云南两个不同生态区玉米蚜种群动态研究

在2013年5-9月,采取5点取样,对云南省昭通温凉玉米种植区及普洱暖热玉米种植区玉米蚜种群动态进行定期、定点、定株的系统调查,明确云南省两种不同生态条件下玉米种植区玉米蚜发生规律及分布特征,为玉米蚜的防治提供理论依据。结果显示:昭通温凉玉米种植区玉米蚜在玉米各生育期均有发生;玉米蚜在抽雄散粉期主要集中在雄穗为害,籽粒建成期以后转移集中在苞叶及雌穗为害;玉米蚜在玉米田始终呈聚集分布,聚集度呈聚集—扩散—聚集趋势。普洱暖热玉米种植区玉米蚜种群数量在玉米进入籽粒建成期后才有所增长;玉米蚜在籽粒建成期以后主要集中在苞叶及雌穗上为害;玉米蚜在玉米田基本呈聚集分布,聚集度始终呈扩散趋势。两地玉米蚜自然种群消长、垂直分布动态,空间动态均具有一定差异,昭通温凉玉米种植区相对更适宜玉米蚜的发生。     

温度对玉米蚜种群增长的影响

研究了温度对玉米蚜RhopalosiphummaidisFitch种群存活率、生殖率及内禀增长率的影响 ,同时测定了不同温度条件下玉米蚜种群的净增殖率、周限增长率、种群倍增时间及稳定年龄组配等种群参数。在 1 0℃和 3 5℃条件下 ,玉米蚜若蚜的死亡率较高 ,特别是 4龄若蚜 ;2 5℃最适宜玉米蚜的生长、发育和繁殖 ,其种群增长最快     

转Bt基因抗虫玉米对玉米蚜种群增长的影响

在人工气候箱条件下研究了玉米蚜（Rhopalosiphum maidis Fitch）取食表达cry1Ab杀虫蛋白Bt抗虫玉米的实验种群生命表.结果表明：两种不同Bt玉米杂交种DK647BTY （MON810转化事件）和NX4777（Bt11转化事件）对玉米蚜的生长、发育、繁殖和存活均无明显的不利影响,玉米蚜在DK647BTY和NX4777两种Bt玉米品种上的内禀增长率rm、周限增长率λ和种群净增殖率R0与各自对照之间没有显著差异;玉米蚜有翅蚜比率、各龄若虫的死亡率在Bt玉米和对照以及不同品种之间没有明显差异;Bt玉米对玉米蚜的寿命和繁殖历期也没有明显差异.表明表达cry1Ab杀虫蛋白的Bt玉米对玉米蚜的生长发育和繁殖没有明显影响.     

黄玛草蛉对两种蚜虫的捕食效能

实验室条件下研究了黄玛草蛉2龄与3龄幼虫对甘蓝蚜以及玉米蚜成虫的捕食功能反应。结果表明:黄玛草蛉2龄与3龄幼虫对2种蚜虫的捕食量均随着猎物密度的增加而增加,寻找效应随着猎物密度的增加而减小。不同龄期幼虫对2种蚜虫的捕食功能反应均符合HollingⅡ模型,黄玛草蛉2龄与3龄幼虫对玉米蚜最大理论日捕食量分别为120.48头、185.18头;黄玛草蛉2龄与3龄幼虫对甘蓝蚜最大理论日捕食量分别为60.60头、86.95头。在相同猎物种类下,黄玛草蛉3龄幼虫对2种蚜虫的捕食量均高于黄玛草蛉2龄幼虫;在相同猎物密度下,黄玛草蛉2龄幼虫与3龄幼虫对玉米蚜的捕食量均高于甘蓝蚜。     

A ribosomal DNA probe to distinguish populations of Rhopalosiphum maidis (Homoptera: Aphididae)

Total DNA from clones of Rhopalosiphum maidis was digested with restriction endonucleases and hybridised with a heterospecific ribosomal DNA probe. DNA banding patterns exhibited sufficient differences to distinguish five different clones, and provided greater resolving power than gel electrophoresis of allozymes. The mechanisms and applications of this marking technique are discussed.     

Suitability of the biomass crop Miscanthus sinensis as a host for the aphids Rhopalosiphum padi (L.) and Rhopalosiphum maidis (F.), and its susceptibility to the plant luteovirus Barley Yellow Dwarf Virus

1 The reproductive performance of two aphid pest species, Rhopalosiphum padi and Rhopalosiphum maidis, was investigated on two seedling growth stages of Miscanthus sinensis, rhizomatous M. sinensis‘Giganteus’ and barley. Rhopalosiphum padi was unable to complete its development on Miscanthus. Rhopalosiphum maidis was most fecund on rhizomatous plants compared with seedling stages. 2 The ability of R. maidis to transmit the RPV isolate of Barley Yellow Dwarf Virus (BYDV) to M. sinensis seedlings was further investigated. Following successful transmission, host plant symptomology and the effect of infection on the yield of Miscanthus were investigated. Total above soil biomass was reduced by around 23% following infection. 3 The inability of R. padi to utilize Miscanthus is reviewed in light of this species’ origin and inability to utilize C₄ host plants. 4 The potential pest status of R. maidis on Miscanthus is discussed together with the impact that Miscanthus cultivation could have on the ecology of this aphid species and BYDV in the U.K.     

A leaf-height-seed (LHS) plant ecology strategy scheme

A leaf-height-seed (LHS) plant ecology strategy scheme is proposed. The axes would be specific leaf area SLA (light-capturing area deployed per dry mass allocated), height of the plant's canopy at maturity, and seed mass. All axes would be log-scaled. The strategy of a species would be described by its position in the volume formed by the three axes.The advantages of the LHS scheme can be understood by comparing it to Grime's CSR scheme, which has Competitors, Stress-tolerators and Ruderals at the corners of a triangle. The CSR triangle is widely cited as expressing important strategic variation between species. The C–S axis reflects variation in responsiveness to opportunities for rapid growth; in the LHS scheme, SLA reflects the same type of variation. The R axis reflects coping with disturbance; in the LHS scheme, height and seed mass reflect separate aspects of coping with disturbance.A plant ecology strategy scheme that permitted any species worldwide to be readily positioned within the scheme could bring substantial benefits for improved meta-analysis of experimental results, for placing detailed ecophysiology in context, and for coping with questions posed by global change. In the CSR triangle the axes are defined by reference to concepts, there is no simple protocol for positioning species beyond the reference datasets within the scheme, and consequently benefits of worldwide comparison have not materialized. LHS does permit any vascular land plant species to be positioned within the scheme, without time-consuming measurement of metabolic rates or of field performance relative to other species. The merits of the LHS scheme reside (it is argued) in this potential for worldwide comparison, more than in superior explanatory power within any particular vegetation region.The LHS scheme avoids also two other difficulties with the CSR scheme: (a) It does not prejudge that there are no viable strategies under high stress and high disturbance (the missing quadrant in the CSR triangle compared to a two-axis rectangle); (b) It separates out two distinct aspects of the response to disturbance, height at maturity expressing the amount of growth attempted between disturbances, and seed mass (inverse of seed output per unit reproductive effort) expressing the capacity to colonize growth opportunities at a distance.The advantage of LHS axes defined through a single readily-measured variable needs to be weighed against the disadvantage that single plant traits may not capture as much strategy variation as CSR's multi-trait axes. It is argued that the benefits of potential worldwide comparison do actually outweigh any decrease in the proportion of meaningful variation between species that is captured. Further, the LHS scheme opens the path to quantifying what proportion of variation in any other ecologically-relevant trait is correlated with the LHS axes. This quantification could help us to move forward from unprofitable debates of the past 30 years, where CSR opponents have emphasized patterns that were not accommodated within the scheme, while CSR proponents have emphasized patterns that the scheme did account for.     

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.

     

Turnover of plant lineages shapes herbivore phylogenetic beta diversity along ecological gradients

Understanding drivers of biodiversity patterns is of prime importance in this era of severe environmental crisis. More diverse plant communities have been postulated to represent a larger functional trait‐space, more likely to sustain a diverse assembly of herbivore species. Here, we expand this hypothesis to integrate environmental, functional and phylogenetic variation of plant communities as factors explaining the diversity of lepidopteran assemblages along elevation gradients in the Swiss Western Alps. According to expectations, we found that the association between butterflies and their host plants is highly phylogenetically structured. Multiple regression analyses showed the combined effect of climate, functional traits and phylogenetic diversity in structuring butterfly communities. Furthermore, we provide the first evidence that plant phylogenetic beta diversity is the major driver explaining butterfly phylogenetic beta diversity. Along ecological gradients, the bottom up control of herbivore diversity is thus driven by phylogenetically structured turnover of plant traits as well as environmental variables.     

Effect of mineral oils on host plant selection and probing behavior of Rhopalosiphum padi

Aphids that colonize and reproduce on potato are some of the most efficient vectors of Potato virus Y (PVY) (Potyviridae: Potyvirus), and hence these aphids have been the focus of the majority of studies to date. However, other non‐colonizing aphids can also function as vectors. Mineral oil is the only product available to growers that effectively prevents the spread of PVY in potato seed production. Most previous studies focused on the effect of mineral oil on the behavior of aphids on their preferential host plant, and consequently there is a lack of information for non‐colonizing aphids on potato plants. The objective of this study was to determine the effect of spraying potatoes with one of two mineral oils, Superior 70 or Vazyl‐Y, on host selection and probing behavior of the non‐colonizing aphid Rhopalosiphum padi (L.) (Hemiptera: Aphididae). The electrical penetration graph (EPG) technique, combined with ethological observations, determined that there was no difference in R. padi behavior on potato plants treated with Superior 70. However, there were few significant changes in R. padi behavior on plants sprayed with Vazyl‐Y, including a delay in the initiation of stylet penetration and an increase in the duration of xylem sap ingestion. These new data support previous results and confirm that the mode of action of mineral oil in the reduction of the spread of PVY is not solely due to the modification of the behavior of aphids.     

Host plant interactions of the corn planthopper, Peregrinus maidis Ashm. (Homoptera: Delphacidae) in maize and sorghum agroecosystems

The corn planthopper, Peregrinus maidis (Ashmead) (Homoptera: Delphacidae) causes serious economic losses in corn and sorghum. The insect occurs mostly at humid low elevations in the tropics and coastal areas of subtropical and temperate regions of all continents, the Caribbean Islands, and islands in the Atlantic, Indian, and Pacific Oceans. This review provides a detailed compilation on the chronological progress made in basic and strategic aspects of research on the interactions between P. maidis and various host plants. The nature of damage by P. maidis and its economic impact, ecobiology in relation to host diversity, abiotic, and seasonal interactions; and life tables and alary polymorphism are discussed. Host plant resistance studies indicate that very few sources of resistance to P. maidis have been identified in maize, sorghum, or pearl millet, warranting a need to standardize rapid and reliable screening methods. The behavioral responses vis-à-vis mechanisms of resistance show the predominance of antixenosis for colonization and/or oviposition with variable degrees of antibiosis affecting life cycle parameters of P. maidis on maize and sorghum. The role of morphological traits, physiological mechanisms, and biochemical factors governing resistance are described. Population dynamics based on density-dependent and density-independent interactions are also discussed. In addition, aspects of P. maidis on chemical control, biological control, and trophobiosis interactions are listed. Future thrusts on research approaches are also discussed. Genetic engineering techniques involving lectin genes in the development of transgenic plants, and the molecular mapping of genes conferring resistance to both P. maidis and its transmitted virus diseases may stimulate further research and lead to better understanding of P. maidis—host plant interactions. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Fine structure of aphid stylet pathways and its use in host plant resistance studies

Conclusion Although there have been reports, based on light microscope observations, of damage to mesophyll tissue as a result of stylet penetration, we saw no evidence of this in our wax sections. However, the use of the electron microscope revealed that such damage does occur, and has also shown that both inter- and intracellular penetration routes exist, often within the same track, whereas we had formerly believed the stylet pathways of these aphids to be almost entirely intercellular. The intramural-extracellular route of penetration, characterised by the presence of stylets and or saliva between the cell wall and plasmalemma, requires the greater resolution of electron microscopy and cannot be distinguished in light microscope preparations.Our results suggest that an accurate indication of the stylet pathway cannot be obtained from the use of light microscopy alone, and raise serious doubts about the value of previous studies describing the route of stylet penetration. Light microscopy shows the track only at the tissue level and not at the cellular level. We advocate that all future studies of aphid stylet penetration should utilise both light and electron microscope studies because only the higher resolution of the latter technique will indicate the true stylet pathway and the end points of the tracks. Only then can the feeding site be determined with any precision.     

南美斑潜蝇寄主选择性与植物次生化合物及叶毛的关系

采用非自由选择法,以刺伤孔（包括取食孔和产卵孔）数为指标,在室内测定了南美斑潜蝇对6科、16种、22个蔬菜品种的寄主选择性。结果表明,南美斑潜蝇对供试蔬菜品种的选择性存在显著差异,选择性大小依次为豆科>菊科>葫芦科>茄科>伞形科>十字花科; 菜豆和茼蒿是南美斑潜蝇最喜欢产卵和取食的寄主,而甘蓝和番茄是其选择性最差的寄主。化学分析和解剖镜观察表明,叶片单宁酸、黄酮含量及叶毛密度在供试品种间存在显著差异： 苦瓜的单宁酸含量最高,其次为豌豆、番茄和青椒,含量最低的为金丝搅瓜、茼蒿、菜豆和美国西芹; 黄酮含量最高的为甘蓝和番茄,其次为苦瓜,最低为茼蒿、菜豆和美国西芹; 南瓜和小白菜的叶毛密度最高,其次为西葫芦、金丝搅瓜和甘蓝,最低为青椒、莴苣和苦瓜。相关分析表明,南美斑潜蝇寄主选择性与叶片单宁酸和黄酮含量呈显著的负相关关系,相关系数分别为-0.4425（ P=0.0392）和 -0.5728（ P=0.0053）,而与叶毛密度相关关系不显著（ R＝-0.1807,P=0.4211）。说明黄酮和单宁酸对南美斑潜蝇产卵和取食具有明显的抑制作用。     

Plant quality vs. risk of parasitism: within-plant distribution and performance of the corn leaf aphid, Rhopalosiphum maidis

1 Colonies of the aphid Rhopalosiphum maidis on Johnsongrass, Sorghum halepense, usually occur inside the whorl. The present work assessed the role of two biotic factors, plant quality and parasitism by Lysiphlebus testaceipes, in determining within‐plant distribution and performance of R. maidis. The mean relative growth rate of aphids inside the whorl and on a mature leaf was compared, and the concentration of hydroxamic acids in those tissues determined as an indicator of plant quality. Parasitism effectiveness and parasitoid behaviour were evaluated using three treatments: aphid colonies placed (1) wholly inside the whorl, (2) on the inner and outer surfaces of the whorl, and (3) on a mature leaf. 2 The mean relative growth rate of aphids was lower on the whorl than on the mature leaf, and hydroxamic acid concentration in the whorl was higher than in the mature leaf. 3 The number of parasitized dead aphids (mummies) inside the whorl was considerably lower than in the other two treatments. Mummies were present in 80% of the replicates in the whorl, whereas mummies were present in all replicates of the other treatments. 4 Host location time of the parasitoid was increased on the mature leaf compared with the other treatments. No significant differences in the residence time of the parasitoid in the aphid colony occurred between treatments. 5 Host location time showed a negative correlation, and residence time of the parasitoid a positive correlation with the number of aphids on the outer surface of the whorl.     

Field overwintering biology of Spiroplasma kunkelii (Mycoplasmatales: Spiroplasmataceae) and its vector Dalbulus maidis (Hemiptera: Cicadellidae)

We studied the corn stunt spiroplasma (CSS), Spiroplasma kunkelii (Mycoplasmatales: Spiroplasmataceae) and its vector the corn leafhopper Dalbulus maidis (Hemiptera: Cicadellidae) under field conditions in Mexico. We surveyed for the presence of CSS in D. maidis by using PCR on samples of adults collected during the 2000–01 and 2003–04 winter (dry) seasons from irrigated low‐elevation sites and un‐irrigated high‐elevation sites. Also, we determined the body size and number of mature eggs of D. maidis females collected during the dry season in 2004 and in females collected on maize seedlings in the first months (June and July) of the wet (summer) season in 2005. Our PCR results showed that CSS was present in leafhopper adults collected during the 2000–01 and 2003–04 dry seasons in irrigated low‐elevation sites. However, in un‐irrigated high‐elevation sites, CSS was present in corn leafhopper adults caught before, but not during, the dry seasons. In these un‐irrigated high‐elevation sites, adult leafhoppers without CSS were recovered during the first 2 months (November and December) of the dry season from the foliage of wild perennial grasses. Females collected on wild perennial grasses in December 2004 showed similar head width and wing length to females caught on maize seedlings in June 2005. However, females collected on maize seedlings in July 2005 had the widest heads, longest wings and highest number of mature eggs. The largest body size of these females that arrived in July 2005 indicates that they are immigrants and support the Roff’s hypothesis that insect migrants should be larger than nonmigrants.     

叶面分离苏云金芽孢杆菌的研究进展

苏云金芽孢杆菌是一种在芽孢形成的同时能形成杀虫晶体蛋白的细菌,广泛存在于土壤、昆虫、贮藏物、仓库尘埃、植被等昆虫接触物上.植物叶片作为Bt分离的重要来源,目前对这方面的研究相对较少,国内刚刚起步.本文就叶面分离Bt的研究成果、叶片采样及分离方法进行阐述.     

红树植物白骨壤叶片的解剖结构及其生态适应性

运用石蜡切片的方法对红树植物白骨壤的叶片进行解剖学的观察和研究。结果表明:白骨壤的叶为异面叶;上表皮为复表皮,有厚的角质膜及下皮层;下表皮上有大量的泌盐腺毛;栅栏组织多层,约占叶肉组织的2/3,海绵组织退化;机械组织和输导组织均很发达。反映了白骨壤叶片的结构与其生活的海生环境高度相适应。     

安徽宿州大方寺林区植物种类及其资源的初步调查

大方寺位于淮北平原萄丘陵地带,天然次生林属于暖温带叶阔叶林。由于自然条件复杂,植物种类丰富,木本植物130余种,草本植物100余种;植被类型多种多样,主要群落为：青檀（Pterooeltis tatarinowii）、牡荆（Witex negundo）、华隐子草（Cleistogenes chinensis）群落,栓皮栎（Quercus wvriabilis）、五角枫（Acer mono）、牡荆（Vitex negundo）裂稃草（Schizachyrium brevifolium）群落和黄连木（Pistacia chinensis）、五角枫（Acer mono）、扁担杆（Creuia biloba）、沿阶草（Ophiopogon bodinievi）群落等三种。大方寺植物资源丰富,具有用材经济植物的约60余种,药用植物200余种,香料及密源植物10余种,纤维植物30余种,庭园观赏植物40余种。