山西省苹果园山楂叶螨对5种杀虫剂抗药性监测

为了明确山西省苹果园山楂叶螨(Amphitetranychus viennensis Zacher)对化学杀虫剂的抗性现状及发展趋势,本文采用玻片浸渍法建立了山楂叶螨相对敏感种群对5种杀虫剂的敏感基线,连续3年(2013-2015年)监测了采自山西省苹果主产区运城苹果园的山楂叶螨对5种杀虫剂的抗性水平及变化动态。监测结果表明:田间监测种群对阿维菌素和三唑锡均处于敏感性下降及低水平抗性阶段,对哒螨灵和噻螨酮的抗性由低水平抗性升至中等水平抗性,对炔螨特处于低水平抗性。田间防治山楂叶螨时,哒螨灵与噻螨酮应淘汰不再使用,阿维菌素、三唑锡、炔螨特则应注意减少用药量及轮换用药,以延缓产生更高水平的抗药性。     

Aphis (Toxoptera) citricidus (Kirkaldy) [Hemiptera: Aphididae] and Chile

As there was no consensus on the presence or absence of Aphis (Toxoptera) citricidus (Kirkaldy) in Chile, a meticulous literature survey has been carried out to clarify the issue. From this survey, it can be concluded that A. (T.) citricidus is not present in Chile, that it has never been cited as present from first‐hand information/observations in this country, and that all available Chilean records of this species are due to old (and now abandoned) taxonomic interpretations or poor transmission of information.     

Variation in response to neonicotinoid insecticides in peach-potato aphids,Myzus persicae (Hemiptera: Aphididae)

Laboratory bioassays applying the neonicotinoid insecticides imidacloprid, acetamiprid and nitenpyram against clones of the peach-potato aphid Myzus persicae (Sulzer) demonstrated that these compounds effectively circumvent the known carboxylesterase, modified acetylcholinesterase (MACE) and knock-down (kdr) insecticide resistance mechanisms in this species. However, some clones showed cross-tolerance (up to 18-fold) of these compounds relative to susceptible standards. A survey assessing the frequency of neonicotinoid tolerance in M persicae in the UK, based on samples collected from the field and glasshouses between 1997 and 2000, showed that such tolerance is still rare. Experiments on neonicotinoid-susceptible and -tolerant populations of M persicae under simulated field conditions in the laboratory showed that, although the latter were well controlled by imidacloprid applied at recommended application rates, they were more likely to survive and reproduce when this compound was applied at lower concentrations. Such conditions are probably periodically present in imidacloprid-treated field and glasshouse crops. Selection favouring tolerant forms of M persicae could lead to increases in their frequency and the evolution of more potent resistance to neonicotinoids.     

Bioassay and field-simulator studies of the efficacy of pymetrozine against peach-potato aphids,Myzus persicae (Hemiptera: Aphididae), possessing different mechanisms of insecticide resistance

Twenty-one clones of the peach-potato aphid, Myzus persicae (Sulzer), carrying various combinations of known mechanisms of insecticide resistance were assessed for their response to the new pyridine azomethine compound, pymetrozine, in leaf-dip bioassays. Pymetrozine was also applied as a foliar spray to populations of four different UK M persicae clones on potato plants in field-simulator chambers. Neither study showed any evidence of cross-resistance to this compound. Pymetrozine, used in conjunction with other effective aphicides, such as pirimicarb and imidacloprid, can therefore play an important role in insecticide resistance-management strategies for M persicae.     

Correlated responses to neonicotinoid insecticides in clones of the peach-potato aphid, Myzus persicae (Hemiptera: Aphididae)

BACKGROUND: Although there are still no confirmed reports of strong resistance to neonicotinoid insecticides in aphids, the peach-potato aphid (Myzus persicae Sulzer) shows variation in response, with some clones exhibiting up to tenfold resistance to imidacloprid. Five clones varying in response to imidacloprid were tested with four other neonicotinoid molecules to investigate the extent of cross-resistance.RESULTS: All four compounds-thiamethoxam, thiacloprid, clothianidin and dinotefuran-were cross-resisted, with ED(50) values ranked in the same order as for imidacloprid. Resistance factors ranged up to 11 for imidacloprid, 18 for thiamethoxam, 13 for thiacloprid, 100 for clothianidin and 6 for dinotefuran.CONCLUSION: This variation in response does not appear to be sufficient to compromise the field performance of neonicotinoids aimed at controlling aphids. However, it highlights the need for careful vigilance and stewardship in all M. persicae populations, and a need to consider neonicotinoids as a single cross-resisted group for management purposes.     

Resistance to Peach-potato Aphid,Myzus persicae Sulzer (Hemiptera: Aphididae) in Potato Cultivars

Previous research suggests that potato cultivars offer little aphid resistance. However, few studies have measured the effects of host cultivar on aphid age dependent life table statistics or related these measures to field performance. In this study, laboratory and field studies assessed four commercial potato cultivars (Anya, Desiree, Pink Fir Apple, Santé) for resistance to Myzuspersicae. Cultivars were found to show considerable differences in resistance. In the laboratory, the intrinsic rate of increase (r_m) and effective fecundity of M. persicae was lowest on cv. Anya and highest on cv. Desiree. Aphids also took longer to develop to adults and were smaller in size on Anya compared with Desiree. Field studies over two seasons found that M. Persicae infestations started earlier on Desiree than on Anya and that the greatest weekly counts were recorded on the former.     

Temporal and spatial dynamics of insecticide resistance in Myzus persicae (Hemiptera: Aphididae)

Advances in understanding insecticide resistance in the peach-potato aphid, Myzus persicae (Sulzer), at the genotypic, biochemical and molecular levels have led to rapid and precise methods for the detection of several resistance mechanisms (elevated carboxylesterase, modified acetylcholinesterase or MACE, and knockdown resistance or kdr) in individual insects, and for monitoring their frequencies over space and time. This paper summarises the results of two long-term surveys of resistance dynamics in M persicae in England, based on samples collected directly from field and glasshouse crops or from four 12.2-m suction traps. The study showed marked fluctuations in resistance frequencies that probably reflect the counteracting forces of selection imposed by insecticides for aphids possessing more copies of esterase resistance genes, and selection against these forms when insecticide use is relaxed. There is growing evidence that several different resistance mechanisms in M persicae have associated fitness costs. In the case of esterase and MACE, these costs are apparently strong enough to effect a decline in resistance frequency over winter, and a more prolonged decline over successive cropping seasons when aphid numbers are insufficient to trigger intensive chemical applications. Changes in the overall frequency of resistance genotypes may also be influenced by the predominance of year-round parthenogenesis in M persicae in the UK, leading to non-random associations between mechanisms and selection operating on clonal lineages rather than individual genotypes.     

Role of Cylindrosporium-type conidia of Mycosphaerella pomi (Pass.) Lindau: cause of Brooks fruit spot of apple, as an infection source in apple orchards

Ascospores of Mycosphaerella pomi, the pathogen of Brooks fruit spot of apple, were produced in pseudothecia on previously infected and overwintered apple leaves from late April through early August in Aomori Prefecture, Japan. In June 2003, the ascospores were germinating and producing Cylindrosporium-type conidia on apple fruit and leaf surfaces in an orchard. After ascospores were sprayed on apple leaves, Cylindrosporium-type conidia developed on the leaf surfaces. Such Cylindrosporium-type conidia caused typical symptoms of Brooks fruit spot on apple trees after inoculations. These results suggested that the Cylindrosporium-type conidia also serve as an infection source, in addition to the ascospores, for Brooks fruit spot in apple orchards.     

新疆地区棉蚜田间种群对10种杀虫剂的抗性

棉蚜是影响新疆棉花种植业的主要害虫之一, 主要依赖化学防治。大量使用化学农药不仅污染环境, 而且对棉蚜产生极大的选择压, 加速抗药性发展。针对近年来新疆多地出现的棉蚜防效下降问题, 采用叶片药膜法, 检测了新疆五家渠、石河子、奎屯、博乐、伊犁和库尔勒地区棉蚜田间种群对10种常用杀虫剂的敏感性。结果表明, 博乐、库尔勒、石河子、五家渠、伊犁、奎屯6个地区的棉蚜田间种群对拟除虫菊酯类和有机磷类杀虫剂产生了极高水平的抗性, 其中对溴氰菊酯、高效氯氰菊酯和氧乐果的抗性分别达到728~2 494倍、353~4 932倍和2 137~9 501倍。对新烟碱类、阿维菌素类和氨基甲酸酯类杀虫剂产生了中、高水平抗性, 其中对吡虫啉、啶虫脒和噻虫嗪的抗性分别为85.2~412倍、221~777倍和122~1 095倍, 对阿维菌素和甲维盐的抗性分别为19.6~220倍和27.66~130倍, 对灭多威和丁硫克百威的抗性分别为91~292倍和6~148倍。其中五家渠棉蚜田间种群对丁硫克百威表现为低抗性, 这可能与该地区施药的频次及药剂种类有关。建议新疆不同区域棉田交替使用新烟碱类、抗生素类和氨基甲酸酯类杀虫剂。     

6种农药对瓜蚜的毒力测定及田间药效

为了筛选防治西瓜瓜蚜的有效药剂,用6种药剂进行了室内毒力测定和田间药效试验。结果表明,1.8%阿维菌素EC对瓜蚜的毒力最高,60g/L乙基多杀菌素SC毒力最低,48hLC50分别为0.38mg/L和2 225.63mg/L。6种药剂毒力大小依次为阿维菌素溴氰虫酰胺氟啶虫胺腈啶虫脒吡虫啉乙基多杀菌素。田间试验结果表明,1.8%阿维菌素EC 3 000倍、10%溴氰虫酰胺OD 2 000倍、22%氟啶虫胺腈SC 4 000倍对瓜蚜速效性及持效性均较好,3~14d防效均达到90%以上,防效差异不显著;20%啶虫脒WP 3 000倍和10%吡虫啉WP 3 000倍速效性及持效性均较差,1d防效分别为31.31%和6.66%,14d防效分别为57.39%和47.80%;60g/L乙基多杀菌素SC 1 000倍防效最差,药后14d的最高防效仅为34.70%。推荐田间轮换使用阿维菌素、溴氰虫酰胺、氟啶虫胺腈防治瓜蚜。     

Field-simulator studies of insecticide resistance to dimethylcarbamates and pyrethroids conferred by metabolic- and target site-based mechanisms in peach-potato aphids,Myzus persicae (Hemiptera: Aphididae)

A range of insecticides was applied at recommended application rates against populations of Myzus persicae (Sulzer) carrying various combinations of three insecticide resistance mechanisms (carboxylesterase-based metabolic resistance and two target-site mechanisms, known as MACE and kdr), supported on either Chinese cabbage or potatoes in field simulator cages. Patterns of response were similar on both host species. MACE conferred extreme resistance to pirimicarb and triazamate (dimethylcarbamate insecticides). The kdr mechanism was associated with resistance to lambda-cyhalothrin, cypermethrin and deltamethrin (pyrethroid insecticides). A mixture of pirimicarb plus lambda-cyhalothrin was only effective against M persicae not carrying kdr or carrying kdr and low carboxylesterase-based resistance. None of the insecticides tested was effective against M persicae carrying both MACE and kdr resistance. The implications of these findings for the formulation of control strategies, based on regular monitoring of resistance genotype frequencies, are discussed.     

Chemical composition and biological activity of Salvia officinalis L. essential oil against Aphis fabae Scopoli (Hemiptera: Aphididae)

Journal of Plant Diseases and Protection - This study investigated chemical composition, repellent and biocidal activities of Salvia officinalis essential oil against Aphis fabae. In total, 19...     

南疆苹果园绣线菊蚜种群时空动态与调查抽样技术

绣线菊蚜Aphis spiraecola是新疆南疆地区苹果园的一种重要害虫,本文在阿克苏地区调查了绣线菊蚜在苹果园的种群消长动态,并分析其种群在果园的空间分布格局、理论抽样数及序贯抽样方法。结果表明,5月至8月苹果园中绣线菊蚜的种群动态曲线呈现出明显单峰,6月为种群发生的高峰期。在发生高峰期,绣线菊蚜在果园呈聚集型分布,种群密度在苹果树不同方位间没有显著差异。该时期苹果园绣线菊蚜的最适理论抽样模型为N=t2/D2(163.90/m+0.16),当防治阈值为1 500头/12枝条时,序贯抽样模型公式为Tn=1 500n±1 534√n。本研究结果为南疆苹果园绣线菊蚜种群调查与测报提供了重要科学依据。     

Assessing the resistance of collard greens genotypes to the cabbage aphid (Brevicoryne brassicae) (Hemiptera: Aphididae)

Phytoparasitica - Severe attacks of Brevicoryne brassicae (Hemiptera: Aphididae) on brassica crops may lead to a significant decrease in yield and can cause plant death. Host plant...     

Green peach aphid,Myzus persicae (Hemiptera: Aphididae), reproduction during exposure to sublethal concentrations of imidacloprid and azadirachtin

BACKGROUND: Resurgence of insect pests following insecticide applications is often attributed to natural enemy disturbance, but hormesis could be an alternative or additional mechanism. Green peach aphid, Myzus persicae (Sulzer), is an important insect pest of many crops worldwide that may be exposed to sublethal insecticide concentrations over time. Here, the hypothesis that exposure to low concentrations of imidacloprid and azadirachtin can induce hormetic responses in M. persicae is tested in the laboratory. RESULTS: When insects were exposed to potato leaf discs dipped in sublethal concentrations of insecticide, almost all measured endpoints—adult longevity, F1 production, F1 survival and F2 production—were affected, and a statistically significant (P < 0.05) stimulatory response was recorded for F2 production following exposure to imidacloprid. No other measures for hormesis were statistically significant, but other trends of hormetic response were consistently observed. CONCLUSIONS: Given that variable distribution and degradation of insecticides in the field would result in a wide range of concentrations over time and space, these laboratory experiments suggest that exposure to sublethal concentrations of imidacloprid and azadirachtin could stimulate reproduction in M. persicae. Copyright © 2008 Society of Chemical Industry