田间高效诱集二化螟雄蛾的性信息素诱芯的筛选

1浙江大学 昆虫科学研究所, 浙江 杭州 310058;2浙江省桐庐县农业技术推广中心, 浙江 桐庐 311500;3浙江省嘉兴市农业经济局, 浙江 嘉兴 314000;4温州医学院健康与环境生态研究所, 浙江 温州 325035;5中国科学院 华南植物研究所, 广东 广州 510650     

稻螟赤眼蜂rDNA特异引物设计及诊断引物在赤眼蜂分子鉴定中的应用

 根据稻螟赤眼蜂(Trichogramma japonicum)的rDNA ITS2序列,利用软件Primer Premier 5.0设计出该寄生蜂的特异引物。通过PCR条件的优化,设计的引物能稳定地扩增出稻螟赤眼蜂的特异性条带,大小为256 bp。应用设计的稻螟赤眼蜂特异引物以及报道的松毛虫赤眼蜂(T. dendrolimi)、玉米螟赤眼蜂(T. ostriniae)和螟黄赤眼蜂(T. chilonis)特异引物对赤眼蜂样品进行PCR扩增分析。结果表明,4对特异引物可从单头蜂稳定地扩增出各自蜂种的目的DNA条带,并且分子鉴定结果与形态学鉴定结果完全一致。     

建国以来江西二化螟的发生、危害及药剂防治回顾

简要分析了我国水稻螟虫发生和为害的历史,阐述了江西二化螟暴发成灾现状及其种群演变规律;在总结二化螟药剂防治经验的基础上,提出了防治抗性二化螟的替代化学药剂。     

Photodegradation of emamectin benzoate and its influence on efficacy against the rice stem borer, Chilo suppressalis

Emamectin benzoate, a novel insecticide with characteristics of translaminar movement into plant leaf tissue, was derived from the avermectin family with improved thermal stability, greater water solubility and a broader spectrum of insecticidal activity than avermectin. To quantify UV photodegradation of emamectin benzoate, HPLC analysis was conducted to quantify residues of MAB1a, the major component in emamectin benzoate, after exposure to UV light for different lengths of time. Results showed both MAB1a concentration and length of UV light exposure (0-120 h) had significant impacts on photodegradation rate. The degradation rate increased as exposure duration increased, but decreased as initial MAB1a concentration increased. Four UV protectants, kojic acid, sodium ligninsulfonate, soybean lecithin and milk, were evaluated for their effect on UV degradation. Results showed that kojic acid could effectively reduce the photodegradation of MAB1a. In addition, the photodegradation of emamectin benzoate was also examined for its influence on the efficacy against the rice stem borer, Chilo suppressalis. The results of the bioassays were consistent with those of HPLC analysis. The initial concentration of emamectin benzoate and exposure duration to UV light both had significant influences on the efficacy against C. suppressalis. As the UV exposure time increased, the efficacy of emamectin benzoate against C. suppressalis decreased. The results indicated that UV photodegradation has a significant effect on the efficacy of emamectin benzoate against C. suppressalis and the effect is concentration-dependant. In addition to understanding the critical factor of UV exposure length, this study also showed that maintaining emamectin benzoate concentration above a certain level in the formulation and the application solution, and applying UV protectants may reduce photodegradation and increase efficacy against target pests.     

二化螟越冬幼虫在稻株内的分布及其控制技术研究

研究了二化螟越冬代幼虫在不同虫口密度田块和不同受害程度稻株内的分布情况以及农事操作技术措施对越冬二化螟的防治效果。结果表明:二化螟幼虫在水稻植株上的分布数量表现为随着稻株离地面高度的升高而减少,且这种分布趋势与田间的二化螟幼虫密度无关;二化螟幼虫在不同受害程度的稻株上的分布均以5~10 cm的稻株部位最多。在翌年春季,在稻草上越冬的二化螟出蛾率(36.44%)高于在稻桩上越冬的二化螟出蛾率(27.11%),但是在稻桩上越冬二化螟的出蛾数量(138.25)极显著高于在稻草上越冬二化螟的出蛾数量(34.25)。"火烧+堆沤"(冬前在田间对稻草进行焚烧,翌年早春再进行堆沤)处理和旋耕处理对越冬二化螟的防治效果均较好,防效分别为71.17%和66.25%,显著高于单独焚烧稻草或单独堆沤处理的防治效果。     

金坛地区螟虫发生概况与防治对策

分析了1995年以来江苏省金坛市二化螟Chilo suppressalis(Walker)、三化螟Tryporyza incertulas(Walker)的发生动态与防治方法,从冬后基数、灯诱数量、秧田期与大田期的防治、成熟期考察等几方面分析了螟虫种群在江苏省金坛市的消长动态,总结了螟虫的防治经验.     

氯虫苯甲酰胺对荻蛀茎害虫的防治效果试验

荻蛀茎夜蛾(Sesamia sp.)、棘禾草螟(Chilo hyrax)是为害芦苇生长的主要害虫,常年发生率高,造成芦苇减产严重。本试验使用氯虫苯甲酰胺对荻蛀茎夜蛾和棘禾草螟进行防治,取得良好效果。     

黔中稻区二化螟的越冬幼虫虫口密度及其自然寄生率

为准确预测预报黔中稻区二化螟越冬后的发生提供理论依据,采用GB/T15792—2009稻桩剥查法对贵阳市花溪区、安顺市平坝县、黔南州惠水县和黔东南州麻江县等稻区二化螟越冬幼虫虫口密度及自然寄生情况进行调查。结果表明:麻江县的越冬幼虫虫口密度最高,达15 741头/667m2;其次为平坝县和惠水县,越冬幼虫虫口密度分别为10 684头/667m2和10 153头/667m2;贵阳市花溪区的越冬幼虫虫口密度最低,仅944头/667m2。大多数地区的雌雄蛹重量有显著差异。调查共采集到5种寄生蜂,包括稻螟小腹茧蜂、螟甲腹茧蜂、大螟钝唇姬蜂、菲岛抱缘姬蜂和黄眶离缘姬蜂;各稻区的寄生率均较低,平坝县二化螟幼虫被寄生率最高,达15.6%,其次为麻江县14.6%、花溪区6.7%和惠水县5.7%。     

Determination of the economic threshold of whitefiy,Bemisia tabaci Genn., on American cotton in the Punjab

Abstract

Studies were conducted to determine the economic threshold of whitefiy, Bemisia tabaci Genn. on cotton at the Cotton Research Station, Muktsar during 1981 to 1983. The results show that the spray on American cotton var LH 372/F 414 against whitefiy be initiated as and when a population of 6 to 8 whitefiy adults/leaf is noticed from mid July onwards or when the middle canopy leaves show yellow spots and are sticky by touch. The average reduction in yield due to whitefiy attack were 8% and 10% in the first and last years and 31% the maximum in 1982–83.     

不同药剂混配组合对二化螟的防治效果

选用毒死蜱、氯虫苯甲酰胺、阿维菌素和甲维盐4种化学药剂的单剂及其混配组合,在室内对二化螟进行了毒力测定,筛选出最佳混配比例（有效成分）：毒死蜱与甲维盐（1∶1）、毒死蜱与氯虫苯甲酰胺（10∶1）、阿维菌素与氯虫苯甲酰胺（1∶1）、 阿维菌素与毒死蜱（1∶1）, 其共毒系数分别为376.77、 254.84、 247.10和682.34。 田间试验结果表明,室内所获得的混配组合对二化螟的防治效果均达到76.4%以上,可有效防治二化螟,且对水稻生长安全。