 at Oshino Iriguchi (C-Area) about 900m high and at Kagosaka (D-Area) about 1104m high, a total of 5, 915 larval trombiculid mites classified into 14 species were collected from 193 small mammal hosts belonging to 5 species of rodents or insectivores, as are shown in the tables 2 to 4. The host-parasite relationships are presented in tables 5 and 6, and the monthly distributions of each species are as in figure 2. It should be noted here that trombiculid fauna of areas C and D exhibit remarkable divergencies (Table 5). Species like kit, fuji or mz were found exclusively in C, whereas such species as int, pall, palp and nag were collected mainly in D. The fauna of the latter area was similar to that of northern Japan or of Hokkaido, whereas the former represented the common features to other low-land forest areas of Honshu. The seasonal distributions of each species of Tsutsugamushi were observed by the monthly collection records expressed as Tsutsugamushi index or mean number of the mites found on th host. Nag was found exclusively in the summer, and palp in the winter season : fuji were collected in the seasons through autumn, winter and summer, whereas kit were distributed from spring, summer to winter and int in the long periods except for May and June with its peak in September : jap was definitely a autumn species attaining its maximum in September, and the appearance of mit was observed in later season around December. The host distributions of the mites also exhibited notable differences by species. As the total, Microtus montebelli and Antelicmys smithii or the members of Microtinae harboured more mites than Apodemus speciosus and the parasite index of Apodemus geisha or Urotrichus talpoides was found to be extremely low. Species like palp, int, kit, mz, Gsa or nag were found to show preferences to the former two species, but no essential differences were seen in fuji or mz and in the case of jap higher index were observed on Ap. spec. than in Micr. or Ant. Three of the species, him, mit, Pha were again demonstrated to prefer Urotrichus as their host. The remarkable differences demonstrated here in the areal, seasonal or host distributions of each species of the mites are, however, not simply caused by the influences of a single facter, but should be interpreted as the results of the composition of these and other effects. The matter of chance or error caused by the uneven distributions of the mites and the hosts on the soil surface should also be taken into consideration. In these types of works, a careful analysis of each effects is required before a conclusion drawn.

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Whilst engaged in the rearing of the tea tussock-moth, Euproctis pseudoconspersa Strand, the following facts were observed and appeared to be worth noting : 1. This species breeds twice a year in Japan, but under a constant temperature, 22-25℃, it can be bred successively throughout the year under captivity. 2. Eggs are laid in batches, each contains about 120 eggs. The diameter of the egg 0.6-0.7mm, the duration of the egg development 20-22 days under above mentioned condition. 3. The number of the larval instars is usually 6-7, often 8, 9, or 10. the duration of the larval period was 46 days in average. 4. The prepupal stage takes 2 days, the pupal stage 18-23 days. The male insect pupates and emerges about two or three days prior to that of the female. 5. The length of the survival of the adult insects was 5-7 days : pairing takes place within 24 hours and in an advanced case the oviposition was observed within two days after emergence. 6. The first instar larva has no urticating spicules excepting a few ones transmitted from the egg covering. In the second instar the larva is provided with the spicule bundles on the first and second abdominal segments, each pair is arranged on the subdorsal line. Another bundles appear in the penultimate instar on the eighth segment, and in the ultimate instar there are spicule bundles throughout from the first to the eighth segment, and further each on the lateral lines. The length of an urticating spicule is from 0.03 to 0.207mm, it becomes longer in a later instar. 7. Inside the cocoon there is a brownish circular band at its anterior one third. This band is composed of numerous urticating spicules, and is more distinct of a female insect. The female moth emerges out carrying the spicules on her abdominal tuft hairs. 8. The larvae show a very strong gregarious habit. The length of the larval period as well as the number of the ecdysis seems to be evidently increased by the decrease of the number of the caterpillers fed together. 9. In the final instar the size of the larvae, as measured by the cranium, does not differ regardless the number of the ecdysis.

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As one of the fly-control measures the digging of the overwintering pupae has been practised in several places of Japan. In this preliminary note was given the result of a survey of the fly-pupae and their parasites collected in the city of Tokyo.

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Technical DDT is known to be a mixture of more than ten other compounds such as p, p'-DDT, o, p'-DDT, etc., and it is believed that p, p'-DDT is most effective for various pests than any other related compounds. It has also been decided by the WHO Expert Committee of Insecticides that the content of the p, p' isomer shall not be less than 70 per cent by weight. During a series of experiments as regard the efficacy of DDT and its related compounds using resistant as well as non-resistant strains of house-fly and human body louse the present author found the following rather remarkable facts. 1. p, p'-DDT was slightly more toxic than o, p'-DDT to house-fly and to the susceptible strain of body louse, but was less effective than o, p'-DDT to the resistant strains of body louse. 2. Pure p, p'-DDT did not kill our resistant strains of house-fly as well as the resistant strains of body louse, whereas the technical DDT containing only 76.5-82.4 per cent p, p-' isomer kills both resistant and non-resistant strains. 3. A synergistic effect can be assumed when p, p'-DDT is applied in a mixture with, o, p'-DDT, or any other related compound. 4. The waste part of DDT production, which is viscous liquid and contains up to only 32% p, p'-isomrs was revealed to be much more effective than pure p, p'-DDT against resistant and non-resistant test-insects. The native Hikone-strains of house-fly which is known to be strongly resistant to p, p'-DDT can be readily killed in laboratory by the waste material of DDT. 5. Thus, it can be said that so far at least our resistatant and non-resistant strains of house-fly and body louse are concerned there is no positive correlation between the efficacy and the amont of p, p' isomer in technical DDT.

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The susceptibility of several species of fly larvae to the emulsion of lindane was compared in the laboratory through the "rice-husks immersion method". The most resistant species was Lucilia illustris, and the susceptibility to lindane increased in the following order : Phaenicia cuprina, Sarcophaga peregrina, Phaenicia sericata, Aldrichina grahami, Calliphora vomitoria. Musca vicina was far more susceptible to lindane than the species stated above.

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1. Several species, which are presumed to be aberrant form (flavism) of Prosimulium yezoense Shiraki, 1935, were collected together with normal individuals at the mountains on Nagano and Yamanasi Pref., Japan. 2. This species was named P. yezoense ab. alpium n. ab.. 3. P. yezoense is a typical mountain breeding species in Japan. The early stages are found in swift mountain streams, and the adults attack man and animal from March to July. 4. The aberrant form is distinguished in the following points from the normal form : (a.) Antenna is blackish brown, with basal two segments and basal half of the third segment is yellowish brown. The latter is black. (b.) Mesonotum, pleurae, scutellum and basal scale is yellow or yellowish brown, with the bright golden pubescence or hairs. The latter is black, with the bright golden pubescence or hairs. (c.) Abdomen is yellowish brown, and becomes blackish brown gradually to posterior end. The latter is blackish brown or black.

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[in Japanese]

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