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1.
1. Colour polymorphisms are common across animals and are often the result of complex selection regimes. Philaenus spumarius (Linnaeus) (Hemiptera, Aphrophoridae) shows a widely studied dorsal colour polymorphism with several described phenotypes whose variation in their occurrence and frequency, as well as their maintenance across time, have been reported. Several selective influences have been suggested to play a role, but the mechanisms underlying the maintenance of this polymorphism are still poorly understood. 2. To explore the adaptive significance of the colour polymorphism of P. spumarius, an experiment was conducted in captivity under semi‐natural conditions to measure survival, reproductive success, and duration of egg maturation. 3. It was found that there was higher longevity, a higher number of oviposition events, and a higher number of eggs laid by trilineatus phenotype females than by typicus and marginellus, supporting previous reports of an increase in trilineatus frequency during the season. The duration of egg maturation did not differ among phenotypes. 4. The higher longevity and fertility of the trilineatus phenotype may compensate, for example, the higher rate of attack by parasitoids and/or higher solar radiation reflectance in this phenotype, which have already been reported in previous studies, constituting a possible mechanism for the maintenance of this polymorphism.  相似文献   
2.
Abstract.  1. Considerable evidence indicates that the Earth's climate has warmed over the past 20 years and most models predict that this process will continue or accelerate. Previous studies involving butterflies and other species have shown that ranges have shifted towards the poles although the mechanisms responsible for these range shifts have not been demonstrated conclusively.
2. Here it is reported that the range of the meadow spittlebug has moved northward along the California coast since 1988.
3. Survival and reproduction of this species in previous laboratory experiments were very sensitive to humidity and temperature. Small deviations from optimal conditions resulted in high mortality.
4. These laboratory results were corroborated by annual field censuses from one location since 1983 in which population densities of spittlebug nymphs were positively correlated with summer humidity and negatively correlated with temperature deviations from the published optimum. Thus it is shown that there are strong links between physiological tolerance and a geographic range shift associated with climatic change.  相似文献   
3.
The feeding of spittlebug nymphs (Philaenus spumarius) from mature xylem vessels was studied by optical and cryo-analytical scanning electron microscopy. Feeding did not produce xylem embolisms and vessels remained liquid-filled during the day. Saliva secreted by the insect forms a hardened lining (salivary sheath) between the stylet bundle and the plant tissues. This sheath is continuous through the hole made by the stylets as they enter a vessel, and it extends into the vessel and along its periphery beyond the breach. The sheath is heterogeneous, with a thin outer layer adjoining the plant tissues and a thicker layer that contacts the stylet bundle. Both layers give positive histochemical reactions for proteins and, in fresh tissues, contain a red, strongly autofluorescent pigment, possibly condensed tannin derived from the plant (which is lost during tissue preparation), and other phenyl propanoid compounds, which are retained and which may produce the intense reaction of the periodic-acid-Schiff's-positive inner layer. It is concluded that the salivary sheath allows the insects to feed from functioning vessels without embolizing them or losing xylem fluid to the surrounding tissues. These findings and others in the entomological literature indicate low daytime tensions in the xylem conduits of the host plants.  相似文献   
4.
Review of the Australian aphrophorid spittlebugs (Hemiptera: Aphrophoridae)   总被引:1,自引:0,他引:1  
Abstract A review of the Aphrophoridae (Hemiptera: Auchenorrhyncha: Cercopoidea) occurring in Australia has revealed closer links between the Australian fauna and those of the Pacific region than were previously acknowledged. A key to the Australian genera is provided along with a diagnosis for each genus and a list of described Australian species with notes on each. Taxonomic changes proposed are: Neoaphrophora China synonymised with Anyllis Kirkaldy; Eurycercopis Kirkaldy synonymised with Interocrea Walker; Aphrophora rufiventris Walker and Philagra vittata Metcalf and Horton synonymised with Philagra parva (Donovan). New combinations proposed are: Amarusa australis (Jacobi) (from Eoptyelus ); Anyllis tiegsi (China) (from Neoaphrophora ); Interocrea nigrofasciata (Kirkaldy) (from Eurycercopis ); Interocrea regalis (Lallemand) (from Clovia ); Liorhina loxosema (Hacker) (from Clovia ). To provide a single reference point for the species and, for species described by Hacker (1926) and Jacobi (1928) , to validate apparent holotype intentions by those authors, lectotypes are designated for: Ptyelus homochrous Hacker; Eurycercopis nigrofasciata Kirkaldy; Clovia regalis Lallemand; Clovia loxosema Hacker; Philagra concolor Hacker; Philagra fulvida Hacker; Philagra recurva Jacobi. The probable whereabouts of the type specimen of Philagra parva (Donovan) are discussed. The origin of the holotype of Novaphrophara tasmaniae Lallemand is discussed; the Australian record is almost certainly incorrect.  相似文献   
5.
The action of trypsin, collagenase, testicular hyaluronidase, sodium dodecyl sulphate (SDS), urea, guanidinium-chloride (GnCl), n-butanol, dioxane, malathion, alkylphenolpolyglycol ether and iso-octylphenoxy-polyethoxy ethanol/dioctyl sodium sulphocyanate (v/v) on the macromolecular structure of the froth which covers the nymphs of Deois sp., a pest of pasture and agriculture, was studied using polarization microscopy. SDS, n-butanol, GnCl and iso-octyl-phenoxy-polyethoxy ethanol/dioctyl sodium sulphocyanate were the most efficient compounds at promoting disorganization and bursting of the froth bubbles at a relatively fast rate. Disorganization of the froth macromolecules could be visualized through attenuation or abolishment of the birefringence attributable to the high macromolecular orientation of structural proteins and proteoglycans in the wall of the froth bubbles.
Résumé L'action de la trypsine, de la colagénase, de l'hyaluronidase testiculaire, du docécil sulphate de sodium (SDS), de l'urée, du chlorite de guanidine (GnCl), du n-butanol, de la dioxane, de l'iso-octilphenoxy-polyetoxy etanol/dioctyl sulphocyanate de sodium (v/v), de l'éther d'alkylphenolpolyglycol et du malathion sur la structure macromoléculaire de l'abri spumeux qui recouvre les nymphes de Deois sp., plaie des pâturages et de l'agriculture, a été observée en microscopie polarisée. Il s'est avéré que le SDS, le n-butanol, le GnCl et l'iso-octil-phenoxypolyetoxy etanol/dioctyl sulphocyanate de sodium sont les agents les plus efficaces de désorganisation et rupture des bulles de mousse, à vitesse assez grande. La désorganisation des macromolécules de la mousse est misse en évidence par la diminution et éventuelle disparition de la biréfringence qui est due à la forte orientation macromoléculaire des protéines structurales et des proteoglycans qui forment la paroi des bulles.
  相似文献   
6.
7.
Daniel C. Peck 《Biotropica》1998,30(4):639-644
Male-specific associations of adult froghoppers (Homoptera: Cercopidae) with alternative food plant hosts is reported. Four accounts from the field and one from the literature are presented: Iphirhina quota on Bourreria costaricensis (Boraginaceae), Huaina inca on Solanaceae sp., Prosapia simulans and Prosapia sp. (near P. bicincta) on Ilex haberi (Aquifoliaceae), and Prosapia bicincta on Ilex cornuta and Ilex opaca. In three cases host use is limited to adults while in two cases use is limited to only adult males. In four cases adults feed on plants that differ taxonomically, structurally and ecologically from hosts normally utilized by all life stages. These associations are not considered aggregations per se because froghoppers are not clustered and because these associations cannot be explained by the usual criteria supporting the adaptiveness of insect aggregations. Indirect evidence suggests that these unusual hosts may be unavailable to nymphs and not sought by females. This passive lack of opportunity by nymphs and females, in tandem with an active selection/attraction by males, is a plausible explanation for the existence of male-specific hosts.  相似文献   
8.
9.
The North Atlantic Oscillation (NAO) is a large‐scale pattern of climate variability that has been shown to have important ecological effects on a wide spectrum of taxa. Studies on terrestrial invertebrates are, however, lacking. We studied climate‐connected causes of changes in population sizes in island populations of the spittlebug Philaenus spumarius (L.) (Homoptera). Three populations living in meadows on small Baltic Sea islands were investigated during the years 1970–2005 in Tvärminne archipelago, southern Finland. A separate analysis was done on the effects of NAO and local climate variables on spittlebug survival in 1969–1978, for which survival data existed for two islands. We studied survival at two stages of the life cycle: growth rate from females to next year's instars (probably mostly related to overwintering egg survival), and survival from third instar stage to adult. The latter is connected to mortality caused by desiccation of plants and spittle masses. Higher winter NAO values were consistently associated with smaller population sizes on all three islands. Local climate variables entering the most parsimonious autoregressive models of population abundance were April and May mean temperature, May precipitation, an index of May humidity, and mean temperature of the coldest month of the previous winter. High winter NAO values had a clear negative effect on late instar survival in 1969–1978. Even May–June humidity and mean temperature of the coldest month were associated with late instar survival. The climate variables studied (including NAO) had no effect on the growth rate from females to next year's instars. NAO probably affected the populations primarily in late spring. Cold and snowy winters contribute to later snow melt and greater spring humidity in the meadows. We show that winter NAO has a considerable lagged effect on April and May temperature; even this second lagged effect contributes to differences in humidity. The lagged effect of the winter NAO to spring temperatures covers a large area in northern Europe and has been relatively stationary for 100 years at least in the Baltic area.  相似文献   
10.
No study of a single nickel (Ni) hyperaccumulator species has investigated the impact of hyperaccumulation on herbivores representing a variety of feeding modes. Streptanthus polygaloides plants were grown on high- or low-Ni soils and a series of no-choice and choice feeding experiments was conducted using eight arthropod herbivores. Herbivores used were two leaf-chewing folivores (the grasshopper Melanoplus femurrubrum and the lepidopteran Evergestis rimosalis), a dipteran rhizovore (the cabbage maggot Delia radicum), a xylem-feeder (the spittlebug Philaenus spumarius), two phloem-feeders (the aphid, Lipaphis erysimi and the spidermite Trialeurodes vaporariorum) and two cell-disruptors (the bug Lygus lineolaris and the whitefly Tetranychus urticae). Hyperaccumulated Ni significantly decreased survival of the leaf-chewers and rhizovore, and significantly reduced population growth of the whitefly cell-disruptor. However, vascular tissue-feeding insects were unaffected by hyperaccumulated Ni, as was the bug cell-disruptor. We conclude that Ni can defend against tissue-chewing herbivores but is ineffective against vascular tissue-feeding herbivores. The effects of Ni on cell-disruptors varies, as a result of either variation of insect Ni sensitivity or the location of Ni in S. polygaloides cells and tissues.  相似文献   
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