三种玉米蚜虫种群的生态位分析

对重庆市郊区1998～1999年春玉米上3种蚜虫种群的数量动态、生态位宽度和生态位重叠进行了系统的分析研究．结果表明,发生在春玉米上的玉米蚜(Rhopalosiphum maidis),禾谷缢管蚜(Rhopalosiphum padi)和麦长管蚜(Sitobion avenae)3种蚜虫混合种群的种群数量消长呈现出5月中下旬和6月下旬两个高峰;在生态位宽度上,Livens生态位宽度指数(Bi)分析表明,麦长管蚜表现出时间上的高度分化,玉米蚜表现出空间上的高度聚集特性,而禾谷缢管蚜的分化并不明显;在生态位重叠上,玉米蚜和禾谷缢管蚜的HturlbeIt生态位重叠指数(Lij)最高,玉米蚜和麦长管蚜次之,禾谷缢管蚜和麦长管蚜最小．在春玉米上发生的3种蚜虫中,玉米蚜具有较强的竞争优势．     

新疆麦田主要蚜虫的生态位

利用生态位理论,对新疆塔城、伊犁两地区麦田的麦双尾蚜Diuraphis noxia (Mordvilko)、麦二叉蚜Shizaphis graminum (Rondani)、麦长管蚜Sitobion avenae (F.)和禾谷缢管蚜Rhopalosiphum padi (L.)等4种麦蚜生态位宽度和重叠度进行了估测和分析。在塔城麦田麦双尾蚜时间生态位宽度最大,麦双尾蚜和麦二叉蚜时间生态位重叠最大,竞争激烈。伊犁麦田禾谷缢管蚜时间生态位宽度最大,麦二叉蚜在空间生态位和时 空二维生态位上均占有明显的优势,麦长管蚜和麦双尾蚜的时间生态位重叠最大,麦长管蚜和麦二叉蚜在空间生态位和时 空生态位重叠最大。     

麦长管蚜和禾谷缢管蚜对小麦植株挥发物及蚜害诱导挥发物的行为反应

用四臂嗅觉计测定了麦长管蚜Macrosiphum avenae和禾谷缢管蚜Rhopalosiphum padi对小麦植株挥发物及麦蚜取食诱导挥发物的行为反应,揭示了2种麦蚜的嗅觉及小麦植株的诱导防御反应特点.在所选的13种小麦植株挥发物及蚜害诱导挥发物组分中,6-甲基-5-庚烯-2-酮、6-甲基-5-庚烯-2-醇和水杨酸甲酯对这2种蚜虫表现出强的驱拒作用;反-2-己烯醛对麦长管蚜的有翅和无翅蚜的吸引作用最强;反-2-己烯醇对禾谷缢管蚜的无翅蚜吸引作用最强,反-3-己酰醋酸酯对禾谷缢管蚜有翅蚜的吸引作用最强.说明麦蚜取食能诱导小麦植株的防御反应,麦长管蚜和禾谷缢管蚜及其不同蚜型间嗅觉反应的特点不同.     

新疆麦蚜主要天敌的生态位

利用生态位理论,对新疆塔城、伊犁两地区麦田麦蚜主要天敌类群瓢虫类、食蚜蝇类、斑腹蝇类、蚜茧蜂类和蚜小蜂类的生态位宽度和重叠度进行了计算和分析。瓢虫类在塔城和伊犁小麦田的时间生态位宽度均较长。塔城食蚜蝇类和瓢虫类的时间生态位重叠度最大。伊犁麦田食蚜蝇类空间生态位最宽,瓢虫类时-空生态位宽度最大,斑腹蝇类和瓢虫类时间生态位的重叠度最大,蚜小蜂和斑腹蝇空间生态位以及时-空生态位的重叠度最大。对伊犁大麦田和燕麦田蚜虫的天敌生态位也进行了计算分析。     

麦长管蚜和禾谷缢管蚜对小麦挥发物的触角电位反应

采用活体蚜虫测定法,利用EAG技术比较分析了麦长管蚜Sitobion avenae和禾谷缢管蚜Rhopalosiphum padi有翅及无翅成蚜对小麦挥发物及麦蚜取食诱导挥发物组分的嗅觉反应,揭示了两种麦蚜的嗅觉变异特点。结果表明：麦长管蚜对水杨酸甲酯、反-2-己烯醛、反-2-己烯醇、-6-甲基-5-庚烯-2-酮和-6-甲基-5-庚烯-2醇的反应较强,禾谷缢管蚜对水杨酸甲酯、反-3-己烯乙酸酯、-6-甲基-5-庚烯-2-酮和-6-甲基-5-庚烯-2-醇的反应较强,并得到了剂量反应曲线。麦长管蚜的有翅和无翅成蚜对6-甲基-5-庚烯-2-酮、反-2-己烯醇和水杨酸甲酯的反应差异显著;禾谷缢管蚜的有翅和无翅成蚜对反-2-己烯醇、辛醛、里那醇、水杨酸甲酯和反-3-己烯乙酸酯的EAG反应差异显著,其原因与禾谷缢管蚜迁移及转主为害的生物学特性有关。     

麦长管蚜和禾谷缢管蚜对吡虫啉敏感性的比较研究

采用麦穗浸渍法在室内测定了麦长管蚜Macrosiphumavenae(Fabricius)和禾谷缢管蚜Rhopalosiphumpadi(L .)对吡虫啉可湿性粉剂和乳油的敏感度。结果表明 ,禾谷缢管蚜对吡虫啉的敏感度是麦长管蚜的 3～ 4倍 (基于LC50 的比较 )。在北京、河南、江苏、湖北、四川等地同浓度的吡虫啉对禾谷缢管蚜的防治效果要好于麦长管蚜 (特别是在低浓度时尤为明显 )。依据我国不同省份小麦穗蚜的优势种不同 ,建议用吡虫啉防治小麦穗蚜时 ,在南方麦区 ,禾谷缢管蚜为优势种的麦田 ,吡虫啉用药量为 15～ 3 0g(a.i) hm2 ;北方麦区 ,以麦长管蚜为优势种的麦田 ,吡虫啉的用药量应大于 3 0g(a.i) hm2 。     

植物篱对小麦蚜虫及其天敌种群的影响

采用坡地种植蓑草、苜蓿、香根草和紫穗槐等植物篱的方法,研究了其对小麦蚜虫及其天敌种群的影响.结果表明： 在20°坡度试验区,紫穗槐植物篱显著抑制了麦蚜种群的发生,且麦田拟寄生物的密度等于或显著低于香根草区.在12°坡度试验区,苜蓿和蓑草推迟了麦蚜种群发生的高峰期,蓑草作为植物篱可以显著抑制麦蚜种群数量;苜蓿区麦田拟寄生物密度显著高于对照,瓢虫种群密度等于或显著高于蓑草区.蓑草挥发物对麦长管蚜和禾谷缢管蚜均有驱避作用,而显著引诱猫蛛科1种蜘蛛;苜蓿挥发物对麦长管蚜具有引诱作用;苜蓿和蓑草挥发物对瓢虫的行为反应均无明显影响.紫穗槐和蓑草作为坡地植物篱,不仅能防护水土流失,而且有助于调控害虫及其天敌种群.     

基于EPG的麦长管蚜、麦二叉蚜和禾谷缢管蚜取食行为比较

麦长管蚜Sitobion avenae (Fabricius),麦二叉蚜Schizaphis graminum (Rondani)和禾谷缢管蚜Rhopalosiphum padi (Linnaeus)虽然都取食小麦,但其取食部位、传毒能力均有差异。利用EPG研究了3种麦蚜在同一寄主植物上的取食行为,结果显示:(1)禾谷缢管蚜在取食过程中G波出现的时间最早,G波总的持续时间和每次刺探G波的平均持续时间都明显长于麦长管蚜和麦二叉蚜。麦长管蚜第1次E1波的时间、E1波总的持续时间和每次刺探E1波的平均持续时间都明显比麦二叉蚜和禾谷缢管蚜要长。麦二叉蚜E2波总的持续时间和每次刺探E2波的平均持续时间都明显长于麦长管蚜和禾谷缢管蚜。表明3种蚜虫各自拥有不同取食策略。禾谷缢管蚜比其它两种蚜虫需要更多的水分和无机盐,麦长管蚜通过分泌大量唾液增大对食物的利用率,麦二叉蚜通过增加韧皮部取食时间以满足对营养的需要。(2)刺探过程中麦二叉蚜pd波出现的次数为(51.97±7.82)次,高于麦长管蚜的(44.73±4.52)次和禾谷缢管蚜的(32.99±4.22)次。麦二叉蚜pd波Ⅱ-2和Ⅱ-3亚波的时间最长,禾谷缢管蚜最短,三者之间差异达显著水平。表明与其它两种麦蚜相比,麦二叉蚜在取食过程中口针与细胞间的接触频率更高,与细胞内获毒和传毒相关的Ⅱ-3波和Ⅱ-2波持续时间更长,增加了获毒和传毒的几率,是其传毒能力最强的机理。     

美国杂交杏李花果期节肢动物的生态位分析

美国杏李园害虫中绣线菊蚜与山楂叶螨的生态位宽度较宽,占据空间较大,为害虫优势种群,在空间维度上害虫之间存在较大竞争;大草蛉在各期的生态位宽度最大,说明大草蛉是重要的优势天敌,且天敌与主要害虫在空间上相遇机率较大;天敌之间生态位重叠指数较高,表明主要天敌之间存在明显的相互竞争关系;美国杏李园天敌对主要害虫在时间维度上有较强的追随效应和控制作用.主要天敌的数量与主要害虫绣线菊蚜种群数量追随关联度顺序为草蛉类>龟纹瓢虫>蜘蛛类>异色瓢虫>其它瓢虫类>食蚜蝇类>七星瓢虫>多异瓢虫.草蛉类和龟纹瓢虫与绣线菊蚜的模糊贴近度最高,说明这两种天敌与绣线菊蚜的同域效应高,对绣线菊蚜有较强的追随作用,抑制着绣线菊蚜种群数量的增长.     

天敌对麦长管蚜和麦二叉蚜种群数量影响程度的分析

通过对１９９３～１９９６年两种麦蚜种群数量及其天敌数量的系统调查,并采用灰色关联分析法,研究各种天敌对两种麦蚜种群数量的影响程度,得出对麦长管蚜种群数量影响最大的是龟纹瓢虫、蚜茧蜂和食蚜蝇;对麦二叉蚜种群数量影响最大的是草间小黑蛛,其次是龟纹瓢虫．     

小麦不同品种上麦蚜及其天敌的数量变动

试验结果表明小麦品种 (系 )的抗性对麦蚜种群数量影响很大 ,百株蚜量随着小麦品种抗性增强而下降。而同一小麦品种对不同种蚜虫的抗性存在质的差异 ,铭贤 1 69品种 ,蚜高峰期百株蚜量麦长管蚜 63 0头 ,禾谷缢管蚜只有 1 1 5头 ,两者相差 5 5倍。另一方面 ,小麦品种抗性对麦田天敌的种群数量影响不大 ,而对天敌的发生期有些影响。因此 ,小麦品种抗性、天敌对麦蚜的自然控制能力 ,可把小麦中后期的蚜虫虫口密度控制在经济损失允许水平之下。     

黄板、黄盆及灯光对麦长管蚜和禾谷缢管蚜的诱捕效果

通过黄板、黄盆及灯光的监测,研究了其对麦长管蚜Sitobion avenae(Fabricius)和禾谷缢管蚜Rhopalosiphum padi(L.)诱捕作用,结果表明2种麦蚜对黄盆的趋性最好,黄盆诱捕量分别为黄板诱捕量的7.94、2.13倍。黑光灯和荧光灯对2种麦蚜的诱捕作用比较试验表明,黑光灯对2种麦蚜的诱捕效果较好。黄盆和黑光灯2种监测手段的结合能够为预测预报提供准确可靠、适时的测报结果。     

Biological and Morphological Features Associated with English Grain Aphid and Bird Cherry-Oat Aphid Tolerance in Winter Wheat Line XN98-10-35

Journal of Plant Growth Regulation - The English grain aphid, Sitobion avenae Fabricius (Hemiptera: Aphididae), and bird cherry-oat aphid, Rhopalosiphum padi L. (Hemiptera: Aphididae), are two...     

Assessment of aphid lethal paralysis virus as an apparent population growth‐limiting factor in grain aphids in the presence of other natural enemies

The influence of aphid lethal paralysis virus (ALPV), Rhopalosiphum padi virus (RhPV), natural enemies and fungal infection on the population growth of Rhopalosiphum padi and Sitobion avenae in the wheat fields of the Western Cape Province of South Africa was investigated at two sites. Time‐specific life tables were compiled for R. padi at one site. During the logarithmic phase of the development of R. padi aphids, natural enemies were not present in high numbers and the apparent large‐scale mortality observed appeared to be due to other causes. During the decline phase of this aphid population, the population size was reduced by 49%. This reduction coincided with a calculated high mortality of 70 aphids per plant. A dramatic decline in R. padi numbers and a high incidence of ALPV present in the aphid population was experienced during this period. Virus assays were carried out by double‐antibody sandwich enzyme‐linked immunosorbent assay (DAS‐ELISA) and an indirect immunofluorescent technique. Entomophthorales‐type fungal infection of aphids also reached its highest level during the decline phase, but at a later stage than ALPV infection, with a calculated level of 21 aphids per plant. This suggested that the presence of ALPV limited population development in R. padi. Similar results were obtained with S. avenae.     

Patterns of resistance to three cereal aphids among wheats in the genus Triticum (Poaceae)

Forty-one accessions of wild and cultivated wheats belonging to 19 Triticum species were tested in the field for resistance to three species of aphids, Rhopalosiphum padi Linnaeus, Sitobion avenae Fabricius and Schizaphis graminum Rondani. Antibiotic resistance was estimated by the increase in biomass of aphids over 21 days on adult plants. Overall resistance was estimated by the plant biomass lost due to aphid infestation. All three species of aphids survived and reproduced on all wheats, and reduced spike biomass compared to uninfested controls. The level of antibiosis varied among wheat species and among accessions, with accessions from three, five and one species showing antibiosis to R. padi, S. avenae and S. graminum, respectively. Overall resistance to the three aphid species was observed in five to seven accessions per aphid species. Resistance was usually specific to one aphid species. The frequency of accessions with antibiosis or overall resistance was associated with the ploidy level of the plant species. Except for overall resistance to R. padi, resistance was highest for diploid species and lowest for hexaploid species. No consistent relationship between resistance and level of domestication was detected. Accessions of the wild wheats, Triticum boeoticum Bois, Triticum tauschii (Coss.) Schmal. and Triticum araraticum Jakubz. exhibited high levels of resistance to aphids, as did Triticum monococcum L. which is derived from T. boeoticum. Nevertheless, individual susceptible or resistant accessions occurred at all levels within the evolutionary tree of wheat.     

Sources of variation in the interaction between three cereal aphids (Hemiptera: Aphididae) and wheat (Poaceae)

The relative contributions of host plant, herbivore species and clone to variation in the interaction between cereal aphids and wheat were investigated using five clones each of three species, Rhopalosiphum padi (Linnaeus), Sitobion avenae (Fabricius) and Schizaphis graminum (Rondani), on seedlings of two cultivars of Triticum aestivum L. and one cultivar of Triticum durum Desf. More individuals and biomass of R. padi than of the other two species were produced on seedlings. The three wheat cultivars lost similar amounts of biomass as a result of infestation by aphids, with the amount lost depending on aphid species: S. avenae caused the lowest loss in biomass. Variation in aphid biomass production was due mostly to differences among aphid species (70%), less to the interaction between wheat type and aphid species (7%), and least to aphid clone (1%). The specific impact of the aphids on the plants ranged from 1.7 to 3.7 mg of plant biomass lost per mg of aphid biomass gained, being lowest for R. padi and highest for S. graminum. Variation in plant biomass lost to herbivory was due mostly to unknown sources of error (95%), probably phenotypic differences among individual seedlings, with 3% due to aphid species and none attributable to aphid clone. For these aphid-plant interactions, differences among aphid clones within species contributed little to variation in aphid and plant productivity; therefore, a small sample of clones was adequate for quantifying the interactions. Furthermore, one clone of each species maintained in the laboratory for about 200 parthenogenetic generations was indistinguishable from clones collected recently from the field.     

THE MANNER OF TRANSMISSION OF SOME BARLEY YELLOW-DWARF VIRUSES BY DIFFERENT APHID SPECIES

Some barley yellow-dwarf (BYD) viruses isolated from cereal crops in Great Britain were transmitted by Rhopalosiphum padi , L. and others were not. Sitobion fragariae (Walker), S. avenae (Fabricius), and Metopolophium dirhodum (Walker) all transmitted viruses of both types, but they usually transmitted those of which Rhopalosiphum was a vector less readily than did R. padi. The transmissibility of a virus by a given aphid species was not affected by transmission with another, less efficient, vector species. Neomyzus circumflexus (Buckt.) and Rhopalosiphum maidis (Fitch) transmitted the few viruses with which they were tested.
A few R. padi acquired virus from infected leaves during 30 min. feeding and inoculated healthy seedlings during 15 min. feeding, but the minimum total time taken to acquire and transmit was 10 hr. and 32 hr. were needed for about half the aphids that were able to acquire and transmit virus to do so. This may indicate the existence of a short latent period of the virus in the vector, although the evidence is not conclusive. The times spent on infected plants influenced the results more than those spent on healthy ones; many transmissions occurred with short feeding times on healthy plants so long as the time spent on infected leaves was long, but the reverse was not true. Nymphs of R. padi that moulted after they left infected plants on which they fed long enough to become infective, infected slightly fewer plants than adults fed for the same times.     

五种类型农药不同剂量与施药时期对麦蚜防治效果及麦粒农药残留的影响

采用喷雾法,研究了辛硫磷、高效氯氰菊酯、抗蚜威、阿维菌素和吡虫啉5种类型农药的3种剂量在不同施药时期对麦长管蚜Sitobion avenae(Fabricius)和禾谷缢管蚜Rhopalosiphum padi(Linnaeus)的防治效果、防后对小麦千粒重的影响和籽粒中农药残留分析。结果表明,不同剂量的各种药剂,第1次施药药后1d对麦长管蚜与禾谷缢管蚜的防治效果均在80%以上,药后3d防效分别在90%和84%以上,药后5d防效分别在95%和92%以上;不同种类或不同剂量处理的防治效果之间存在显著差异(P<0.05)。第2次施药后1～5d对麦长管蚜的防效均在90%以上。与对照比较,施药1次小麦千粒重增加率为2.02%～11.93%;施药2次,千粒重增加率为8.01%～15.87%。农药残留检测结果显示,不同种类不同剂量浓度下在冬小麦扬花末期喷施1次农药和间隔5d的灌浆中期第2次农药,以及春小麦田相似农药处理,其籽粒中农药残留均有一定程度的检出,但均未超出限定标准;而在小麦乳熟期(与第1次施药间隔10d,距离成熟收获15d)喷施第2次农药,其中高效氯氰菊酯和吡虫啉已经达到或超出残留限量标准。