日本応用動物昆虫学会誌
Online ISSN : 1347-6068
Print ISSN : 0021-4914
ISSN-L : 0021-4914
52 巻, 4 号
選択された号の論文の7件中1~7を表示しています
総説
  • 浅野 昌司, 宮本 和久
    原稿種別: 総説
    2008 年 52 巻 4 号 p. 183-192
    発行日: 2008/11/25
    公開日: 2009/03/18
    ジャーナル フリー
    Effect of spores on enhancing the insecticidal activity of Bacillus thuringiensis (Bt) delta-endotoxin (refer to toxin) has been reported to vary depending on the species of insect and variety of Bt, procedure of toxin preparation, bioassay methods and so on. Some studies have demonstrated a remarkable synergistic effect of spores on the insecticidal activity of toxin, but others have not. These discrepancies have raised the following questions: Are spores necessary for the insecticidal activity of Bt toxin? Why is there so much variation in synergistic action between spores and toxins? What problems are there with the bioassay method for judging synergism? To address these questions, we reviewed studies on the interaction between spores and toxins in the insecticidal action of Bt and outlined the problems which should be clarified further to elucidate the role of spores in the insecticidal activity of Bt toxin.
原著
  • 石島 力, 佐藤 安志, 大泰司 誠
    原稿種別: 原著
    2008 年 52 巻 4 号 p. 193-200
    発行日: 2008/11/25
    公開日: 2009/03/18
    ジャーナル フリー
    The development, sex ratio, emergence rate, and body size of the egg parasitoid Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae), reared on the eggs of Adoxophyes honmai and Homona magnanima, were investigated in the laboratory at five constant temperatures (16, 20, 24, 28, and 32°C). Although the developmental rate of T. dendrolimi reared on both hosts increased significantly with increasing temperature, the developmental rate of T. dendrolimi reared on the eggs of H. magnanima increased significantly with increasing temperature more rapidly than those reared on the eggs of A. honmai. The developmental zero and total effective temperatures for females and males reared on the eggs of A. honmai were 11.7°C and 120.5 degree-days and 11.5°C and 119.0 degree-days, respectively. The developmental zero and total effective temperatures for females and males reared on the eggs of H. magnanima were 11.7°C and 114.9 degree-days and 11.7°C and 116.3 degree-days, respectively. The sex ratios (female/total) of adults emerging from the eggs of A. honmai and H. magnanima were 0.76–0.89 and 0.71–0.77, respectively. The sex ratio of adults emerging from the eggs of A. honmai was significantly higher than that of adults emerging from the eggs of H. magnanima. The percentage adult emergence rates of T. dendrolimi [{numbers of emerged adults/(numbers of emerged adults+numbers of dead individuals inside eggshells)}×100] reared on the eggs of A. honmai and H. magnanima were 23.5–73.4% and 41.8–85.0%, respectively. The adult emergence rates of T. dendrolimi reared on both hosts decreased significantly at an accelerating rate with increasing temperature. The head widths of female and male adults emerging from the eggs of A. honmai were 0.172–0.186 mm and 0.168–0.188 mm, respectively, whereas those of female and male adults emerging from the eggs of H. magnanima were 0.202–0.216 mm and 0.195–0.212 mm, respectively. The head widths of T. dendrolimi reared on the eggs of A. honmai increased significantly with increasing temperature. In contrast, the head widths of T. dendrolimi reared on the eggs of H. magnanima decreased significantly at an accelerating rate with increasing temperature.
  • 橋本 健一, 飯島 和子, 小川 賢一
    原稿種別: 原著
    2008 年 52 巻 4 号 p. 201-206
    発行日: 2008/11/25
    公開日: 2009/03/18
    ジャーナル フリー
    The photoperiodic response curve for pupal diapause induction of the white cabbage butterfly, Pieris rapae crucivora Boisduval was determined in several populations of the Japan Archipelago. Larvae were reared under different photoperiods ranging from 8L16D to 16L8D at 20±0.5°C. The critical photoperiods for pupal diapause induction were 14 h 40 min for the Iwamizawa population (43°10′N), 13 h 15 min for the Sendai population (38°15′N), 13 h 10 min for the Nagaoka population (37°23′N), 12 h 08 min for the Okayama population (34°39′N), 11 h 50 min for the Matsuyama (33°50′N) and Kagoshima (31°35′N) populations and 11 h 15 min for the Naze population (28°23′N). The critical photoperiod increases as latitude increases. This result suggests that adaptation to a cool climate in a higher latitude region shifts the critical photoperiod for pupal diapause induction towards a longer range. The developmental zero for the larval stage in the Sapporo (43°03′N) and Matsuyama populations was calculated as 9.8°C and 9.6°C for the larval stage, respectively. These results are discussed in relation to seasonal adaptation for each population.
  • 平江 雅宏, 田村 克徳, 福田 善通
    原稿種別: 原著
    2008 年 52 巻 4 号 p. 207-213
    発行日: 2008/11/25
    公開日: 2009/03/18
    ジャーナル フリー
    The occurrence of biotypes of pest insects virulent to resistant crop varieties is a serious problem for the utilization of resistant crops; therefore, it is important to prevent the occurrence of resistance-breaking biotypes by examining their characteristics. In this paper, the development and reproduction of three biotypes of the green rice leafhopper Nephotettix cincticeps (Uhler) were examined on resistant rice varieties of Chugoku 105 (carrying the resistance gene Grh1), Saikai 182 (Grh2), and Aichi 80 (Grh3(t)). Biotypes 1, 2, and 3 exhibited a high survival rate, short developmental period, long adult longevity and high fecundity on the respective Grh1, Grh2, and Grh3(t)-carrying resistant varieties to which they are virulent. The total sugar content of the honeydew excreted by these biotypes was high, suggesting that each biotype has the ability to suck phloem sap from the resistant variety to which it is virulent. The nymph survivorship and development, adult longevity, fecundity, and total sugar content of honeydew excreted by the three biotypes were similar to those observed in the non-selected line of the Nipponbare variety carrying no resistance gene. These results indicate no fitness difference in development and reproduction between the three biotypes and the non-selected line of N. cincticeps on susceptible rice varieties.
  • 森 克彦, 高木 一夫, 柑本 俊樹, 後藤 哲雄, 小林 政信
    原稿種別: 原著
    2008 年 52 巻 4 号 p. 215-223
    発行日: 2008/11/25
    公開日: 2009/03/18
    ジャーナル フリー
    The seasonal fluctuation and species composition of spider mites and their predators on soybean were investigated in an agrochemical sprayed plot and an unsprayed control plot from 1999 to 2001 in Ibaraki, central Japan. Sprayed plots were treated with cypermethrin and fenitrothion (1999), acephate and imidacloprid (2000), and permethrin (2001). In both plots, spider mite populations showed three peaks in 1999 (June, August and October–November), and two in 2001 (August and September–November). In 2000, the populations peaked only once (August), because soybean flowered and fruited more than one month earlier than in other years and as a result, all leaves had dropped by late September. Of the spider mite species sampled, Tetranychus kanzawai Kishida, T. parakanzawai Ehara, T. pueraricola Ehara et Gotoh and T. urticae Koch (green form) dominated in both plots and at almost all times. Predators were phytoseiid mites, such as Gynaeseius liturivorus (Ehara), Amblyseius tsugawai Ehara, Neoseiulus californicus (McGregor), and N. womersleyi (Schicha), and insects like Scolothrips takahashii Priesner and Feltiella sp. The population density of G. liturivorus was positively related to the occurrence of phytophagous thrips until August when the thrips became scarce. Synchronized with spider mite density were phytoseiid mites other than G. liturivorus after August, and Scolothrips takahashii throughout the observation periods. Agrochemical spraying had an initial detrimental effect on phytoseiid mites and S. takahashii, but they had recovered by two–four weeks after spraying, suggesting that the effect of chemical spraying on predators was weak.
短報
  • 西東 力, 土井 誠, 田上 陽介, 杉山 恵太郎
    原稿種別: 短報
    2008 年 52 巻 4 号 p. 225-229
    発行日: 2008/11/25
    公開日: 2009/03/18
    ジャーナル フリー
    The leafminers Liriomyza trifolii and L. sativae are exotic crop pests in Shizuoka Prefecture, Japan, and were first recorded in 1990 and 2001, respectively. From surveys conducted in the Prefecture between 1992 and 1994, seven parasitoid species were reared from L. trifolii, of which Neochrysocharis formosa and Chrysocharis pentheus were the most abundant. Surveys in 2004 and 2006 recorded 12 parasitoid species from L. sativae, and the most abundant parasitoids were once again N. formosa and C. pentheus. In both surveys, high female ratios were found in populations of N. formosa, suggesting that this species is parthenogenetic. Our surveys indicate that N. formosa and C. pentheus are the dominant parasitoid species of exotic invasive Liriomyza spp. and may play a key role in regulating their populations.
  • 重久 眞至
    原稿種別: 短報
    2008 年 52 巻 4 号 p. 229-232
    発行日: 2008/11/25
    公開日: 2009/03/18
    ジャーナル フリー
    Seasonal changes in egg diapause induction and the effects of photoperiod and temperature on the sorghum plant bug, Stenotus rubrovittatus (Matsumura), were investigated. Female bugs were collected approximately every five days from fields in Azuchi, Shiga Prefecture from mid-August to early October for three years, from 2004 to 2006. The proportion of diapause eggs produced by the collected females increased rapidly in mid-September, reaching approximately 100% in October. Bugs were reared from egg to adult at three temperatures: 20, 25 and 30°C, combined with eight photoperiods, ranging from 11.5L12.5D to 15L9D. The critical photoperiod for egg diapause induction fell between 13L11D and 14L10D at 25°C; however, the critical photoperiod for females reared at 20°C became slightly longer, and females reared at 30°C tended to lay non-diapause eggs. The percentage of diapause eggs produced by the females reared at 30°C was 73.0, 41.9 and 80.1% under 12.5L11.5D, 12L12D and 11.5L12.5D, respectively.
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