Electrophoretic studies on populations of Myzjus persicae in Scotland from March to July, 1976

Specimens of Myzus persicae have been collected from field populations in Scotland and scored electrophoretically for their phenotypes at three polymorphic loci. These phenotypes were almost invariably present in individuals in one of a small number of favoured combinations, suggesting that these populations may be oligogeneous, that is, composed of large numbers of copies of a few favoured combinations of alleles. Temporal and spatial sampling at sites in East and West Scotland in 1976 has shown that different allele combination types were present in the two areas. Populations in E. Scotland contained very few specimens belonging to the organophosphorus (OP) resistant clone types (using esterase activity to infer resistance); instead there were large numbers of an OP susceptible type which has not been detected in England, but which came to predominate on cabbage and potato host plants at every site sampled during the period of rapid population increase. In contrast, populations in W. Scotland were characterised by substantial numbers of specimens belonging to OP resistant clone types and by an almost complete absence of this susceptible type. Two other distinguishable OP susceptible types were found to be common to both areas. The W. Scotland populations closely resemble N. England populations while those in E. Scotland appear to be unique to that area. Specimens of OP resistant types were only detected in E. Scotland after the beginning of June and in such relative proportions as to strongly suggest that they were migrants from W. Scotland or N. England.     

Electrophoretic detection of the internal parasite, Aphidius matricariae in Myzus persicae

The presence of the internal parasite (Aphidius matricariae) of the aphid Myzus persicae can be identified by electrophoresis, and staining of several enzyme systems, of which malate dehydrogenase is recommended as the most reliable. It is suggested that the technique could be extended to other small insects, and that pest populations can be screened for percentage parasitism as an adjunct to insecticide and integrated control field trials.     

Genetic, biochemical, and behavioral uniformity among populations of Myzus nicotianae and Myzus persicae

Prior to designation as distinct species, an appellation presently in question, the tobacco aphid, Myzus nicotianae Blackman (Homoptera: Aphididae), was classified as a tobacco-feeding form of the green peach aphid, Myzus persicae (Sulzer). In this study, RAPD polymorphisms distinguished members of the Myzus persicae complex (M. persicae and M. nicotianae) from three outgroup Myzus species (M. cerasi (F.), M. hemerocallis Takahashi, and M. varians Davidson). Polymorphisms within the complex did not separate populations on the basis of host association (tobacco versus other host plants) or geographic origin (collections from the United States, Europe, and Japan). Similarly, while GC-MS analysis of cuticular hydrocarbon profiles revealed both developmental and inter-populational differences within the M. persicae complex, it did not separate populations of tobacco feeding aphids from those collected off non-tobacco hosts. Finally, with the exception of their responses to a choice between lettuce and collards, the host preference behavior of a green peach aphid population, a red tobacco aphid population, and a green tobacco aphid population was indistinguishable in host preference experiments. These results add to a growing body of evidence suggesting M. nicotianae and M. persicae are conspecific.     

Microsatellite variation in cyclically parthenogenetic populations of Myzus persicae in south-eastern Australia

We examined the population structure of the introduced aphid, Myzus persicae collected mainly from its primary host, Prunus persica, in south-east Australia. Myzus persicae has been present in Australia since at least 1893. Samples were collected in the spring of 1998 from two mainland and three Tasmanian localities and isofemale lines were established in the laboratory. The reproductive mode (life cycle), karyotype and 17-locus microsatellite genotype of each clone were determined. All populations showed significant population differentiation (F(ST) 0.058-0.202) even over small geographic distances (<50 km). All clones were karyotypically normal except for a subset of clones from one site that was exposed to the carbamate insecticide, Pirimor, the week prior to sampling. Those clones were heterozygous for an autosomal 1,3 translocation frequently associated in M. persicae with insecticide resistance. In contrast to other loci and despite being on different chromosomes, loci myz2(A) and M55(A) showed general and significant linkage disequilibrium. These loci may be affected by epistatic selection. We discuss the observed high clonal diversity, moderate but significant population differentiation, general conformance to Hardy-Weinberg equilibria and low linkage disequilibria with particular focus on the global population biology of M. persicae.     

Electrophoretic study of genetic variation in British Myzus persicae (Sulz.) (hemiptera,aphididae)

Thirty-five clones of the green peach aphid, Myzus persicae Sulz., representing a wide range of host plants and geographical origins, were examined electrophoretically. Only 11 of 26 enzymes were active enough for subsequent work. Since genetic crosses are very difficult to make in the parthenogenetic M. persicae, assigning bands to loci and alleles is necessarily arbitrary. Thirty-two isozyme bands were detected. Only two of these (Est-1 and Est-3) migrated to different distances in some clones. This is a very low level of interclone variation, considering the known properties and origins of the clones. The peculiar feeding habits of aphids may perhaps partly explain the inactivity of so many enzymes in M. persicae (which are active in other insects). The scarcity of interclone variation in isozyme migration distance in M. persicae clones may be the result of its fast parthenogenetic reproduction and high migration ability of alates, combined with the effects of natural and artificial selection (e.g., by insecticides). Surviving genotypes may be rather few, each represented by numerous individuals. The only type of widespread electrophoretic variation is in the intensity of two esterase bands (Est-1 and Est-2). Five hypotheses are presented to explain this variation and discussed in view of evidence from other organisms.     

Spatial and temporal genetic variability in French populations of the peach-potato aphid,Myzus persicae

The peach-potato aphid, Myzus persicae (Sulzer), has a complex reproductive mode in which some lineages reproduce by continuous parthenogenesis, whereas others reproduce sexually once a year. The climate is thought to act directly on the reproductive mode, because sexual eggs are the only form that can resist frost in cold regions. Sexual reproduction necessitates an obligatory host alternation that may result in long-distance dispersal. Here, we examined the genetic variability at seven microsatellite loci of populations of M. persicae in France, where both reproductive modes occur. We provide clear genetic evidence that the breeding system affects genotypic variability, as cyclically parthenogenetic aphids are far more variable than their obligately parthenogenetic counterparts. A temporal decrease in genetic variability and a temporal genetic differentiation effect suggest the existence of selective factors that play an important role in shaping the genetic structure of M. persicae populations. Lastly, differences in the population structure between reproductive modes suggest that the migration associated with the change of host during sexual reproduction lowers the level of population differentiation.     

不同地理种群烟蚜形态特征差异分析

烟蚜Myzus persicae是一种世界性的重要农业害虫。为探讨我国不同地理种群烟蚜形态特征变异情况, 本研究测量了我国18个地理种群烟蚜的体长、 体宽、 头宽、 各足腿节长、 各足胫节长等18个形态性状度量特征和Q值, 并进行方差分析和基于欧氏距离与地理距离和海拔差距的Mantel Test, 利用各形态特征与体长的比值构成的比例特征进行系统聚类和主成分分析。结果表明： 部分地理种群烟蚜的形态性状差异显著。系统聚类和主成分分析表明, 18个烟蚜地理种群中贵州贞丰种群（ZF-GZ）与其他种群相比差异最大, 陕西南泥湾（NNW-SX）、 湖南慈利（CL-HN）、 安徽谯城（QC-AH）和重庆武隆（WL-CQ）种群差异最小, 其他种群间的差异程度介于这两者之间。Mantel Test显示欧氏距离与地理距离、 海拔高度差距都不具有相关性。烟蚜种群的形态分化不符合地理隔离模式, 地理气候条件对种群形态有一定影响, 种群形态差异的形成是多种因素综合作用的结果, 但具体作用机制尚不明确。     

植物提取物和药剂对蔬菜蚜虫实验和自然种群的联合控制作用

研究白蝴蝶（Syngonium podophyllum ）乙醇提取物、苍耳（Xanthium sibiricum ）乙醇提取物、机油乳剂和0.3%印楝素乳油对桃蚜（Myzus persicae）和萝卜蚜（Lipaphis erysimi）的控制效果.室内四因子（1/2实施）二次正交回归旋转组合设计测试对有翅蚜的忌避作用,结果表明,对有翅桃蚜的主要忌避作用物为苍耳乙醇提取物,当苍耳提取物与白蝴蝶乙醇提取物混用,以及机油乳剂和印楝素混用时,对桃蚜有翅蚜的忌避效果提高;而对萝卜蚜有翅蚜的忌避作用主要受苍耳提取物和白蝴蝶提取物的影响.这些干扰作用均是非线性的.田间试验结果,单独使用白蝴蝶提取物对有翅成蚜有较强的驱避作用;对萝卜蚜自然种群的干扰控制作用以4种植物提取物和药剂混配效果最好,达95.7%;对桃蚜自然种群干扰控制效果最好的则是白蝴蝶提取物,控制效果达87%;同时,白蝴蝶提取物与印楝素乳油混配以及苍耳提取物与印楝素乳油混配,对两种蚜虫的控制效果均达80%以上.     

Diaeretiella rapae limits Myzus persicae populations after applications of deltamethrin in oilseed rape

In fall, Myzus persicae (Sulzer) (Homoptera: Aphididae) may exhibit population resurgence in winter oilseed rape in France. This resurgence may arise from pyrethroid treatments against Coleoptera (Psylliodes chrysocephala L.) that either kill parasitoids present during treatment or prevent recolonization by off-crop parasitoids. We studied the impact of Diaeretiella rapae (M'Intosh) (Hymenoptera: Braconidae) on populations of M. persicae when parasitoids were introduced on deltamethrin-treated plants at increasing intervals after treatment. Parasitoids were introduced 1, 2, 7, or 14 d posttreatment on individually caged plants infested with established populations of M. persicae. Aphids were counted 7, 14 and 21 d after parasitoid introduction. First, we observed that both the pesticide and the parasitoid reduced aphid population growth and that their effects were additive. Second, there was no mortality of parasitoids exposed to treated leaves in a device with a refuge area, and only 20% of mortality without the refuge area. Furthermore, deltamethrin residues had no effect on the reproduction of D. rapae females. Compared with the known toxicity of deltamethrin to D. rapae on glass, this low mortality may have been due to both the high liposolubility of deltamethrin (leading to a rapid diffusion of residues in the oilseed rape leaf cuticle) and to the existence of a refuge area. This work suggests that D. rapae could limit populations of M. persicae in the fall, even after pyrethroid treatment, because the presence of deltamethrin residues had little impact on the parasitoid.     

Genetic variation in Myzus persicae populations associated with host-plant and life cycle category

Random amplified polymorphic DNA (RAPD) analysis was applied on 96 clones of Myzus persicae (Sulzer) (Homoptera: Aphididae) representing seven populations collected from different host-plants and regions of Greece. Ten decamer random primers were used to evaluate genetic variation among the examined samples. Despite the variability found between clones, no specific RAPD marker was detected to discriminate the different populations. A significant finding was that aphids from peach and pepper, which were collected far away from tobacco-growing regions, especially those from peach, showed genetic divergence from the tobacco-feeding clones. Moreover, data analysis revealed a significant genetic divergence between holocyclic and anholocyclic populations from tobacco. Lastly, holocyclic clones showed higher level of estimated heterozygosity than the nonholocyclic (anholocyclic, androcyclic and intermediate) ones.     

烟蚜及其捕食性天敌草间小黑蛛种群空间结构分析

采用地统计学原理和方法,拟合了不同时期烟蚜种群及其捕食性天敌草间小黑蛛种群的空间结构模型,分析了其空间关系．结果表明,不同时期烟蚜种群的空间结构模型均为球型,空间格局呈聚集型分布,空间相关距离在2．0252～4．1495m之间,异质系数为10281．36～300216．30,空间依赖程度为12176．81～303433．70;不同时期草间小黑蛛种群的空间结构模型也均为球型,空间格局呈聚集型分布,空间相关距离在3．7328～4．8983m之间,异质系数为1．4482～4．4134,空间依赖程度为1．6941～5．8167．该结果和方法可用于监测烟田目标害虫的时空格局动态．     

Supercooling of Myzus persicae in relation to gut content

The supercooling distribution curves of Myzus persicae varied in response to feeding position, diet and age. Unfed instar I aphids supercooled to temperatures lower than –20 °C. Feeding aphids supercooled to higher temperatures, the earlier instars on subsidiary veins supercooling to lower temperatures than the late instars and adults on the main veins. Starvation decreased supercooling ability in some adult aphids. The supercooling ability of aphids feeding on sucrose solutions through a Parafilm membrane decreased in response to an increasing concentration, the position being reversed on 25% sucrose. Varying the amino acid concentration had no effect. The possible effects of this variable supercooling ability on the winter survival of the aphid are discussed.     

Host-correlated morphological variation of Myzus persicae (Hemiptera: Aphididae) populations in Greece

Morphological variation in nine characters of 157 clones of Myzus persicae (Sulzer) was examined by multivariate analysis. The clones were collected from peach, Prunus persica, the primary host and the secondary hosts tobacco, Nicotiana tabacum, cabbage, Brassica oleracea, sugarbeet, Beta vulgaris and pepper Capsicum annuum. The 156 clones originated from various regions of Greece, both in the north, where a large part of the population has an annual bisexual generation on peach, and in more southerly regions, where populations are predominantly unisexual. One clone was collected from tobacco in Caserta, Italy. All clones were laboratory-reared on potato. Canonical variate analysis, hierarchical cluster analysis and a non-parametric classification tree method both revealed morphological differences associated with the host-plant on which they were collected. The scores of the first two canonical variates separated the tobacco-feeding clones from those originating from other secondary host-plants. However, in tobacco-growing areas the tobacco-feeding form predominated in spring populations on peach, and was sometimes found on other secondary hosts. In addition, using cluster analysis, the clones from tobacco which were sampled in the most southeasterly region showed a relatively large phenotypic distance from those collected further north and west. Moreover, clonal phenotypes were affected both by host plant and by long-term parthenogenetic rearing. However, in spite of these effects, the tobacco form was generally distinguishable from aphids originating from other hosts, indicating that the difference must have a genetic basis. In separate analyses of the clones originating from secondary hosts no association was found between morphology and either life cycle category or colour. Discriminant analysis showed that 89% of 1723 specimens could be correctly classified into the two groups.     

Antibiotic resistance in potato cultivars to the aphid Myzus persicae

Commercially-grown potato cultivars were assessed for antibiotic resistance to Myzus persicae in a culture room at 19°C with a 2°C range and a 16 h photoperiod. The resistant rankings obtained were consistent for the following aphid metrics: maturation time, teneral adult weight, embryo complement and the production of nymphs. Intrinsic rates of increase (r_m) correlated with the above parameters of aphid growth and reproduction but this was not always the case for nymphal survival rate. The cultivars Ulster Tarn, Record and Maris Piper were relatively resistant to M. persicae and cultivars Desirée and King Edward were the most susceptible. When the aphid clone or the culture plants were changed there was no significant effect on the relative resistance of the potato cultivars under test. The relationship between the number of embryos in teneral adults and the production of nymphs by aphids was examined by grouping aphids in weight batches. There was a strong relationship between these two variables.     

Feeding studies on gynoparae, males and apterous virginoparae of Myzus persicae on potato by electrical penetration graph

Abstract:  Feeding behaviour of parthenogenetic apterae, post-teneral gynoparae and males of a holocyclic parthenogenetic lineage of Myzus persicae (Sulzer) (Hem., Aphididae) was studied on potato plants, Solanum tuberosum L. (Solanaceae) by DC-electrical penetration graph recording. Differences were observed between morphs during the 7-h recordings, specifically in the first phase of subcuticular probing and in xylem and phloem-related activities. The time required for the first penetration and first cell puncture of the non-vascular tissues was shorter in apterae than in gynoparae and males. Apterae more often showed phloem activities and sustained sap ingestion (100%) than winged morphs ( ca. 25%). In addition, phloem ingestion was much longer in apterae than in winged morphs, 3458 s and 25–70 s respectively. In contrast, winged morphs spent 14–21% of the available time ingesting sap from xylem while in apterae xylem sap uptake was only for 2% of the time. Furthermore, the data showed that males perform in general all the feeding behaviours that other conspecific morphs exhibit. The differences in feeding behaviour among morphs of M. persicae are discussed in relation to host specialization and to their possible involvement in non-persistent transmission of viruses.     

Assessment of the potential for and development of organophosphorus resistance in field populations of Myzus persicae

A survey of esterases in field populations of the peach-potato aphid, Myzus persicae was made during the spring of 1975. Assay was by electrophoresis of single aphid homogenates, and the known association between the activity of an esterase and resistance to organophosphorus insecticide (OP) was used to infer resistance in field populations. The resistant variant replaced the susceptible in populations which had been treated with OP and another variant with threefold (approximately) more esterase activity appeared to be replacing the resistant variant in populations which have been treated twice with OP. The significance of this for control of M. persicae is discussed. Differences in resistance between aphids in different parts of the same field, and the widespread association of these esterase variants in favoured combinations with two electrophoretic variants at another locus have also been investigated.     

云南烟蚜抗药性机制研究

通过比较云南烟蚜敏感品系和抗性品系的解毒酶(α-乙酸萘酯羧酸酯酶、β-乙酸萘酯羧酸酯酶)和靶标酶(乙酰胆碱酯酶)的活力,研究了烟蚜对有机磷、拟除虫菊酯和氨基甲酸酯类杀虫剂抗性的生化机制,并通过酯酶基因扩增检测和钠离子通道突变检测,研究了其抗性的分子机制。结果表明:α-乙酸萘酯羧酸酯酶活力增强是烟蚜对有机磷类、氨基甲酸酯类杀虫剂及拟除虫菊酯类杀虫剂的抗性机制之一;乙酰胆碱酯酶在烟蚜对有机磷杀虫剂抗性中起重要作用;3个抗性品系烟蚜均没有发生酯酶基因扩增,抗拟除虫菊酯品系烟蚜发生了钠离子通道突变。     

Over-wintering of aphids,especially Myzus persicae,Sulzer, in root clamps

Mangold clamps in many districts of the British Isles were found to provide overwintering sites for Myzus persicae (Sulz.), Hyperomyzns staphyleae (Koch) and Aulacorthum solani (Kalt.). After a severe winter, when other means of overwintering are few, clamps may be the most important source of Myzus persicae. Only Myzus ascalonicus Doncaster was found in swede clamps.
Factors affecting the infestation of clamped mangolds by M. persicae were the number of aphids on the crop when lifted, the methods of topping and clamping the roots, and the temperature in the clamp. M. persicae was introduced on the leaves, and close topping was often an efficient means of control. Close topping did not control Hyperomyzus staphyleae; normally, this aphid does not seem to be a root-feeding species, but with artificially colonized mangolds it fed on both exposed roots and foliage. It is not known how this species enters the clamps. The temperature in clamps was influenced by that of the outside air and the type of cover, but changes were long-term and did not reflect diurnal variations in external air temperature. Straw, covered with soil, was the best form of cover.
In addition to harbouring Myzus persicae , mangold clamps are also important sources of sugar-beet yellows virus.     

Redox responses of Arabidopsis thaliana to the green peach aphid,Myzus persicae

The green peach aphid (Myzus persicae) is a phloem-feeding insect that causes economic damage on a wide array of crops. Using a luminol-based assay, a superoxide-responsive reporter gene (Zat12::luciferase), and a probe specific to hydrogen peroxide (HyPer), we demonstrated that this aphid induces accumulation of reactive oxygen species (ROS) in Arabidopsis thaliana. Similar to the apoplastic oxidative burst induced by pathogens, this response to aphids was rapid and transient, with two peaks occurring within 1 and 4 hr after infestation. Aphid infestation also induced an oxidative response in the cytosol and peroxisomes, as measured using a redox-sensitive variant of green fluorescent protein (roGFP2). This intracellular response began within minutes of infestation but persisted 20 hr or more after inoculation, and the response of the peroxisomes appeared stronger than the response in the cytosol. Our results suggest that the oxidative response to aphids involves both apoplastic and intracellular sources of ROS, including ROS generation in the peroxisomes, and these different sources of ROS may potentially differ in their impacts on host suitability for aphids.