Aphis （Hemiptera： Aphididae） species groups found in the Midwestern United States and their contribution to the phylogenetic knowledge of the genus

A phylogeny of the genus Aphis Linnaeus, 1 758 was built primarily from specimens collected in the Midwest of the United States. A data matrix was constructedwith 68 species and 41 morphological characters with respective character states of alate and apterous viviparous females. Dendrogram topologies of analyses performed usingUPGMA （Unweighted Pair Group Method with Arithmetic Mean）, Maximum Parsimony and Bayesian analysis of Cytochrome Oxidase I, Elongation Factor 1-α and primary endosymbiont Buchnera aphidicola 16S sequences were not congruent. Bayesian analysis strongly supported most terminal nodes of the phylogenetic trees. The phylogeny wasstrongly supported by EFI-α, and analysis of COl and EFI-α molecular data combined with morphological characters. It was not supported by single analysis of COI or Buch-hera aphidicola 16S. Results from the Bayesian phylogeny show 4 main species groups： asclepiadis,fabae, gossypii, and middletonii. Results place Aphis and species of the generaProtaphis Bōrner, 1952, Toxoptera Koch, 1856 and Xerobion Nevsky, 1928 in a monophyletic clade. Morphological characters support this monophyly as well. The phylogenyshows that the monophyletic clade of the North American middletonii species group belong to the genus Protaphis： P. debilicornis （Gillette ＆ Palmer, 1929）, comb. nov., P. echinaceae（Lagos and Voegtlin, 2009）, comb. nov., and P. middletonii （Thomas, 1879）. The genus Toxoptera should be considered a subgenus of Aphis （stat. nov.）. The analysis also indicatesthat the current genus Iowana Frison, 1954 should be considered a subgenus of Aphis （stat. nov.）.     

山羊草属二倍体物种核rDNA ITS区序列及其系统发育关系分析

测定了山羊草属（Ａｅｇｉｌｏｐｓ）二倍物种核ｒＤＮＡ ＩＴＳ区序列,发现其碱基粉介于６０１－６０７之间,比报道的小ｒｉｕｃｅａｅ）其他属的ＩＴＳ区我略长,Ｇ＋Ｃ含量达６１．１％～６２．９％,序列间的分化距离为０．００５０～０．０４６８。用ＰＨＹＬＩＰ３．５ｅ软件包对所测得的ＤＮＡ数据进行聚类分析,结果显示：１．Ａｅ．ｓｐｅｌｔｏｉｄｅｓ与该组其他种相距很远,支持将其从Ｓｉｔｏｐｓｉｓ组中独立出来,     

Molecular and morphological differentiation between Aphis gossypii Glover (Hemiptera,Aphididae) and related species,with particular reference to the North American Midwest

The cotton aphid, Aphis gossypii, is one of the most biologically diverse species of aphids; a polyphagous species in a family where most are host specialists. It is economically important and belongs to a group of closely related species that has challenged aphid taxonomy. The research presented here seeks to clarify the taxonomic relationships and status of species within the Aphid gossypii group in the North American Midwest. Sequences of the mitochondrial cytochrome oxidase 1 (COI), nuclear elongation factor 1-α (EF1-α), and nuclear sodium channel para-type (SCP) genes were used to differentiate between Aphid gossypii and related species. Aphis monardae, previously synonymised with Aphid gossypii, is re-established as a valid species. Phylogenetic analyses support the close relationship of members of the Aphid gossypii group native to North America (Aphid forbesi, Aphid monardae, Aphid oestlundi, Aphid rubifolii, and Aphid rubicola), Europe (Aphid nasturtii, Aphid urticata and Aphid sedi), and Asia (Aphid agrimoniae, Aphid clerodendri, Aphid glycines, Aphid gossypii, Aphid hypericiphaga, Aphid ichigicola, Aphid ichigo, Aphid sanguisorbicola, Aphid sumire and Aphid taraxicicola). The North American species most closely related to Aphid gossypii are Aphid monardae and Aphid oestlundi. The cosmopolitan Aphid gossypii and Aphid sedi identified in the USA are genetically very similar using COI and EF1-α sequences, but the SCP gene shows greater genetic distance between them. We present a discussion of the biological and morphological differentiation of these species.     

棉花型和黄瓜型棉蚜(Aphis gossypii Glover)的寄主适应性及转移通道

采用寄主转接建立生命表的方法研究了棉花型和黄瓜型棉蚜对不同寄主植物的适应性,以及两寄主型棉蚜是否可通过中间桥梁寄主实现寄主互换的问题。结果表明,两寄主型棉蚜直接互换寄主后,其存活和繁殖力显著下降,表现为棉花型和黄瓜型棉蚜的净增殖率比在原寄主上分别下降980倍和12倍,平均世代寿命缩短5～12d。两寄主型棉蚜均能利用木槿植物,并且适应性没有显著差异。但是两寄主型棉蚜均不能在车前草和大叶黄杨上存活和繁殖后代。西葫芦作物对棉蚜在木槿、棉花和黄瓜寄主上的相互转移起到了重要的桥梁寄主作用。冬寄主木槿上棉蚜可通过甜瓜或西葫芦转移到黄瓜寄主上,棉花和黄瓜上棉蚜也可通西葫芦作物分别转移到黄瓜和棉花作物上,从而形成棉蚜在不同寄主植物间的相互转移通道,造成为害和病毒病的扩张。     

台湾乳白蚁与赭黄乳白蚁的异名关系---基于形态与分子特征的分析(等翅目：鼻白蚁科）

乳白蚁属Coptotermes是鼻白蚁科Rhinotermitidae最具经济意义的属之一,其中的台湾乳白蚁Coptotermes formosanus Shriaki分布广、适应性强,个体在不同种群以及不同巢龄间外部形态存在明显变异,已报道多个同物异名。本研究发现在模式产地重新采集到经形态学鉴定为赭黄乳白蚁Coptotermes ochraceus Ping et Xu的标本,其形态特征与台湾乳白蚁相似度较高,又以线粒体16S rRNA和CO II基因作为分子标记,将两者进行了序列比对,并与美国国立生物技术信息中心(NCBI)中台湾乳白蚁以及其他一些乳白蚁种类的相应序列一起进行了遗传差异比较和同源性分析。结果表明,台湾乳白蚁与赭黄乳白蚁16S rRNA和CO II序列的遗传差异均明显小于台湾乳白蚁与属内其它种之间的差异;在基于两种分子标记构建的支序图中,台湾乳白蚁和赭黄乳白蚁均聚为一支,并得到了很高的自展支持率。综合分子和形态两方面的证据,本研究建议赭黄乳白蚁为台湾乳白蚁的次异名。     

The role of plant chemical cues in determining host preference in the generalist aphid parasitoid Aphidius colemani

The host preference behaviour of the generalist aphid parasitoid Aphidius colemaniwas investigated using a Y-tube olfactometer. Female A. colemanishowed a preference for the host-plant complex on which they had been reared, even though the same aphid host was involved, demonstrating a host plant preference. This preference was not evident when the parasitoids were dissected from their mummies prior to adult emergence. Host plant preference exhibited during host selection appeared to be induced by chemical cues encountered on the mummy case at the time of emergence, but preferences could be changed by subsequent foraging experiences. It is concluded that plant chemical cues play a major role in determining initial preferences through a process of emergence conditioning but that learning processes, involving cues encountered during oviposition in or contact with the host, can modify these initial preferences.     

The distribution of aphids in response to variation among individual host plants: Uroleucon rudbeckiae (Homoptera: Aphididae) andRudbeckia laciniata (Asteraceae)

Abstract. 1. An investigation was conducted to determine the effects of variation among individual plants of Rudbeckia laciniata L. on the distribution and abundance of the aphid Uroleucon rudbeckiae (Fitch).
2. Wild plants were examined repeatedly for up to 2¹/₂ years to obtain information about plant growth and flowering, and about aphid densities on individual plants.
3. Aphid densities on individual plants were positively associated with several measures of plant vigour, including height, growth since previous year, and occurrence of flowers.
4. The colonization of plants by alate aphids was more highly correlated with plant height than with plant exposure. Aphid densities on individual plants were more strongly associated with plant height than with number of colonists.
5. In all years there were many hosts which were never colonized by aphids. Some of these plants produced shoots but did not flower. Experimental infestation of these plants showed that they were unsuitable for aphid growth and reproduction. Some plants which did flower and which escaped aphid infestation were nevertheless suitable hosts. Previously unsuitable host individuals were able to support aphids when grown under glass-house conditions.     

杀虫剂及不同地区寄主植物对棉蚜酯酶的影响

通过滤纸酯酶反应法比较 4种有机磷杀虫剂对北京和山东高密地区取食不同寄主植物的棉蚜β-乙酸萘酯 (β -NA)酯酶的抑制作用。结果表明高密地区不同寄主植物上的棉蚜 β -NA酯酶活力高的个体多于北京地区 ,同时辛硫磷对高密地区不同寄主植物上的棉蚜 β -NA酯酶的抑制作用亦高于北京地区 ,而久效磷和DDVP对两地区不同寄主植物上的棉蚜种群中 β-NA酯酶的抑制作用相似。     

基于Cytb基因序列探讨蝽亚科11种昆虫的系统发育关系

对蝽亚科6属11种昆虫线粒体DNA细胞色素b基因部分序列进行PCR扩增和序列测定。比较其同源性,统计密码子使用频率并应用生物学软件构建分子系统树。在获得的432bp序列中,碱基T,C,A和G的平均含量分别是38．1,18．2,31．9和11．8％,表现出强烈的AT偏向性;就每个氨基酸密码子来看,第3位点的A＋T含量较高,达到85．5％。该序列片段中共有162个核甘酸位点发生变异（约占37．5％）,种间序列差异范围为0．9％～19．4％,平均为16．6％,变异较大。以筛豆龟蝽Megaeopta cribraria为外群,通过多种方法构建的系统发育树拓扑结构一致,这6属11种昆虫大致形成4个分支：珀蝽属、碧蝽属、菜蝽属3属的关系最接近,形成一个分支;真蝽属的3种聚为1支,与第1支形成姊妹群;曼蝽属的2种形成1支;麻皮蝽位于系统树的基部,为分化较早的1支,是蝽亚科中较为原始的类群。     

An investigation of the resistance to cabbage aphid in brassica species

Fifteen Brassica species and subspecies, as well as accessions of Arabidopsis thaliana and Eruca sativa, were evaluated for their resistance to the cabbage aphid, Brevicoryne brassicae, in the field and laboratory at Horticulture Research International (HRI) Wellesbourne in 1992. In the laboratory, aphid performance was measured in terms of pre-reproductive period, reproductive period, population increase and insect survival. Using these parameters it was possible to identify brassicas possessing antibiosis resistance. In the field B. brassicae attack was assessed in terms of numbers of insects and it was possible to determine aphid preferences for alighting on different species. High levels of antixenosis and antibiosis resistance were discovered in accessions of Brassica fruticulosa and B. spinescens, in a Brassica juncea breeding line and in Eruca sativa. Partial resistance was found in several other Brassica species. The potential of these various sources as donors of resistance genes to be bred into cultivated brassicas is discussed.     

Plant structure and the foraging success of Aphidius rhopalosiphi (Hymenoptera: Aphidiidae)

Abstract. 1. A study of searching behaviour on wheat and host preference of Aphidius rhopalosiphi (DeStefani-Perez) is described.
2. Parasitoids divided their time equally between the leaves but spent very little time on the ear.
3. After contact with honeydew or an aphid host, parasitoids were arrested in a particular area and increased the time spent searching.
4. Aphids feeding on the ear were parasitized less successfully, since their position between the grains protected them from parasitoid attacks.
5. A.rhopalosiphi exhibited no preference for Metopolophium dirhodum (Walker) or Sitobion avenae (Fabricius), although the handling time for the latter was significantly longer; this resulted in fewer S.avenae being parasitized when it was abundant. Parasitoids did not switch between hosts in these experiments.
6. As a result of its searching behaviour, A.rhopalosiphi will encounter and parasitize M.dirhodum feeding on the leaves more frequently than S.avenae, which feeds on the ear. This will limit the parasitoid's ability to regulate populations of the cereal aphid S. avenae.     

Aphid responses to non-host epicuticular lipids

Initiation of stylet penetration by aphids depends on the sensory assessment of a number of plant surface features including colour, texture and phytochemicals (volatile and non-volatile). Video recording behaviour of the black bean aphid, Aphis fabae, showed that these insects rapidly inserted their stylets following contact with host plants (beans), but were reluctant to penetrate non-hosts (oats). However, when epicuticular waxes were stripped from oats, using cellulose acetate, aphids penetrated the plant surface significantly earlier than on oats with the wax layer intact. Chloroform extraction of epicuticular lipids, followed by coupled gas chromatography-mass spectrometry, revealed a complex blend of wax components on beans, whereas one compound (1-hexacosanol) predominated on oats. Epicuticular lipids were applied to artificial (glass) substrates in order to investigate their behavioural activity. Initiation of a stylet penetration attempt by A. fabae was delayed when the oat extract or pure 1-hexacosanol were applied, but the bean extract had no behavioural effect. The results suggest that epicuticular lipids play an important role in the early stages of host-plant selection by A. fabae.     

从Cyt b基因序列探讨Grophosoma属和Dybowskyia属的分类地位(半翅目:蝽科)

对蝽科11种昆虫的线粒体细胞色素b（Cyt b）基因部分序列进行测定和分析,在获得的长度为432bp的序列片段中,碱基T、C、 A、G的平均含量分别为38.8%、18.0%、31.6%和11.6%, A＋T平均含量为70.4%,明显高于G＋C含量（29.6 %）.密码子第三位点的A＋T含量高达86.1%.属种间序列变异丰富,有179个核苷酸位点发生变异,变异率为41.4%,碱基替换多发生于第三位点.以筛豆龟蝽Megacopta cribraria为外群构建的系统发育树表明：滴蝽属与蝽亚科其它属关系较远,条蝽属与蝽亚科其它属关系较近,结合形态特征与序列变异情况,支持将滴蝽属从蝽亚科划出并入舌盾蝽亚科,但条蝽属的分类地位仍需要进一步探讨.     

寄主植物叶片物理性状对潜叶昆虫的影响

潜叶昆虫广泛分布于鳞翅目、双翅目、鞘翅目和膜翅目中,其幼虫潜入叶片内部生活和取食,是一类用于研究植物-昆虫-天敌种间关系和协同进化的重要模式生物。有些潜叶昆虫是重要农林害虫。相比外食性昆虫,在叶内取食的潜叶昆虫幼虫更易受到叶片物理性状的直接影响。叶片的着生位置、朝向、大小、颜色和表皮毛等直接决定潜叶虫成虫的取食和产卵选择,从而影响幼虫的空间分布和寄主适应。叶片的某些物理性状也会直接影响幼虫的取食行为、生长发育和被寄生率。研究叶片物理性状的防御作用以及潜叶昆虫对这些防御的适应,有助于了解潜叶昆虫-寄主植物的协同进化。另一方面,外界环境和遗传育种都有可能改变植物叶片的物理特性,而对潜叶害虫产生抗性,从而实现潜叶害虫的可持续生态控制。     

Host plant relationships and life cycles of the aphid genusCryptomyzus

The host plant relationships of the aphid genusCryptomyzus were studied by field sampling and laboratory experiments. Host plant suitability and host plant preference were assessed in the laboratory using parthenogenetic females of the summer generations (exules). Differences in reproductive performance and host plant preference were found between closely related taxa ofC. galeopsidis. Host plant preference was correlated with reproductive performance in these forms ofC. galeopsidis. This indicated that evolutionary divergence has occurred and this justifies their status as separate species. It did not prove possible to induce an improvement in the performance of theC. galeopsidis fromLamium galeobdolon onGaleopsis tetrahit, the host plant of a closely related taxon. The life cycles and host plant relationships ofCryptomyzus are defined, including the previously unknown life cycles ofC. heinzei, C. ballotae and two forms ofC. galeopsidis. The results are discussed in relation to host use and their significance for differentiation between closely related aphid taxa.

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Résumé Les relations des pucerons du genreCryptomyzus avec leurs plantes hôtes ont été étudiées dans la nature et au laboratoire. L'adéquation de la plante et le choix de l'insecte ont été examinés au laboratoire sur des femelles parthénogétiques des générations estivales (exules). Les différences de performances reproductives et de choix des hôtes étaient liées étroitement à la position taxonomique deC. galeopsidis; chez ces formes deC. galeopsidis les choix entre hôtes étaient liés aux performances reproductives. Ceci indique qu'il y a eu une divergence évolutive et justifie leur statut d'espèces distinctes. Ceci ne prouve pas qu'il soit possible d'induire une amélioration des performances deC. galeopsidis deLamium galeobdolon surGaleopsis tetrahit, plante hôte d'un taxon voisin. Les cycles et les relations avec les plantes hôtes de tous les taxa deCryptomyzus ont été précisés, y compris pour les cycles jusqu'alors inconnus deC. heinzei, C. ballotae et de 2 formes deC. galeopsidis. Ces résultats sont discutés en fonction de l'utilisation de l'hôte et de leur signification pour la différenciation de taxa très voisins de pucerons.

     

Seasonal host alternation by the andromeda lace bug,Stephanitis takeyai (Heteroptera: Tingidae) between its two main host-plant species

I studied the seasonal occurrence of the andromeda lace bug,Stephanitis takeyai, on its two main host-plant species. In a secondary forest in Kyoto, this bug altered its hosts seasonally, i.e., from an evergreen shrub,Pieris japonica, in winter to a deciduous shrub,Lyonia elliptica, in summer. In contrast, in Nara park where fewL. elliptica were available, the bug exploited onlyP. japonica. Thus, seasonal host alternation by this bug is not obligate. A comparison of adult longevity and fecundity on the two host-plant species demonstrated the higher quality ofL. elliptica as a food resource. Corresponding to this difference in host quality, there was a dramatic difference in the seasonal population growth in the two study sites. In Nara, the population size at the beginning of the 2nd generation was almost the same as in the overwintered generation, whereas in Kyoto the population size in the 2nd generation was approximately one hundred times as large as in the overwintered generation. Thus seasonal host alternation is adaptive for the bug. In a previous study, I reported that overwintering as eggs in living leaves of their hosts is likely to be common among all the related species of this bug. Thus, this trait can be considered to be a phylogenetic constraint to the group. I speculate that host alternation by this bug has been derived because it is more adaptive from autoecy on an evergreen plant, similar to the pattern currently found in Nara, and that this bug can not only exploit deciduous host due to a phylogenetic constraint.