For the purpose of investigating the relation between the oribatid fauna and the vegetation of ground, one year soil sampling test (1959/60) was achieved in a west suburb of Tokyo. Two adjacent groves of different vegetation, i.e. Quercus acutissima CARRUTH. and Pinus densiflora SIEB. et ZUCC., were selected. The soil sampling was made with a can of 8cm in diameter and 5cm in depth. Thirty four soil samples, 2 samples per each sampling of 17 days, were taken out from each grove between 9.30a.m. and 10.30a.m. and were dried in improved BERLESE apparatus to collect oribatid mites.
Of a total of 3874 mites (32 species), 2165 (30) originate from Quercus-grove and 1709 (21) from Pinus-grove. It tells that the soil under Quercus-grove have a fauna of oribatid mites richer than that of Pinus-grove. The species peculiar to Quercus-grove are Meristacarus sp., Nanhermannia parallela AOKI, Belba sp., Gymnodamaeus sp., Oppia quadricarinata (MICH.), Oppia sp. 1, Oppia sp. 3, Tetracondyla clavata AOKI, Anachipteria grandis AOKI, Ceratozetes japonicus AOKI and Phthiracalurus rostralis WILLM. The species peculiar to Pinus-grove are Eremaeus hepaticus (KOCH) and Eremaeus sp. The species obtained from both groves are Epilohmannia ovata AOKI, Cryptacarus hirsutus AOKI, Eohypochthonius gracilis (JACOT), Liochthonius ensifer (STR.), Nothrus biciliatus KOCH, Eremobelba japonica AOKI, Suctobelba naginata AOKI, Oppia nova (OUDMS.), Oppia sp. 2, Oppia sp. 4, Scheloribates laevigatus (KOCH), Tectocepheus velatus (MICH.), Cultroribula latus AOKI, Punctoribates punctum (KOCH), Protoribates lophotrichus (BERL.), Protoribates sp., Galumna sp., Rhysotritia ardua (KOCH), and Hoplophorella cucullata (EWING). Whereas the Pinus-grove contains only two peculiar species and almost all the species from this grove are common to the Quercus-grove, the latter has eleven peculiar species.
From a point of view of dominancy and constancy, the species found from the two groves were classified according to the standard offered by KROGERUS (1932). Anachipheria grandis AOKI and Suctobelba naginata AOKI were qualified for dominant species in Quercus-grove, Protoribates lophotrichus (BERL.), Epilohmannia cylindrica (BERL.) Punctoribates punctum (KOCH) and Oppia nova (OUDMS.) were dominant in Pinus-grove, and Eohypochthonius gracilis (JACOT), Cultroribula latus AOKI and Rhysotritia ardua (KOCH) were dominant in both groves. The constant species for both Quercus- and Pinus-groves were Eohypochthonius gracilis (JACOT), Cultroribula latus AOKI, Epilohmannia cylindrica (BERL.), Rhysotritia ardua (KOCH), Protoribates lophotrichus (BERL.) and Oppia nova (OUDMS.). In addition, Anachipteria grandis AOKI, Epilohmannia ovata AOKI, Cryptacarus hirsutus AOKI, Ceratozetes japonicus AOKI and Scheloribates laevigatus (KOCH) were recognized as constant species exclusively for _Quercus-grove. However, none of species was found as constant species exclusively for Pinus-grove. Considering their dominancy, constancy and commonness between both groves a determination of the characteristic species in each grove was made: Anachipteria grandis AOKI and Suctobelba naginata AOKI belong to Quercus-grove, and Epilohmannia cylindrica (BERL.), Protoribates lophotrichus (BERL.) and Oppia nova (OUDMS.) to Pinus-grove as characteristic species. It is obvious that such a difference in the oribatid fauna between the two groves results only from the difference of vegetation

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Flower-visiting habits of 6 species of the genus Megachile were examined during from April to October in 1952-1959. Two common species, M. tsurugensis and M. nipponica, have 2 or 3 generations a year. These bees have already developed ovaries at the time of emergence, and make flower-visiting in the complete form of request (request type A or B). The flowers of Leguminosae and Compositae were visited predominantly by M. tsurugensis and M. nipponica. Moreover, both species preferred such flowers as follows: Trifolium repens, Astragalus sinicus, Vicia unijuga, Lespedeza cyrtobotrya, Cirsium japonica, Aster sp., Erigeron annuus. The tube renting habits of M. tsurugensis and M. nipponica seem to be favorable for practical use as pollinators, because it is possible to protect and multiply these bees by means of artificial providing of their nesting sites.

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In the previous paper, the seasonal trend of the occurrence of E. zinckenella and the crop damage caused by the insect in the Kantô district was reported. In the present paper, the author wishes to discuss the relation between temperature or moisture and development of the species. The oviposited eggs were collected every morning and were bred in petri dishes solitarily, under the constant temperatures of 20°, 25° and 30°C. The larvae were supplied with soy bean pods. Observations were made on the developmental velocities of all stages, the longevities of the adult moths, and also on the effect of moisture on the pupation.
The developmental zero point was found to be 13.9°C for egg stage, and 14.9°C and 15.1°C for larval stage with female and male respectively, and 15°C and 14.6°C for pupal stage with female and male respectively. The sum of effective temperature was calculated as 67.9, 168.1, 166.5, 135.7 and 147.1 day degrees respectively. Comparing the above data with those of other Lepidopterous insects, it was found that this species belongs to the group characterized by having higher developmental zero point but having lower sum of the effective temperature in 1 generation. This fact is considered to account for that the species is of tropical insect and of multivoltine type.
Estimation made by applying the law of sum of effective temperature, indicates that this insect should repeat about three generations in a year in Kantô district and about four generations in Shikoku and Tôkai-kinki districts. These computed data coincide fairly well with actual data of the observations.
The larvae which were bred under the short day illumination and low temperature hardly pupated and remained as larvae for a long time. But these larvae were able to pupate when sufficient temperature and humidity were given.
The longevities of the reared moths were about 13 days at varying temperatures with average was 25°C. In this case no significant difference was found between male and female, but when water and food were not supplied, the longevity of the moth became as 9.5 days at 25°C and 5.7 days at 30°C, the female moth showing more or less longer duration than the male moth.

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The author performed histochemical as well as histological observations on the vitally stained and fixed materials using mottled translucent silkworm larvae, translucent and their normal segregants with many dyes. The results obtained were as follows:
1. In the case of injection and oral administration of several basic dyes to the mottled larvae, the opaque (normal) portion in the integument was stained deeply but translucent portion was scarcely colored, and silk glands and Malpighian tubes were stained in mosaic feature. Especially neutral red showed excellent stainability in those tissues. While the integument scarcely colored after injection and oral administration of acidic dyes, but many other organs were stained uniformly with acidic dyes.
2. There was no great difference between nucleic acid of normal cells and that of translucent ones by pyronine-methyl green staining.
3. As to fixed materials, epidermal cells, silk glands and Malpighian tubes of both translucent and normal larvae were stainable with neutral red and nile blue, translucent cells of the epidermis in mottled mutant larva being stained more deeply than normal cells. The above mentioned result is different from that of vital staining with basic dyes.
4. It was observed that there were many vacuoles in the epidermal cell of translucent larva and of the translucent portion of mottled larva, but normal epidermal cells had no or few vacuoles, the epidermal cytoplasm of the normal larva being more compact than that of the translucent one.
5. No clear difference was observed between translucent and normal segregants concerning phosphatase activity.
6. In view of the above mentioned results, it is conceivable that the electric charge and properties of cytoplasm play an important role for adsorption and reservation of uric acid and some pigments and dyes in epidermal cells.

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Experiments were made to know the relation between the body fluid of the paddy borers and the yellow muscardine fungus. Overwintered larvae of the rice stem borer and paddy borer were infected with spores of the yellow muscardine fungus by means of inoculation and injection and the hyphal growth was observed 20 hours after infection at 25°C. The hypha growth was hastened as the larvae near to pupation, and the length of hypha grew significantly longer after March, although the diameter of the spermatocyst did not change until May. Further the hyphal growth in relation to the weight of the overwintered larvae was also examined. It was observed in case of rice stem borer that the heavier the weight of the larvae, and in case of paddy borer the lighter the body weight, the longer the hypha and the larger the spermatocyst as well as the testis.
It was also confirmed in the first generation larvae of both species that the hyphal growth of the yellow muscardine fungus became faster as the larval inster advanced. A comparative test with various muscardine fungi other than the yellow muscardine did not reveal such definite results.
These results seem to show that the high susceptibility of overwintered larvae to the fungus near to pupation is controlled mainly by their humoral condition.
The authors believe that the number of moths in the first generation which is much controlled by the yellow mascardine fungus, is possibly forecasted by measuring the susceptibility of the overwintered larvae to this fungus.

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This investigation was conducted to know the distribution structure of rice stem borer larvae as well as the injury in the area which is divided into several parts that the administrative (such as district, aza or village, town, and city etc.) or geographical divisions were considered as the units of their ecological fields. In 1957 and 1958, the paddy field having a radius of 300 metres with a forecasting lighttrap in its center, at the Yata-district; in 1959, the lower plain (1500ha) along the Hidaka River, Hidaka Gun, Wakayama Prefecture; in 1960, the lower plain of the Kinokawa-River in Kii-district, Wakayama-City were respectively singled out for this investigation.
The numbers of the infested plants and stems and the larvae found in them were counted at the utmost-infested of the first brood (the middle of July), at the end period of the first brood (the middle of August) and after the larvae of the second brood were all scattered away (the middle of October), respectively.
The results obtained in this invetigation can be summarized as follows:
1. In the case of the utmost-infested period, the intensity of injury differs by location though it was not so remarkable as in the case of the second brood. Especially in the case of the larger area as much as 1500ha, the percentage of infested plant in one district was found to be six to nine times as much as the one of another. In the case of 1959, the percentages of infested plant in the plain districts were smaller than the sloped districts.
2. In the case of the end period of the first brood, the infested stem or larvae density was observed to be remarkably lowered by the environmental resistances. But also in this period high densities were equally found in the districts where an abundant population density was observed in the previous period, and in most of the districts, the population densities were not decreased equally by effects of parathion.
3. In the case of the second brood, the differences of densities between the districts were not always corresponded with the first. And the aggregated distribution was found peculiarly in district location. This tendency of aggregation in this period was far more remarkable than in the first brood period and the number of infested stems reached ten times as much as in the first brood period. And the locations where high injuries observed were constantly the same place all through this four years investigation.

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Experiments of the above title are done by middle rotations of the homogenizer, which rotates a little more than 26 r.p.m. and mixes moths twice per rotation by the action of agitation vane inserted at 45 degree to the base of a drum. As the number of an unit group, 600 and 200 moths are adopted in accordance with the ordinary custom of egg producers. Results are as follows.
1. After rotation of the homogenizer for only five seconds, the distribution of almost all groups of diseased moths becomes already binomial or normal.
2. As the rotation time of the homogenizer becomes longer and longer, the distribution of diseased moths tends more and more to fit the normal formula than the binomial, and in some cases, it takes PEARSON'S II-type distribution curve or in other cases, even if rare, more than halves of the number of experiments centre to the position of population mean value p, though their mode deviate slightly to right or left side of the position p'.
3. The effect of homogenizing action of this machine seems to be not seriously influenced by the percentage of diseased moths.
4. Interaction-test, comparing p & p' and q & q' or by SNEDECOR'S R×2 method using population variance, pq, shows in all cases the uniformity of variance, after rotated samples for five seconds or more.
5. Inspections using confidence interval p±3√pq/nκ and p±2√pq/nκ show equivalence in all former cases and in latter cases, when the time of rotation becomes fifteen seconds or longer. POISSON distribution inspection using x²-test also proves to be equivalent in all cases of experiments.
6. Abstraction of the required number of moths to be inspected can be easily done from any part of their unit group by picking out at a sampling and the number of sampling units, fifty, may not necessarily be needed, if the homgenizer is previously used.
7. If the high rotatory speed is used, the required time of rotation can be reduced to half, however in order to exclude fine scales of moths, infected with spores of pébrine, by the electric fan, the rotation time for thirty seconds may be desirable.

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The author investigated the relation between the time of oviposition and the overwintering of eggs, in order to make clear the conditions of the overwintering in the brown planthopper eggs.
The eggs were reared in the weighing bottles in which relative humidity was kept 100 percent under the condition of natural temperature. The results obtained are as follows:
1) The number of hibernated eggs closely related with the time of oviposition at the end of autumn, thereupon the later the eggs were oviposited at this time, the more the hibernated eggs increased.
2) The stage of embryonic development of the hibernating eggs were subjected to the influence of which the time of the oviposition was early or late in autumn.
The later the eggs were oviposited in autumn, the more the hibernated eggs at the yellow spot stage increased.
As the results mentioned above, it was thought that the stage of embryonic development of the hibernated eggs was the yellow spot stage.
3) According to the results of observations on the fluctuation of the percentages of the survival eggs and the eggs having hatching-ability, the percentage of the survival eggs did not decrease remarkably during the overwinter period from the end of January to the beginning of April but the percentage of the eggs having hatching-ability decreased with the time passed from the end of January onwared gradually, and it showed the tendency to decrease rapidly after the growth of hibernated eggs with the rising of the temperature in spring.

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An attempt was made to determine if several inducing agents avairable for the silkworm polyhedroses might be also effective to induce polyhedroses of several other lepidoptera, Barathra brassicae, Hyphantria cunea, Antheraea pernyi, Malacosoma neustria testacea and Lymantria dispar. In general, none of the tested stressors (excessive cold, EDTA, Na-EDTA, formalin and hydrogen peroxide etc.) significantly increased the incidence of polyhedroses. The difference between the silkworm, Bombyx mori and these wild insects in the response to these stressors may be attributed either to the lack of the occult virus or to low aptitude in the wild insects.
The cytoplasmic polyhedrosis virus of Bombyx mori was transmittable to Antheraea pernyi. The shapes of polyhedra formed in the mid-gut epithelium of the latter were not uniform and differed from those of silkworm polyhedra used for the inoculation, which were either tetragonal or hexagonal.
In Hyphantria cunea the authors found tetragonal and triangular nuclear polyhedra, which could be considered to be formed by different viruses respectively. When fed a mixture of the two viruses, the insects were all mixedly infected. The feeding of triangular polyhedra followed later by the feeding of tetragonal polyhedra resulted in the formation of only triangular polyhedra in most of the infected larvae, and the remaining insects were mixedly infected. It was suggested that the first invading virus interfered with the second virus in the infection and multiplication. However, in the case of the feeding of tetragonal polyhedra followed later by the feeding of triangular polyhedra the interference of the first invading virus with the second one was scarecely observed. It may be that the tetragonal polyhedron virus was less virulent than the triangular polyhedron virus and interfered in lower degree with the latter virus.

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Two kinds of fresh water fish, Pseudorasbora parva and Oryzios latipes, were tested on the suitability to material of bioassay. First, the characters of their suscetibility were studied by affecting them with 24 kinds of pesticides. And it was shown that both kinds of fish were very susceptible to most of hydrochloric insecticides and some of other kinds. It was also observed that many of the fish poisoned with organophosphoric insecticides had crooked abdomens with internal bleeding which were not caused with other kinds of pesticides, while most of the fish poisoned with antibiotics showed neither hyperaction nor convulsion till they were killed.
Then the following bioassays were carried out, making use of the above-mentioned characters.
(1) PCP in water was traced and the controlling factors of its decomposition were studied with P. parva.
(2) Endrin residue on the persimon fruits and cabbage leaves was traced also with P. parva.
(3) The pond water supposed to be contaminated with Parathion was tested with O. latipes and a water-flea, Moina macrocopa, which are different from each other in the susceptibility to Parathion.
All these tests were performed with success, proving the possibility of using these fish as material of bioassay.

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The anesthetizing effect and toxicity of carbon dioxide to adults of the flesh fly, Sarcophaga peregrina Robineau-Desvoidy, and the adzuki-bean weevil, Callosobruchus chinensis L., were studied. The longer the time of exposure to CO₂, the longer was the inactivation of the insect. Carbon dioxide appeared to be non-toxic to flesh flies when they were exposed to it for as long as 70 minutes. Exposure for 180 minutes, however, resulted in definite toxicity. No toxic effect due to exposure to carbon dioxide was detected in the adzuki-bean weevil.

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