The effect of flowering calendula and cuphea plants on Orius insidiosus survival and predation of Aphis glycines

Flowering oilseed crops have the potential to diversify agroecosystems currently dominated by corn and soybeans and improve the provision of ecosystem services such as pest control. Nectar and pollen feeding may increase natural enemy fitness and searching behaviour, increasing their survival and prey consumption rates. The soybean aphid (Aphis glycines Matsumura; Hemiptera: Aphididae) is a particularly widespread and costly agricultural pest. In this study, we evaluate the effects of two flowering oilseed crops, cuphea and calendula, on the survival of the insidious flower bug (Orius insidiosus Say; Hemiptera: Anthocoridae) and its consumption levels of A. glycines placed on soybean plants. We also evaluated the survival of O. insidiosus when placed on glandular and non-glandular cuphea varieties. The amount of A. glycines that remained unconsumed by O. insidiosus did not differ among treatments. Because mortality levels of O. insidiosus were higher on glandular compared to non-glandular cuphea plants, glandular trichomes, or plant hairs, may play a role in impeding movement and prey consumption by O. insidious.     

沈阳地区吸虫塔监测大豆蚜迁飞动态及其与气象因子关系的分析

【目的】明确沈阳地区吸虫塔对大豆蚜Aphis glycines(Matsumura)迁飞活动的监测效果以及对其有显著影响的气象因素,为大豆蚜防控提供预警信息。【方法】2009年至2014年采用吸虫塔(Suction trap)对大豆蚜的迁飞活动进行自动、实时监测。结合当年田间大豆蚜动态调查,分析吸虫塔诱捕量与田间蚜量的相关性;采用逐步回归分析研究了吸虫塔诱捕量与气象因素的关系。【结果】监测及分析结果表明,吸虫塔诱捕量与田间大豆蚜量之间存在显著的相关性。吸虫塔诱捕的始见期和首次高峰期均早于田间发生的大豆蚜始见期和盛发期,吸虫塔的监测结果对田间蚜虫的发生可以起到预警的作用。诱捕量与气象因子的逐年回归模型分析结果显示,温度和降水量是影响大豆蚜有翅蚜迁飞的重要气象因素;总回归模型显示,试验期间,吸虫塔当年度诱捕量与前一年度冬季极端最低温、4—6月均温、6—7月最低温、9月均温具有正相关同步协同作用,而与6—7月降雨量和9月雨日具有负相关反向抑制作用。【结论】吸虫塔监测结果比较清晰的展示了大豆蚜的迁飞习性,很好的拟合了当年田间大豆蚜的种群动态。结合气象因子和诱捕量的预测模型研究,为吸虫塔及时准确的发挥预警功能提供必要的理论指导和实践依据。     

宁夏危害枸杞的蚜虫种类为棉蚜、桃蚜和豆蚜

宁夏是我国最重要的枸杞Lycium chinense Miller生产基地,蚜虫是危害枸杞的重要害虫。多年来枸杞蚜虫一直作为一个未定名物种使用Aphis sp.。2015年作者对宁夏危害枸杞的蚜虫进行了标本采集,经中国科学院动物研究所乔格侠研究员鉴定确认是常见的3种蚜虫,分别是棉蚜Aphis gossypii Glover、桃蚜Myzus persicae(Sulzer)和豆蚜Aphis craccivora Koch。本文提供了它们的鉴定检索表和简要形态特征描述、寄主植物和分布情况。     

The impact of β‐azido(or 1‐piperidinyl)methylamino acids in position 2 or 3 on biological activity and conformation of dermorphin analogues

The synthesis of new dermorphin analogues is described. The (R)‐alanine or phenylalanine residues of natural dermorphin were substituted by the corresponding α‐methyl‐β‐azidoalanine or α‐benzyl‐β‐azido(1‐piperidinyl)alanine residues. The potency and selectivity of the new analogues were evaluated by a competitive receptor binding assay in rat brain using [³H]DAMGO (a μ ligand) and [³H]DELT (a δ ligand). The most active analogue in this series, Tyr‐(R)‐Ala‐(R)‐α‐benzyl‐β‐azidoAla‐Gly‐Tyr‐Pro‐Ser‐NH₂ and its epimer were analysed by ¹H and ¹³C NMR spectroscopy and restrained molecular dynamics simulations. The dominant conformation of the investigated peptides depended on the absolute configuration around C^α in the α‐benzyl‐β‐azidoAla residue in position 3. The (R) configuration led to the formation of a type I β‐turn, whilst switching to the (S) configuration gave rise to an inverse β‐turn of type I′, followed by the formation of a very short β‐sheet. The selectivity of Tyr‐(R)‐Ala‐(R) and (S)‐α‐benzyl‐β‐azidoAla‐Gly‐Tyr‐Pro‐Ser‐NH₂ was shown to be very similar; nevertheless, the two analogues exhibited different conformational preferences. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.     

棉蚜在棉株上数量动态的初步研究

棉蚜(Aphis gossypii)是棉花苗期至花铃前期的主要害虫之一。长期以来,由于大量使用化学药物,其抗药性不断增加。为了掌握棉蚜种群数量消长的一般规律,给寻找其他有效的防治方法提供依据,本文对棉蚜实验种群的数量动态与其宿主棉株的关系进行了初步探讨。现将结果报道如下。     

Inheritance of resistance to the cowpea aphid in cowpea

Summary Inheritance of resistance to cowpea aphid, Aphis craccivora Koch, in three resistant cultivars of cowpea, Vigna unguiculata (L.) Walp, was studied. The parents, F₁ and F₂ population were grown in an insect-proof screenhouse. Each 3-day-old seedling was infested with 10 apterous adult aphids. Seedling reaction was recorded when the susceptible check was killed. The segregation data revealed that the resistance of ICV11 and TVU310 is governed by single dominant genes. All the F₂ seedlings of the cross ICV10xTVU310 were resistant, indicating that they have the same gene for resistance. However, the F₂ populations from the crosses ICV10xICV11 and ICV11xTVU310 segregated in a ratio of 151, indicating that the dominant genes in ICV11 and TVU310 are non-allelic and independent of each other. The resistance gene of ICV10 and TVU310 is designated as Ac₁ and that of ICV11 as Ac₂.     

Preliminary experiments on the potential of hoverflies [Dipt.: Syrphidae] for the control of aphids under glass

Control ofAphis gossypii Glover populations on isolated cucumber plants grown at 21°C was achieved on days 2, 3, or 4 by larvae ofMetasyrphus corollae (F.) hatched from eggs laid on the plants on day 0. With 45% of hoverfly eggs viable, greater than 9 aphids per egg at the end of oviposition resulted in a failure of control. Larvae 1, 2, or 3 days old prevented aphid increase unless there were more than 15, 26 or 41 aphids per larva respectively. Continuous control on single caged cucumber plants was possible providing that the presence of 1 gravid hoverfly was maintained in the cage, but elimination of the aphid population was observed in only 1 instance. A possible role for hoverflies in crop protection under glass is discussed.

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Résumé On parvenait à réduire des populations d'Aphis gossypii Glover fixés sur plants isolés de concombres, croissant à 21°C, au moyen de larves deMetasyrphus corollae (F.) écloses d'œufs pondus sur les plantes au tout début de l'expérience (jour 0) en 2, 3 ou 4 jours. Avec 45% d'œufs viables de Syrphes, une proportion supérieure à 9 pucerons/œuf en fin de ponte, entraine l'échec du “control”. Les larves agées de 1, 2 ou 3 jours empêchaient l'accroissement des populations à moins qu'il y eut plus de 15, 26 ou 41 Aphides/larve respectivement. Le “control” continu sous cage sur de simples plants de concombres était possible pourvu que la présence d'une seule ♂ gravide de Syrphe soit maintenue en cage, mais l'élimination de la population de pucerons n'était observée que dans 1 seul cas. Le róle possible des Syrphes dans la protection des cultures protégées est discutée.

     

基于EPG的三种刺吸式害虫在苹果苗上的取食行为比较

【目的】苹果绵蚜Eriosoma lanigerum、绣线菊蚜Aphis citricola和梨网蝽Stephanitis nashi是苹果园的一类重要害虫,它们以刺吸式口器对苹果树造成不同程度的危害。本研究旨在明确这3种刺吸式昆虫在苹果树上取食行为差异。【方法】利用刺吸电位(electrical penetration graph, EPG)技术对苹果绵蚜和绣线菊蚜成虫在苹果苗韧皮部和非韧皮部上的EPG指标,以及苹果绵蚜、绣线菊蚜和梨网蝽成虫苹果苗上的取食行为进行了比较分析,分析了这3种害虫的成虫在苹果苗上取食8 h各种波形平均持续时间的占比。【结果】结果表明,苹果绵蚜和绣线菊蚜成蚜在苹果苗上均产生6种取食波形,即非刺探波(np)、路径波(C)、意外穿刺细胞非主动取食细胞波(pd)、木质部取食波(G)、韧皮部唾液分泌波(E1)和韧皮部取食波(E2);而梨网蝽成虫取食过程中只产生非刺探波(np)、表皮刺穿波(A)、叶肉细胞取食波(Gc)和木质部取食波(E)4种波形。从蚜虫在苹果苗非韧皮部上取食的EPG指标看,苹果绵蚜成蚜pd波平均时间显著高于绣线菊蚜的,而刺探次数、np波总时间和pd波次数均显著低于绣线菊蚜的。从蚜虫在苹果苗韧皮部上取食的EPG指标来看,除第1次出现E2波的时间外,各指标没有显著差异。从3种害虫在苹果苗上取食8 h各波形的占比来看,梨网蝽成虫的np波总时间所占比例最高(53%),其次是绣线菊蚜成虫的(24%),苹果绵蚜成虫的最低(为1%)。同时,苹果绵蚜和绣线菊蚜成虫取食波为E2波,所占总时间比例分别为35%和25%,而梨网蝽的取食波为Gc波(占总时间比例为36%)和E波(占总时间比例为11%)。【结论】本研究阐释了苹果园刺吸式口器害虫的生态位分离和取食行为学机制,为果园刺吸式口器害虫的综合治理提供了理论依据。     

Are ant-aphid associations a tritrophic interaction? Oleander aphids and Argentine ants

Summary Oleander aphids, (Aphis nerii), which are sporadically tended by ants, were used as a moded system to examine whether host plant factors associated with feeding site influenced the formation of ant-aphid associations. Seasonal patterns of host plant utilization and association with attendant ants were examined through bi-weekly censuses of the aphid population feeding on thirty ornamental oleander plands (Nerium oleander) in northern California in 1985 and 1986. Colonies occurred on both developing and senescing plant terminals, including leaf tips, floral structures, and pods. Aphids preferentially colonized leaf terminals early in the season, but showed no preference for feeding site during later periods. Argentine ants (Iridomyrmex humilis) occasionally tended aphid colonies. Colonies on floral tips were three to four times more likely to attract ants than colonies on leaf tips, even though the latter frequently contained more aphids. Ants showed a positive recruitment response to colonies on floral tips, with a significant correlation between colony size and number of ants. There was no recruitment response to colonies on leaf tips. These patterns were reproducible over two years despite large fluctuations in both aphid population density and ant activity. In a laboratory bioassay of aphid palatability, the generalist predator,Hippodamia convergens, took significantly more aphids reared on floral tips compared to those reared on leaf tips. The patterns reported here support the hypothesis that tritrophic factors may be important in modifying higher level arthropod mutualisms.     

Host-acceptance behaviour of Alloxysta pleuralis, a cynipoid hyperparasitoid of an aphidiid parasitoid Trioxys indicus on aphids

Alloxysta pleuralis parasitizes the larvae of Trioxys indicus, a parasitoid of Aphis craccivora. The pattern of host-searching of A. pleuralis was random regarding the host-stage. Earlier second instar to early fourth instar larvae of T. indicus within the haemocoel of the living aphid were found susceptible for attack, however, the third instar larvae were more parasitized. The rate of oviposition was very low (8.5 eggs/h). The number of pricks into the aphid was significantly more for the aphids that contained susceptible stages of the potential host. The occurrence of superhyperparasitism was lower when the hyperparasitoids were offered a choice of all host stages than were offered no-choice.

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Résumé A. pleuralis est un hyperparasitoïde endophage de Trioxys indicus, parasitoïde d'Aphis craccivora, puceron de Cajanus cajan. Bien que les larves de T. indicus soient susceptibles d'être attaquées du début du second stade au début du quatrième stade, celles du troisième stade sont nettement préférées. L'absence de fifférence entre les fréquences de visites et de contacts avec les hôtes de différents stades a montré que le comportement de prospection de A. pleuralis s'effectue au hasard. Cependant, la fréquence des piqûres/hôte est significativement supérieure chez lez hôtes préférés, ce qui donne une indication sur le fait que A. pleuralis pique un puceron pour rechercher un hôte potentiel. Il est possible que la femelle perçoive la présence de l'hôte dans le puceron en décelant avec les récepteurs sensoiriels de sa tarière les changements physiologiques caractéristiques du puceron parasité, et qu'elle les utilise pour piquer à répétition le puceron jusqu'à ce qu'elle trouve l'hôte potentiel. Le superhyperparasitisme était relativement faible et plus fréquent dans les expériences où l'hyperparasite n'avait pas de choix.