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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 4
Displaying 1-12 of 12 articles from this issue
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Atsushi SUGIMOTO1978 Volume 22 Issue 4 Pages 219-227
Published: November 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSExperiments in rearing melon fly larvae were mostly carried out using an insect colony reared for successive generations in the laboratory. For uniform distribution of eggs on an artificial larval medium, a suspension of eggs in tomato juice was poured on the medium. Temporarily lowering the rearing room temperature was also found to be highly effective in accelerating “popping off” of larvae from the medium. After testing the composition of various larval media based on wheat bran, BST-3 was found to be the most suitable for mass rearing. Approximately 8 pupae with an average weight of 15mg were recovered for each milliliter of this medium, and the yield averaged more than 70%. This medium also gave a 50-60% yield in the case of eggs of wild melon flies. Accordingly, a large cage was designed to accommodate 500, 000 mature larvae grown on the medium described above. Furthermore, a high-nutrition medium for mass rearing of larvae was also tested and about 14 pupae with an average weight of 14mg were recovered for each milliliter of the medium. Despite the high temperature maintained in the medium, pupae and emerged adults developed normally.View full abstractDownload PDF (2790K) -
Hiromu AKAI, Shigeru SATO, Sakae SAKATE1978 Volume 22 Issue 4 Pages 228-233
Published: November 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe hemocytes of the wild silkworm, Antheraea yamamai G. were observed by a transmission electron microscope. They are classified into five classes; prohemocytes, granular cells, spherule cells, plasmatocytes, and oenocytoids. The prohemocytes are undifferentiated hemocytes containing undeveloped cytoplasmic organelles. The granular cells produce many specific cytoplasmic granules which are secreted into the hemocoel. The rough endoplasmic reticulum forms numerous large characteristic cisternae. A small number of spherule cells were detected in the hemocytes. Several characteristic spherules containing fine granules are found in the cytoplasm. Plasmatocytes are spindle-shaped or pear-shaped, and have no cytoplasmic inclusion. Oenocytoids are large cells, and contain few fine fibrous inclusions in the cytoplasm. In comparison with Bombyx hemocytes, Antheraea hemocytes are similar in fundamental hemocyte classification. However, several differences of the hemocyte differentiation from Bombyx hemocyte are found in each hemocyte type, particularly granular cells, spherule cells, and oenocytoids. Hemocyte classification and differentiation is also discussed.View full abstractDownload PDF (3485K) -
Akira TSUCHIYAMA1978 Volume 22 Issue 4 Pages 234-237
Published: November 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSA bioassay of Bacillus thuringiensis subsp. kurstaki formulation to larvae of the diamondback moth, Plutella xylostella L. using an artificial diet was performed. When the reference formulation was bioassayed, the variance of LC50 was nearly the same as that with the silkworm (Bombyx mori L.). The potency of the sample was calculated by the formula below to estimate BMU (Bombyx mori unit) and PXU (Plutella xylostella unit).
Potency of sample=LC50 reference formulation/LC50sample×1, 000 BMU/mg (orPXU/mg)
A sufficiently high correlation coefficient between BMU and PXU (r=0.997) was obtained. BMU calculated from PXU was very close to the experimental results.View full abstractDownload PDF (444K) -
Keizo HAYASHIYA, Yuko UCHIDA, Michio HIMENO1978 Volume 22 Issue 4 Pages 238-242
Published: November 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSSedimentation tests were performed by adding RFP purified from the silkworm digestive juice to NPV extracted from the nuclear-polyhedral body of a diseased silkworm by two methods, a capillary tube and an agglutination plate. The white line of the precipitate clearly occurred at the border of the RFP and NPV layers in buffer solutions when they were carefully introduced into the capillary tube. The precipitate was also observed in the pH range of 7.5-8.5 when these two solutions were mixed in the bottom of the agglutination plate. RFP also reacted with silkworm flacherie virus (FV) to precipitation, but the reactions with tabacco mosaic virus (TMV) and Autographa california NPV (AcNPV) were negative. RFP did not precipitate with proteins such as serum albumine, histone, and the protein of the polyhedral body of silkworm NPV.View full abstractDownload PDF (1808K) -
Jong-tae KANG, Keizi KIRITANI1978 Volume 22 Issue 4 Pages 243-249
Published: November 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSA total of 22 wooden frames (30×30×20cm) covered with cheese wire net were set up in a fallow paddy field and were introduced 20 mature nymphs of Nephotettix cincticeps each either with or without a subadult female of Lycosa pseudoannulata. The number of leafhoppers disappeared was counted weekly in the frame from late January to late March. The number of leafhoppers was kept at 20 per frame by adding artificially on each census.
In terms of the number of samples and biomass, it was thought the effective predators were mostly consisted of L. pseudoannulata, micryphantid spiders, staphylinids and carabids. Concerning 4 species of predators which represent each predator group, i.e. L. pseudoannulata, Oedothorax insecticeps, Paederus fuscipes and Pterostichus longinquus, the numbers of mature nymphs of N. cincticeps attacked per day were examined at different temperatures: 5, 10, 15, 20 and 25°C. The calculated predation zero points were respectively 5.2, 1.4, 8.6 and 4.0°C. Above 10°C L. pseudoannulata was definitely superior to others in attacking the prey. The daily mean temperatures at 2cm above the ground surface in the experimental field was higher than that measured at 1.2m by about 7°C and rarely recorded below the predation zero point of L. pseudoannulata suggesting the continuous predation on N. cincticeps throughout the winter. The mean total number of leafhoppers disappeared in the frames was 19.5 with the presence of L. pseudoannulata as against 3.7 without it.
As a result it was suggested L. pseudoannulata plays an important role as a mortality factor of N. cincticeps even in winter. Based on the relationship between the number of N. cincticeps disappeared and the predator days (No. predators×No. days present) of L. pseudoannulata, it was shown that N. cincticeps may be decreased to one-half during the winter in the presence of L. pseudoannulata at a density of 5 individuals per m2 early in the overwintering season.View full abstractDownload PDF (878K) -
Shiro KOBAYASHI, Hideki TAKANO1978 Volume 22 Issue 4 Pages 250-254
Published: November 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSSecond and third generations adults of Pieris rapae crucivora were marked and released shortly after emergence. The results of multi-recapture showed that the adult duration was 4.58±0.24 days (female) and 5.44±0.26 days (male) for the second generation, and 3.24±0.05 days (female) and 3.06±0.04 days (male) for the third. The butterflies of the second generation dispersed in all directions from the release site, while those of the third generation flew mostly in easterly and southerly directions. It is suggested that the reduction of adult duration in the third generation is attributable to increased emigration and mortality.View full abstractDownload PDF (474K) -
Juro KOYAMA1978 Volume 22 Issue 4 Pages 255-259
Published: November 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDamage by the rice leaf beetle, a rice insect pest, was studied from 1975 to 1977 in Akita, in northern Japan. When the percentage of leaves injured by the larvae of the rice leaf beetle exceeds 30%, yield loss of rice occurred in some experimental paddy fields. But in other experimental paddy fields, an injury rate exceeding 30% did not cause yield loss of rice. The injury by the larvae tended to cause yield loss in fields in which the increase in the number of tillers was slow or the percentage of productive tillers was small. The yield loss of rice plants injured by the larvae resulted from reduction of the number of ears per hill.View full abstractDownload PDF (557K) -
I. An Analysis of Survivorship Curves in Relation to Mortality FactorKazuo EMURA, Akio KOJIMA1978 Volume 22 Issue 4 Pages 260-268
Published: November 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSIn the study of the threshold density for insecticidal control of Oulema oryzae, it is necessary to understand the population dynamics of the insect. Survivorship curves were therefore examined in 9 paddy fields. The survival rates of the 3rd instar larvae varied greatly among fields (8.7-64.9%), but 30.7% in the average. Mortality was especially high among 1st instar larva. The average survival rates from eggs of pupae and adults were 15.2% and 10.2%, respectively. The principal mortality factor for eggs was a parasitic wasp, but its effect was insignificant. The larvae, especially young larvae, are very sensitive to air humidity, and this fact was experimentaly demonstrated. Therefore, it is thought that in the field, larval mortality is largely due to low air humidity. From above examination, we concluded that survival of this insect is greatly dependent on weather conditions. Finally, we the feasilibity of using the survivorship curve for estimation of the threshold density for insecticidal control of this insect is discussed.View full abstractDownload PDF (1190K) -
Mitsuo OYAMA, Sadao WAKAMURA, Noboru TAKIGAWA, Seiya KAMANO, Muneo OKA ...1978 Volume 22 Issue 4 Pages 269-280
Published: November 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe injury of Spodoptera litura to the taro plant (Colocasia) can be prevented by masstrapping using traps baited with synthetic sex pheromone and by spraying with nuclear-poly-hedrosis virus. Mass-trapping and releasing synthetic mating disruptants did not significantly suppress the larval population density, probably because the plots used in both treatments were smaller than the flying area of adults. The experimental results suggest that successful control of S. litura population would be possible if a more extensive area were treated. The number of males captured in traps increased with an increase of the larval population density from July to August. These results indicate the feasibility of successful forecasting of the population density of this insect. The timely spraying of young larvae with nuclear-polyhedrosis virus would enable significant suppression of the population density of the larvae at 5th and 6th instars, which most injurious to the taro plant.View full abstractDownload PDF (1958K) -
Norizumi SHINKAJI, Tetsuzô HAMAMURA, Wataru ASHIHARA1978 Volume 22 Issue 4 Pages 281-283
Published: November 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe feeding activity of Pyrrhalta humeralis adults decreased significantly after ca. 2 weeks from the adult emergence of June, and was maintained at a low level towards the end of August or the beginning of September.View full abstractDownload PDF (1021K) -
Susumu TAKEDA, Masami NAKANE(HIKICHI)1978 Volume 22 Issue 4 Pages 283-285
Published: November 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (877K) -
Seiya KAMANO1978 Volume 22 Issue 4 Pages 285-286
Published: November 25, 1978
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (763K)
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