40％毒死蜱·噻嗪酮有机硅乳油防治螺旋粉虱田间药效试验

【目的】明确40％毒死蜱·噻嗪酮有机硅乳油对螺旋粉虱的防治效果和持效期,为螺旋粉虱防治提供科学依据。【方法】试验设40％毒死蜱·噻嗪酮有机硅乳油500、1000、2000倍液,48％毒死蜱乳油、10％啶虫脒微乳剂、20％噻嗪酮乳油、2．5％联苯菊酯乳油、4．5％高效氯氰菊酯乳油1000倍液,以及清水和空白对照处理;在螺旋粉虱成虫高峰期进行喷药试验。【结果】40％毒死蜱·噻嗪酮有机硅乳油1000倍液药后1、7、35d对螺旋粉虱的防效分别为100．00％、93．83％、和86．70％;药后2、7、14d观察,未见番石榴树出现药害现象。【结论】40％毒死蜱·噻嗪酮有机硅乳油对螺旋粉虱有较好的速效性和持效性,且对番石榴生长无不良影响,可作为螺旋粉虱的防治药剂在番石榴生产上推广应用。建议在螺旋粉虱成虫高峰期使用40％毒死蜱·噻嗪酮有机硅乳油1000倍液进行喷雾防治。     

The Toxicity and Detoxifying Mechanism of Cycloxaprid and Buprofezin in Controlling Sogatella furcifera (Homoptera: Delphacidae)

The effects of cycloxaprid (a modified neonicotinoid insecticide) and buprofezin (a thiadiazine insecticide) on mortality of the white-backed planthopper (WBPH), Sogatella furcifera, were determined in laboratory assays. Cycloxaprid killed WBPH nymphs and adults but buprofezin killed only nymphs, and cycloxaprid acted faster than buprofezin. One day after infestation, mortality of third-instar nymphs was >65% with cycloxaprid at 125 mg liter⁻¹ but was <38% with buprofezin at 148 mg liter⁻¹. By the 4th day after infestation, however, control of nymphs by the two insecticides was similar, and cycloxaprid at 125 mg liter⁻¹ caused ≥80% mortality of adults but buprofezin at 148 mg liter⁻¹ (the highest rate tested) caused almost no adult mortality. LC₅₀ values for cycloxaprid were lowest with nymphs, intermediate with adult males, and highest with adult females. Although buprofezin was slower acting than cycloxaprid, its LC₅₀ for nymphs 5 d after infestation was 3.79-fold lower than that of cycloxaprid. Mean carboxylesterase (CarE) specific activity of nymphal WBPH treated with cycloxaprid and buprofezin was higher than that of control, but there was no significant difference between cycloxaprid and control (no insecticide), and it was significantly higher for buprofezin than those of cycloxaprid and control. For glutathione S-transferase and mixed function oxygenase, the specific activity of nymphal WBPH treated with buprofezin was significantly higher than those of cycloxaprid and control, too.     

灰飞虱对杀虫剂的抗性分子机制研究进展

灰飞虱是中国长江流域和黄淮地区重要的农业害虫,由于杀虫剂的广泛与大量使用,已导致其对多种杀虫剂产生了抗性。深入研究其抗药性分子机制,可为灰飞虱抗性的快速检测和治理提供重要理论基础。文章总结了灰飞虱对毒死蜱、吡虫啉、溴氰菊酯、噻嗪酮、氟虫腈和乙虫腈等杀虫剂的抗性分子机制研究进展,主要包括抗性相关解毒酶和转运蛋白基因的筛选与功能验证,以及靶标位点突变等重要研究成果,指出该研究领域当前存在的问题主要有抗性基因的功能验证及调控路径、抗性新基因的鉴定及交互抗性和多重抗性机制不明确等,并展望了其未来发展方向,认为:可利用CRISPR/Cas9基因编辑技术验证抗性基因功能;可将转录组测序结合生物信息学手段用于鉴定新抗性基因及抗性调控基因,以探明交互抗性和多重抗性机制;应深入至蛋白组学水平探讨抗性机制;需开发配套的高效田间施药技术,以达到杀虫剂减施增效的目的。     

褐飞虱对噻嗪酮的抗药性监测

1996-2007年间采用稻茎浸渍法测定了我国8省(区)27个褐飞虱种群对噻嗪酮的敏感性。 在1996-2002年间, 江苏\[江浦(JPZY)、仪征(YZZY)和南通(NTZY)\]、安徽\[安庆(AQNS)\]、广西\[南宁(GXNY)和桂林(GLNS)\]褐飞虱种群对噻嗪酮均为敏感至敏感性下降 (抗性倍数为0.3~3.5倍)。 在2005-2007年间,监测到江苏 \[江浦(JPZY), 2005年\]和海南\[陵水(HNLS),2007年\]褐飞虱种群对噻嗪酮达中等水平抗性(抗性倍数分别为28.8倍和19.4倍);其余种群如广西\[南宁(GXNY)和桂林(GLNS)\]、湖南\[常德(CDTY)\]、浙江\[余姚(YYLJ)\]、江西\[新建(XJSM)\]、安徽\[和县(HXLY)、潜山(QSMC)\]及江苏\[南通(NTZY)\]等地褐飞虱种群对噻嗪酮为低水平抗性(抗性倍数为5.6~9.1倍);而江西\[上高(SGMS)\]、浙江\[兰溪(LXYC)\]和湖北\[孝感(XGXC)\]3个褐飞虱种群对噻嗪酮仍为敏感至敏感性下降(抗性倍数2.5~4.1倍)。室内饲养22代,用噻嗪酮对1996年采自安徽\[安庆(AQNS)\]的褐飞虱间断筛选13代,它的LC50下降了30%,筛选前后抗性水平没有明显差异;随后连续筛选15代,抗性倍数达1157.7倍。上述结果表明,褐飞虱对噻嗪酮已产生低到中等水平抗性,如果连续单一使用噻嗪酮,褐飞虱将具有产生高水平抗性的风险。此外,还对褐飞虱的抗性治理进行了讨论。     

中国水稻主产区褐飞虱对3种杀虫剂的抗性监测

2006-2009年,用稻茎浸渍法连续监测了广西南宁市、广东阳江市、湖南东安县、福建福清市、江西上高县、湖北孝感市、浙江金华市、江苏通州市和安徽和县共9个地区褐飞虱种群对吡虫啉、噻嗪酮和氟虫腈的抗性变化。结果表明:褐飞虱种群对吡虫啉的抗性仍处于高水平至极高水平抗性阶段(105.5~459.7倍),但2009年监测到东安、孝感、上高种群对吡虫啉的抗性已有下降趋势;褐飞虱种群对氟虫腈的抗性有增长趋势,2006到2009年褐飞虱种群对氟虫腈由敏感至低水平抗性(<6.9倍)发展到了中水平至高水平抗性(13.5~43.3倍);由于2005年吡虫啉在高抗地区的禁用,褐飞虱种群对噻嗪酮的抗性上升速度加快,2009年已处于低水平至中水平抗性阶段(7.0~14.4倍)。这表明在吡虫啉、氟虫腈被禁用后,大面积单一使用噻嗪酮进行防治,褐飞虱对噻嗪酮的抗性有可能加速发展。     

Insecticide resistance management of Bemisia tabaci (Hemiptera: Aleyrodidae) in Australian cotton – pyriproxyfen,spirotetramat and buprofezin

BACKGROUND

Bemisia tabaci is a globally significant agricultural pest including in Australia, where it exhibits resistance to numerous insecticides. With a recent label change, buprofezin (group 16), is now used for whitefly management in Australia. This study investigated resistance to pyriproxyfen (group 7C), spirotetramat (group 23) and buprofezin using bioassays and available molecular markers.

RESULTS

Bioassay and selection testing of B. tabaci populations detected resistance to pyriproxyfen with resistance ratios ranging from 4.1 to 56. Resistance to spirotetramat was detected using bioassay, selection testing and sequencing techniques. In populations collected from cotton, the A2083V mutation was detected in three populations of 85 tested, at frequencies ≤4.1%, whereas in limited surveillance of populations from an intensive horticultural region the frequency was ≥75.8%. The baseline susceptibility of B. tabaci to buprofezin was determined from populations tested from 2019 to 2020, in which LC₅₀ values ranged from 0.61 to 10.75 mg L⁻¹. From the bioassay data, a discriminating dose of 200 mg L⁻¹ was developed. Recent surveillance of 16 populations detected no evidence of resistance with 100% mortality recorded at doses ≤32 mg L⁻¹. A cross-resistance study found no conclusive evidence of resistance to buprofezin in populations with high resistance to pyriproxyfen or spirotetramat.

CONCLUSIONS

In Australian cotton, B. tabaci pest management is challenged by ongoing resistance to pyriproxyfen, while resistance to spirotetramat is an emerging issue. The addition of buprofezin provides a new mode-of-action for whitefly pest management, which will strengthen the existing insecticide resistance management strategy. © 2023 Commonwealth of Australia. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

噻嗪酮在茶园环境中的残留行为研究

参照《农药残留试验准则》,采用田间试验方法,研究在不同地域、不同气候带、不同施药季节条件下杀虫剂噻嗪酮在南京、南宁地区茶园环境中的残留行为,并进行环境影响因素（降水、温度）分析,药剂的作物适用性及区域适用性分析,探讨了不同种植地域MRL值制定的依据。结果表明,噻嗪酮在不同环境条件下的残留行为不同。同季节施药后在两地茶叶上的消解规律相近,统计分析表明两地区的残留消解行为无显著性差异,半衰期为3.97～4.69 d;不同施药季节的降水及气温均可显著影响噻嗪酮在茶叶上的残留状态,降水可明显减少其残留量,而低温则可延长其残留半衰期;在土壤中的残留消解受土壤性质的影响较大,在南京、南宁地区的半衰期相近,但消解过程差异显著,半衰期为10.34～29.96 d。除2008年南京地区外,其他地区与年份不同处理剂量的噻嗪酮药后7 d在茶叶上的残留量均小于10 mg.kg-1,据此并参考国内外噻嗪酮MRL值的制定情况,建议延用国标（GB/T8321.6—2000）的MRL值10 mg.kg-1,建议噻嗪酮在茶叶上使用的安全间隔期为7 d。     

高效低毒农药替代甲胺磷防治水稻害虫的田间试验

试验结果表明稻虫杀净对稻纵卷叶螟、稻飞虱和三化螟三种水稻主要害虫防治效果与甲胺磷相当，且对稻田有益生物种群的杀伤力小。     

3种杀螨剂对顶孢霉菌株胞外蛋白酶和几丁质酶活性的影响

研究了螺螨酯、噻嗪酮和吡螨胺在不同浓度下处理对顶孢霉胞外蛋白酶和几丁质酶活力的影响。结果表明,螺螨酯各浓度处理对顶孢霉胞外蛋白酶和几丁质酶活性均无影响,噻嗪酮高浓度处理顶孢霉在培养的前4 d对胞外蛋白酶活性有轻微的抑制作用,随培养时间延长,抑制作用不明显;而低浓度处理下,即在1.25 mg/L浓度下培养7 d,其酶活力是第1天的3.97倍,对顶孢霉胞外蛋白酶活性有刺激作用。吡螨胺对顶孢霉胞外蛋白酶和几丁质酶活性有抑制,且随浓度增高和培养时间延长抑制作用越明显。