观赏性昆虫在园林绿化中的运用

在通常的城市绿地系统规划中,植物类型的选择和配置一般仅考虑其改善生态环境方面的效应。不同的植物群落上生活着不同的昆虫群落。在昆虫群落中,观赏性昆虫,譬如蝴蝶、蟋蟀和萤火虫等,则可作为一种新兴的生态景观应用于绿化中,可形成动态的景观。本文通过对崇明地区的观赏性昆虫类群调查及其与植物关系的理论分析,提出了适合崇明地区的观赏性昆虫造景方案,提供了营建生态小区的新思路。     

昆虫对植物次生物质的代谢适应机制及其对昆虫抗药性的意义

植物次生物质(plant secondary metabolites)对昆虫的取食行为、生长发育及繁殖可以产生不利影响,甚至对昆虫可以产生毒杀作用。为了应对植物次生物质的不利影响,昆虫通过对植物次生物质忌避取食、解毒代谢等多种机制,而对寄主植物产生适应性。其中,昆虫的解毒代谢酶包括昆虫细胞色素P450酶系（P450s）及谷胱甘肽硫转移酶（GSTs）等,在昆虫对植物次生物质的解毒代谢及对寄主植物的适应性中发挥了重要作用。昆虫的解毒酶系统不仅可以代谢植物次生物质,还可能代谢化学杀虫剂,因而昆虫对寄主植物的适应性与其对杀虫剂的耐药性甚至抗药性密切相关。昆虫细胞色素P450s和GSTs等代谢解毒酶活性及相关基因的表达可以被植物次生物质影响,这不仅使昆虫对寄主植物的防御产生了适应性,还影响了昆虫对杀虫剂的解毒代谢,因而改变昆虫的耐药性或抗药性。掌握昆虫对植物次生物质的代谢适应机制及其在昆虫抗药性中的作用,对于明确昆虫的抗药性机制具有重要的参考意义。本文综述了植物次生物质对昆虫的影响、昆虫对寄主植物次生物质的代谢机制、昆虫对植物次生物质的代谢适应性对昆虫耐药性及抗药性的影响等方面的研究进展。     

Phytophagous insect fauna tracks host plant responses to exotic grass invasion

The high dependence of herbivorous insects on their host plants implies that plant invaders can affect these insects directly, by not providing a suitable habitat, or indirectly, by altering host plant availability. In this study, we sampled Asteraceae flower heads in cerrado remnants with varying levels of exotic grass invasion to evaluate whether invasive grasses have a direct effect on herbivore richness independent of the current disturbance level and host plant richness. By classifying herbivores according to the degree of host plant specialization, we also investigated whether invasive grasses reduce the uniqueness of the herbivorous assemblages. Herbivorous insect richness showed a unimodal relationship with invasive grass cover that was significantly explained only by way of the variation in host plant richness. The same result was found for polyphagous and oligophagous insects, but monophages showed a significant negative response to the intensity of the grass invasion that was independent of host plant richness. Our findings lend support to the hypothesis that the aggregate effect of invasive plants on herbivores tends to mirror the effects of invasive plants on host plants. In addition, exotic plants affect specialist insects differently from generalist insects; thus exotic plants affect not only the size but also the structural profile of herbivorous insect assemblages.     

植食性昆虫唾液效应子和激发子的研究进展

植食性昆虫与寄主植物通过协同进化形成了复杂的防御和反防御机制.本文系统综述了昆虫唾液效应子和激发子在植物与昆虫互作中的作用及机理.昆虫取食中释放的唾液激发子被植物识别而激活植物早期免疫反应,昆虫也能从口腔分泌效应子到植物体内抑制免疫;抗性植物则利用抗性(R)蛋白识别昆虫无毒效应子,启动效应子诱导的免疫反应,而昆虫又进化...     

Response of natural populations of predators and parasitoids to artificially induced volatile emissions in maize plants (Zea mays L.)

1 In response to herbivore attack, maize plants (Zea mays L.) emit a specific blend of induced volatiles. Artificial damage and subsequent treatment of the damaged site with caterpillar regurgitant induces the same response. The induced volatile chemicals are known to be highly attractive to several parasitoids of herbivores in laboratory bioassays, but very limited information is available on how the plant odours affect entomophagous insects in the field. 2 Experiments were conducted to determine if induced maize volatiles attract parasitic and predatory insects under field conditions and whether they affect their spatial distribution. 3 In a preliminary field experiment with blue sticky traps near treated (damaged and treated with caterpillar regurgitant) and healthy plants, more entomophagous insects (total number of parasitic Hymenoptera, Anthocoridae and Syrphidae) were trapped near treated plants than near healthy plants. 4 In a second experiment, attraction to the induced volatiles was monitored with sticky traps placed next to treated and healthy maize plants in a regular maize field. No significant differences between the two treatments were found, but significantly more insects (parasitic wasps, thrips and anthocorid bugs) were trapped near to the top of plants than on traps placed near the mid‐stem. Displacement of these insect groups within the field seemed to occur principally over the canopy, but under severe weather conditions they travelled lower in the canopy. 5 In a third experiment, the effect of induced maize odours on the spatial distribution of predators and parasitoids was investigated by placing sticky traps at different distances from healthy and treated plants. The higher catches of parasitoids near treated plants and the increased presence of these insects on the downwind side of treated plants support the notion that herbivore‐induced maize odours attract natural enemies of maize pests in the field.     

Fatal attraction: carnivorous plants roll out the red carpet to lure insects

We provide the first experimental test of the hypothesis that the coloration of carnivorous plants can act as a signal to lure insects and thus enhance capture rates. An experimental approach was needed to separate effects of the visual appearance of plants from those of traits that may correlate with appearance and also affect capture rates. We compared insect capture rates of pitcher plants with artificially coloured red and green pitchers in a paired design, and found that plants with red pitchers captured significantly more flying insects. Thus, we present the first experimental evidence of visual signalling in carnivorous plants. Further, it has previously been suggested that carnivorous plants use contrasting stripes or UV marks on their pitchers to lure insects; our results emphasize that insect traps do not need to sport contrasting colours to be attractive; it might be sufficient to be different from the background.     

Epidemiological study of Cucumber green mottle mosaic virus in greenhouses enables reduction of disease damage in cucurbit production

Since 2007, the tobamovirus Cucumber green mottle mosaic virus (CGMMV) has become widespread in Israel, causing severe damage to trellised cucumber and melon in greenhouses and watermelon grown in open fields. To reduce disease damage below the economic threshold, this study focused on four objectives: (a) monitoring the patterns of virus distribution within commercial cucumber greenhouses; (b) studying the potential transmission of CGMMV by agrotechnical activities; (c) virus localization in plant tissues; and (d) searching for techniques that might be adapted for mitigating the disease in trellised cucurbit growth. The results of our surveys demonstrated the role of contaminated seeds and soil as primary inoculum sources, and secondary spread caused by agrotechnical activities. The patterns of secondary disease spread were demonstrated in a series of inoculation experiments involving contaminated knives, shears or hands on wet and dry plants, conducted under research‐greenhouse conditions. In parallel experiments using CGMMV‐specific antibody and secondary antibody conjugated to Alexa fluor 488, the viral coat protein was visualized in several plant tissues: phloem, xylem, trichomes and grasping tendrils. In addition, commercial‐greenhouse experiments were aimed at reducing the number of inoculum sources by identifying and removing infected plants from the plots (early monitoring) prior to agrotechnical activities and/or by adding intermediate medium (IM), such as virus‐free compost, to the planting pits at the planting stage. It is suggested that the use of IM combined with early monitoring, awareness of worker mobility (from contaminated structures to young planting areas) and proper sanitation (e.g. disinfection of agrotechnical tools) may reduce the yield losses caused by CGMMV below the economic threshold.     

Ant- and plant-mediated indirect effects induced by aphid colonization on herbivorous insects on tall goldenrod

We studied the indirect effects of an aphid Uroleucon nigrotuberculatum on density and performance of herbivorous insects through tending ants and modification of plant traits on a tall goldenrod Solidago altissima in Japan. To examine ant-mediated indirect effects of the aphid on the leafhopper and geometrid moth caterpillars, we conducted an experiment in which we manipulated aphid densities. The aphid decreased the density of these herbivorous insects through ant-mediated indirect effects, because honeydew scattered by the aphid-attracted ants that then removed them. To examine plant-mediated indirect effects of the aphid on two temporally separated insects, a scale insect and a grasshopper, we compared the density and performance of these herbivorous insects on aphid-inoculated plants and aphid-free plants. Aphid-induced plant modifications had different effects on the scale insect and grasshopper. The aphid indirectly decreased the density and survivorship of the scale insect. On the other hand, the number of grasshoppers increased as a result of the increased number of leaves and the increased nitrogen content induced by prior aphid feeding. However, aphid infestation did not affect the survival of the grasshopper. Thus, the aphid has large indirect effects on co-occurring herbivorous insects through the removal behavior of tending ants and on temporally separated herbivorous insects through changes in quality and quantity of the tall goldenrod.     

春季城市中华蜜蜂的食物结构与蜂蜜金属元素含量——以四川省内江市为例

中华蜜蜂Apis cerana cerana是我国重要的本土传粉者,为评价城市生境对中华蜜蜂的生态价值,在四川省内江市城区人工饲养蜂群,调查和测定了其春季的食物来源和蜂蜜质量。结果表明,春季城市园林中开花植物资源丰富,中华蜜蜂可有效地采集花蜜、花粉等食物资源;城郊农作物也是其积极采集的食物对象。除油菜Brassica napus var.oleifera初花期外,蜂蜜中油菜花粉比例均低于50%,表明即使存在开花大宗作物,春季园林植物仍然是城市蜂群重要的食物来源。蜂蜜中金属元素含量在不同蜂群、时间存在一定差异,未检测出危害较大的铬、镉和铅,但样品中检测出微量的铝和钒,且城市蜂蜜锌含量总体高于非城市,提示蜂蜜无重金属污染,但应注意风险防范。本研究对于理解城市园林植物为访花昆虫提供的食物质量和指导城市养蜂具有参考价值。     

Settling preferences of the whitefly vector Bemisia tabaci on infected plants varies with virus family and transmission mode

Virus infection may change not only the host‐plant phenotypic (morphological and physiological) characteristics, but can also modify the behavior of their insect vector in a mutualistic or rather antagonistic manner, to promote their spread to new hosts. Viruses differ in their modes of transmission and depend on vector behavior for successful spread. Here, we investigated the effects of the semi‐persistently transmitted Tomato chlorosis virus (ToCV, Crinivirus) and the persistent circulative Tomato severe rugose virus (ToSRV, Begomovirus) on alighting preferences and arrestment behavior of their whitefly vector Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Middle East Asia Minor 1 (MEAM1) on tomato plants (Solanum lycopersicum L. cv. Santa Clara, Solanaceae). The vector alighting preferences between infected and uninfected plants in choice assays were apparently influenced by the presence of ToCV and ToSRV in the whiteflies or by their previous exposure to infected plants. The observed changes in vector behavior do not seem to benefit the spread of ToCV: non‐viruliferous insects clearly preferred mock‐inoculated plants, whereas ToCV‐viruliferous insects landed on mock‐inoculated and ToCV‐infected plants, indicating a partial change in insect behavior – ToCV was able to directly affect the preference of its vector B. tabaci, but this change in insect behavior did not affect the virus spread because viruliferous insects landed on mock‐inoculated and infected plants indistinctly. In contrast, ToSRV‐viruliferous insects preferred to land on mock‐inoculated plants, a behavior that increases the probability of spread to new host plants. In the arresting behavior assay, the majority of the insects remained on mock‐inoculated plants when released on them. A greater number of insects moved toward mock‐inoculated plants when initially released on ToCV‐ or ToSRV‐infected plants, suggesting that these viruses may repel or reduce the nutritional quality of the host plants for B. tabaci MEAM1.     

Changes in Cry1Ac Bt transgenic cotton in response to two environmental factors: temperature and insect damage

The efficacy of Cry1Ac Bacillus thuringiensis (Bt) cotton plants against field populations of Helicoverpa armigera (Hübner) has been inconsistent over the growing season. Any reduction in efficacy (where efficacy is the capacity of the plant to affect the survival of the insect) increases the opportunities for H. armigera to evolve resistance to Bt toxin. Changes in efficacy could be due to changes at the level of gene expression and/or in the physiological makeup of the plant and may be induced by environmental conditions. Two environmental factors, temperature and insect damage, were investigated. Temperature was found to affect efficacy, whether plants were grown at different temperatures continuously or were exposed to a change in temperature for a short period. Damage caused by chewing insects (H. armigera larvae) produced a dramatic increase in the efficacy of presquare Bt cotton. In contrast, damage by sucking insects (aphids) did not induce changes in efficacy. Changes in efficacy seemed to be mediated through modification of the physiological background of the plant rather than changes in the level of Cry1Ac expression or in the concentration of the Bt toxin. The impact of the non-Bt responses of plants on strains of H. armigera should be evaluated. It is possible that by enhancing existing defensive mechanisms of plants, the rate of evolution of resistance to Bt toxins could be retarded by increasing the plants overall toxicity through the additive effects of the toxins and plant defenses.     

Are dominant plant species more susceptible to leaf‐mining insects? A case study at Saihanwula Nature Reserve,China

Dominant species significantly affect interspecific relationships, community structure, and ecosystem function. In the field, dominant species are often identified by their high importance values. Selective foraging on dominant species is a common phenomenon in ecology. Our hypothesis is that dominant plant groups with high importance values are more susceptible to leaf‐mining insects at the regional level. Here, we used the Saihanwula National Nature Reserve as a case study to examine the presence–absence patterns of leaf‐mining insects on different plants in a forest‐grassland ecotone in Northeast China. We identified the following patterns: (1) After phylogenetic correction, plants with high importance values are more likely to host leafminers at the species, genus, or family level. (2) Other factors including phylogenetic isolation, life form, water ecotype, and phytogeographical type of plants have different influences on the relationship between plant dominance and leafminer presence. In summary, the importance value is a valid predictor of the presence of consumers, even when we consider the effects of plant phylogeny and other plant attributes. Dominant plant groups are large and susceptible targets of leaf‐mining insects. The consistent leaf‐mining distribution pattern across different countries, vegetation types, and plant taxa can be explained by the “species‐area relationship” or the “plant apparency hypothesis.”     

Insect herbivory in climber–host shrubs associations: Benefit or detriment?

Spatial proximity between different plant species could modify the sign (positive or negative) of plant–herbivore interaction. The chance of a plant being detected and colonized by herbivorous insects depends not only on the plant's own traits but also on the identity of the neighbouring plants that grow with it. The closest proximity between plants occurs in climbers and their host. We conducted a field experiment to assess the effect of spatial association between a climber plant, Vicia nigricans (Fabaceae), and two host shrubs, Berberis buxifolia (Berberidaceae) and Schinus patagonica (Anacardiaceae), on insect herbivory levels, reproductive output and growth. The presence and identity of the host shrubs affected the herbivory levels of the climber V. nigricans, but not the reproductive output. For the climber, the probability of being attacked by insects could depend on the characteristics of the host shrub. Taking the opposite perspective, climber association affected different traits of the host shrubs. The association with the climber decreased leaf damage (positive), tended to decrease leaf production (negative) and did not affect reproductive output (neutral). Our findings suggest that spatial association between plant species could change the sign of the interactions between plants and insects affecting different traits. By taking into account the perspective of both plants involved in the association, this study shows and emphasizes that plant–animal interactions strongly depend on the community context.     

Effects of a mud snail <Emphasis Type="Italic">Cipangopaludina chinensis laeta</Emphasis> (Architaenioglossa: Viviparidae) on the abundance of terrestrial arthropods through rice plant development in a paddy field

The effects of a mud snail, Cipangopaludina chinensis laeta (Martens) (Architaenioglossa: Viviparidae), on terrestrial arthropods through rice plant development in a paddy field were investigated in 2013 and 2014 by a field experiment. There were no significant differences between treatments in the abundance of aquatic organisms, which comprised several functional feeding groups in both years. The presence of mud snails did not significantly affect plant height and soil plant analysis development values, either, except in June 2014, when tiller number and biomass of the rice plants tended to be larger in plots with snails versus those without. Significantly higher abundances of terrestrial organisms, including phytophagous pest insects and other insects, but not natural enemies of the pest insects, occurred in plots with snails. As shown by principal component analysis, the community structure of the terrestrial organisms was significantly different between the two treatments in both years. The results of this study indicate that mud snails play an important role in the paddy field ecosystem, in which they influence the biomass production of rice plants and the abundance of organisms in terrestrial ecosystems through direct and indirect interactions at different trophic levels.     

Distribution pattern of allergenic plants in the Beijing metropolitan region

Urbanization has significantly affected the composition and distribution pattern of plant species within and around cities. Plants with airborne pollens can cause seasonal allergic symptoms that are intensified by increasing air pollution and temperature. In urban landscapes, the reduced native biodiversity, increased exotic biodiversity, and species homogenization may all affect the abundance and distribution of allergenic plants. We investigated the plants with airborne pollens in the Beijing metropolitan region to determine the distribution pattern of allergenic plants as influenced by urbanization. Our results show that native allergenic plants dominated the urban area in the region. The species richness of allergenic plants, particularly the exotic plants with airborne pollens, significantly differed between land use types. The higher the plant diversity in the urban area, the higher the frequency of allergenic plant occurrence. Despite the homogenization of the allergenic plant communities, their characteristic species were still present across the metropolitan region. The flowering allergenic plants also differed between the different land use types. We suggest that some common allergenic plants should be avoided by urban planners, especially those that are exotic to the region. Humans susceptible to pollinosis should stay away from places that are concentrated with allergenic plants, and be aware of the flowering phenology of allergenic plants.     

Invasive interactions: can Argentine ants indirectly increase the reproductive output of a weed?

The direct and indirect interactions of invasive ants with plants, insect herbivores, and Hemiptera are complex. While ant and Hemiptera interactions with native plants have been well studied, the effects of invasive ant–scale insect mutualisms on the reproductive output of invasive weeds have not. The study system consisted of Argentine ants (Linepithema humile), boneseed (Chrysanthemoides monilifera monilifera), and sap-sucking scale insects (Hemiptera: Saissetia oleae and Parasaissetia nigra), all of which are invasive in New Zealand. We examined the direct and indirect effects of Argentine ants on scale insects and other invertebrates (especially herbivores) and on plant reproductive output. Argentine ants spent one-third of their time specifically associated with scale insects in tending behaviours. The invertebrate community was significantly different between uninfested and infested plants, with fewer predators and herbivores on ant-infested plants. Herbivore damage was significantly reduced on plants with Argentine ants, but sooty mould colonisation was greater where ants were present. Herbivore damage increased when ants were excluded from plants. Boneseed plants infested with Argentine ants produced significantly more fruits than plants without ants. The increase in reproductive output in the presence of ants may be due to increased pollination as the result of pollinators being forced to relocate frequently to avoid attack by ants, resulting in an increase in pollen transfer and higher fruit/seed set. The consequences of Argentine ant invasion can be varied; not only does their invasion have consequences for maintaining biodiversity, ant invasion may also affect weed and pest management strategies.     

Effects of insect-vector preference for healthy or infected plants on pathogen spread: insights from a model

Insects vector many plant pathogens and often have higher or lower densities on infected plants than on healthy plants. Two hypotheses may explain this observation: insects may preferentially orient toward and select one plant type (referred to as orientation preference) or insects may reside on infected plants for longer or shorter periods than on healthy plants (referred to as feeding preference). The effects of feeding preference and orientation preference were compared alone and in combination using a spatially explicit model. With feeding preference for healthy or infected plants, the qualitative relationship between the percentage of plants infected and the rate of pathogen spread was not affected. However, feeding preference for healthy plants increased rates of pathogen spread, whereas feeding preference for infected plants decreased rates of pathogen spread. Unlike feeding preference, orientation preference for healthy and infected plants produced qualitatively different relationships between the percentage of plants infected and the rate of pathogen spread. With orientation preference for healthy plants, the pathogen spread slowly when few plants were infected, but quickly once most plants were infected. In contrast, with orientation preference for infected plants, the pathogen spread quickly when few plants were infected, but slowly once most plants were infected. In sensitivity analyses, we found that assumptions about the latent period (time between infection and when insects can recognize a plant as being infected) and persistence (length of time an insect remains inoculative) altered the aforementioned effects in some cases. The results illustrate that feeding and orientation preference affect pathogen spread differently, highlighting the importance of elucidating the mechanisms that control vector preference for healthy versus infected plants.     

Oviposition site preference and developmental performance of a gall‐inducing leafhopper on galled and non‐galled host plants

Oviposition preferences of herbivorous insects affect offspring performance. Both positive and negative links between oviposition preference and offspring performance have been reported for many species. A gall‐inducing leafhopper, Cicadulina bipunctata Melichar (Hemiptera: Cicadellidae), feeds on various Poaceae plants and induces galls of enhanced nutritional value for their offspring. Although gall induction by C. bipunctata improves nymphal performance, the oviposition preference of females between galled and non‐galled host plants is still unclear. In this paper, the nymphal performance and oviposition and feeding‐site preference of C. bipunctata were investigated using galled wheat, Triticum aestivum L., and non‐galled barley, Hordeum vulgare L., as host plants. The survival rate of C. bipunctata on wheat was significantly higher than on barley. In the choice test, significantly more eggs were laid into barley, whereas the number of eggs deposited on both hosts was not significantly different in the no‐choice test. The number of settling individuals per leaf area was not significantly different between wheat and barley, suggesting no clear preference for oviposition between these plants. Experience as a nymph with a growing host did not affect oviposition preference as adult female. The inconsistent correspondence between offspring performance and oviposition preference of C. bipunctata may reflect the high mobility of nymphs and/or differences in leaf area between host plants. The results indicate that the previous finding that oviposition preference and offspring performance are not always positively correlated in herbivorous insects is applicable to gall‐inducing insects.     

Three-way interaction among plants,bacteria, and coleopteran insects

Main conclusion

Coleoptera, the largest and the most diverse Insecta order, is characterized by multiple adaptations to plant feeding. Insect-associated microorganisms can be important mediators and modulators of interactions between insects and plants. Interactions between plants and insects are highly complex and involve multiple factors. There are various defense mechanisms initiated by plants upon attack by herbivorous insects, including the development of morphological structures and the synthesis of toxic secondary metabolites and volatiles. In turn, herbivores have adapted to feeding on plants and further sophisticated adaptations to overcome plant responses may continue to evolve. Herbivorous insects may detoxify toxic phytocompounds, sequester poisonous plant factors, and alter their own overall gene expression pattern. Moreover, insects are associated with microbes, which not only considerably affect insects, but can also modify plant defense responses to the benefit of their host. Plants are also frequently associated with endophytes, which may act as bioinsecticides. Therefore, it is very important to consider the factors influencing the interaction between plants and insects. Herbivorous insects cause considerable damage to global crop production. Coleoptera is the largest and the most diverse order in the class Insecta. In this review, various aspects of the interactions among insects, microbes, and plants are described with a focus on coleopteran species, their bacterial symbionts, and their plant hosts to demonstrate that many factors contribute to the success of coleopteran herbivory.

     

植物蜡质及其与环境的关系

陆生植物的地上部分如叶、茎、花、果实等的表面覆盖着一层蜡质,它是由一系列复杂化合物组成的具有三维微结构的疏水层,在植物生长和发育过程中起着不可或缺的作用,具有很好的生物学功能。作为植物与环境的第一接触面,蜡质对外界环境因子的响应较敏感,当植物受到外界不利环境因子胁迫时,蜡质会改变自身晶体结构形态或化学组分构建防御机制以减少胁迫因子的作用,有效地协调植物与环境的关系。综述了近年来国内外关于植物蜡质的研究进展,在阐述蜡质层结构及其化学组分的基础上,着重介绍植物与环境因子的作用,包括非生物环境因子如水分、温度、光照、环境污染等以及植食性昆虫和病原菌等生物环境因子的作用。研究显示,胁迫环境下植物蜡质化学组分的变化,是由于不利环境因子的作用足以改变蜡质各产物的合成途径,从而影响蜡质产物。植物蜡质利用各种生理、化学机制对胁迫环境因子的适应以及响应,是植物适应各种生境的基础,因此通过对植物蜡质与环境关系的研究为进一步解析植物与环境关系提供证据。