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.     

三种常用杀虫剂对广西蒙山地区柑橘木虱的田间防效试验

试验在广西梧州市蒙山县蒙山镇甘棠村金秋砂糖橘种植园开展,通过利用三种常用杀虫剂防治柑橘木虱的田间防效试验可知,22.4% 螺虫乙酯SC 、21%噻虫嗪EC、1.8%阿维菌素EC对柑橘木虱均有较好的防效,其中1.8%阿维菌素EC1440倍的防效最优,其次是21%噻虫嗪EC 3360倍,但两者防效差异不显著。三种药剂的持效期均可达15天以上,可在柑橘木虱防治上交替使用。     

24%螺虫乙酯悬浮剂防治琯溪蜜柚害螨田间药效试验

2010—2011年进行24%螺虫乙酯悬浮剂防治蜜柚害螨的田间药效试验,结果表明:24%螺虫乙酯悬浮剂对蜜柚害螨具有理想的防治效果,结合速效性杀螨剂使用,效果更好。     

烟粉虱对螺虫乙酯的抗性监测及交互抗性测定

为明确螺虫乙酯在湖北地区的抗性水平以及与其存在潜在交互抗性风险的常用药剂类型,采用着卵叶片浸渍法,于2013年对湖北省13个烟粉虱MEAM1和MED隐种地理种群对螺虫乙酯的抗药性进行了监测,并以室内敏感品系SUD-S为参照,对经螺虫乙酯连续17代抗性筛选的WH-2种群进行了交互抗性分析。结果表明:湖北省13个烟粉虱地理种群对螺虫乙酯均表现出极低的抗性,LC50介于0.015~0.081 mg/L之间;其中MED隐种WH-2种群对螺虫乙酯的抗性最高,LC50为0.081 mg/L。在室内用螺虫乙酯对MED隐种WH-2种群连续17代抗性筛选后,其对螺虫乙酯的抗性倍数上升约7倍。经螺虫乙酯筛选的WH-2种群对吡虫啉、乙酰甲胺磷、灭多威、氟氯氰菊酯、氰戊菊酯和氟啶虫胺腈均产生了低水平的交互抗性,抗性倍数分别为8.699、7.165、5.317、6.681、2.958、5.662倍,而对毒死蜱和阿维菌素无交互抗性。表明烟粉虱在湖北省部分地区对螺虫乙酯存在低水平抗性,且螺虫乙酯与部分常用杀虫剂存在交互抗性风险。     

香蕉花蕾注射螺虫乙酯和吡虫啉对黄胸蓟马的防效及药剂在果实中的残留

黄胸蓟马是中国香蕉上重要害虫，生产上对该虫仍缺乏较为有效的防治手段。本研究采用香蕉花蕾注射法施用22.4%螺虫乙酯悬浮剂 (SC) 和70%吡虫啉水分散粒剂 (WG)，研究了其对黄胸蓟马的防效，并采用超高效液相色谱-串联质谱法 (UPLC-MS/MS) 分析了药剂在香蕉果实中的残留。药效试验表明:于香蕉现蕾初期，22.4%螺虫乙酯SC和70%吡虫啉WG分别按有效成分0.12和0.18 g/株的剂量注射施药1次，对黄胸蓟马的防效分别为89%和86%。残留试验表明:花蕾注射施药后，螺虫乙酯和吡虫啉在香蕉果实中的半衰期分别为9.2和6.5 d，且在施药后95 d的香蕉成熟果实中未检测到其残留。本研究表明，香蕉花蕾注射螺虫乙酯与吡虫啉对黄胸蓟马具有良好的防治效果与安全性，可推荐在香蕉园轮换使用。     

QuEChERS-超高效液相色谱-串联质谱法测定果蔬中螺虫乙酯、丁醚脲及代谢物残留

建立了QuEChERS前处理-超高效液相色谱-串联质谱 (UPLC-MS/MS) 测定果蔬中螺虫乙酯、丁醚脲及其6种代谢物 (螺虫乙酯-烯醇、螺虫乙酯-烯醇-糖苷、螺虫乙酯-单羟基、螺虫乙酯-酮-羟基、丁醚脲-脲和丁醚脲-甲酰胺) 残留量的分析方法。样品经破壁机匀浆，V(乙腈) : V(甲酸)=10 : 1混合溶液涡旋提取，定制的QuEChERS净化管净化，岛津Shim-pack XR-ODS色谱柱分离 (75 mm × 2.0 mm，1.6 μm)。采用电喷雾离子源正离子多反应监测模式进行质谱检测，外标法定量。丁醚脲-脲和丁醚脲-甲酰胺在0.001~0.1 mg/L范围内线性关系良好，其他6种化合物在0.005~0.5 mg/L范围内线性关系良好，R2 ≥ 0.999 3。验证了梨、葡萄、西瓜、芥蓝、芹菜和韭菜6种基质下方法的准确度和精密度，在0.001~0.5 mg/kg添加水平下，8种化合物的平均回收率在68%~94%之间，相对标准偏差在5.4%~15%之间，定量限为0.001~0.005 mg/kg。该方法简便、快速、可靠，适用于同时测定果蔬中上述8种化合物残留。     

螺螨酯和螺虫乙酯在覆膜金橘中的降解残留规律研究

为评价螺螨酯和螺虫乙酯在覆膜金橘中使用的安全性,研究了螺螨酯、螺虫乙酯及其代谢产物在覆膜金橘中的残留分析方法和残留动态规律,建立了金橘中螺螨酯、螺虫乙酯及其代谢产物的超高压液相色谱-串联质谱（UHPLC-MS/MS）检测方法。结果表明,在0.002~2.5 mg/kg添加水平范围内,螺螨酯、螺虫乙酯及其4种代谢产物在金橘中的添加回收率为86.9%~101.2%,相对标准偏差为2.3%~6.8%,方法检出限为0.1~5.0 μg/kg,定量限为0.5~ 1.0 μg/kg。螺螨酯和螺虫乙酯母体在覆膜金橘中的消解符合一级动力学方程,消解半衰期分别为14.1 d和23.1 d。最终残留实验结果表明,按照推荐的施药剂量使用,施药2次后15 d收获,螺螨酯和螺虫乙酯在覆膜金橘中的残留量均低于最大残留限量值（均为0.5 mg/kg）。     

螺虫乙酯与噻虫嗪混配对菊花烟粉虱的毒力、防效及安全性研究

采用滤纸药膜法测定了螺虫乙酯与噻虫嗪混配对菊花烟粉虱的联合毒力,测定共毒系数CTC为122.97~167.43,表现增效作用。据此确定最佳配比,配制成增效混剂40%SC,并研究了其对菊花烟粉虱的毒力和防效及其对观赏菊花安全性,结果表明在推荐有效成分剂量90g a.i.·hm-2、二倍量180g a.i.·hm-2及四倍量360g a.i.·hm-2下对金盏菊、翠菊、万寿菊等3种观赏菊花植株生长无明显异常影响,具有较好的安全性;田间药效良好,其用量60~90g a.i.·hm-2的效果达75.60%~90.67%,优于22.4%螺虫乙酯SC和25%噻虫嗪WG。该增效混剂防治菊花烟粉虱的速效性和持效性皆佳。     

Spirodiclofen and spirotetramat bioassays for monitoring resistance in citrus red mite, Panonychus citri (Acari: Tetranychidae)

BACKGROUND: Citrus red mite, Panonychus citri (McGregor), is a key pest of San Joaquin Valley California citrus. Spirodiclofen was registered for mite control in 2007, and spirotetramat for scale control in 2008. Because of the potential for resistance to spirodiclofen to develop in spider mites, and cross‐resistance to spirotetramat used for other citrus pests, bioassay methods for resistance monitoring were developed. RESULTS: The responses of four populations of adult female, egg and larval stages of P. citri to spirodiclofen were compared to determine the most robust bioassay method for this pesticide. Adult females responded with a higher LC₉₉ and larval stages exhibited higher control mortality and a lower slope of response compared with the egg stage. Thus, the egg stage was found to be the most suitable stage for testing. Egg production and egg shape were significantly affected by spirodiclofen treatment of adult female mites. Bioassays with the related compound spirotetramat revealed that P. citri egg hatch was less affected by this compound, requiring the assessment of mortality to be extended to 11 days after treatment when the hatched larvae succumbed to the pesticide. Discriminating concentrations of 10 ppm for spirodiclofen and 31.6 ppm for spirotetramat in an 11 day bioassay were tested against eight field populations of P. citri, and 99–100% mortality resulted. CONCLUSION: These results provide a baseline for the response of P. citri to spirodiclofen and spirotetramat that will aid resistance management in California citrus. Copyright © 2011 Society of Chemical Industry