Note: Insecticide resistance in<Emphasis Type="Italic">Helicoverpa armigera</Emphasis> from cotton-growing areas in Turkey

Insecticide resistance inHelicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is one of the most important constraints on cotton production in Turkey. We investigated the susceptibility ofH. armigera strains collected from cotton fields in the Adana, Hatay and Antalya provinces to insecticides which are in wide use. LD₅₀ values for tralomethrin, lambda-cyhalothrin, endosulfan, profenofos and methomyl were determined by topical bioassay. At the LD₅₀ levels, resistance ratios for tralomethrin were 24.7-, 19.7- and 15.7-fold in the Adana, Hatay, and Antalya strains, respectively; and for lambda-cyhalothrin were 41-, 20-and 40-fold, respectively. Resistance ratios ranged from 1.2- to 2.1-fold in all field strains for endosulfan, profenofos and methomyl, with no significant resistance. These results suggest the presence of resistance to tralomethrin and lambda-cyhalothrin inH. armigera strains collected from cotton fields, but no resistance to endosulfan, profenofos or methomyl could be observed.     

我国棉铃虫对Bt蛋白Cry1Ac抗性现状及分子机制研究进展

棉铃虫Helicoverpa armigera是一种全球性的重要农业害虫,主要为害棉花、玉米和大豆等作物。长期种植单价Bt棉花（表达Cry1Ac蛋白）会使棉铃虫田间种群承受单一、持续的选择压力,必然会导致棉铃虫对Cry1Ac的抗性发生演化。该文概述我国棉铃虫田间种群对Cry1Ac的抗性现状、自然庇护所对棉铃虫Cry1Ac抗性演化的延缓作用以及棉铃虫对Cry1Ac抗性的遗传多样性,并对今后我国关于棉铃虫Bt抗性的治理对策进行了展望。     

Resistance selection and biochemical characterization of spinosad resistance in Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

A Helicoverpa armigera population was collected from Shandong province, China. After 15 generations of selection in the laboratory, the H. armigera strain developed more than 20-fold resistance to spinosad. At LD₅₀ level, no significant cross-resistance was found between spinosad and chlorpyrifos, methomyl, avermectin and chlorfenapyr except for fenvalerate with a low cross-resistance of 2.4-fold. However, LD₉₉ values of fenvalerate against the parental and resistant strains were not different significantly. After inhibitors were used, spinosad resistance could be partially suppressed by piperonylbutoxide (PBO) and triphenylphosphate (TPP), but not by diethylmaleate (DEM). Activities of p-nitroanisole O-demethylase (ODM) developed to 8.26-fold compared with the parental strain, but no obvious changes were found in activities of carboxyl esterase (CarE) and glutathione-S-transferase (GST). The results indicated that resistance to spinosad in the cotton bollworm might be associated with an increase in cytochrome P450 monooxygenase.     

Note: Pyrethroid resistance and possible involvement of glutathione<Emphasis Type="Italic">S</Emphasis>-transferases in<Emphasis Type="Italic">Helicoverpa armigera</Emphasis> from Turkey

An introductory study was conducted to investigate the pyrethroid resistance ofHelicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) strains in Turkey, collected from cotton fields in the Adana and Antalya provinces, through two different synthetic pyrethroid insecticides: lambda-cyhalothrin and esfenvalerate. In addition, the roles of glutathioneS-transferases (GSTs) in this resistance mechanism were analyzed. It was found that whereas resistance ratios for lambda-cyhalothrin (LD₅₀ levels) were 3- and 98-fold increased in the Adana and Antalya strains, respectively, esfenvalerate ratios were 3.3- and 92.3-fold increased in the Adana and Antalya strains, respectively, with respect to the susceptible strain. Furthermore, Adana and Antalya strains showed 2.4- and 2.9-fold higher GST activities than the susceptible strain, respectively. In the Antalya field strain, the minor increase in GST activity compared with the resistance levels implies that GSTs may be not greatly involved in this resistance. It also provides evidence that they could not be the only metabolic mechanism responsible for resistance to lambda-cyhalothrin and esfenvalerate inH. armigera from Turkey. http://www.phytoparasitica.org posting Nov. 16, 2006.     

棉铃虫Bt抗性种群的RAPD-PCR初步分析

经室内筛选获得了棉铃虫对Bt杀虫剂、Bt毒蛋白和转Bt基因棉的抗性种群。利用RAPD技术 ,成功地扩增得到 105条多态性条带 ,经过聚类分析发现 ,棉铃虫对Bt产生抗性后在基因水平发生了变异。RAPD技术不仅可以用来鉴定棉铃虫对Bt是否产生抗性 ,而且可以区分不同的Bt抗性种群     

Toxicity of chlorantraniliprole to Cry1Ac-susceptible and resistant strains of Helicoverpa armigera

Transgenic Bt cotton expressing Cry1Ac is important in controlling various agricultural pests, including Helicoverpa armigera. Especially for transgenic crops that are cultivated in large expanses, avoiding resistance development is a key for ensuring sustainability of Bt technologies. Integrated pest management, in which transgenic crops are strategically combined with rational pesticide use, may help to prevent H. armigera resistance acquisition in Bt cotton. In this study, we evaluated the toxicity of a novel insecticide (chlorantraniliprole) on Cry1Ac-susceptible and resistant individuals of H. armigera. More specifically, we assessed the effect of chlorantraniliprole on the activity of two enzymes and conducted laboratory bioassays to determine its toxicity on H. armigera larvae. Chlorantraniliprole increased esterase and glutathione-S-transferase activities in Cry1Ac susceptible and resistant populations of H. armigera. Cry1Ac resistant populations XJ-F (Cry1Ac resistance ratio 21.8-fold), XJ-10.0 (95.8-fold) and BTR (3536.5-fold) did not show cross-resistance to chlorantraniliprole, with LC₅₀ values of 0.0733 (μg/mL) in XJ-F, 0.0545 (μg/ml) in XJ-10.0 and 0.0731 (μg/mL) in BTR, which were close to that in the susceptible strain 96S (0.0954 μg/mL). Our work shows that chlorantraniliprole could be considered to be integrated in Bt cotton management schemes to delay the H. armigera resistance development.     

棉铃虫对菊酯类药剂的抗性狭义遗传力

通过单对交配设计不同的交配家系,采用半同胞法分析了棉铃虫对三氟氯氰菊酯和氰戊菊酯的抗性狭义遗传力,并对2种菊酯类药剂的抗性发展速度进行评价。结果表明,棉铃虫对三氟氯氰菊酯和氰戊菊酯的抗性狭义遗传力分别为0.2476±0.0248和0.4625±0.1578,说明棉铃虫对氰戊菊酯的抗性发展速度要快于三氟氯氰菊酯。另外,通过方差分析发现,在棉铃虫对拟除虫菊酯类药剂的抗性遗传中,母体效应对其没有影响。     

Pyrethroid resistance mechanisms in Australian Helicoverpa armigera

In 1983, at the onset of pyrethroid resistance in Australian Helicoverpa armigera, three resistance mechanisms were identified. They were: a strong nerve insensitivity (Super-Kdr), penetration resistance (Pen), and a factor which was overcome by piperonyl butoxide (PBO). Super-Kdr nerve insensitivity appeared to be a major cause of pyrethroid resistance and contributed to high-order resistance (> 100-fold). From 1987 to 1990, to monitor the effect of the Australian Helicoverpa insecticide resistance management strategy on insecticide resistance, we conducted a survey of the frequencies of these mechanisms in field-collected H. armigera. The relative importance of the Pen and Pbo mechanisms in resistant H. armigera have increased but Pen and Pbo confer only low order (～ 20-fold) resistance. We found no evidence of the 1983 Super-Kdr mechanism in the latest samples, but, instead, found another distinct Kdr-type mechanism. This mechanism was correlated with very low-order nerve insensitivity and was of little toxicological significance. The impact of the Helicoverpa insecticide resistance management strategy on pyrethroid resistance in H. armigera is discussed.     

Insensitive acetylcholinesterase causes resistance to organophosphates in Australian Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

Organophosphates are valuable insecticides used to control Helicoverpa armigera on cotton in Australia. Those most commonly used for Helicoverpa spp. control are pro-fenofos, parathion-methyl and chlorpyrifos. However, there is an emerging organophosphate-resistance threat in Australian H. armigera, which is compounded by cross-resistance between profenofos and parathion-methyl. An insensitive acetylcholinesterase has been identified as the common resistance mechanism. No resistance to chlorpyrifos has been detected and acetylcholinesterase remains fully sensitive to the chlorpyrifos oxon. © 1998 Society of Chemical Industry     

华北棉区棉铃虫对三种杀虫剂的抗性监测

为明确华北棉区棉铃虫Helicoverpa armigera田间种群对3种常用杀虫剂的抗性,于2014—2015年和2018—2019年分别采集河南、河北、山东和山西4个省的棉铃虫田间种群,采用浸叶法于室内测定棉铃虫对辛硫磷、三氟氯氰菊酯和甲维盐的抗性水平。结果表明,各监测点棉铃虫对辛硫磷处于中等水平抗性,在2014—2015年和2018—2019年的抗性倍数分别为13.0~58.5倍和21.1~55.3倍,棉铃虫对辛硫磷的抗性发展相对缓慢;各监测点棉铃虫种群对三氟氯氰菊酯已产生中等至高水平抗性,并呈现逐年上升的趋势,其中河北沧县、河南安阳、山西盐湖种群的抗性倍数由2014年的61.0倍、22.5倍和24.0倍上升至2019年的91.1倍、44.7倍和61.3倍,山东夏津种群的抗性最高,2019年抗性倍数达到216.3倍;棉铃虫种群对甲维盐表现为低至中等水平抗性,河北沧县、河南安阳、山西盐湖和山东夏津种群的抗性倍数分别为8.2~40.4倍、5.8~16.6倍、5.5~23.4倍和11.0~36.6倍。表明4个监测地区的棉铃虫田间种群对3种杀虫剂已经产生了不同程度的抗性,建议减少这3种杀虫剂的使用频次,并注意与其他杀虫剂交替轮换使用,以延缓棉铃虫抗药性的发展。     

Genetics of Heliothis and Helicoverpa resistance to chemical insecticides and to Bacillus thuringiensis

Genetic linkage maps of Heliothis virescens and Helicoverpa armigera are being used to identify and characterize resistance-conferring genes. The insensitive acetylcholinesterase conferring resistance to organophosphorus insecticides and the insensitive sodium channel conferring resistance to pyrethroids have both been mapped in H. virescens. The linkage mapping approach permits a genetic dissection of resistance, even when the mode of action and lethal target are not precisely known, such as for the insecticidal toxins from the bacterium Bacillus thuringiensis (Bt). We have identified and mapped a major Bt-resistance locus in a strain of H. virescens exhibiting up to 10000-fold resistance to Cry1Ac toxin and are currently developing a linkage map for H. armigera with a set of ‘anchor’ loci to facilitate comparison with H. virescens. Both species are currently experiencing their first significant selective pressure in the field by transgenic cotton expressing Cry1Ac, and timely identification of resistance mechanisms and their underlying genetic basis will be essential in successfully managing the Bt resistance that will eventually appear. ©1997 SCI     

寄主植物调控棉铃虫种群对气候变暖的不对称响应

为明确全球气候变暖对不同寄主植物上棉铃虫Helicoverpa armigera种群发生的影响，通过收集2008—2019年全国范围、华北地区、华东地区、西北地区及华中地区7种寄主植物（小麦、玉米、大豆、棉花、花生、蔬菜和其他粮食作物）上棉铃虫成灾面积及各地区平均温度数据，采用单因素方差分析法及广义线性模型分析不同寄主植物上棉铃虫种群的发生程度。结果显示，玉米、大豆、花生和蔬菜寄主植物上棉铃虫成灾面积显著增加，棉花上棉铃虫成灾面积显著降低。玉米（全国范围、华北地区）、花生（全国范围、华中地区）及蔬菜（华东地区）上棉铃虫成灾面积随着温度距平的升高而显著增加；但棉花上棉铃虫成灾面积随着温度距平的升高而显著降低。如全国范围内，在玉米和花生上，2014—2019年棉铃虫成灾面积均显著高于2008—2013年，其增加比率分别为24.0%和34.3%；在棉花上，2014—2019年棉铃虫成灾面积显著低于2008—2013年，其降低比率为62.0%。表明全球气候变暖显著增加了玉米、花生及蔬菜上棉铃虫成灾面积，而棉花上棉铃虫成灾面积的降低主要受转Bt基因棉花种植的影响。     

The selective feeding of cotton bollworms (Helicoverpa armigera) on transgenic and non-transgenic cotton leaves from consecutive cultivation fields

Abstract

The aim of this study was to determine whether target-insects selectively feed on transgenic or non-transgenic crops after consecutive cultivation in fields. We sampled leaves from insect-resistant single-transgenic cotton (expressing Cry1Ac gene), pyramided-transgenic (expressing Cry1Ac and CPTI genes) and conventional cotton that were consecutively cultivated for three years in a field. Cotton bollworm (Helicoverpa armigera) collected from the cotton field was reared and its next-generation larvae were fed the three types of cotton leaves in a laboratory. The leaf area damaged by the cotton bollworm larvae was not significantly different among single-transgenic, pyramided transgenic and conventional cotton leaves. There was no significant difference found in the leaf damage among the combination groups of the three cotton types. The survival rate of the bollworms was comparable among the combination groups. The results demonstrated that the cotton bollworms did not selectively feed on transgenic or non-transgenic cotton leaves after consecutive cultivation, which may be due to the resistance evolution of the target-insects and decreased Bt content in transgenic cotton leaves.     

棉铃虫para同源基因III-IV接头DNA片段序列分析

利用反转录 PCR技术 ,用一对特异性寡核苷酸引物 ,分离获得棉铃虫 para同源基因 III- IV接头约30 0 bp DNA片段 ,发现在 Bao D- R和 Bao D- S品系间存在 4个核苷酸差异 ,但在推导的氨基酸组成上没有差别。对比分析表明 ,分离获得的棉铃虫 III- IV接头氨基酸组成与烟芽夜蛾 hscp片段同一区域有 98.1%的氨基酸相同 ,与德国蜚蠊 CSMA的氨基酸有 93.5%相同 ,与果蝇 para基因有 88.9%的氨基酸相同     

Insecticide resistance in Helicoverpa armigera in South India

Cypermethrin, quinalphos, endosulfan and methomyl were bioassayed against strains of Helicoverpa armigera collected from field crops in Andhra Pradesh and Tamil Nadu, South India, during the 1989-90 and 1990-91 cropping seasons. In 1989, high levels of resistance to cypermethrin were recorded in strains from cotton in the cotton-growing regions of Guntur, Andhra Pradesh and Coimbatore, Tamil Nadu, and from pigeon pea near Hyderabad. There was no evidence for resistance to quinalphos or methomyl at that time. In 1990-91 sampling was more extensive and although tolerance to cypermethrin was lower than the previous season, the survey indicated that pyrethroid-resistant populations were present throughout much of Andhra Pradesh. Tolerance to quinalphos had increased slightly in 1990-91, while resistance to methomyl had increased substantially, particularly in the cotton-growing area of Guntur. Endosulfan tolerance had increased slightly compared to strains tested in 1986-88 in an earlier study. The geographic and temporal variations in severity of pyrethroid resistance in H. armigera in Andhra Pradesh are believed to arise because of dynamic interactions between local selection pressure and immigration of resistant and susceptible moths at certain times of the year.     

DNA-based screening for an intracellular cadherin mutation conferring non-recessive Cry1Ac resistance in field populations of Helicoverpa armigera

A number of cadherin mutants conferring resistance to Bt toxin Cry1Ac have been reported in three major lepidopteran pests, including Helicoverpa armigera. Unlike most of the cadherin mutants conferring recessive resistance, an allele (r₁₅) with a 55aa deletion in the intracellular domain of cadherin (HaCad) was previously identified to cause non-recessive resistance to Cry1Ac in H. armigera. In the present study, a DNA-based PCR method was developed to screen the r₁₅ allele from field populations of H. armigera collected from the main cotton planting areas of China in 2011 and 2012. Three heterozygous r₁₅ alleles were detected from 562 moths collected from northern China (with intensive Bt cotton planting), and r₁₅ allele frequency was estimated to be 0.0027. However, no r₁₅ allele was detected from 314 moths collected from Xinjiang (with limited Bt cotton use). Although all the r₁₅ alleles have the same deletion in the cDNA sequence, at least four different indels causing loss of exon 32 have been detected in the genomic DNA sequences flanking exon 32 of HaCad. Multiple origins of the r₁₅ alleles illustrate parallel genotypic adaption of H. armigera to the selection pressure of Bt cotton.     

A perspective on management of Helicoverpa armigera: transgenic Bt cotton,IPM, and landscapes

Helicoverpa armigera is a major pest of agriculture, horticulture and floriculture throughout the Old World and recently invaded parts of the New World. We overview of the evolution in thinking about the application of area‐wide approaches to assist with its control by the Australian Cotton Industry to highlight important lessons and future challenges to achieving the same in the New World. An over‐reliance of broad‐spectrum insecticides led to Helicoverpa spp. in Australian cotton rapidly became resistant to DDT, synthetic pyrethroids, organophosphates, carbamates and endosulfan. Voluntary strategies were developed to slow the development of insecticide resistance, which included rotating chemistries and basing spray decisions on thresholds. Despite adoption of these practices, insecticide resistance continued to develop until the introduction of genetically modified cotton provided a platform for augmenting Integrated Pest Management in the Australian cotton industry. Compliance with mandatory resistance management plans for Bt cotton necessitated a shift from pest control at the level of individual fields or farms towards a coordinated area‐wide landscape approach. Our take‐home message for control of H. armigera is that resistance management is essential in genetically modified crops and must be season long and area‐wide to be effective. © 2016 Society of Chemical Industry     

棉铃虫对化学杀虫剂的抗性现状及分子机制研究进展

棉铃虫Helicoverpa armigera是一种世界性分布的重大杂食性农业害虫,长期大量使用化学药剂防治棉铃虫导致其对不同种类杀虫剂产生了抗性。抗性分子机制的阐明有利于棉铃虫的科学防控和抗性治理。该文主要综述棉铃虫对化学杀虫剂的抗性发展现状,以及近年来棉铃虫抗药性分子机制的研究进展,包括解毒酶代谢能力增强、靶标敏感性降低和表皮穿透能力下降等方面,并就未来研究工作和棉铃虫抗性治理新技术进行了展望。     

Expression and inheritance of nerve insensitivity resistance in larvae of Helicoverpa armigera (Lepidoptera: Noctuidae) from China

Nerve insensitivity resistance to synthetic pyrethroids was detected in a resistant field strain (JSFX-R) of the cotton bollworm, Helicoverpa armigera (Hübner), using a neurophysiological assay in which extracellular spontaneous neuronal activity was measured in response to cis-cypermethrin. The nerve insensitivity mechanism was selected using a combination of toxicological and neurophysiological methods. The third-instar larvae in selected strains of Family-37 and CTR strain expressed a very high resistance to fenvalerate (RF = 2060-fold and 805-fold, respectively) and high cross-resistance to DDT (RF = 1927-fold and 2384-fold, respectively) which was not affected by two metabolic synergists, PBO and DMC. The frequency of nerve-insensitive individuals detected in neurophysiological assays (54, 81 and 100% for JSFX-R strain, and the selected strains Family-43 and Family-37, respectively) was not only positively correlated (R² = 0.968) with the frequency of non-PBO-synergisable resistant individuals detected in toxicological tests (37.5, 62.5 and 90% for JSFX-R strain, Family-43 and Family-37, respectively), but also positively correlated (R² = 0.978) with the frequency of DDT-resistant individuals detected in toxicological tests (40, 67.5 and 93.3% for JSFX-R strain, Family-43 and Family-37, respectively). Analysis of dose–mortality lines to DDT and fenvalerate from F₁ hybrids (R♀ × S♂) indicated that nerve insensitivity resistance to DDT and fenvalerate in the CTR strain was inherited in an incompletely recessive pattern. Degree of dominance (D) was estimated to be −0.66 (± 0.06) (DDT) and −0.26 (± 0.04) (fenvalerate). The dose–mortality curves to DDT in back-cross progeny were strongly suggested, by chi-square analysis, to be fitted with those expected of a one-gene model. Evidence for the co-existence of nerve insensitivity and oxidative metabolic resistance mechanisms within individual H armigera and the effects of their interaction on the expression of resistance to fenvalerate are discussed. © 1999 Society of Chemical Industry     

Reduced fitness associated with spinosad resistance in <Emphasis Type="Italic">Helicoverpa armigera</Emphasis>

The fitness cost of spinosad resistance was investigated in the cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae). Laboratory experiments were conducted to compare relative fitness of H. armigera between the spinosad-susceptible and -resistant strains. During the experiments, the average development periods of the resistant strain were lengthened by 4–5 days, reflected in a prolongation of egg, larval and pupal periods. Furthermore, pupal survival, pupal weight, the mean life span of emerged adults, eggs laid and hatched decreased greatly in the resistant strain in comparison with the susceptible strain. Other life-cycle parameters such as larval survival, larval wet weights, prepupal periods, pupation ratio, and sex ratio did not change significantly. As a result, both net replacement rate (R ₀) and intrinsic rate of increase (r _m) were reduced for the resistant strain. Our results clearly indicated that relative fitness of resistant individuals was reduced in the absence of spinosad. Rational measures including pesticide rotations should be expected to delay development of resistance to spinosad in H. armigera field populations from China.