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Volume 22 (1978)
- Issue 4 Pages 219-
- Issue 3 Pages 1-
- Issue 2 Pages 51-
- Issue 1 Pages 1-
Volume 22, Issue 1
Displaying 1-11 of 11 articles from this issue
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I. Influence of Larval DensityHiroyuki NARUSE1978 Volume 22 Issue 1 Pages 1-6
Published: February 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe relationship between larval density of the peach leaf-miner and the degree of defoliation of peach tree has been investigated in 1975. From July to September, the number of leaves per shoot decreased remarkably, and the cause of this heavy defoliation was mostly attributed to the injury of high larval population of the miner from third to sixth generation. The defoliation rate at a given survey time (percentage of leaves dropped by the next survey time) was lineary related with the logarithm of larval density per leaf on the same date, and the lower threshold of larval density that brought about defoliation was estimated to be about 2 per leaf. A similar, but less clear relationship was found between larval density and defoliation rate of individual trees. The leaves which located near the base of new shoots had higher possibility of defoliation than those situated near the top. Among the leaves being at a similar level on shoot, however, there was a tendency that the rate of defoliation rose with increase in the number of inhabiting larvae on the leaf. The mortality of larvae by these defoliation was considered to act as the density dependent process and play a role in the regulation of the peach leaf-miner population.View full abstractDownload PDF (676K) -
Hiroichi MATSUURA, Kazuki MIYASHITA1978 Volume 22 Issue 1 Pages 7-11
Published: February 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe larvae of Agrotis ipsilon HUFNAGEL began to appear in Ishikawa Prefecture in mid-May and continued to occur until mid-September when their number declined rapidly and disappeared altogether by early October. Their disappearance in the fall seemed to be connected with their overwintering, since the day-length became shorter than 12hr during that period. The larvae were therefore reared at 20° and 26°C for different photoperiods in order to reveal the relationship between diapause induction and photoperiod, but they failed to enter diapause under any conditions tested. Adult females obtained from these rearings were kept in actographs to detect the photoperiodic effect on their nocturnal activities, but no such effect was observed. In addition, the development of ovaries under short-day as well as long-day conditions was found to have been completed by the 6th day after emergence. Therefore, it was difficult to explain the disappearance in the fall of this insect by either the induction of diapause or migration under the influence of the seasonal change in photoperiod. However, since N. OKABE and A. TOMISAWA have found a few adults under the floors of houses in February, 1977, the possibility of overwintering in the adult stage remains to be examined.View full abstractDownload PDF (1227K) -
Makoto YASUDA1978 Volume 22 Issue 1 Pages 12-17
Published: February 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe citrus red mite was reared singly or in a group on a citrus leaf at 25°C with 16hr illumination. The net reproduction rate per generation (R0) and the intrinsic rate of natural increase (r) were estimated to be 19.57 and 0.1708, respectively, on the basis of the results of the individual rearings. When a single female adult was introduced on a citrus sapling, the number of female adults increased rapidly for 3 or 4 generations to reach peak density and then decreased drastically to a low level. The phase of population increase corresponded well with the equation of exponential growth (Nt=N0er0t), and the instantaneous growth rate (r0) was estimated to be 0.113, which was very close to the estimated value of the intrinsic rate of natural increase. The rapid decline of the mite population after attaining peak density was mainly caused by the dispersal of adults. The dispersal occurred when the population increased to a high density of 40 or more female adults per leaf, which caused serious deterioration of the leaf (indicated by 80∼100% of an index of injury). A mass dispersal of adults from one leaf to others was often observed under such conditions.View full abstractDownload PDF (790K) -
IV. The Correlation of Wood Mice Species and Floor Plants of Young PlantationsShoei OTSU1978 Volume 22 Issue 1 Pages 18-21
Published: February 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThis investigation was carried out in forests situated at altitudes ranging from 560 to 680 meters on the eastern side of Mt. Shirataka (alt. 994m). Two types of plantation, a young Japanese cedar (Cryptomeria japonica D. DON.) and a young Japanese red pine (Pinus densiflora SIEB. et ZUCC.), were selected for the investigation. The floor plants of both plantations consist of Japanese pampas grass (Miscanthus sinensis ANDERSS.), weeds, young broad-leaved deciduous trees, bamboo grass (Sasa paniculata MAKINO et SHIBATA), or arrowroot (Pueraria Thunbergiana BENTH.). The collection of voles and mice at 8 different plots were made by means of snap trapping with sweet potato as the bait. Microtus montebelli montebelli was abundant in the weeds of the floor plants of both plantations. Clethrionomys rufocanus andersoni was frequently found in the floor weeds of the young Japanese cedar plantation. Apodemus speciosus speciosus was also very common in this type of plantation, especially that having young broad-leaved deciduous trees on its floor. Apodemus geisha geisha was also found frequently in the same plot.View full abstractDownload PDF (540K) -
Shigetoshi MIYAJIMA1978 Volume 22 Issue 1 Pages 22-25
Published: February 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThis paper reports on the stability of a cytoplsmic-polyhedrosis virus (CPV) of the silkworm to chemicals in order to obtain suitable chemicals and their concentrations for purification of CPV. A CPV readily lost its infectivity by chloroform and chloroform-n-butanol (1:1), but was not affected by treatment with 1×10-1, 1×10-2 and 1×10-3M ethylenediaminetera-acetic acid (EDTA), 5, 10, 20 and 40% carbon tetrachloride, and 1M magnesium chloride at 50°C for 60 minutes, respectively. No difference in the response to chemicals was observed between two strains of CPV, i, e, the hexagonal polyhedron and tetragonal types.View full abstractDownload PDF (454K) -
Yoshio MATSUNAGA1978 Volume 22 Issue 1 Pages 26-32
Published: February 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSWhen petroleum emulsions were sprayed on Satsuma orange trees in January, initial penetration of low-viscosity oil into leaf tissue was faster than that of viscous oil. Ten or more days after the application, however, the level of viscous oil in leaf tissue became higher than that of low-viscosity oil. Cold-hardiness of orange trees decreased with the lapse of time after oil spray. It also decreased faster with a decrease of oil viscosity, owing to the greater penetrative properties of oil. After an adequate period for penetration of oil into leaf tissue, however, no apparent difference in lowering cold-hardiness was found among treatments with oils of different viscosities. These results indicate that decrease in cold-hardiness is closely related to the oil level in leaf tissue. The lowering of cold-hardiness in oil-sprayed trees might be due to abnormal consumption of soluble sugars in leaves. No oil contained in new leaves developed after oil application.View full abstractDownload PDF (913K) -
Hideakira TSUJI, Katsuhiro FUJITA1978 Volume 22 Issue 1 Pages 33-37
Published: February 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSFormothion (0, 0-dimethyl S-[N-methyl-N-formylcarbamethyl] phosphorodithioate) and MTMC (2-tolyl-N-methylcarbamte) showed no synergistic action, either when topically applied to last instar nymphs or when incubated with ChE in whole body homogenate of nymphs. However, they showed high synergistic action when dusted in powder form over rice plants in test pots into which nymphs were released. Synergistic action was remarkable when one of the insecticides was topically applied to the stem of rice plants and another was dusted over the plants in powder from, and also when both insecticides were applied to the stem of rice plants. These results indicate that synergistic action was realized through systemic and/or fumigant effects of the insecticides, which thus operated on the nymphs indirectly. BPMC (2-sec-butylphenyl-N-methylcarbamate), MPMC (3, 4-xylyl-N-methylcarbamate), and NAC (1-naphthyl-N-methylcarbamate) also showed synergistic action when topically applied to rice plants in combination with formothion.View full abstractDownload PDF (596K) -
Kaname MATSUMOTO, Akio FUJIWARA1978 Volume 22 Issue 1 Pages 38-39
Published: February 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (209K) -
Atsushi SUGIMOTO, Takashi KOBAYASHI1978 Volume 22 Issue 1 Pages 40-43
Published: February 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (537K) -
Shun-ichi NAKAO1978 Volume 22 Issue 1 Pages 43-45
Published: February 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (427K) -
Eizi KUNO1978 Volume 22 Issue 1 Pages 45-46
Published: February 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (204K)
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