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Volume 41 (1997)
- Issue 4 Pages 187-
- Issue 3 Pages 115-
- Issue 2 Pages 75-
- Issue 1 Pages 1-
Volume 41, Issue 1
Displaying 1-9 of 9 articles from this issue
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Masatoshi MOCHIZUKI1997 Volume 41 Issue 1 Pages 1-5
Published: February 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSTo examine the permethrin resistance of Amblyseius womersleyi (Hiranuma-1 strain), 10 successive permethrin selections were carried out under laboratory conditions by spraying the pesticide solution on the mites on a leaf disc. During six selections with wettable-powder (WP) permethrin concentrations of 400ppm, the survival rates increased from 35.5% to 61.6%. Since the emulsifiable concentrate (EC) of permethrin is more toxic than the WP formulation, the next four selections were switched to EC permethrin concentrations of 50ppm. The survival rates increased from 8.7% to 31.6% during these selections. The WP permethrin LC50 of this selected strain (SEL10) was 522.6ppm. Although this LC50 is only twice as high as that of the initial strain (Hiranuma-1), it is much higher than the recommended permethrin concentration for tea growers. The resistance stability of permethrin, methidathion and methomyl of the SEL10 strain was monitored after the selection. The permethrin resistance level remained stable for 20 months, and then decreased greatly. The methidathion and methomyl resistance level decreased slightly over the monitored period.View full abstractDownload PDF (1304K) -
Takenari INOUE, Hiroaki MIYATA, Toshiaki SAKAI, Koumei INOUE, Masatosh ...1997 Volume 41 Issue 1 Pages 7-15
Published: February 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSA total of 184 Illicium anisatum L. plantations were surveyed in Shikoku Island, Southwest Japan, to analyze damage caused by the Camphor Tree Weevil, Dyscerus hylobioides (DESBROCHERS) larvae. In Kochi, Ehime, Tokushima and Kagawa, 81%, 77%, 58% and 14% of plantations were invaded by this weevil, respectively. Damaged plantations were distributed widely in the west and south parts of the island (Kochi, Ehime and southern Tokushima), but there were few in northeast parts (Kagawa and northern Tokushima). Multiple regression analyses show that the percentage of trees injured by D. hylobioides larvae is higher with increasing plantation age and is high in plantations near forests. Damage is high in weedy plantations, but lower with increased frequency of spraying agricultural chemicals. To reduce damage to plantations, we recommend controlling weeds and spraying insecticides, especially in west and south parts of Shikoku.View full abstractDownload PDF (1609K) -
Hiroshi SUENAGA, Akira TANAKA1997 Volume 41 Issue 1 Pages 17-25
Published: February 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe seasonal abundance of larvae of the beet armyworm, Spodoptera exigua (HÜBNER), was surveyed by counting in garden-pea, Pisum sativum L., fields in Yamakawa Town in Kagoshima Prefecture, Japan, in 1992 and 1993. S. exigua larvae were found after the plant height reached about 10cm, with the maximum occurrence at around 13 to 26cm. After the plant reached about 30cm, the number of the larvae remained at less than three per 100 plants until late November. This pattern was observed in all fields irrespective of the seeding time from mid-August to early October. A delay of about 10 days in seeding time (late August) reduced the maximum abundance of larvae to <50% of that in fields seeded in mid-August. Further delayed seeding (early October) reduced the maximum abundance to 10%-20%. Pheromone trap catches from August 1992 to March 1994 showed six occurrence peaks for nine traps in 1993. The first peak occurred in late April, the 2nd to 4th between June and August, the 5th in late September to early October, and the last in mid- to late-November. The 5th and 6th peaks also occurred around the same time in 1992.View full abstractDownload PDF (1060K) -
Shozo ENDO1997 Volume 41 Issue 1 Pages 27-31
Published: February 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe rice leaf folder, Cnaphalocrocis medinalis GUENÉE, is a serious pest of rice plants in southwest Japan, and is a main target of chemical control. The susceptibility of adults and larvae to insecticide was compared by topical application. The LD50 of cartap for adults was smaller than that for larvae. However, in the case of monocrotophos and acephate, the LD50 values for adults were much larger than those for larvae. Analysis of the fate of the insecticides showed that the intake of monocrotophos and acephate was larger for adults than larvae. For acephate, less methamidophos was produced in adults than in larvae, but a homogenate of adults produced more methamidophos from acephate than for larvae. There were no differences in sensitivity to those organophosphorus insecticides of acethylcholinesterase between adults and larvae. It is believed that monocrotophos and acephate are stored in some tissues in adults.View full abstractDownload PDF (600K) -
Masahiko MORISHITA1997 Volume 41 Issue 1 Pages 33-38
Published: February 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSI studied the seasonal occurrence of the two-spotted spider mite, Tetranychus urticae KOCH (green form), in chrysanthemum and pea fields and the dispersal between fields in central Wakayama Prefecture, Japan. During the summer, before pea planting, T. urticae are never observed on weeds near the pea fields. However, the mites occurred at high densities on chrysanthemums throughout the year, including the cultivation and nursery period, and move into pea fields in September. T. urticae survive and oviposit prolifically on chrysanthemum under experimental conditions, whereas T. kanzawai fail to develop to adulthood. These results show that chrysanthemums are the principal host of T. urticae, from where the mites migrate to pea fields.View full abstractDownload PDF (1140K) -
Katsuo TSUDA, Nobuhiko NAKASHIMA, Masahiro YAMANAKA, Yoshio OHIRA, Tak ...1997 Volume 41 Issue 1 Pages 39-44
Published: February 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSVirus-like particles were isolated from the Brown-Winged Green Bug, Plautia stali. Diseased nymphs revealed typical symptoms of virus infection. Re-infection of healthy nymphs with haemolymph of diseased nymphs resulted in typical disease symptoms. Infected nymphs died within several days with severe symptoms. The haemolymph maintained virulence for nymphs after filtration of 0.22-μm pore size and after serial passage through nymphs. One opalescent band was seen after sucrose density-gradient centrifugation. The band had virulence to nymphs and contained spherical particles estimated about 30nm in diameter by electron microscopy. These results indicated that the particles are a virus.View full abstractDownload PDF (1756K) -
Takafumi TSUTSUMI, Masahiro YAMANAKA1997 Volume 41 Issue 1 Pages 45-49
Published: February 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSInfection by the entomogenous fungus, Beauveria brongniartii, of adults of the Yellow Spotted Longicorn Beetle, Psacothea hilaris was examined by dispersing conidia using non-woven fabric sheet containing the fungus. The mortality of adult beetles was 100% when they were reared 50cm from the sheet for 7 days. When the adult beetles were allowed contact with leaves contaminated by dispersed conidia, the mortality was 30%-40%. Sheets containing the fungus covered with an opaque plate were hung on fig trees to control P. hilaris adults. The mortality of adult beetles collected 10 days after attaching the sheet was 90%, but decreased to 57% after 31 days. More than 107 conidia/cm2 exhibiting infectivity to P. hilaris adults were detected for 55 days after sheet attachment.View full abstractDownload PDF (1276K) -
Yoshinori KUNIMOTO, Masateru INOUE1997 Volume 41 Issue 1 Pages 51-54
Published: February 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe deposition index of acaricide was measured using water-sensitive paper, and the relationship between this index and mite mortality was examined by laboratory and field tests. The acaricide deposition index and mortality of an acaricide-susceptible strain of the Two-Spotted Spider Mite, Tetranychus urticae KOCH were observed in laboratory tests. The results indicate an exponential relationship fenpyroximate. On the other hand, in direct observations using directscarlet liquid, the relationship between the deposition index and the actual deposition of droplets is exponential. In field tests with tebufenpyrad on eggplants, higher deposition indices resulted in higher mortalities of the Kanzawa Spider Mite, T. kanzawai KISHIDA. When the deposition index was 5 or more the mite mortality reached more than 70%. We propose that a deposition index of more than 5 measured by water-sensitive paper is a requisite condition for effective spraying.View full abstractDownload PDF (1206K) -
Keiji YASUDA, Kazuko TAKAYESU, Katsue UEHARA1997 Volume 41 Issue 1 Pages 55-58
Published: February 25, 1997
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSBeauveria bassiana infected Cylas formicarius irrespective of temperature between 15 and 31°C. No infection was observed at relative humidities of less than 43%. The median tolerance limit for conidia density per cm2 was 2.2×109 (male) and 3.7×109 (female).View full abstractDownload PDF (796K)
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