Host microhabitat location by stem-borer parasitoidCotesia flavipes: the role of herbivore volatiles and locally and systemically induced plant volatiles

The origin of olfactory stimuli involved in the host microhabitat location inCotesia flavipes, a parasitoid of stem-borer larvae, was investigated in a Y-tube olfactometer. The response of femaleC. flavipes towards different components of the plant-host complex, consisting of a maize plant infested with two or more larvae of the stem borerChilo partellus, was tested in dualchoice tests. The concealed lifestyle of the stem-borer larvae did not limit the emission of volatiles attractive to a parasitoid. A major source of the attractive volatiles from the plant-host complex was the stem-borer-injured stem, including the frass produced by the feeding larvae. Moreover, the production of volatiles attractive to a parasitoid was not restricted to the infested stem part but occurs systemically throughout the plant. The uninfested leaves of a stem-borer-infested plant were found to emit volatiles that attract femaleC. flavipes. We further demonstrate that an exogenous elicitor of this systemic plant response is situated in the regurgitate of a stem-borer larva. When a minor amount of regurgitate is inoculated into the stem of an uninfested plant, the leaves of the treated plant emit volatiles that attract femaleC. flavipes.     

0.3%印楝素乳油防治水稻二化螟药效试验

0.3%印楝素乳油对水稻二化螟有较好的防治效果,用药后14 d防效达90%左右,而且对稻株无药害,可以作为当前防治二化螟的选择药剂。     

瑞香狼毒提取物对水稻螟虫的杀灭活性研究

本文研究了瑞香狼毒根部粗粉乙醇提取物对水稻害虫大螟和二化螟的毒杀活性,当浓度为2.0g/L、作用时间为72h,乙醇提取物对大螟致死率为92.4%,二化螟的死亡率为20.9%。同时还系统研究了瑞香狼毒根部粗粉其它极性溶剂提取物对大螟和二化螟的胃毒活性、杀卵活性和内吸活性,结果表明瑞香狼毒对水稻大螟和二化螟具有一定的杀灭作用。     

间二酰胺类化合物NC-1的设计、合成及杀虫活性

为发现高效杀虫剂,采用活性药效基团融合策略,以2-氟-3-氨基苯甲酸甲酯和2-三氟甲基苯胺为起始原料,设计、合成了间二酰胺类化合物N-[2-溴-4-(全氟丙烷-2-基)-6-(三氟甲基)苯基]-3-[N-(氰甲基)苯甲酰胺基]-2-氟苯甲酰胺(NC-1),其结构经1HNMR、13CNMR和HRMS确证。初步的室内生物活性测试结果表明,化合物NC-1具有优异的杀虫活性,在质量浓度0.05 mg/L下对小菜蛾的致死率为96.67%,在质量浓度0.625 mg/L下对二化螟的致死率为93.33%。化合物NC-1可作为先导化合物或候选杀虫剂进行深入研究与开发。     

Feeding responses ofChilo partellus (Swinhoe) (Lepidoptera: Pyralidae) larvae to sorghum plant phenolics and their analogs

Phagostimulatory responses of third-instar larvae ofChilo Partellus to phenolic components identified in an ethyl acetate extract of the leaf whorls of 3-week-old plants ofSorghum bicolor cultivar IS 18363 were studied in no-choice bioassays. The major components in the extract were identified as 4-hydroxybenzaldehyde and 4-hydroxybenzoic acid, with 4-hydroxy-3-methoxycinnamic acid, 3,4-dihydroxycinnamic acid, and 4-hydroxycinnamic acid present in minor amounts. All but 4-hydroxycinnamic acid were stimulatory at the doses tested. 4-Hydroxybenzaldehyde was more stimulatory than other potential biogenetic analogs. Hydroxybenzoic acids generally elicited greater feeding response than cinnamic acids, and the pattern of oxygen substitution in the benzene ring was related to bioactivity.     

66%氟虫酰胺·氟虫腈WG防治水稻二化螟和稻纵卷叶螟效果

防治水稻二化螟和稻纵卷叶螟田问试验表明:66%氟虫酰胺·氟虫腈WG对水稻二化螟和稻纵卷叶螟具有优良的防治效果,39.6～49.5 g g.a.i./hmM2防治二化螟的保苗效果为75.42%～83.05%,杀虫效果78.95%～84.120%;防治稻纵卷叶螟的保叶效果为77.51%～84.34%.杀虫效果89.55%～92.89%.     

双酰肼类蜕皮促进剂对水稻二化螟的触杀与内吸作用比较

采用点滴法和盆栽土壤处理法分别测定了双酰肼类杀虫荆虫酰肼、JS118和抑食肼(RH5849)对二化螟的触杀与内吸作用，并与氟虫腈和杀虫单进行了比较。结果表明，虫酰肼和JS118对二化螟4龄幼虫的触杀毒力相当，LD50分别为0．0252、0．0310μg／头，约是氟虫腈的十分之一、杀虫单的11～13倍；抑食肼的触杀毒力(LD50为0．2720μg／头)约是虫酰肼和JS118的十分之一。然而，抑食肼20、40ga．i．／667m^2处理盆栽土壤后3、7d，对二化螟、蚁螟的内吸杀虫效果分别迭66．9％～89．0％和84．4％～96．7％，与氟虫腈(2ga．i．／667m^2)、杀虫单(40ga．i．／667m^2)接近或相当，而虫酰肼和JS118(5、10ga.i．／667m^2)无明显内吸杀虫作用。     

水稻二化螟耐寒性的研究

水稻二化螟越冬幼虫在普通低温－15（30d）,－20（4,6,8,10d）,－23（4d）,－25℃（4d）下的死亡率分别为3．33％,6．67％,13．33％,23．33％,26．67％,30％,56．67％;田间越冬初期、中期、后期由低温引起的死亡率分别为0,4．85％,9．96％。越冬幼虫能耐受一定的强低温－28（90min）,－30（30min）,－32℃（10min）。不同时期越冬幼虫的耐寒性有很大差异,其过冷却点在翌年3月中旬以前呈上升趋势,3月中旬以后又逐渐下降。不同地理纬度区越冬幼虫的耐寒性也有差异,表现为过冷却点随地理纬度的升高而上升。首次提出二化螟在越冬期间通过耐冻和避冻两种策略来越冬。     

水稻钻蛀性害虫之二化螟药剂筛选试验结果初报

为筛选生产上防治二化螟的有效药剂,2016年进行了田间药剂筛选试验。结果表明,10个药剂中以10%甲氧虫酰肼悬浮剂(制剂用量1 200 g/hm~2)对二化螟的防效最优,药后25 d的白穗率为1.9%,防效在92%以上,防效好于其他供试药剂,且持效期长。5%丁虫腈乳油(制剂用量1 500mL/hm~2)、10%阿维·氟酰胺悬浮剂(制剂用量675 g/hm2)防效较好,其余药剂效果不太理想。     

水稻钻蛀性害虫药剂防治试验研究

为筛选防治水稻钻蛀性害虫的有效药剂,2016年开展了防治水稻大螟、二化螟田间试验研究。试验结果表明:10%阿维·甲虫肼SC 1 200 mL/hm~2、20%氯虫苯甲酰胺SC 150 mL/hm~2、5.7%甲氨基阿维菌素苯甲酸盐SC 450 g/hm~2对大螟的防治效果好。33%阿维·抑食肼WP 900 g/hm~2、5.7%甲氨基阿维菌素苯甲酸盐SC 450 g/hm~2、10%阿维·甲虫肼SC 1 200 mL/hm~2、20%氯虫苯甲酰胺SC 150mL/hm~2对二化螟的防治效果好。连续用药2次处理的防效明显好于1次用药处理,生产上应根据大螟和二化螟的发生情况确定防治次数。