In previous paper, the author reported that 30℃ and 85% R.H. were most suitable condition for the formation of hypopus as well as the reproduction of Lardoglyphus konoi observed as total counts of the whole mites in each stage. The present study was made to observe the mode of breeding and hypopus formation of L. konoi in various kinds of diet from which supposed nutrient substances were reduced. These substances were obtained from fish meal and dried yeast powder which were treated respectively with water (at 5℃ for 24hr), boiling water (at 100℃ for 24hr), ethanol or acetone (at 5℃ for 7 days). Two groups of diet were prepared with the above residue as follows : (1) mixture of dried yeast powder and residue of fish meal treated with various kinds of solvent at ratio of 6 : 4,(2) mixture of fish meal and residue of dried yeast powder treated with various kinds of solvent at ratio of 4 : 6. Initially 300 mites were inoculated on 10g of the diet. They were kept at 30℃ and 85% R.H. regulated with saturated KCl solution. On any kinds of diet with the residue of fish meal, total count of mites in each stages was low while the ratio of the hypopus formation was higher in general. Total count of the mites was low on the diet, mixture of untreated fish meal and residue of dried yeast powder extracted with boiling water, while the ratio of the hypopus formation was the highest. Number of the mites was high on the diet, mixture of untreated fish meal and residue of dried yeast powder extracted with water at 5℃, whereas hypopus ratio showed next to the above. The highest count of the mites was observed on the diet; untreated fish meal and yeast powder which was dried and reground after soaking in to boiling water for 24hr, but the hypopus ratio was low.

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低毒性有機燐殺虫剤Dowco-214のゴキブリ類に対する殺虫効力を局所施用, および接触法によって評価した結果は, つぎのように要約される。1.微量滴下法によるチャバネゴキブリ雄成虫に対する効力は, (LD)_<50>ではdichlorvosについでDowco-214が高く(LD)_<90>ではDowco-214が最も高い効力を示した。またDowco-214はワモンゴキブリ雄成虫に対してdichlorvos, Dursbanについで高い効力を示し, クロゴキブリ雄成虫に対し, Dowco-214はDursbanに劣るが, diazinonと有意な差はなく, (LD)_<90>ではdiazinonにまさる効力であった。2.限定時間接触法によるガラス板, および合板上の残効性は, 前者では比較的短いが, 後者ではfenitrothionについで長期間殺虫力を示した。3.継続時間接触法による合板上での残効性の場合, Dowco-214はfenitrothionと同程度であり, Dursban, diazinonよりすぐれていた。以上の試験結果から, Dowco-214はゴキブリ類に対しすぐれた殺虫効力, および残効性を有し実用性は期待できると考えられる。

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A simplified technique was devised for the analysis of various sugars in adult mosquitoes. The sugar meal in the diverticulum of mosquitoes was applied directly on a filter (Toyo No. 51 A) and the ordinary one-dimensional paper-partition chromatography was carried out with standard sugar solutions. The results obtained by this simplified method were as acurate as that obtained by the previously reported and more complicated ones, by homogenizing the samples, concentrating it and developing on the filter paper. Moreover, the procedure is very simple and many samples can be tested within a short period of time, and thus it can probably be used to the field experiments. Employing this procedure, sugar preference tests were carried out with Culex pipiens pallens and C.p. molestus. Lactose was least preferred among the sugars examined and there was no significant difference in preference among fructose, glucose, sucrose and maltose. It was also observed that the hydrolysis of sugars began 3 hours after the intake. Detection of disaccharide become almost impossible 4 hours after the intake and sugars disappeared after 8 hours indicating the complete digestion and absorption of these sugars.

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In order to ascertain the feeding preferences of the Norway rats, Rattus norvegicus, on some unexperienced baits, the breeding and feeding tests were conducted under laboratory conditions. The animals used were a laboratory colony of Norway rats which had been reared with a particular simple bait from childhood to maturity. The bait adopted were commercially available wheat flour, ground peanut fish meal, crushed sweet potato, and powdered rat food (bait for rearing experimental animals). In the test, the criterion of preference was based on comparing the amount of consumption of different kinds of baits set at the same time in each test cage. As shown in the results, there were significant differences in the amount of consumption among the test baits. Raw sweet potato and ground peanut were marked by more preferable than the other baits. It is of interest that raw sweet potato was highly preferred by the rats whether the rat had experience in eating it or not. The growth of test animals in various tests were also observed. The rats reared with a rat food, a ground peanut, or a fish meal were in very good health, whereas the rats reared with a sweet potato were so poor health that a few rats could hardly survive. From the result obtained, it may be considered that the preferences of Norway rats for a particular bait depends upon its flavour more than its nutritional content or the previous dietary experience.

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日本各地で得られたP. hirtipes-groupに属する標本を詳細に検討した結果, わが国で1954年以来, P. hirtipes (Fries, 1824)とされていたものは, 北欧産P. hirtipes (Fries)とは明らかな差異があり, 京都産と北海道産のものとの間にも差異が認められた。そこで, 京都産, 北海道産のものをそれぞれ, P. kiotoense Shiraki 1935,P. jezoenicum (Matsumura, 1931)とし, これらの再検討と, P. hirtipes-groupに属する新種P. kaniiの記載を行ない, 以上の3種のkeyを与えた。

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Eggs of Tripteroides bambusa, Uranotaenia bimaculata, Armigers subalbatus and 10 species of Aedes were preliminary observed with a scanning electron microscope and a reflected lighting microscope. Their shape, size and chorionic fine sculpturings were illustrated and described. The description of the eggs of Aedes nobukonis is new. The results show that the shape, size and chorionic sculpturings provide specific characteristics for identification except for three species belonging to subgenus Stegomyia, Aedes aegypti, albopictus and flavopictus, which have striking similarities in their appearances and fine structures on the surface.

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日本産ミドリハナバエ属については, 加納・篠永(1967), 篠永・加納(1971)が成虫5種を記載しているほか, 篠永ら(1972)がキタミドリハナバエO. caesarionを北海道から日本新記録種として報告している。わが国では, 本属の幼虫はすべて牛その他の大形草食獣糞より発生するが, とくに放牧場の牛糞からの発生が多い。しかし, 沖繩の石垣, 西表島などでは, 水牛糞がおもな発生源である。本属の幼虫の形態については, 日本では石島(1967がミドリハナバエO. coeruleaの3令幼虫を記録しているのみである。著者らは, 野外で採集した雌成虫を新鮮な牛糞と砂糖水を与えて飼育し, 産卵させて3令幼虫をえた。図と記載のごとく, ミドリハナバエ属の幼虫は腹部第12節に特徴があり, そのうちでもanal plateとanal, subanal, postanal, extra-anal papillaeなどの有無, 形態とその組合せなどは種の特徴として重要でありこれらによって種の同定も可能である。

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クロゴキブリの潜伏空間の好みと, それに影響する個体間の相互作用を実験的に調べた。潜伏用のシェルターは白色の厚紙製の筒で, 一般用に長さ12cm, 両端の開口部4cm×高さ(高さは0.5cm, 1cm, 2cmおよび4cm), また若い幼虫用には長さ3cm, 開口部2cm×高さ(0.5cmおよび1cm)のものを用いた。実験ではテスト容器中に3種または2種のシェルターを並べておき25℃24時間後にその中のどれにゴキブリが潜伏したかを調べた。結果は次の通りである。1.成虫 : 単独成虫の選好反応ではシェルターの高さを1cm>2cm>4cm》0.5cmの順位で好むことがわかった。0.5cm. 1cm. 2cmのシェルター組合せであらかじめ乾燥標本を1cmシェルターに入れておいても, 生きた単独成虫はそれを避けることなく1cmのシェルターを選好した。しかし生きた成虫2頭の反応では, 通常同居を避けてそれぞれが1cmと2cmのシェルターに分かれて入った。これら3個うち1個のシェルターをゴキブリの排泄物や臭いで条件づけるとその中に同居する場合が若干生じたが, なお大部分のゴキブリは条件づけに関係なく2個のシェルターに分かれて入った。1cmと0.5cm, または1cmと4cmの組合せでは1cmのシェルターに2頭が共存する場合がかなり生じた。3種のシェルターに16頭の成虫を用いると1cmと2cmのシェルター内に数頭ずつが同居したが, 0.5cmのシェルターにはほとんど入らなかった。2.老令幼虫 : 成虫同様にして単独の6令および7令幼虫にシェルターを選好させると, その高さを0.5cm>1cm>2cmの順で好むことがわかった。2頭同時の反応では0.5cmと1cmのシェルターに分かれる場合が多かった。6&acd;8令の混合幼虫を16頭同時に入れると3種のシェルターに数頭ずつ入った。3.若い幼虫 : 成虫とは異る装置とシェルターでテストしたが, 単独の3令および5令幼虫は1cmシェルターよりも0.5cmシェルターを強く好んだ。しかし1令幼虫はどちらのシェルターにも同じように入った。2頭同時にテストすると3令および5令期には2個のシェルターに分かれる傾向が強い。しかし1令期はむしろどちらか一方のシェルターに2頭が接近し合って同居する傾向が極めて明らかであった。一方, 成虫と同じ装置で100頭の1令幼虫を同時にテストすると, シェルターに入る個体は少なく, 外で集合するものが多かった。4.以上から, クロゴキブリ成虫同士は互に排他的であり, 同居または集合状態は最適潜伏空間が限定されたときみられるものと思われる。この場合ゴキブリ自身による潜伏場所の条件づけは互の排他性を若干弱めるが, その作用は強力ではないようである。また少なくとも3令以上の幼虫は成虫と類似の性質をもっているとみられる。他方, 1令幼虫は明らかに互に接近し合って集合する性質が強いといえる。

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It has been reported that the guppy Poecilia reticulata is an effective predator of mosquito larva. This paper describes the results of studies particularly with respect to predation efficiency under laboratory conditions. Observations were made on the predatory activity of guppies on pupae, as well as on larvae. These studies were carried out in order to develop more effective utilization of the guppy for Culex pipiens control. Two guppies were placed in each aquarium containing two liters of water and maintained at constant laboratory temperature of 26℃ and 600 lux illumination. Known numbers of larvae were introduced into each aquarium at 10 : 00 am every morning. The number of larvae eaten within a two-hour period increased when the prey population increased from 50 to 100. However, the number of larvae eaten was more or less constant when the prey population was more than 100. For example, when 50 larvae were given, the number consumed was about 17.7; when 100 larvae were given, about 23.1 larvae were eaten; when 300,or more, larvae were given, about 23-24 larvae were also consumed. Similar results were obtained when 0.7g of powdered laboratory animal food was introduced into each container along with the mosquito larvae. The number of larvae eaten by the guppies under condition of high larvae population plus the powdered food did not show any significant difference as compared with the number of larvae consumed at high larval density and without the powdered laboratory food. It was observed that when the guppy population was increased and the larvae supplied were at the ratio of 50 larvae/guppy, there were more larvae consumed per guppy under high guppy population than under lower guppy population. The relationship between the number eaten per guppy (y) and the population of guppy (x) is shown by the formula y=0.432x+10.683. When prey density of each container is constant the relationship does not follow as shown in the above formula, since the number of larvae eaten per guppy decreases when the guppy population is high. Guppy attacks mosquito pupae actively when the guppy population is high. Many pupae were killed during a 24-hour period when both guppies and pupae were contact in a container, although any external injury was not found on pupal skin.

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Experiments were carried out with two guppies in each of 200 liter tanks placed outdoors under natural summer condition of Tokyo; water temperature was around 25-27℃. There was a control tank for each of the above experimental tanks. Five egg rafts of Culex pipiens pallens were given each morning for seven days. Each egg raft contained an average of 249 eggs. It was observed that guppies pecked at and ate the rafts; the number eaten was estimated at three rafts per day. Some of the larvae had hatched from the eggs, but it was difficult to estimate the number which did because of their small size. In any case, no larvae were found on the eighth morning. In order to determine the number of larvae of different developmental stages which was eaten per day, various stage of larvae were introduced in each tank. When 2,000 larvae, which had recently hatched from egg were supplied, it was noted that 369 of them had pupated after six to ten days. In the control tank wherein there were no guppies 1,614 larvae survived and pupated. It was estimated that 386 of the original 2,000 larvae in the control tank died naturally. If one assumes that an approximately equal number of larvae will die naturally in the experimental tank, then the actual number of larvae consumed was estimated at 1,245,or (2,000-369)-(2,000-1,614), during the larval period. When 500 larvae of age three days after hatching were supplied in the same way as mentioned above, the number of larvae eaten was estimated at 249 larvae by the end of the pupation period; under similar conditions, 142 four-day larvae were consumed; 50 five-day larvae; and 35 six-day were eaten. From the above the number of larvae eaten per day was calculated in the case of 0 to two days old larvae as : (1245-249)/3=332 larvae. In the same way, 107 three-day old larvae, 92 four-day old and 15 five-day old larvae were eaten per day. When a mixed-age population of larvae were supplied, the number eaten was greater in younger-aged larvae than older ones. However, some older ones were always eaten in spite of the presence of young larvae still remaining in the tank, although the number of older larvae consumed was less in comparison when a homogeneous age-group population was available.

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Four tanks, labeled A, B, C, and D, containing 750 liters of water, were placed outdoors near the laboratory. Breeding of Culex pipiens pallens was found in each tank in early June, 1972. Twenty guppies, or 10 mature pairs, were introduced in two of the tanks, B and C, on 9 June 1972. Tank B was then treated with fenitrothion 1ppm, tank C remained untreated. Tank D was treated with fenitrothion 1ppm on the same day, and tank A, the control tank, received neither guppies nor fenitrothion. The observation for each tank was conducted using a ladle to count the larvae and pupae densities every two or three days. Also counts of total number of egg rafts on the water surface were made on the same day. These observations were made until the end of September. According to the results, the larvae and pupae dramatically disappeared on the fourth day after fenitrothion treatment in both tanks B and D. In the case of tank D, the chemical treatment had to be repeated five times during a two-month period due to the outbreak of larvae every 10 or 20 days. Tank B, however, received no additional chemical treatment after the initial treatment because of the presences of the guppies. A number of pupae was observed for three weeks after introduction of guppies to tank C, but all pupae had disappeared by the end of this period. More than 100 rafts a day of oviposition were observed in tanks A and D. However, no rafts were recognized from tanks B and C, except for very few days during the peak time of oviposition activity of mid-summer. As Part II of the present report series showed, these egg rafts were eaten by guppies in each tank. Thus, in tanks B and C no adult mosquitoes emerged throughout the summer season.

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During the period from April 1971 to March 1972,a study was made on the seasonal change of composition rate of autogenous Culex pipiens molestus (Cpm) and anautogenous C.p. pallens (Cpp) in an underground room of a building in the midtown area of Nagoya City, central Japan. (1) For differentiating Cpm females from Cpp, the following five characters were used : Ommatidial number of the compound eye (square value of average number per row : x_1) and the following ratios of the various parts of wing, namely, Rc/Mc ratio (x_2), WL/Rs ratio (x_3), P/D ratio (x_4) and Rc/Rs ratio (x_5). On the bases of the discriminant values calculated using the discriminant function, Z_5=x_1-1.207 x_2+0.1953 x_3-28.99 x_4-3.322 x_5,mosquitoes with the smaller discriminant values than the critical point (25.24) were regarded as Cpm and those with the larger values as Cpp. As a result, most of the discriminant values were less than the critical point and the modes of them were within the range of 16.1 to 22.0; this suggested that most of the female mosquitoes collected with a light trap in the building seemed to be Cpm (Fig. 1). (2) A small number of these specimens, however, were considered to be Cpp, judging from their larger discriminant values. These Cpp mosquitoes were obtained mainly during spring to autumn, when their field populations usually prevailed in this district. Monthly rates of Cpp females were highest (ca. 10%) in midsummer, but the annual rate was as low as about 2% (9/480) (Fig. 1 and Table 1). (3) The number of female Cpm mosquitoes collected in the building, as compared with that of male, was predominantly larger in the monthly catch during the summer. So that, the monthly intermixing rate of Cpp was seemingly low in females, but considerably higher in males during the summer season (Table 2 and Fig. 2). (4) A confirmatory test was made as follows in order to put the discriminat function to the practical use. The above-mentioned function (Z_5) was used only for the indistinguishable specimens (0.8%) which had the transformed ommatidial numbers between 67.52 (8.22/row=1% lower rejection limit for Cpp) and 73.30 (8.56/row=1% upper rejection limit for Cpm). The result thus reached was proved to be the same as that obtained from the calculation for all the specimens under study.

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