Seasonal prevalence of mosquitoes were studied during the period from June to December, 1951, using three methods (a. Collection of adult invaded houses using exhauster. b. Biting collection using goat and chicken as baits. c. Larval collection around houses) and following results were obtained. 1. 5 genera, 12 species of adult mosquitoes were collected in the houses and Culex pipiens occupied the great majority of the specimens (67.4%). 2. Mosquitoes collected by biting collection using goat as a bait were 4 genera and 7 species and the majority of the specimens were C. tritaeniorhynchns (64.2%). 3. Those of using chicken were 3 genera and 6 species and the majority species were C. pipiens (89.8%). 4. Larval surveys were done in 11 habitats and 2 genera and 5 species were obtained. C. pipiens occupied the great majority of the specimens (97.6%). 5. The peaks of population curves obtained differed with species and collecting methods.

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1. Cockroaches living in the vessels which entered the port of Kobe were collected over a period of 2 years and 8 months, from April 1953 to November, 1955. 2. Sixkinds of cockroaches were found during the period mentioned above. The species are as follows : Periplaneta americana L., Periplaneta australasiae F., Blattella germanica L., Stylopyga rhombifolia S., Neuphoeta cinerea O., Leucophaea surinamensis L. 3. The number of Blettella germanica L. found dead as the result of HCN-fumigation using for deratting in the vessel was supposed to be the real number of cockroaches living there. 4. 120 vessels were fumigated with HCN and 719, 801 Blattella germanica L. were found dead. 5. Investigation on the incidences of Blattela germanica L. was made each on the seasonal changes of climate (winter-19.13%, spring-28.41%, summer-27.74%, autumn-24.70%), on the classification of compartment (galley-66.94%, pantry & dining-room-17.11%, crew quarters-7.6%, provision store rooms-6.76%, officer's quarters & passenger quarters-1.38%, ) on the description of vessel (cargo boat-42.70%, passenger boat-34.35%, tanker-22.12%), on the age of vessel (within 1 year-3.11%, 1-3 years-23.07%, 3-5 years-27.91%, 5-10 years-16.73%, over 10 years-29.91%), and on the kind of route (Formosan, Okinawa & Korean line-12.53%, North American, European line-30.37%, South-East Asiatic, Middle Near Eastern & African line, Central-South American line-57.09%) 6. This investigation was done on the influence of the last HCN-fumigation effected on Blattella germanica L. (within 6 months-26.32%, 1/2-1 year-34.28%, 1-2 years-24.86%, over 2 years 14.52%).

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1) It is one of the purposes of the present paper to report the evidence of high level resistance to DDT observed in Japanese houseflies. 2) The large-scale malaria control program in Hikone City, Japan, resulted in such a remarkable success as no patient was reported since 1954. However, DDT resistant houseflies have developed in this city. 3) The result of tests on resistibility of houseflies to DDT and BHC indicates that the field population in this city is consisted of two distinct groups, i. e., the DDT resistant and nonresistant. However, no BHC resistance has developed in this field population. 4) Among the progeny of DDT resistant flies, several morphological mutants have been found. (The full contents of this paper will be translated in English in a publication of World Health Organization, Japanese contributions to the study of insecticide-resistance problem, in press.).

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Studing two larval parasites, Apanteles conspersae Fiske (Braconidae) and Sturmia picta Baranoff (Tachinidae), infesting the Far Eastern urticating moth, Euproctis flava Bremer, the following worth noting facts were observed : 1. Apanteles conspersae -1) Excepting a few cases, the parasite larva comes out from the body of (n-3)th instar larva of host (the nth instar=the final instar) and pupates on it. 2) The host alives even 17-18 days after the parasite larva escaped from it. 3) The parasitic number per host is from 1 to 11. 4) The parasitic rate is 15% and the emergent rate is 94%. 5) The prepupal and pupal stages were 7-12 days and the adults emerged during the period on May 11. to June 9. 2. Sturmia picta -1) The parasite larva comes out from the body of (n-2)th instar larva of the host and then pupates. 2) The larva of the infested host cocoons in the (n-2)th instar and dies as a result of escape of the parasite 3) The parasitic number per host is one. 4) The parasitic rate is 8% and the emergent rate is 67%. 5) The prepupal and pupal stages are 12-16 days and the adult emerged from May 30. to June 2.

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An ecological study on the compositions of the early stages of black fly associations and their seasonal successions were conducted in Biwataki stream in the suburbs of Tokyo. The observation on fourteen stations in the stream (Fig. 1) was continued from March 1956 to February 1957. The physical characteristics of the stations of the stream is given in Table 1. 2. The aggregate number of studied stations through one year amounted to 119 stations, and on 90 stations of them, the specimens of black flies were found. The species and number collected is given in Table 2. 3. The phenomenon of the spacial habitat segregation in the stream was observed as in Fig. 2. According to the distribution of black flies, Biwataki stream seems to divide into four habitat groups. Namely, the stream is constituted by four zones, which are represented by Simulium bidentatum, S. aokii+S. tuberosum, tub. +S. japonicum and S. subcostatum respectively. And toward the upper part of the stream, five species are arranged in an order of bid., aok., tub., jap. and sub. 4. When the composition of black fly associations was analized, there were 26 types. The types, which amounted the number of collection to above three times, is given in Table 3. 5. If we analize the seasonal prevalence of early stages of black flies in the stream, there were five types showing in Fig. 4. It seemed that tub. is the perennial nucleus, bid. is an vernal-estival, aok. is an estival-autumnal, jap. is an hiemal-vernal and sub. is vernal type respectively. 6. Habitat segregation of early stages of black flies seems to divide into two types. The first type encloses the phenomenon which segregate their habitats as the results of the coaction of each other species. As shown in Fig. 3, bid. is the dominant species occupying 94-100% of the number collected on Station A from April to August, and tub. is the dominant species on the same place during February and March. The two species are equally balanced during October and January. In spring and summer, when bid. occurs on Station A, tub. seems to retrocede toward upper stream, and in winter when bid. is absent, tub. appears at Station A. Moreover, other species seems to shown the second type of habitat segregation which establish the intimate physiological connections to their habitat conditions. 7. Environmental factors concerning the habitat segregation of early stages of black flies were discussed. From point of view based on so-called macro-habitat, the composition of early stages of black flies associations seems to affect mainly by the "Type of Stream" regarded as a complex made of various physical attributes of a stream. The local distribution of habitat of black flies may be determinated mainly by the water temperature, but within a single stream the influence of water temperature may not always be decisive.

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As a part of the quantitative taxonomic studies on the trombiculid mites or Tsutsugamushi of Japan, specimens of Trombicula nagayoi Sasa et al. and the related species collected from three representative districts were measured. The group of mites obviously belongs to the autmnaalis-group, subgenus Neotrombicula, genus Trombicula. Three species have been recorded from Japan, namely Trombicula japonica Tanaka et al., Trombicula nagayoi Sasa et al. and Trombicuia ichikawai Sasa. They could mainly be differentiated by the size of scutum and by the number of dorsal setae rows. As the results of the extensive collections made in these several years at various districts of Japan, groups of specimens showing somewhat intermediate characters have been accumulated. For example, a part of larval specimens of nagayoi collected at Yamanaka were found to have the same dorsal chaetotaxy as that of ichikawai, or those of japonica from Hokkaido showed variations towards the characters in nagayoi. Standard measurements of the scutum (AW, PW, pl) and the classifications of the dorsal chaetotaxy were made with the specimen-groups of questionable taxonomic status. Ecological observations such as the seasonal distributions of larvae and the geographical distributions of each forms, or the comparative morphological studies on the laboratory reared nymphs were also applied to elucidate their specific features. Through these studies, it was almost unequivocally confirmed that the three types represented isolated and independent natural populations, and constituted different species, as were recognized by the original describers. However, it was also shown that they may exhibit different variational ranges in their morphological characters by the localities of collections.

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The knockdown effects of lindane and diazinon on house fly and German cockroach were compared with each other in the forms of kerosene solution, aceton solution or dust using contact and spray tests. In general, the kerosene solution of lidane gave quicker knockdown effect than that of diazinon and, on the contrary, in the form of aceton solution or dust, diazinon proved to give quicker effect than lindane. On the contact tests on house fly, the following results were obtained : The median knockdown time (KT-50) was comparatively longer even in lower concentration of lindane, but of diazinone the KT-50 was rather shorter in lower concentration, or, in other words, the difference of the knockdown effect between the higher and the lower concentrations was smaller in lindane than in diazinon. This seemed to be caused partly by the higher volatility of lindane. From these results, the authors were led to the conclusion that the knockdown effect of chemicals might be estimated differently by using different form of chemicals, different method of application, or different species of test insects. The relationship between dosage and mortality should be persumed to compare the efficacy of chemicals.

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[in Japanese]

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The author has collected three species of fleas from the bodies and the nests of Eurasian small flying-squirrels, Pteromys volans amygdali (Thomas, 1906). They are : 1. Hystrichopsylla microti Scaron, 1950, 2. Rhadinopsylla japonica Sakaguti & Jameson 1956, 3. Monopsyllus argus (Rothschild, 1908). A single specimen of Hystrichopsylla microti was found in the nest but not found on the bodies of mammals. This species has hitherto been found on the wild vole of Microtus montebelli, house rat of Rattus rattus and some insectivora such as Talpa micrura and Urotrichus talpoides. Pteromys volans amygdali seems not the only host of this flea. The last two species, Rhadinopsylla japonica and Monopsyllus argus are found both on the bodies and in the nests of the flying-squirrel, sometimes separately and sometimes together. The former is rather scarce and the latter occurs more abundantly. But both species of fleas are also collected from the bodies and the nests of white-cheeked giant flying-squirrel, Petaurista leucogenys, which is a larger species but has the same habitat as Pteromys volans. Rhadinopsylla japonica is strictly confined to these two flying-squirrels, Monopsyllus argus, however, although found frequently on these two flying-squirrels, also occurs occasionally on a Eurasian squirrel, Sciurus vulgaris together with the allied species, Monopsyllus indages. However, Monopsyllus argus rarely occurs on Martes melampus. Both species of the host, flying-squirrels which are parasitised by both species of fleas, Rhadino-psylla japonica and Monopsyllus argus show closely similar living habits. Sometimes the nest of the small Pteromys volans is occupyed by the large Petaurista leucogenys. It is, therefore, supposed that Pteromys volans amygdali discussed in this paper is the true host of the two species of fleas, Rhadinopsylla jopcnica and Monopsyllus argus, as well as Petaurista leucogenys which is a larger species of Pteromys volans amygdali.

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Stenoponia montana Darskaya has been reported in 1949 by Darskaya as a new species in the mountain forests of northern Korea. The present article deals with the records of the species from the mountain regions of central Japan, Nagano- and Kyoto- prefectures with systematic descriptions, host relations and some ecological notes. In winter, from end of October to February, the species is found on the bodies of several species of small rodents such as Apodemus speciosus, Ap. sylvaticus, Rattus rattus, Microtus montebelli and Eothenomys smithii and in one single instance on the Japanese yellow marten, Martes melampus. Eggs, before oviposition, are observed in the abdomens of four specimens of the species. The eggs are long ovoid and occur in pairs in the abdomens. The surface of the egg is uniformly covered by beautiful network consisting of smaller pentagonal and hexagonal cells. The micropylar openings on the anterior pole are found about 60 in number, whereas the posterior apparatus is found to consist of about 30 openings.

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The bat flea fauna of Japan has not been sufficiently studied. Only two species Ischnopsyllus indicus Jordan, 1931 and I. elongatus (Curtis, 1832) have been reported by Kumada & Saito (1953) and Yamashita & Haga (1954). In the present paper, the third species, Nycteridopsylla galba Dampf, 1910 is reported from Chiba prefecture, central part of Japan, on the body of Oriental Large Noctule, Nyctalus aviator. The species of fles has been described by Dampf (1910) from "bat" of Shanghai and Ischnopsyllus wui, which is synonymous to N. galba, has been reported afterwards by Hsu (1936) from "bat" on Soochow, 60 miles west from Shanghai. The descriptions by Dampf and Hsu, both are based upon the male specimens and the female of the species has not yet been described. Therefore, the writer describe the female sex in this paper. It is thought that a few species of bat fleas have previously been known in Japan, but other species will be added to our native fauna in the future if we examine carefully many specimens of bats from the different parts of Japan.

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Four Geophilids, Prolamnonyx holstii (Pocock) (Geophilomolpha, Mecistocephalidae) were found in the feces excreted by clyster. The infested host was a 6 years old boy and chief symptoms seemed to be caused were slight fever, abdominalgia, headache, vomiting, and discharge of mucous bloody feces. After removal of the parasites, these symptoms recovered and the boy showed good appetite and vitality. The specimens were deposited in the Department of Parasitology, Kurume University School of Medicine.

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The discription and analysis on an alive adult Collembora, Hypogastrura communis (Folsom) found in jejunum of a stray dog kept in the laboratory for about three weeks after the capture, were done in this paper. Species was identified by Dr. Hajime Uchida, Hirosaki University, and the specimens was preserved in the Department of Parasitology, Kurume University School of Medicine.

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One or two percent malathion emulsion with sugar was sprayed in pens and manure heaps, and the effect against the flies was estimated by the change of the population. When 1% emulsion was sprayed in pens at the rate of 80cc per square meter, the population of fly was kept comparatively lower for 4 or 5 days than before the application. But only for 1 or 2 days it was effective by the application of 40cc per square meter. On manure heaps, even the application of 120cc or 240cc of 2% emulsion per square meter did not show distinct decrease of the population of fly.

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