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Volume 10 (1966)
- Issue 4 Pages 167-
- Issue 3 Pages 105-
- Issue 2 Pages 55-
- Issue 1 Pages 1-
Volume 10, Issue 2
Displaying 1-9 of 9 articles from this issue
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I. Season of EmergenceRyoh-ichi OHGUSHI1966 Volume 10 Issue 2 Pages 55-63
Published: June 25, 1966
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSSeasonal occurrences of citrus flat-headed borer, Agrilus auriventris SAUNDERS were observed since 1962 to 1965 at Omura, Nagasaki Prefecture. Dead citrus trees which were attacked by the larvae of citrus flat-headed borer were put in outdoor cages during the spring of each year and numbers of emergent adults of the beetles were collected daily until the end of autumn. The numbers of emergent adults in every 5 days duration were shown in Fig. 1 (1962), Fig. 3 (1963), Fig. 5 (1964) and Fig. 6 (1965) with the mean temperature and rainfall of periods concerned. Seasonal variations of emergence of same species which were observed at two different stations of Nagasaki Prefecture in 1962 and 1963 were shown for comparison. And the data on emergence (begining of emergence, peak of emergence and the end of emergence) obtained at the various districts of Japan sach as Kumamoto, Wakayama, Nara and Nagasaki were shown in Table 2. It seems that the emergence of this species begins at the middle of May or the beginning of June and continues until the middle of October. The peak of emergence was seen in June or July and sometimes August or September. Generally, the emergent activity of citrus flat-headed borer was observed in the morning of fineday. But some of individuals emerged in cloudy or rainy day. The sex ratio of this species was nearly 1:1 in almost cases. And the seasonal and daily emergence of both sexes have shown similar tendencies.View full abstractDownload PDF (757K) -
Takuji ISHII1966 Volume 10 Issue 2 Pages 64-68
Published: June 25, 1966
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSA certain number of small brown planthoppers, having red-colored eyes, was obtained in F2 by crossing within general black-eyed small brown planthoppers collected from the field of our experiment station at Sapporo in October 1962. The occurrence of red-colored eye of this species seems to be new record. Inheritance of red color in eye was studied and was found to follow the Mendelian simple recessive gene explanation. Some ecological characters of both strains, black and red eyed, were compared but notable differences were not pointed out in preoviposition period, percentage of hatching, mortality at nymphal stages, nymphal growth, percentage of the appearance of the macropterous females, relation between renewing interval of food and the percentage of appearance of the macropterous females, phenomenon of diapause, acquisition and ability of transmission of the northern cereal mosaic virus. But certain differenses were recognized in sexual proportion of emerged adults, oviposition period, and number of eggs laid. The red-eye individuals were not found in the field, and the red-eye strain does not differ from the black-eye strain in its behavior. Accordingly, it may be possible to utilize the red-eye strain as a marked indvidual in the study of relation between transmission of viruses and ecology of this species.View full abstractDownload PDF (721K) -
II. Supplementary Experiments on the First Problem (Infection Formula of Pébrine Disease)Kaku OHSHIMA, Tadashi FUJIWARA, Yasuharu HIROSE, Yo KABASAWA, Kiichi S ...1966 Volume 10 Issue 2 Pages 69-77
Published: June 25, 1966
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSWhen the number of a lot containing a few diseased larvae was limited to 20, 000, the following facts were revealed: The infectivity of pébrine of a lot of newly hatched larvae containing 0.5% composed of the lightly diseased and the heavily diseased was exceedingly inferior to that of the larvae containg 0.05% of the lightly diseased. Expressing the infectivity by multiplication power, it became 73.5 times in the former, while 1, 117.6 times in the latter in the moth stages. The infectivity of heavily diseased larvae is very low. The multiplication power of the disease by 6 infected larvae mixed in a lot at 3rd day of 2nd instar was only 5.7 times in the moth stage, being 0.25%. The results above are common phenomena of silkworm reared in both seasons, spring and summer. These results sugget that the difference of increment of the number of diseased moths of a lot may be derived from the following two factors: 1. Hereditarily, lightly diseased larvae can live long and repeatedly attack healthy larvae, however, when their number are few, the chance of attacking the same larvae may be few, thus increasing the number of diseased larvae during the periods of 4th and 5th instars which are the source producing diseased moths (1966), but when their number are numerous, the reversed phenomenon may be probable by the repeat infection against the same larvae, thus decreasing the diseased moths. 2. Heavily diseased larvae: Early death and very few repeat infection. It is also suggested that the optimum number of lightly diseased larvae which produce the maximum percentage of infected moths may exist at the beginning of hatching.View full abstractDownload PDF (1175K) -
Hisashi ABE1966 Volume 10 Issue 2 Pages 78-83
Published: June 25, 1966
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSWild mice were trapped by snap-traps from 15 localities of Hokkaido which have various types of vegetations. Clethrionomys rufocanus bedfordiae (THOMAS) 277, C. rutilus mikado (THOMAS) 10, Apodemus argenteus TEMMINCK 224, and A. speciosus ainu THOMAS 51 were obtained. Three habitat factors, coverage, density of vegetation, and litter layer, were measured by the standard shown in Table 2 in the area of about 3m radius from a trap station at which a mouse was obtained. C. rufocanus bedfordiae is most common in the grass-field type of vegetation with large coverage, high density, and rich litter layer, and decreases in number toward the forest type of vegetation with low density and poor litter layer. C. rutilus mikado inhabits the forest and shrub types of vegetations with large coverage, high density, and rich litter layer, but is usually rare and sparse in Hokkaido. A. argenteus is a typical resident of the forest type of vegetation and rare or absent in grass field. This mouse does not prefer a particular grade of the coverage of shrub stratum or a particular depth of litter layer, but does prefer low density of vegetation. A. speciosus ainu is not so common in Hokkaido as the former species and does not appear to prefer a particular type of vegetation. The structure of the habitat, however, is somewhat similar to that of C. rufocanus bedfordiae.View full abstractDownload PDF (799K) -
II. On the Gestation Period and the Growth after the BirthShoei OTSU1966 Volume 10 Issue 2 Pages 84-88
Published: June 25, 1966
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSRecently the damages to young reforested trees by hares particularly to cryptomeria (Cryptomeria japonica D. DON), red pine (Pinus densiflora SIEB. et ZUCC.) and larch (Larix leptorepis MURRAY) have become serious in Yamagata Prefecture. The so-called Tohoku hare, Lepus brachyurus angustidens HOLLISTER, is very common in this district and wanders actively in the forest at night biting the growing top, branch and bark of the stem of the sapling.
The ecological study of the hare is fundamental for the control but so far little has been done. This paper is a part of the study dealing with the gestation period and the growth rate after the birth of the hare. Observations and measurements were done with 102 specimens. The results are as follows: The gestation period is 32-34 days as observed in 8 pregnant females. From the observation on gestation period it was suggested that the ovulation of this hare occurred after the copulation. The gestation period of this hare is longer than the domestic rabbit (Oryctolagus cuniculus var. domesticus (GMELIN)). The increase of body length of new born young continued for about 200 days after the birth until it reached about 49cm. The augmentation of body weight is continued for 260 days and reached about 2, 600g. The ear length and cranium length attained maximum of 8cm and 9.2cm respectively when the body weight increased to 2, 300g. The hind-limb length obtained maximum 15cm when the body weight became 2, 100g. The cranium width increased to its maximum much earlier becoming 4.5cm in the individual weighing 1, 800g.View full abstractDownload PDF (509K) -
An Example of Interrelation between a Polyphagous Predator and Its Principal PreysToshio OKU, Takashi KOBAYASHI1966 Volume 10 Issue 2 Pages 89-94
Published: June 25, 1966
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSIn 1963 and 1964 observations were made to ascertain the influence of the predation of Orius sp. on the aphid population in a soy-bean field at Morioka. Orius sp. increased rapidly from mid July to late August or early September, and fed mainly on aphids (Aphis glycines and Aulacorthum solani), spider mites (Tetranychus kanzawai, etc.), and less frequently on thripids (Taeniothrips glycines and Thrips hawaiiensis?, etc.) in the field. Dispersion of adults of the predator from the soy-bean field seemed to occur after soy-bean plant reached maximum growth. In 1963 the populattion of A. glycines was diminished by the predation of Orius sp. in early August, but it gradually recovered in parallel with increase of tetranychid, which is one of the principal preys of Orius sp. On the other hand, A. glycines multiplied towards August without any temporal decrease in the population in 1964, when an early outbreak of the tetranychid was observed. Every year Aulacorthum solani received profound predacious effect due to Orius sp., but gradually increased towards September. These phenomena were discussed in relation to the relative abundance in the principal preys of Orius sp. and their behaviour.View full abstractDownload PDF (729K) -
Masakatus YAMASHITA1966 Volume 10 Issue 2 Pages 95-96
Published: June 25, 1966
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (813K) -
Sumio NAGASAWA, Isamu NAKAYAMA, Haruko SHIMIZU1966 Volume 10 Issue 2 Pages 96-99
Published: June 25, 1966
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (450K) -
Tetsusaburo TACHIKAWA1966 Volume 10 Issue 2 Pages 99
Published: June 25, 1966
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (111K)
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