吡虫啉防治水稻褐飞虱

吡虫啉对水稻褐飞虱有特效，每亩用１０％可湿性粉剂１０￣１５克，防效９５％左右，持效期４０天以上，显著优于噻嗪酮。适宜施药技术：于褐飞虱主害代前一代初龄若虫高峰期，亩用吡虫啉有效剂量１￣１．５克喷雾。     

白背飞虱,褐飞虱对杀虫剂敏感性的演变

关于白背飞虱对杀虫剂的敏感性已有不少报道。据介绍在1967～1976年期间白背飞虱对有机氯、有机磷、氨基甲酸酯类杀虫剂的敏感性无变化;而有关褐飞虱对杀虫剂敏感性的变化有过一些报道:Nagata 等(1979)报导了对有机磷杀虫剂的抗性,Kilin 等(1981)、     

稻褐飞虱的抗药性研究

用毛细管点滴法测定了16种杀虫剂对褐飞虱的触杀毒力。1985～1990年,褐飞虱对同一杀虫剂的敏感度变异不大,抗药性发展缓慢。作者认为,褐飞虱在一定时间内不会出现抗药性突增的变化,氨基甲酸酯类仍可作为防治药剂,但需加强监测。     

不同杀虫剂防治水稻褐飞虱田间药效评价

2013年对褐飞虱进行6种杀虫剂田间防治效果评价。结果表明:施药后5 d和10 d,22%氟啶虫胺腈SC、20%呋虫胺SG、25%噻虫嗪WG、50%吡蚜酮WG对褐飞虱的防效分别为77.9%~90.9%和77.0%~90.5%,20%异丙威EC、25%噻嗪酮WP的防效分别为40.1%~65.9%和20.6%~49.9%。22%氟啶虫胺腈SC、20%呋虫胺SG、25%噻虫嗪WG、50%吡蚜酮WG防效较好。建议在实践中,轮换使用噻虫嗪、吡蚜酮、呋虫胺、氟啶虫胺腈防治褐飞虱。     

几种杀虫剂及其混剂对褐飞虱的毒力测定

采用药膜法测定了8种常用杀虫单剂及5种杀虫混剂对褐飞虱4龄若虫的室内毒力。结果表明:8种单剂对褐飞虱的毒力顺序为毒死蜱吡虫啉哒螨灵灭多威烯啶虫胺联苯菊酯啶虫脒吡蚜酮。5种混剂中,哒螨灵+吡虫啉1.5∶1、2∶1和哒螨灵+烯啶虫胺1.5∶1表现为增效作用,其中以哒螨灵+吡虫啉1.5∶1毒力最高;哒螨灵+吡虫啉1∶1、哒螨灵+啶虫脒、哒螨灵+烯啶虫胺1∶1、2∶1表现为相加作用;其它混剂表现为拮抗作用,其中哒螨灵+吡蚜酮1.5∶1毒力最低。     

30％吡虫啉微乳剂对水稻褐飞虱田间药效试验

30％吡虫啉微乳剂是一种新型杀虫剂,对多种农作物上的蚜虫有特效。作者用该药剂防治水稻褐飞虱,结果表明：喷施30％吡虫啉微乳剂75－100g/hm^2防效高达95％以上。     

几种药剂防治褐飞虱效果比较

选择毒死蜱、噻虫嗪、噻嗪酮、啶虫脒、吡虫啉、氟虫腈等6种药剂进行了防治褐飞虱田间试验,结果表明,当前,氟虫腈、毒死蜱(高含量)、噻虫嗪和噻嗪酮对水稻褐飞虱防治效果较好,药后7～10d,平均校正防治效果达到81.9%～92.7%;褐飞虱对吡虫啉产生了极高抗药性,防治效果显著下降。     

环氧虫啶对褐飞虱毒力的温度效应

采用室内喷雾法测定了环氧虫啶对褐飞虱杀虫活性的温度效应。结果表明:在20℃、25℃和30℃条件下,环氧虫啶的LC50分别为0.425 mg/L、0.171 mg/L和0.022 mg/L,环氧虫啶对褐飞虱的活性随温度的升高而升高,为正温度系数农药。环氧虫啶在30℃时的毒力为20℃时的19.32倍。     

氟硅菊酯对水稻褐飞虱的生物活性及田间防治效果

室内生测结果表明:氟硅菊酯对褐飞虱3龄若虫的LC50值为9.98 mg/L,与吡蚜酮相比,氟硅菊酯对褐飞虱3龄若虫的LC50值是吡蚜酮的14.14倍;田间试验结果表明:氟硅菊酯具较好的速效性、持效性,药后3 d,5%氟硅菊酯EC(制剂用量)1500～4 500 mL/hm2对褐飞虱的防治效果为76.39%～94.00%,药后21 d,5%氟硅菊酯EC(制剂用量)3000～4500 mL/hm2对褐飞虱的控制效果仍有73.88%～89.22%,因此从防效和经济的角度考虑,5%氟硅菊酯EC控制褐飞虱最佳制剂用量为3000～4500 mL/hm2,防治适期宜在褐飞虱低龄若虫高峰期.     

不同方法测定7种杀虫剂对水稻褐飞虱室内毒力的比较研究

采用Potter喷雾法、盆栽喷雾法和根内吸法测定7种药剂对褐飞虱的室内毒力,并对这3种方法进行了比较。结果表明:3种方法测得的药剂对褐飞虱室内毒力结果比较一致,均以烯啶虫胺的毒力为最高,吡蚜酮和毒死蜱毒力较低。Potter喷雾法操作方便,最适合于对褐飞虱室内活性的筛选,但药后调查时间不宜太长。     

吡蚜酮与异丙威复配对褐飞虱的增效作用和田间防治

室内生测结果表明:吡蚜酮与异丙威质量比为1∶2,对褐飞虱3龄若虫具有较高的生物活性,其LC50值为11.01 mg/L,共毒系数为166.65,表现出明显的增效作用;按此配比加工成30%吡蚜·异丙威WP(有效成分:吡蚜酮10%、异丙威20%).田间防治结果表明:该混剂对褐飞虱表现出良好的速效性和持效性.药后3 d,30%吡蚜·异丙威WP 450～600 g/hm2对褐飞虱若虫的防治效果为90.83%～94.94%,药后21 d,30%吡蚜·异丙威WP 450～600 g/hm2对褐飞虱若虫的防治效果仍有87.60%～89.32%,均好于对照药剂吡蚜酮、异丙威对褐飞虱的防治效果.从防效和经济的角度考虑,30%吡蚜·异丙威WP推荐剂量为450 g/hm2,防治适期宜在褐飞虱若虫高峰期.     

Insecticidal Effects of Extracts from Two Rice Varieties to Brown Planthopper, Nilaparvata lugens

Ether extracts from a resistant rice variety, Jingxian 89, and a susceptible variety, Qidaizhan, were significantly toxic to Nilaparvata lugens adult females, causing 98% and 73.5% mortalities, respectively. The area covered honeydew droplets excreted by N. lugens adult females while feeding on Qidaizhan was 28.5-fold more than the area of those feeding on the resistant variety, Jingxian 89. The honeydew covered areas were reduced 29.7- and 8.8-fold, respectively, after feeding on plants treated with the ether extracts from both varieties. Among the fractions from each variety, fractions 9 (three sterols) from both varieties and fraction 10 (3-nitraphthalic acid) from Jingxian 89 showed significant repellent effects on the planthoppers. Further bioassays revealed that fraction 9 from extracts of both varieties at 0.02 mg/ml or higher deterred the feeding activity of the planthoppers, whereas the deterrent effects of fraction 10 from the extract of Jingxian 89 were 100- to 500-fold stronger than those of fraction 9. Fraction 10, identified as 3-nitraphthalic acid, unique in Jingxian 89, was extremely toxic to N. lugens adult females, and the LC₅₀ and LC₉₀ were 0.00045 and 0.00525 mg/ml, respectively. After extensive bioassays and analysis, we concluded that 3-nitraphthalic acid plays a key role in the resistance to N. lugens adult females.     

褐飞虱抗药性及再猖獗研究进展

褐飞虱是一种重要的农业害虫,其对许多杀虫剂都产生了抗药性。对褐飞虱抗药性的形成和发展及其抗药性机理等方面进行了综述,并对该虫的再猖獗进行了探讨。     

Characterization of MicroRNAs Associated with Reproduction in the Brown Planthopper,Nilaparvata lugens

Insects have a robust capacity to produce offspring for propagation, and the reproductive events of female insects have been achieved at the molecular and physiological levels via regulatory gene pathways. However, the roles of MicroRNAs (miRNAs) in the reproductive development of the brown planthopper (BPH), Nilaparvata lugens, remain largely unexplored. To understand the roles of miRNAs in reproductive development, miRNAs were identified by Solexa sequencing in short-winged (SW) female adults of BPH. Small RNA libraries derived from three developmental phases (1 day, 3 days, and 5 days after emergence) were constructed and sequenced. We identified 905 miRNAs, including 263 known and 642 novel miRNAs. Among them, a total of 43 miRNAs were differentially expressed in the three developmental phases, and 14,568 putative targets for 43 differentially expressed miRNAs (DEMs) were predicted by TargetScan and miRanda. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of the predicted miRNA targets illustrated the putative roles for these DEMs in reproduction. The progress events were annotated, including oogenesis, lipid biosynthetic process, and related pathways such as apoptosis, ABC transporters, and amino acid metabolism. Four highly abundant DEMs (miR-9a-5p, miR-34-5p, miR-275-3p, and miR-317-3p) were further screened, and miR-34-5p was confirmed to be involved in the regulation of reproduction. Overexpression of miR-34-5p via injecting its mimics reduced fecundity and decreased Vg expression. Moreover, target genes prediction for miR-34-5p showed they might be involved in 20E signaling cascades, apoptosis, and gonadal development, including hormone receptor 4 (HR4), caspase-1 (Cp-1), and spermatogenesis-associated protein 20 (SPATA20). These findings provide a valuable resource for future studies on the role of miRNAs in BPH reproductive development.     

0.3%印楝素乳油对水稻褐飞虱的生物活性

系统研究了印楝素对褐飞虱的生物活性。试验结果表明,0.3%印楝素乳油对褐飞虱具有拒食、内吸、抑制生长发育等作用。3.00mg/L和6.00mg/L印楝素溶液处理稻茎,对褐飞虱的拒食率分别为67.91%和77.65%,拒食中浓度AFC50为0.6126mg/L。3.00mg/L的印楝素溶液经根内吸传导12h和24h后,褐飞虱若虫校正死亡率分别为81.63%和88.47%,LC50值分别为1.4028mg/L和1.1115mg/L。印楝素经根内吸传导的速度较快,3.00mg/L和1.50mg/L浓度下,LT50值分别为4.1812h和23.0409h。亚致死剂量处理后,褐飞虱若虫的体重和蜜露分泌量都显著降低,1.00mg/L处理后3d、7d,体重减轻比率分别为52.49%和48.08%,蜜露分泌量减少比率分别为58.01%和62.60%。田间试验结果也表明,0.3%印楝素乳油对褐飞虱具有良好的控制效果。