Argas japonicus Yamaguti, Clifford & Tipton were allowed to feed on citrated, heparinized or defibrinated whole bloods of various animals through a chicken skin. The age or sex of the ticks, blood temperatures, 37° and 42℃, fresh or stored chicken bloods and skins did not have any influence on the feeding rate of the tick. Optimal blood temperature lied between 35°&40℃, though the tick fed on blood at a wide range of temperature, 24.5°-44.3℃. The temperature gradient between blood and atmosphere did not have any influence on the feeding of the tick. Ticks fed on mammalian bloods indiscriminately, but some bloods seemed not to be suitable as the food of the tick. Protonymphs were reared up to adults by serial feedings on various bloods through the chicken skin. With the fresh, defibrinated chicken blood, 92.5% of the protonymphs gave rise to adults; 75% of individuals were reared up to adults with the defibrinated chicken and rabbit bloods stored in the deep freezer; only 42.5% gave rise to adults with the citrated chicken blood; all individuals died after feeding once or twice on the defibrinated sheep blood stored in the deep freezer. The AT-31 strain of Japanese encephalitis virus imbibed by the tick through the chicken skin was detectable in the tick for 5 days. It was proved that the orally infected virus did not multiply in the tick, though the virus introduced into the hemocoel could propagate.

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Prosimulium sarurense n. sp. is described based on the specimens taken from the streams of Saruru river, the southern region of Hidaka range, Hokkaido. The species seems to be closely related to Prosimulium yezoense Shiraki, 1935,but differs from it in the structure of genitalia in both sexes and pupal respiratory organs.

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Haematopota nagashimai, a new species is described from the northern part of Honshu Island, Japan. This species is closely related with H. rufipennis Bigot, but H. nagashimai can be distinguished from H. rufipennis by its dark brown scutellum, glossy black abdomen without any stripes or spots and a bilobed extension of basal callus on frons.

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Examinations were carried out on the influence of the quality of larval food substances on the duration of aquatic stage, wing length and autogenous reproduction of Culex pipiens molestus and hybrids of C. p. molestus and C. p. pallens, using the laboratory colonies. Three kinds of larval diets, (A) 3 parts of laboratory chow for insect and 1 part of powdered yeast, (B) powdered yeast aloned and (C) 3 parts of potato starch and 1 part of powdered yeast were used. Fifty larvae of each strain or hybrid just hatched out were put into a glass jar containing 25mg of one of the three diets suspended in 300ml tap water. The larvae were transported everyday to a newly prepared jar with the diet of 50mg, 75mg, and 100mg on the 2nd, 3rd, 4thdday and after, respectively. Females were dissected on the 4th day after emergence. Developmental rate and mean of wing length of each strain or hybrid were maximum in diet A and minimum in diet C. In molestus, the percentages of females with mature eggs were 95.6 to 100,78.3 to 88.9 and 39.2 to 70.9 and the mean numbers of mature eggs in the females were 86.1 to 112.1,59.6 to 70.5 and 24.9 to 45.7 in diet A, B, and C respectively. In hybrids, the percentages of females with mature eggs were a little lower than those of molestus in each diet, while the mean number of the eggs were nearly the same as in molestus.

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Owing to the outbreak of the stink bug (ground bug), Aethus indicus, and its invasion into houses, a large number of the inhabitant in the Amami Islands was afflicted, during the summer season 1974. Thus, ecology of the bug has been investigated at Okinoerabu Island, one of the outbreak areas, since 1975. The census of the bugs on ground surface were carried out at various topographical and biological environments. As a result, the bug was collected only at the areas flourishing with foxtailgrass, Setaria viridis (L.), fingergrass, Digitaria sanguinalis (L.), but not at othertareas. The population density of the adults was as high as 500 per square meter at the suitable habitats. We observed frequently the bugs sucking from the seeds of foxtailgrass on the ground. Rearing in the laboratory giving the seeds as food, it took them 54 days in average to develope from egg to adult emergence during the summer. In the field, the female adults having mated and containing mature eggs were not found in October and thereafter. Since they mate and deposit eggs in the spring, we presume that the field population complete its life cycle twice a year.

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The active flight of the stink bug (ground bug), Aethus indicus, to an electric lamp was observed for several nights during July and August in 1975. The flight activity was in a unimodal type which commenced at after sunset and ended at midnight. The number of adults landed on the pan trap, which was 30co in diameter and placed just under the lamp, exceeded 100 per 5min in maximum. However, such an mass flight was suppressed by wind in over 3.3m per sec. We consider that their flight is activated by such a faint light intensity in the twilight. Dissection of the ovaries of the females, which were attracted to the light, showed the different degrees of maturation. These individuals were, it seemed, not stimulated with their particular reproductive requirement. On the other hand, we could observe that the adults rearing in the laboratory without food had a tendency to crawl out to the surface at sunset time. This phenomenon was extremely less when enough food was given. Therefore, it was expected that the flight activity was initiated for their food finding.

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A new mutant, reddish eye (rd), was isolated from the Taipei strain of Aedes (Finlaya) togoi (Theobald), and has been found to be recessive and closely linked to the sex locus (or chromosome segment) m with a recombination value of less than 1%. This allele expresses itself only in the pupal eye with full penetrance and fairly constant expressivity, and can be used as a good genetic marker.

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Surveys of house dust mites were carried out during a period from December 1974 to January 1976 in two households in the suburbs of Tokyo, one in a newly buit concrete apartment house, and another in a nine year old wooden Japanese style house. Both had the rice straw mats (tatami) as the floor material. The mites were isolated from dust collected with a vacuum sweeper at monthly intervals. The dust samples were sieved first with a 9 mesh and a 200 mesh sieve, and fine dust on the 200 mesh was collected and weighed; 0.5g of the fine dust was transferred to a 100ml beaker, sstirred in 50ml of Darling's solution (mixture of equal amount of glycerine and saturated sodium chloride solution in water) for 10min, and was centrifuged for 5 min at 300 r.p.m. The supernatant containing mites were filtered with a Buchner filter, and the mites on the filter papers were collected with a needle under a stereomicroscope. The recovery rate of mites from house dust with this centrifugation and floatation method was estimated to be about 80% of the total mites contained in the original materials. The house dust collected from the new straw mat surface in December 1974 before the apartment house was inhabited contained large numbers of Tyrophagus putrescentiae and Glycyphagus destructor and also small numbers of Tydeus sp. and Tarsonemts sp. These mite species are considered to be breeding in the straw materials. On the other hand, mites of the family Pyroglyphidae, especially Dermatophagoides farinae and D. pteronyssinus began to appear from about one month after the family moved in the house, reached a peak in July at the end of the rainy season and in the beginning of summer. The increase in the predatory mites of the family Cheyletidae and of Mesostigmata occurred after this in September or October. The total number of mites isolated from 14 dust samples collected at monthly intervals from the old Japanese style house was 17,142 and more than twice larger than that of the new apartment house. The most abundant was Dermatophagoides pteronyssinus (48.0%), followed by D. farinae (33.8%) : The seasonal density of the seven groups of mites was shown in a table; the peak density of Dermatophagoides was seen also in July.

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A new insect growth regulator, PH 60-40 [N-(4-chlorophenyl)-N′-(2,6-difluorobenzoyl) urea] was tested on the mature larvae of the stable fly, Stomoxys calcitrans (L.), by a fly medium method and by hens as a feed additive. One ppm of PH 60-40 in the fly breeding medium gave almost complete inhibition of the cuticle formation of the flies during pupal metamorphosis. PH 60-40 also satisfactorily suppressed adult emergence from chicken manure at the same concentrations. Thus, PH 60-40 seems to be efficient for control of the stable fly.

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Three new trombiculid mites of the genus Doloisia from Amami Island, Japan are figured and described. These are D. minamii n. sp. and D. satoiana n. sp. that were collected from nest holes of Amami Spinous Country-rat, Tokudaia oshimensis oshimensis (Abe, 1933), and from soil under rocks as unengorged larvae. D. zentokii n. sp. was collected from Black rat, Rattus rattus and Amami Spinous Country-rat. Doloisia (Doloisia) minamii Suzuki, n. sp., Fig. 1 A-G Diagnosis of larva : This species is related to D. satoiana Suzuki, n. sp. and D. okabei (Sasa et al., 1952), but differs from them in one or more of the following characters : palpal formula, shape of sensillae, shape and dimensions of scutum, number of coxal setae and number of dorsal setae. Measuring 190μm×130μm when unengorged of 10 paratypes. Palpal formula B/B/NBB+4B・N, eyes 1+1,small. Galeal seta nude. Scutum roughly triangle. Sensilla fusiform, AL setae nude or weakly barbed (Fig. 1). Scutal measurements as in Table 1. Dorsal setae 40 to 44 in total, arranged 4-10-8-8-8-2,sternal setae 2-2. Coxal setae I was 3 rarely 4,II, 5 rarely 4,III, 9 to 12 usually 12. Specialized setae on legs as in Fig. 1,G. Leg I : Length of tarsus, 50μm; a long mastifemorala, 2 genualae, 1 microgenuala, 2 tibial spurs, 1 microtibiala, 1 pretarsala, 1 subterminala, 1 parasubterminala, 1 tarsal spur, 1 microtarsala. Leg II : Length of tarsus, 42μm; 1 genuala, 1 tibial spur, 1 tibiala, 1 pretarsala, 1 tarsal spur, 1 microtarsala. Leg III : Length of tarsus, 55μm; 1 genuala. This species were collected from nest holes of Amami Spinous Country-rat, Tokudaia oshimensis oshimensis (Abe, 1933) and from soil under rocks. Holotype and 10 paratypes are deposited in the National Science Museum, National History Institute, Shinjuku, Tokyo, and 5 paratypes are preserved in collections of author. Doloisia (Doloisia) satoiana Suzuki, n. sp., Fig. 2 A-G Diagnosis of larva : This species somewhat resembles to D. okabei (Sasa et al. 1952) in having globose sensilla, but it is separable by a nude seta on dorsal tibial a of palpus, in D. okabei having nude seta on genual, dorsal tibiala and lateral tibiala of palpus. Average body length and width of 10 paratypes 180μm×125μm when unengorged. Palpal formula B/B/NBB+4B・N, small eyes 1+1. Galeal seta nude. Scutum shaped like triangle with round anterior margin. Sensilla globose, AL setae short and weakly barbed (Fig. 2). Scutal measurements as in Table 2. Dorsal setae total 36 to 38,arranged 4-10-8-6-6-2-2,sternal setae 2-2. Coxal setae 2-5-10 to 12. Specialized setae on legs as in Fig. 2,G. Leg I : Length of tarsus, 43μm; a long mastifemorala, 2 genualae, 1 microgenuala, 2 tibial spurs, 1 microtibiala, 1 pretarsala, 1 subterminala, 1 parasubterminala, 1 tarsal spur, 1 microtarsala. Leg II : Length of tarsus, 36μm; 1 genuala, 2 tibial spurs, 1 pretarsala, 1 tarsal spur, 1 microtarsala. Leg III : Length of tarsus, 43μm; 1 genuala. This new species were collected from soil of nest hole of Amami-hare, Pentalagus furnessi (Stone, 1900), and from soil under rocks and tree holes. Holotype and 20 paratypes are deposited in the National Science Museum, Natural History Institute, Shinjuku, Tokyo and also 20 paratypes are preserved in collections of author. Doloisia (Doloisia) zentokii Suzuki, n. sp. Fig. 3 A-G Diagnosis of larva : D. zentokii n. sp. is colsely related to D. nasicola (Domrow and Nadchatram, 1962) in having 2-2-2 sternal setae. But it is separated by the most setal number on coxa I, II, III, most dorsal setae in number and by scutal characters. This species is also related to D. okabei (Sasa et al., 1952) and D. satoiana, from which it is separated by the number of sternal setae and setal number an coxa I, II, III. Average length and width of engorged specimens (10 paratypes) 510μm×350μm. Palpal formula B/B/NNB+4B・N, very small eyes 1+1 or absent. Galeal seta nude. Scutum shaped like triangle. Sensilla glob

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Six new species of trombicuilid mites are figured and described from Amami Island, Kagoshima Prefecture, Japan. Cordiseta (Kayella) nakayamai n. sp. were collected only from the nest hole of Amami-hare, Pentalagus furnessi (Stone, 1900). Schoengastia (Schoengastia) hanmyaensis n. sp. were collected from sand in the nesting hole of Streaked Shearwater, Colonectris leucomelas, on Hanmya Island, a small uninhabited island of the Amami Island. Ascoschoengastia (Ascoschoengastia) noborui n. sp. were collected mostly from soils below the tree holes and ground holes. Walchiella (Walchiella) amamiensis n. sp. from nest holes of Amami-hare and Amami Spinous Country-rat, Tokudaia oshimensis oshimensis (Abe, 1933), and from soil under tree holes and rocks. Miyatrombicula (Miyatrombicula) okadai n. sp. from nest holes of Amami-hare and soils below tree holes. Eutrombicula (Siseca) haematocheiri n. sp. were found on unusual hosts, land crabs, Sesarma (Ho-ometopus) haematocheir (De Haan, 1835) and Potamon dehaani (White, 1847), and from soils below the tree holes and ground holes. Genus Cordiseta and Schoengastia and Subgenus Siseca are the first records in Japan.

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The interference of the larval populations of Culex pipiens molestus was studied in the successive cultures by introducing groups of 200 or 500 1st-instar larvae in several day intervals. The pupation rates (survival rates of larvae) varied from 88.5% to 4.3% depending on the absence or presence of the interstadial interference. The alternative decreases and increases of the pupation rates in the successive populations demonstrated the self-regulation of mosquito larvae by means of short-living interference chemicals. The percentages of emergence and oviposition, and the day intervals required for larvae to pupate showed no significant interference effects. The mean numbers of eggs in a raft, however, showed slight decreases as the introduction of new populations was repeated. The reproduction capacity (numbers of eggs produced per larva), which are the multiple products of the above figures, also showed the pronounced ups and downs depending on the size of the preceding surviving larval population. The reproduction capacity, 14.9 of the 200 larva populations in the beginning decreased to 1.2 in the 8th population, and 6.9 of the 500 of larva populations ended at 0.9 in the 7th population. The interstadial as well as intrastadial interference of mosquito larvae therefore not only regulates their own population but governs the sizes of the following generations. The importance of larval density in the population dynamics of mosquitos was stressed.

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Fourteen species of the Nepalese Tabanidae were recorded based upon the materials collected by Hokkaido University Scientific Expedition to the Nepal Himalayas 1968 and those by T. Matsumura in 1972,with descriptions two new species, Tabanus adhabarensis and T. kumatai n. spp.; decription of the male Hybomitra lyneborgi Chvala; and notes on four species new to Nepal, Chrysops flavocincta Ricardo, T. oxyceratus Bigot, T. macer (Bigot) and Haematopota albofaciatipennis Brunetti, and on eight species known there, C. designata Ricardo, C. dispar (Fabricius), Hy. lamades Philip, Hy. lyneborgi Chvala, Hy. mouchai Chvala, T. fulvimedius Walker, Hippocentrodes desmotes Philip and Hae. philipi Chvala.

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Morphological data of eggs of Anopheles sinensis and A. lesteri from Okinawa Is. in comparison with those from Kyushu were presented. Some previous works related to our stsdy were briefly discussed. Necessity of taxonomical reinvestigation on the Palearctic sinensis sibling species group was suggested.

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The nectar feeding activities of Aedes albopictus, which was captured from the field by biting-collection method, were investigated in 1975. The anthrone reaction by Van Handel (1972) was used to detect fructose in the mosquitoes. The nectar feeding rates of 752 males and 1179 females were 62.6% vs 57.0% respectively during the period from late-June to mid-October. Chisquare analysis showed no significant difference between the sexes except late-June female collection and the average feeding rate was 59.1% in the total 1931 mosquitoes. Sugar detection in the mosquitoes collected in the morning (06 : 00-08 : 00) and in the evening (16 : 30-17 : 30) resulted that the five cases were significantly high in the feeding rates in the morning but other six cases showed no significant difference between the both collections. The mosquitoes collected after typhoon were anthrone-positive at the rate of only 18.3%. This suggests that many nectar sources were temporarily damageable by heavy rain and wind.

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