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Volume 35 (1991)
- Issue 4 Pages 269-
- Issue 3 Pages 181-
- Issue 2 Pages 103-
- Issue 1 Pages 1-
Volume 35, Issue 2
Displaying 1-9 of 9 articles from this issue
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Yoshinori KUNIMOTO, Norizumi SHINKAJI, Hiroshi AMANO1991 Volume 35 Issue 2 Pages 103-108
Published: May 25, 1991
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSReproductive compatibility and morphological differences in the aedeagus were investigated for the diapausing (Dc) and non-diapausing (Nc) types of P. citri, and for P. ulmi (U). The duration of copulation was shorter when Dc_??_ was paired with any female type compared to other crosses. Among the crosses with Dc_??_, the duration of copulation increased successively with Nc_??_, U_??_ and Dc_??_. There was reproductive incompatibility between Dc and U but the mechanism is not clear. Morphological differences in the aedeagus were found between Dc, Nc and U. The aedeagus of Dc is similar to that of U but it can be distinguished by a bent hook top. A remarkable difference was found in the shape of the aedeagus between Dc and Nc.View full abstractDownload PDF (1518K) -
3. Reciprocal Transplant of OvariesYutaka KAWAGUCHI, Yutaka BANNO, Katsumi KOGA, Hiroshi DOIRA, Hiroshi F ...1991 Volume 35 Issue 2 Pages 109-113
Published: May 25, 1991
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSReciprocal transplant of an ovarian imaginal disc was performed on day 1 of the fifth instar between full-sib females of giant-egg forming (Ge) and normal-egg forming (+Ge) larvae segregated by the T (W; 3) Ze/os sch×os sch/Ge cross. When a normal ovary was implanted into a Ge female, the implanted ovary produced eggs that were normal in size, length and width, thus being the same as those derived from untreated normal females. However, the eggs derived from the host's intrinsic ovary were large in comparison to those of the untreated Ge mutant. Reciprocal ovary transplantation resulted in the production of Ge-size eggs from the implanted Ge ovary, and normal-size eggs from the +Ge ovary of the host. In both cases, the yolk protein content of Ge-size eggs was higher than that of normal-size eggs as seen in the respective controls.View full abstractDownload PDF (2231K) -
Shigekazu WAKISAKA, Ritsuko TSUKUDA, Fusao NAKASUJI1991 Volume 35 Issue 2 Pages 115-122
Published: May 25, 1991
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSLife tables were constructed for the diamondback moth, Plutella xylostella living in a broccoli field in Okayama in June, September and October 1989. Four plots were established to evaluate the role of natural enemies and the effect of rainfall on the survival: (1) All natural enemies and rainfall excluded by net and plastic roof; (2) Rainfall excluded by plastic roof; (3) Ground fauna excluded by tangle-foot coated fence; and (4) Control plot. One third to one half of individuals disappeared in the early immature stages. Since the mortality rate was lower in the plots with no rainfall, wash-off of eggs and larvae by rain and drowning of young larvae after rain are considered to be the major mortality factors. Water sprays also washed eggs and larvae off broccoli leaves. The percentage parasitism by the larval parasitoid, Apanteles plutellae, and the pupal parasitoids, Diadromus subtilicornis and Tetrastichus sokolowskii, was high in September. Temperatures of more than 30°C tended to delay development, and reduced the survival of immature stages and the fecundity of females. When the diamondback moth was fed on the wild cruciferous weed Capsella bursa-pastoris, its reproductive ability was lower than that when feeding on crops.View full abstractDownload PDF (961K) -
Hiroshi NAKAMURA, Takashi SUGIYAMA, Hidetoshi OKAMOTO1991 Volume 35 Issue 2 Pages 123-129
Published: May 25, 1991
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSA mark-and-recapture study and a census of adult-emergence holes were carried out in a Japanese cedar stand at Tyunan-cho, Kagawa Prefecture in 1987 to clarify the characteristics and factors of adult movement of the sugi bark borer, The recapture rate on the same tree was 72.2% of all recaptures. Adults tended to be captured less on trees where more emergence holes were observed, and did not stay on trees with more than 12 emergence holes. Adults captured on trees near the edge of the stand, or which emerged late in the season, moved to other trees more frequently. About 28% of marked adults did not move to other trees during the season and the rate changed with the adult density per tree. The mean distance of movement was 13.94m with movement of females being significantly greater than movement of males. The frequency distribution of the movement distance indicated that there may be two movement patterns: short-distance movement and long-distance movement. There was no direction tendency. Male adults stayed on the same tree longer than females and the duration decreased with increased numbers of movements. The ecological significance of the movement pattern is discussed in relation to selection of trees most suited to larval survival.View full abstractDownload PDF (943K) -
I. Effects of Infestation at Different Growth Stages of Soybean PlantHiroya HIGUCHI1991 Volume 35 Issue 2 Pages 131-135
Published: May 25, 1991
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe effects of common cutworm infestation on soybean yield were evaluated by inoculating different growth stages of soybeans with egg masses. Yield losses caused by early infestation at the flowering and pod-development stages were attributed mainly to the reduced production of pods per plant. Infestation at later reproductive stages caused yield losses by reducing the weight of individual beans.View full abstractDownload PDF (647K) -
Kenji KOYAMA, Jun MITSUHASHI1991 Volume 35 Issue 2 Pages 137-143
Published: May 25, 1991
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSEssential inorganic salts for the nymphal growth of Laodelphax striatellus FALLEN were examined by changing their composition, and the concentrations of MgCl2⋅6H2O and KH2PO4 in the MED-1 holidic diet. Mg, K and PO4 were found to be essential. MgSO4⋅7H2O could be used as Mg source instead of MgCl2⋅6H2O. The KH2PO4 could be substituted with either K2HPO4 or K3PO4. When H3PO4 was present, KCl, KHCO3, C6H5K3O7⋅H2O and CH3COOK showed about the same nutritive values. When KCl was present, H3PO4, NaHPO4⋅2H2O, Na2HPO4 and Na3PO4⋅12H2O showed similar effects on the nymphal growth.View full abstractDownload PDF (849K) -
V. Relationship between Host Preference and Organophosphorus ResistanceTsutomu SAITO1991 Volume 35 Issue 2 Pages 145-152
Published: May 25, 1991
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe relationship between host preference and organophosphorus resistance in Aphis gossypii GLOVER was investigated by laboratory tests using clones or populations, and by a field test. When a clone with high aliesterase activity was transferred from Cucurbitaceae crops to Solanaceae crops, which are the principal host for aphids with low enzyme activity, the longevity of transferred parent was shortened, the number of progeny was decreased, and the growth of offspring was greatly suppressed. The same effects were noted with the reverse transfer. Adaptation to the new crop family was not found even after the transferred clone had been reared on it for three months. Host plants did not affect the aliesterase activity of each clone. No individuals from field populations on eggplants colonized melon, or vice versa. The clone from Cucurbitaceae and Solanaceae crops could be reared on strawberry, but although the clone from strawberry could be reared on Solanaceae crops, it could not be reared on Cucurbitaceae crops. There were two kinds of aphid preference for Cucurbitaceae and Solanaceae host crops in a field population overwintered as viviparous females on Veronica persica. The aphids on Cucurbitaceae showed higher enzyme activity than those on Solanaceae. Aphids with high aliesterase activity were frequently observed on cucumber but not eggplant in a mixed field. It is suggested that there are different biotypes of aphids on Cucurbitaceae and Solanaceae crops, and that these biotypes are closely associated with organophosphorus resistance.View full abstractDownload PDF (1064K) -
Toru OHTANI, Akio TAKAFUJI, Masateru INOUE1991 Volume 35 Issue 2 Pages 153-159
Published: May 25, 1991
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe seasonal occurrence of Tetranychus kanzawai KISHIDA and two of its predators were studied in an open eggplant field which had been sprayed periodically with each of three synthetic pyrethroids (SP; fenvalerate, permethrin, and fenpropathrin) over about 5 months. The occurrence was compared with the occurrence in fields sprayed with an organophosphorus insecticide (fenitrothion) and or an acaricide (fenbutatin oxide), and in fields that were not sprayed. The mite populations exhibited 3-4 distinct peaks in plots sprayed with fenvalerate or permethrin, and 2-3 peaks in plots sprayed with fenpropathrin about 20 days after spraying. The peak densities in August in the SP plots reached 1, 000-3, 000 adult females per plant, which were much higher than in fields that were not sprayed and in those sprayed with other pesticide(s). The dominant predators in this eggplant field were the phytoseiid mite, Amblyseius longispznosus (EVANS), and the anthocorid bug, Orius sp. In the SP plots, the densities of these predators remained much lower throughout the study period and increased much less in response to increases in mite density than in the other plots, although the density of Orius sp. was relatively high in plots sprayed with fenpropathrin. These results clearly show that the mite outbreaks occurred because of the adverse effects of the SP sprays on the mite predators.View full abstractDownload PDF (849K) -
Manabu SHIBAO, Fukusaburo TANAKA, Ritsuko TSUKUDA, Kenji FUJISAKI1991 Volume 35 Issue 2 Pages 161-163
Published: May 25, 1991
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe overwintering sites and stages of Scirtothrips dorsalis HOOD were investigated both in a grape field and a greenhouse from November 1989 to April 1990 in Okayama. It is suggested that S. dorsalis adults migrate to the overwintering sites before the grape leaves die and fall in November. A few overwintering adults were collected from various sites including bark, litter and soil both in the greenhouse and the grape field throughout the winter.View full abstractDownload PDF (369K)
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