植物挥发性物质在蚜虫寄主定位中的作用

本文综述了植物挥发性物质的化学性质、研究方法及其在蚜虫寄主定位中的作用     

The integrative effects of population density, photoperiod, temperature, and host plant on the induction of alate aphids in Schizaphis graminum

The wheat aphid Schizaphis graminum (Rondani) displays wing dimorphism with both winged and wingless adult morphs. The winged morph is an adaptive microevolutionary response to undesirable environmental conditions, including undesirable population density, photoperiod, temperature, and host plant. Here we studied the integrative effects of population density, photoperiod, temperature, and host plant on the induction of alate aphids in S. graminum. The present results show that these four factors all play roles in inducing alate aphids in S. graminum but population density is the most important under almost all circumstances. In importance, population density is followed by photoperiod, host plant, and temperature, in that order. These results indicate that ambient environmental factors are highly important to stimulation of alate aphids in S. graminum, especially when population density reaches 64 individuals per leaf.     

Molecular data support a rapid radiation of aphids in the Cretaceous and multiple origins of host alternation

Many aphids display a remarkably complex life cycle of host alternation, in which cyclical parthenogenesis is combined with the obligate use of two unrelated host plants. We used mitochondrial ribosomal DNA (partial 12S and 16S) sequences to reconstruct the phylogeny of aphids, to determine how many origins of host alternation and correlated major host-plant shifts have occurred. Our results agreed with previous morphological studies in that species clustered with good support at the level of tribes. There was little well-supported phylogenetic structure at levels deeper than tribes, however, except for the monophyly of two subfamilies, Aphidinae and Lachninae. We argue that aphids experienced a rapid radiation at the tribal level, after host shifting from gymnosperms to angiosperms. A rapid radiation is consistent with aphid fossils, which record the presence of few subfamilies in the late Cretaceous, but most extant tribes by the early Tertiary. Plant fossils also record host plants of aphid tribes diversifying during this time. A hypothesized mechanism by which host alternation has evolved (fundatrix specialization), coupled with the rapid radiation, implies that this life cycle may have originated as often as in the ancestor of each tribe that displays it. We also consider, however, an alternative hypothesis of fewer origins. The basal radiation of Aphididae was dated from molecular sequences to have occurred at approximately 80–150 Mya.     

寄主植物-蚜虫-天敌三重营养关系的化学生态学研究进展

综述了寄主植物－蚜虫－天敌三重营养关系的化学生态学研究,重点阐述了3个研究热点：①植物挥发性物质在蚜虫及其天敌选择寄主行为过程中的作用;②蚜虫信息素和蜜露对蚜虫天敌寄主选择行为的影响;③植物挥发性物质对蚜虫信息系作用的影响。对寄主植物－蚜虫－天敌三重营养关系的全面了解,将为蚜虫的综合治疗提供新思维。     

The scaling of body size and mass in a host-parasitoid association: influence of host species and stage

We describe the allometry of body mass and body size as measured by hind-tibia length in males of Monoctonus paulensis (Ashmead) (Hymenoptera: Braconidae, Aphidiinae), a solitary parasitoid of aphids. To assess the influence of host quality on allometric relationships, we reared parasitoids on second and fourth nymphal instars of four different aphid species, Acyrthosiphon pisum (Harris), Macrosiphum creelii Davis, Myzus persicae (Sulzer) and Sitobion avenae (F.), under controlled conditions in the laboratory. Dry mass was positively correlated with hind-tibia length, and could be predicted from it, in unparasitized aphids, in aphid mummies containing parasitoid pupae, and in the parasitoid. The reduced-major-axis scaling exponents for the regression of dry mass on hind-tibia length were species-specific in aphids, reflecting differences in volume and shape between species. In mummified aphids, the stage at death influenced the size/mass relationship. In males of M. paulensis, the allometric exponent varied between parasitoids developing in different kinds of host. Individuals developing in pea aphid were absolutely larger in dry mass as well as proportionately larger relative to their hind-tibia length. We discuss the allometry of body size and body mass in relation to parasitoid fitness.     

Body size distribution in aphids: relative surface area of specific plant structures

Abstract.

• 1 The distribution of the body sizes of British aphids is right-skewed on a logarithmic axis, as in other taxa. Over the size range 2–5 mm there is a marked decrease in numbers of species with increase in size, which on a log log scale has an exponent of -3, The exponent for the right-hand side of the size distribution of British plants is -0.7.
• 2 The sizes of sixty-eight species of the genus Aphis are weakly correlated with the size of their respective host plants.
• 3 An aphid's size is strongly correlated with the length of its proboscis, which indicates the depth to which it has to probe plant tissues in order to feed.
• 4 On average, trees host more species of aphids than either shrubs or herbaceous plants, which appears to be associated with the relative surface area of specific plant structures. The surface area of plants is mainly made of leaves and most species of aphids are leaf feeders. The largest and least numerous species of aphids feed on the branches and trunks of trees, the proportional cover of which is less than that of leaves.
• 5 Taking into account all the above observations, a functional explanation in terms of the relative surface area of specific plant structures is offered to account for the size diversity curve of aphids.

     

Distribution of Oriental and German cockroaches, Blatta orientalis and Blattella germanica (Dictyoptera), in the United Kingdom

Results are presented of a survey carried out by Rentokil Ltd on the distribution of the Oriental cockroach Blatta orientalis L. and the German cockroach Blattella germanica L. in the United Kingdom. The known ranges of both species are increased considerably by the findings of the survey, with several new vice-county records for Scotland (including the Western Isles), England and Wales. The frequency at which Blatta orientalis was observed in outdoor habitats may indicate that this species sometimes spreads to new areas without human assistance.     

Population differentiation and genetic variation in host choice among pea aphids from eight host plant genera

Habitat choice plays a critical role in the processes of host range evolution, specialization, and ecological speciation. Pea aphid, Acyrthosiphon pisum, populations from alfalfa and red clover in eastern North America are known to be genetically differentiated and show genetic preferences for the appropriate host plant. This species feeds on many more hosts, and here we report a study of the genetic variation in host plant preference within and between pea aphid populations collected from eight genera of host plants in southeastern England. Most host-associated populations show a strong, genetically based preference for the host plant from which they were collected. Only in one case (populations from Vicia and Trifolium) was there little difference in the plant preference spectrum between populations. All populations showed a significant secondary preference for the plant on which all the aphid lines were reared: broad bean, Vicia faba, previously suggested to be a "universal host" for pea aphids. Of the total genetic variance in host preference within our sample, 61% could be attributed to preference for the collection host plant and a further 9% to systematic differences in secondary preferences with the residual representing within-population genetic variation between clones. We discuss how a combination of host plant preference and mating on the host plant may promote local adaptation and possibly ecological speciation, and whether a widely accepted host could oppose speciation by mediating gene flow between different populations.     

温度对黑豆蚜体内共生菌胞数量及宿主体型大小的影响

为了明确饲养温度对黑豆蚜Aphis fabae 内共生菌和宿主蚜虫体型大小的影响,对在室内不同温度下饲养的黑豆蚜内共生菌胞数量和宿主蚜虫体型大小进行了观察和统计分析。结果表明,温度对同一发育时期蚜虫内共生菌胞数量的影响在不同温度范围内有所不同,1龄若蚜体内的菌胞数量除在25℃与35℃间有显著差异外,在其余各温度间没有显著差异; 其余时期的蚜虫内共生菌胞数量在高温（> 30℃）下显著低于较低温度下的菌胞数量,存在负直线相关性。温度对菌胞数量随宿主发育到产仔前的变化趋势有不同程度的影响,在较低温度（15℃、20℃和25℃）下,菌胞数量随虫体发育显著增加; 但在高温（30℃和35℃）下,蚜虫体内菌胞数逐渐增加直到3龄达到最高,然后略有下降（30℃）或显著下降（35℃）。除1龄若蚜外,蚜虫体型大小总体呈现随温度升高而降低的格局,但随其内共生菌数量增多而增大（35℃下除外）。据此认为,温度可能通过作用于蚜虫内共生菌胞数量而影响蚜虫体型的大小。     

Variation and evolution of the complex life cycle in Adelgidae (Hemiptera)

The family Adelgidae is a small group of insects within Aphidoidea (Hemiptera). Adelgids are typically holocyclic with host‐alternation between the primary and secondary hosts, but some anholocyclic species persist either on the primary or secondary host. Like Aphididae, complexities and variation of adelgid life cycles are good models for understanding the evolution of complex life cycles. In this review, we outline the complex life cycles of adelgids, and current status and recent advances in adelgid life cycle studies. We also discuss the evolution of adelgid life cycles by comparing them to closely related aphid life cycles. A switch from holocycly to anholocycly on the primary host needs evolutionary innovations in gallicola behavior and reproduction. This radical evolution can be explained by mutations in a regulatory system that controls the sequence of gene sets producing phenotypes of one morph. In contrast, anholocycly on the secondary host consists of a series of exulis generations already existing in the holocycle. Thus, it may evolve by loss of primary‐host generations through extinction of the primary host, expansion beyond the geographical range of the primary host, or loss of male‐producing sexuparae that return to the primary host. Although the holocycle and its anholocyclic derivatives have been regarded as different species, morphological, ecological and genetic differences are too subtle to separate them into different species. The holocycle and its anholocyclic derivatives should not be split into different species without clearly identifiable morphological differences.     

The effect of host plants on genotype variability in fitness and honeydew composition of Aphis fabae

Aphid species can be polyphagous, feeding on multiple host plants across genera. As host plant species can have large variation in their phloem composition, this can affect aphid fitness and honeydew composition. Previous research showed significant intraspecific genotype variation in the composition of the honeydew carbohydrates of the black bean aphid Aphis fabae, with the ant attractant trisaccharide melezitose showing especially large variation across different genotypes. In this study, we test if variation in melezitose and carbohydrate composition of aphid honeydew could be linked to the adaptation of specific aphid genotypes to particular host plants. To this end, 4 high and 5 low melezitose secreting genotypes of the black bean aphid Aphis fabae were reared on 4 common host plants: broad bean, goosefoot, beet, and poppy. The carbohydrate composition, and in particular melezitose secretion, showed important aphid genotype and host plant interactions, with some genotypes being high melezitose secreting on 1 host plant but not on another. However, the interaction effects were not paralleled in the fitness measurements, even though there were significant differences in the average fitness across the different host plants. On the whole, this study demonstrates that aphid honeydew composition is influenced by complex herbivore–plant interactions. We discuss the relevance of these findings in the context of ant–aphid mutualisms and adaptive specialization in aphids.     

英国国家公园建设活动管控的经验与启示

随着国家公园试点工作在全国的进一步推进,包括管理制度在内的各类议题就一直处于探讨之中。英国国家公园因其大量的居民点分布其中而与中国的国家公园试点区有着诸多相似之处,其成熟的建设活动管控制度对中国的国家公园也有着借鉴作用。本文以英格兰地区为对象,对英国国家公园建设活动管控的制度基础、管控程序2方面进行分析。最后在分析中国自然保护地建设管控问题的基础上,提出针对中国国家公园建设活动管控制度的建议。     

Oviposition preference and life history traits in cactophilic Drosophila koepferae and D. buzzatii in association with their natural hosts

Drosophila koepferae and D. buzzatii are two closely related cactophilic species inhabiting the arid lands of southern South America. Previous studies have shown that D. buzzatii breeds primarily on the necrotic cladodes of several Opuntia cacti and D. koepferae on the rotting stems of columnar cacti of the genera Trichocereus and Cereus. In this paper, we analyze the patterns of host plant utilization in a locality where both Drosophila species are sympatric. Field studies showed an absence of differential attraction of adult flies to the rots of two major host cacti: O. sulphurea and T. terschekii. However, the proportion of D. buzzatii flies emerged from the rotting cladodes of O. sulphurea was significantly higher than in T. terschekii. In laboratory experiments, egg to adult viability in single species cultures varied when both Drosophila species were reared in media prepared with O. sulphurea or T. terschekii. In addition, between-species comparisons of flies emerged from single species cultures showed that D. buzzatii adults were smaller and developed faster than D. koepferae. Furthermore, analysis of flies emerged in mixed species cultures showed differences in oviposition preference and oviposition behavior. We discuss the observed between-species differences and suggest that these traits are the result of adaptation to specific patterns of spatial and temporal predictability of their respective preferred host plants: columnar are less dense and less ephemeral resources, whereas the opuntias are more abundant, and fast rotting cacti. This revised version was published online in July 2006 with corrections to the Cover Date.     

Variations on a theme: sources of heterogeneity in the form of the interspecific relationship between abundance and distribution

1. A positive interspecific relationship between abundance and distribution is widely considered to be one of the most general patterns in ecology. However, the relationship appears to vary considerably across assemblages, from significant positive to significant negative correlations and all shades in between. 2. This variation has led to the suggestion that the abundance-distribution relationship has multiple forms, with the corollary that different patterns may inform about, or have different, causes. However, this variation has never been formally quantified, nor has it been determined whether the observed variation is indicative of sampling error in estimating a single effect or of real heterogeneity in such relationships. Here, we use the meta-analytical approach to assess variation in abundance-distribution relationships, and to test different hypotheses for it. 3. Analysis of 279 relationships found a mean effect size of 0.655, which was both highly significantly different from zero and indicative of a strong positive association between abundance and distribution. However, effect sizes were highly heterogeneous, supporting the contention that this relationship does indeed have multiple forms. 4. Most notably, relationships vary significantly in strength across realms, with the strongest in the marine and intertidal, intermediate relationships for terrestrial and parasitic assemblages, and the weakest relationships in freshwater systems. Effect sizes in all of the aquatic realms are homogeneous, suggesting that realm is an important source of the heterogeneity observed across all studies. We posit that this may be because the different spatial structure of the environment in each realm affects the opportunity for the dispersal of individuals between sites. 5. Some of the remaining heterogeneity in effect sizes for terrestrial assemblages could be explained by partitioning assemblages by habitat, scale, biogeographical region and taxon, but considerable heterogeneity in effect sizes for terrestrial and parasitic assemblages remained unexplained.     

The effect of plant phenology on the induction of alatae and the development of populations of Metopolophium dirhodum (Walker), the rose-grain aphid, on winter wheat

In field experiments apterous Metopolophium dirhodum produced significantly more alatae when reared on mature plants (milky ripe stage) than on young plants. Nymphal and adult survival and relative growth rate were little affected by the developmental stage of the host plant. Relative growth rate and fecundity were strongly related to temperature. Laboratory experiments confirmed that the developmental stage of wheat had no significant effect on survival or relative growth rate of the aphids. However, laboratory grown plants did not produce the levels of alate production seen in field crops and in the field experiments. It is suggested that in investigations into the effects of the host plant on cereal aphids field grown plants should be used whenever possible. Alate production is proposed as the major plant induced factor affecting the development of M. dirhodum populations on wheat in the field. Alatae developed on mature plants even when the number of aphids was very low.     

Genetic heterogeneity, reproductive isolation and host preferences in mealy aphids of the Hyalopterus pruni complex (Homoptera, Aphidoidea)

Three taxa were detected by allozyme markers within the mealy aphids of the Hyalopterus pruni complex, having different cultivated Prunus species as main primary hosts. The genetically closer H. pruni and H. amygdali A ( D _Nei= 0.10) never share primary hosts, whereas H. amygdali A and B ( D _Nei= 0.32) may occasionally share them, producing few F₁ hybrids. The three species proved reproductively isolated in the field, with no gene exchange. Their speciation seem to have occurred long before the agricultural revolution, crop colonization representing a host range expansion rather than a host shift, as in sympatric speciation.     

梨园芳香植物间作区蚜虫与天敌类群的相互关系

在梨园中设置不同种类的芳香植物间作处理区、自然生草区和清耕区(对照),研究不同芳香植物间作区蚜虫及其天敌类群组成、种群时序动态与时间生态位指数的变化,并进行灰色关联分析。结果表明,不同芳香植物间作处理区蚜虫及其天敌类群数量、时序特征、时间生态位宽度与重叠指数存在明显差别。在梨树年生长周期中,薄荷、孔雀草和罗勒间作区的梨黄粉蚜、绣线菊蚜、梨二叉蚜与天敌类群的时序变化趋势相似,但发生的时段及数量与对照区存在显著差异。各个处理区中3种蚜虫的时间生态位宽度指数均较小,而天敌类群的时间生态位宽度指数较大;芳香植物间作区中蚜虫(孔雀草间作区的绣线菊蚜除外)及捕食性天敌的生态位宽度指数均大于对照区。各个处理区中蚜虫及(与)天敌之间的时间生态位重叠指数差异明显。各处理区中不同的天敌类群对某一特定的蚜虫的关联度相似,而不同间作处理区某一特定的天敌类群对3种蚜虫的关联度存在明显差异。芳香植物间作改变了梨园生态环境中的蚜虫及其天敌类群数量和组成,害虫种群数量明显减少,益害比(1∶1)明显大于自然生草区(1∶2.1)和清耕区(1∶3.3)。结论:芳香植物间作能有效降低蚜虫种群数量,是一种农业防治蚜害的优选方法。     

江苏扬州地区蔬菜烟粉虱寄主调查及种群动态

2002—2003年对江苏扬州地区露地蔬菜上的烟粉虱寄主植物、危害,及主要蔬菜上的烟粉虱种群动态进行了调查。共查到烟粉虱寄主植物10科39种(变种),主要分布在葫芦科、十字花科、豆科、茄科和菊科等蔬菜上,其中以黄瓜、豇豆、花菜和长茄发生较为严重;露地蔬菜上的烟粉虱发生在6月上旬至11月中旬,发生高峰期在8月下旬至9月上中旬;随着蔬菜的种类、季节和年份的不同,田间烟粉虱的发生为害也有所不同。