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Volume 36 (1992)
- Issue 4 Pages 217-
- Issue 3 Pages 153-
- Issue 2 Pages 81-
- Issue 1 Pages 1-
Volume 36, Issue 4
Displaying 1-9 of 9 articles from this issue
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Akio TATARA, Kaichi FURUHASHI1992 Volume 36 Issue 4 Pages 217-223
Published: November 25, 1992
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe relationship between the density of S. dorsalis on satsuma mandarin fruit and damage at harvest was analyzed from investigations in 12 mandarin groves in Shimizu, Shizuoka Prefecture during 1984-1988. Damage to the pedicel of fruits started to appear in early June and was maximum in early August. Silver-scar damage to the stylar end of fruits appeared from mid-August and was maximum at mid-September. Based on regression analysis of the damage to larval density, damage to the pedicel at harvest is related to the maximum larval density during the infestation period. However, no relationship was detected between damage to the stylar end and maximum larval density. The economic threshold for the fruit pedicel was calculated to be 8.0% expressed as a ratio of sampled fruits in which the larvae were found from early June to late July. The larvae were more aggregated than the adults within a tree and between trees.View full abstractDownload PDF (1396K) -
Hiroshi ADACHI, Takashi NARABU, Yoji MOMOTA1992 Volume 36 Issue 4 Pages 225-230
Published: November 25, 1992
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe root-knot nematode, Meloidogyne incognita, was cultured monoxenically on oriental-melon (Cucumis melo L.) roots transformed by Agrobacterium rhizogenes at various temperatures. The developmental zero degree of the nematode was 10.9°C. The day-degrees for the onset of oviposition were 293, and 473 for completing one generation after inoculation with 2nd-stage juveniles. There were no significant differences in the dimensions of eggs and pre-parasitic 2nd-stage juveniles between transformed roots and intact plant roots, although a slight temperature-dependency was seen in body length, tail length, and the a-avalue of juveniles. Regarding the infectivity on six differential host plants, juveniles produced on transformed roots were the same as those produced on intact host plant roots. These results suggest that the transformed root system is appropriate for culture of root-knot nematodes under sterile conditions.View full abstractDownload PDF (2095K) -
Masaru KOBAYASHI, Masashi YONEKAWA, Marcia N. YOKOYAMA, Masao NAKAGAKI ...1992 Volume 36 Issue 4 Pages 231-237
Published: November 25, 1992
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSWe carried out ultramorphological characterization of spermatogenesis in A. yamamai, A. pernyi, and their reciprocal hybrids (F1) as part of basic studies on the reproduction of wild silkworms. A spermatogonium derived from a primordial germ cell was differentiated by somatic cell division into a primary spermatogonium and a cyst-wall cell. The former proliferated by division until 64 (26) cells were produced. These 64 cells were linked by cell-bridges. This structure was retained until the stage of chondriosome-body formation in the spermatid. The 64 spermatogonia were enclosed by a gonocyst differentiated from a cyst-wall cell. The synaptonemal complex formed in the spermatocyte nucleus was detected in both parents and reciprocal hybrids, indicating that synapsis of homologous chromosomes occurs both in parents and interspecific hybrids. Maturation divisions in A. yamamai (Y) and A. pernyi (P) were found to involve prereduction. Karyogamy was observed during the chondriosome-body formation only in the spermatid of Y×P and P×Y hybrids. Sperms with plural axial filaments in the flagellum were found in both hybrids. These abnormal sperms comprised 40-50% of the sperms in one sperm packet. The motile function of sperms in fertilization is probably harmed by these abnormal sperms.View full abstractDownload PDF (5698K) -
Toshio MASUDA, Osamu KIKUCHI1992 Volume 36 Issue 4 Pages 239-245
Published: November 25, 1992
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe pathogenicity of two Verticillium lecanii isolates (MG-Vl-18 isolated from whitefly, Trialeurodes vaporariorum, and MG-Vl-45 from cotton aphid, Aphis gossypii) was investigated by inoculation experiments. Both MG-Vl-18 and MG-Vl-45 were pathogenic to T. vaporariorum, A. gossypii and Myzus persicae, but host specificities were observed. MG-Vl-18 was more pathogenic to larvae and adults of T. vaporariorum than MG-Vl-45. The pathogenic difference was especially noticeable in the larval stage at concentrations of 104-106conidia/ml. The pathogenicity of MG-Vl-45 was stronger than that of MG-Vl-18 to A. gossypii (apterous adults) and M. persicae (apterous and alate adults). The mortalities caused by the two isolates were almost the same (96-100%) at high concentrations (107, 108conidia/ml), but in the case of MG-Vl-18, the time to the death was longer than for other isolates. At lower concentrations (106, 105, 104conidia/ml), the mortalities at 9 days posttreatment for MG-Vl-45 were higher than those for MG-Vl-18. The sizes of conidia and blastospores were different between MG-Vl-18 and MG-Vl-45. MG-Vl-45 produced large conidia and blastospores with dimensions of 8.3×2.5μm (length×width) and 13.1×2.7μm compared to MG-Vl-18 with dimensions of 3.4×1.3μm and 5.5×2.7μm, respectively. The mycelial growth of MG-Vl-18 was faster than that of MG-Vl-45.View full abstractDownload PDF (962K) -
Kazuo KAWADA, Izumi YAMASHITA1992 Volume 36 Issue 4 Pages 247-251
Published: November 25, 1992
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSLongistigma liquidambarus (TAKAHASHI) was discovered feeding on Liquidamber formosana HANCE at Taihoku and Nanto, Taiwan in 1925 by TAKAHASHI. Its distribution is very limited and almost nothing about it has been reported since then. L. liquidambarus was first noted in Kurashiki, Japan in autumn 1990 and it was subsequently identified in Tsukuba, Kyoto, Osaka, Itami, Okayama, Kure, Nangoku, and Kochi. The Japanese specimens are compared with those from Taiwan. The life cycle of the species in Japan is not well known, but the aphid probably reproduces parthenogenetically all year around. Oviparous females and males have not been found yet. The distribution, seasonal prevalence and likely future spread in Japan are also discussed.View full abstractDownload PDF (2428K) -
Takeshi UJIYE, Rut MORAKOTE1992 Volume 36 Issue 4 Pages 253-255
Published: November 25, 1992
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSTen species of chalcidoid parasitoids were reared from the citrus leafminer, Phyllocnistis citrella in Thailand. Among them, Ageniaspis sp. seemed to be the most dominant and important biological control agent.View full abstractDownload PDF (1139K) -
Kiyoshi KASAMATSU, Masaomi OGAWA1992 Volume 36 Issue 4 Pages 256-258
Published: November 25, 1992
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSThe reproductivity of a fenpropathrin-resistant strain (FS-strain) of Tetranychus urticae (KOCH) was compared with that of a susceptible strain of the same origin (INM-strain) at temperatures of 20°C, 25°C and 30°C. The number of eggs produced by the FS-strain was lower than the number produced the INM-strain, especially at 30°C. There was no significant difference for hatchability of eggs, total development time and survival rate of immature stages and adults between strains. The intrinsic rate of natural increase (rm) was lower in the FS-strain than in the INM-strain at each temperature. These results suggest a lower fitness value for the FS-strain than for the original INM-strain.View full abstractDownload PDF (423K) -
Ryoichi HAMADA1992 Volume 36 Issue 4 Pages 258-259
Published: November 25, 1992
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDuring study of egg parasitism of Spodoptera litura (FABRICIUS) (Lepidoptera: Noctuidae), three species of Trichogramma (Hymenoptera: Trichogrammatidae) and one species of Telenomus (Hymenoptera: Scelionidae) were seen emerging from host eggs. Comparing the egg masses parasitized by Trichogramma spp. and Telenomus sp., percent of egg masses parasitized by the former was higher than that by the latter, whereas percent of parasitized eggs among attacked egg masses by the latter was higher than that by the former.View full abstractDownload PDF (245K) -
1992 Volume 36 Issue 4 Pages 267
Published: 1992
Released on J-STAGE: February 12, 2009
JOURNAL FREE ACCESSDownload PDF (141K)
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