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Volume 15 (1971)
- Issue 4 Pages 175-
- Issue 3 Pages 109-
- Issue 2 Pages 51-
- Issue 1 Pages 1-
Volume 15, Issue 1
Displaying 1-6 of 6 articles from this issue
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Atsushi KOKUBO1971 Volume 15 Issue 1 Pages 1-7
Published: March 25, 1971
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe adult emergence of the pine-moth, Dendrolimus spectabilis BUTLER is generally once a year in Japan, but in some localities a second adult emergence occurs in autumn. It is said that a part of the first generation larvae which appeared earlier in the year emerges as the second adult. In this paper, results of field observations carried out in the Kashima district of Ibaraki Prefecture where many second adults emerge annually are presented. The first adults emerged from late June to mid July every year though the peak of emergence changed from year to year, and this emerging time was about two weeks earlier than that of the one-brood areas where the adults emerged once a year. It seemed that the phenomenon mentioned above had a close relation to the annual emergence of the second adults. In ordinary years almost all of the survivals in the first generation became the second adults, but in some years the number was considerably small. It appeared that the rate of emergence of the second adult was affected not only by climatic conditions but also by individual insect differences. In addition, the weight of the second adult was about half as that of the first adult.View full abstractDownload PDF (899K) -
Nobuo OHKUBO, Ryoiti KISIMOTO1971 Volume 15 Issue 1 Pages 8-16
Published: March 25, 1971
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDaily periodicity of flight activity of the brown planthopper, Nilaparvata lugens STÅL, inthe 4th and 5th emergence periods from late August to early September and late September to October, and that of the green rice leafhopper, Nephotettix cincticeps UHLER, in the same period was investigated with a JOHNSON & TAYLOR'S suction trap of 12 inches. N. lugens adults took off at sunrise and sunset in late August. Light intensity adequate for take-off was about 1-200lux. It was considered that the periodicity of N. lugens was a bimodal crepuscular type. But in the later season as a result of suppression by low temperature three types of flight periodicity curves were observed. Namely, bimodal crepuscular, unimodal crepuscular at sunset and diurnal. The threshold temperature for take-off was about 17°C. Flight behaviour was also suppressed by wind of over 11km/hr. N. cincticeps adults took off only after sunset. Light intensity for take-off was 0.1-20lux, considerably lower than that for N. lugens. Take-off was suppressed by winds of over 12km/hr, but no clear suppression by low temperature was evident, at least until the beginning of October, when density of N. cincticeps became low. It was observed that N. lugens aduls to take off moved up to the top of rice plants and after take-off flew upright unless drifted by wind. The simultaneous take-off of many adults was observed. Sex-ratio (% of females) of take-off adults of N. lugens was about 20% in the beginning of each emergence period and tended to increase to 60%, representing 44.1% as an average. Almost the same trend was observed in N. cincticeps. No N. lugens that mated was captured among the flying 46 and 96 females at the peak period of each generation. These flights were considered to have the characteristics of migratory flights.View full abstractDownload PDF (1711K) -
Makoto NAKAJIMA, Haruo YOSHIDA1971 Volume 15 Issue 1 Pages 17-22
Published: March 25, 1971
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe purpose of this study was to clarify the changes in ultraviolet sensitivities to killing during the instar stage. When larvae were exposed to ultraviolet light, with a dose of 7×104ergs/mm2, at various stages from hatching to the end of the third instar, a pronounced cyclic change in radiosensitivity to killing was observed during each instar. The most sensitive stage for killing was when about 60 percent of the age of each instar was reached, corresponding to the late DNA synthetic period in the epidermal cells which are presumed as the critical organ. Furtheremore, it was confirmed that the killing effect of ultraviolet light was photoreactivable to a certain extent. Possible mechanisms behind the phenomena of such killings have been discussed.View full abstractDownload PDF (824K) -
Syunro UTIDA1971 Volume 15 Issue 1 Pages 23-30
Published: March 25, 1971
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSInfluences of temperature on the number of eggs deposited, egg mortality, larval and pupal mortality, number of adults emerged, duration of developmental period and adult longevity of six different species of Bruchid infesting stored beans were studied under laboratory conditions. Callosobruchus maculatus was most resistant to high temperature, not only in oviposition but also in egg mortality and larval mortality. C. analis was the next. C. rhodesianus and C. phaseoli showed high mortality in the high temperature range. Zabrotes subfasciatus and C. chinensis were intermediate. The optimum range of temperature for oviposition, survival of egg and of the larvae was different for different species and different geographical strains, and showed the same order of differences with respect to high temperature resistance. Based upon the law of total effective temperature, point of developmental zero was estimated. It was 18°C or 17°C for C. maculatus and 13°C or 12°C for C. chinensis and C. phaseoli. C. rhodesianus, C. analis and Z. subfasciatus took intermediate temperatures. This order was almost the same with that of high temperature resistance.View full abstractDownload PDF (825K) -
IV. Effect of Prolonged Exposure to Light on BreedingShoei OTSU1971 Volume 15 Issue 1 Pages 31-35
Published: March 25, 1971
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSTohoku hare, like other wild mammals, manifests periodical sexual activity according to the season. Minimal ovarian weight is observed during the season from November until January. Generally, gradual enlargement of size with increase in weight is seen from the end of Feburuary or from early March. During the breeding season, in spring and summer, the ovary is large in size and active. It undergoes rapid degeneration from September or sometimes from October. In the present experiment the effect of prolonged light exposure upon breeding was studied, with special reference to ovarian activity. From December 11, 1968, 25 mature females and 10 males in captivity were exposed daily to natural daylight from sunrise to 9a.m. and then artificial light was added until 9p.m. An increase in ovarian weight was observed from 50 days after the start of the experiment, namely from the end of January. However, a similar state of ovarian activity is not normally attained until late Feburuary or early March in the wild. Though the exposure experiment was ended on May 6, the ovary showed no signs of degeneration even on Apil 12. This year, the first pregnant female was captured in the wild on Feburuary 26 and one female gave birth to a litter of 3 on April 5. However, in the experiment a pregnant female was observed on January 30 and one female gave birth to a litter of one on Feburuary 22. The experimented animals continued to give birth until April 10. From April 11 to June 29 breeding seemed to be ceased but from June 30 it began again and continued until August 22. It is worthy to note that the ovaries, both of the wild animals or of the animals experimented, contained fully grown follicles at all seasons of the year.View full abstractDownload PDF (1657K) -
Fumiki TAKAHASHI, Kuniyasu MIZUTA1971 Volume 15 Issue 1 Pages 36-43
Published: March 25, 1971
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe life cycle of A. rhopaloides, which makes a gall on the branchlets of the “Moso” bamboo, Phyllostachys pubescens, was studied in relation to those of three parasitic hymenopterous species in a bamboo forest near Kyoto City. Galls were sampled several times from the forest at fixed intervals. Species of insects in a gall and their developmental stages were determined by dissecting the galls and examining soft-X ray photography. The hostparasite relationship and the time of parasitization were examined by covering the bamboo branches with nylon-gause bags. The adult of A. rhopaloides emerges in early May and oviposits on the young buds of bamboo branchlets, which develops to a gall. Only one larva develops in a gall until September when it pupates and goes into hibernation. The adult of Diomorus aiolomorphi emerges in middle and late May and oviposits on a young gall which was developed by A. rhopaloides. The larva of D. aiolomorphi, however, does not parasitize on the larva of A. rhopaloides, but has an inquilinous life. The larva usurps a gall and feeds on its interior tissues as the larva of A. rhopaloides does. Though several numbers of eggs (x=3.28) are deposited in a gall, only one individual survives and completes its larval development by August of the same year. The larva hibernates during the larval stage and pupates in April of the following year. The larva of Eupelmus sp. parasitizes on the larva of A. rhopaloides and hibernates during the larval stage. Only one adult wasp emerges from one gall in late May or early June. Homoporus japonicus is a multivoltine species. The first emergence occurs in June, and the next emergence from August to October. Some individuals seem to pass three generations in a year, but the abundance of such individuals could not be determined. Several numbers of larvae parasitize on the larva of A. rhopaloides and about 4.4 adult wasps emerge from one gall. They hibernate in the larval stage. The sex ratios (_??_:_??_) of the four species are as follows: A. rhopaloides: 3:1, D. aiolomorphi: 1:1, Eupelmus sp.: 1 or a little more: 1, H. japonicus: 2.4:1.View full abstractDownload PDF (2315K)
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