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1.
    
The species diversity and seasonal abundance of biting midges of the genus Culicoides (Diptera: Ceratopogonidae) were studied in northwestern Argentina during the period 2003–2005. A total of 5437 Culicoides specimens were collected using CDC light traps in three areas of the mountainous rainforest area. The most common species were Culicoides paraensis (Goeldi) and C . insignis Lutz, Culicoides lahillei (Iches), C . venezuelensis Ortiz & Mirsa, C . debilipalpis Lutz and C . crescentis Wirth & Blanton were also collected. Culicoides paraensis was abundant during the summer, and C . insignis and C . lahillei during late summer and early fall. Accumulated rainfall was the climatic variable most related to fluctuation in abundance of C . paraensis .  相似文献   

2.
Abstract.
  • 1 Swarms of Culicoides impunctatus males were examined in the field in Scotland. Most swarms were close to midge emergence/breeding grounds over a variety of vegetation, some of which clearly acted as swarm markers. Low light (0–1000 lux) and still/humid conditions favoured swarming.
  • 2 Swarm size ranged between less than 10 and more than one thousand midges. The modal size was 200 individuals. The smallest swarms were usually columnar in shape and the larger swarms ovoid.
  • 3 Midges behaved individually within swarms, moving in an elliptical manner characteristic of other dipterans in swarms.
  • 4 Swarms were classified as either ‘persistent’ or ‘transient’ in terms of their shape, size and stability. Wind was the most influential factor in disrupting swarms.
  • 5 Swarms were confirmed as mating sites for C.impunctatus.
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3.
2019年4月至12月期间,在深圳市福田红树林生态公园定期通过人诱、灯诱以及扫网法等方法采集吸血蠓,对公园内吸血蠓类进行生态监测,统计公园内吸血蠓类多样性、种类构成及其吸血行为.结果显示,公园内吸血蠓共有2属5种,不同月份吸血蠓组成不同.其中优势种为台湾铗蠓Forcipomyia taiwana(Shiraki),次优...  相似文献   

4.
    
We investigated whether biting midges in peridomestic environments are affected by environmental management practices and the presence of domestic animals. We used CDC light traps to collect midges in 112 residences across 24 locations along tourism routes of Maranhão, Brazil. The collection areas were characterized as follows: i) peridomestic area with domestic animals and without management (dirty); ii) peridomestic with domestic animals and management (clean); iii) peridomestic without animals and with management (clean); iv) peridomestic without animals and without management (dirty). The first two treatments had higher biting midge species richness and abundance, respectively. Generalized linear models indicated a positive correlation between the presence of domestic animals and midge abundance, with an approximate four‐fold increase in Culicoides (Diptera: Ceratopogonidae) abundance in peridomestic areas with animals. The same model showed that domestic animals have no influence on richness. Environmental management does not appear to influence species richness or abundance of biting midges.  相似文献   

5.
The ultrastructure of the strong mediodorsal setae in terrestrial stage IV larvae of Atrichopogon (Meloehelea) oedemerarum and A. (M.) meloesugans was examined using light, scanning and transmission electron microscopy. Serrated setae placed on prominent processes are distributed in pairs on all thoracic and abdominal segments. Setae are innervated by a single dendrite and their surface has no pores. The trichogen cell is not retracted from the setal lumen on completion of the hair-forming process but fills the mediodorsal seta also when the larval cuticle is fully sclerotised. Such a phenomenon was previously reported in terrestrial larvae of the genus Forcipomyia. We suggest that the mediodorsal setae described in Atrichopogon are plesiotypic mechanoreceptors for the subfamily Forcipomyiinae. They are preserved in the truly terrestrial larvae of Atrichopogon, but modified to secretory setae in the genus Forcipomyia. Both genera bearing distinct mediodorsal setae have developed functional tracheal gills, unknown in other biting midges.  相似文献   

6.
蒋晓红  常琼琼  段琛  侯晓晖 《昆虫学报》2019,62(9):1090-1101
【目的】通过发现更多的形态特征,以实现库蠓属Culicoides近似种的准确鉴定和区分。【方法】利用扫描电镜和光学显微镜观察新替库蠓Culicoides newsteadi Austen成虫的形态特征细节,包括具有重要鉴定意义的结构特征,如两性成虫的复眼、触角、触须、口器、中胸盾板、小盾板、翅、后足胫节、爪和生殖器等结构。【结果】发现新替库蠓雌成虫具有6种触角感器,包括腔锥感器、短毛形感器、长毛形感器、刺形感器、直锥形感器和弯直锥形感器;雌雄成虫的盾斑均呈卵形;雄成虫的阳基侧突端部具复杂分支。雌成虫的复眼连接处距离为1.3个小眼面;雌成虫大颚呈剑状,具14~17枚三角形齿;雄成虫后足胫节具16~19枚端梳。【结论】通过光学显微镜和扫描电镜获得的形态特征不仅为蠓科的分类和系统发育研究提供更多的信息,而且为流行病研究和疾控工作提供更多的帮助,进而为蠓科昆虫形态信息的数字化、立体化和网络化提供资料。  相似文献   

7.
    
The light trap is the tool of choice for conducting large‐scale Culicoides (Diptera: Ceratopogonidae) vector surveillance programmes. Its efficacy is in doubt, however. To assess this, hourly changes in Culicoides activity over the 24‐h diel were determined comparatively by way of light trapping and aerial sweeping, and correlated against light intensity. In the Netherlands, sweeping around cattle at pasture revealed that, in early summer, Culicoides are active throughout the diel, and that their abundance peaks during the crepuscular period and falls to a low during the brightest hours of the day. By contrast, the light trap was able to accumulate Culicoides only at night (i.e. after illuminance levels had dropped to 0 lux and midge activity had begun to decline). Although Culicoides chiopterus and species of the Culicoides obsoletus complex were similarly abundant around livestock, they differed critically in their hours of peak activity, being largely diurnal and nocturnal, respectively. This polarity helps to explain why, routinely, the C. obsoletus complex dominates light trap collections and C. chiopterus does not. Inability to accumulate Culicoides at light intensity levels above 0 lux means that, at ever‐higher latitudes, particularly beyond 45° N, the progressive northward lengthening of the twilight period will have an increasingly adverse impact upon the efficacy of the light trap as a vector surveillance tool.  相似文献   

8.
    
During the northern Europe epidemic of bluetongue (BT), Onderstepoort‐type blacklight traps were used to capture Culicoides Latreille (Diptera: Ceratopogonidae) biting midges weekly between November 2006 and December 2008 on 21 livestock farms in the Netherlands. Proven and potential vectors for the bluetongue virus (BTV) comprised almost 80% of the midges collected: the Obsoletus complex, constituting C. obsoletus (Meigen) and C. scoticus Downes & Kettle (44.2%), C. dewulfi Goetghebuer (16.4%), C. chiopterus (Meigen) (16.3%) and C. pulicaris (Linnaeus) (0.1%). Half of the 24 commonest species of Culicoides captured completed only one (univoltine) or two (bivoltine) generations annually, whereas multivoltine species (including all BTV vectors) cycled through five to six generations (exceeding the one to four generations calculated in earlier decades). Whether this increment signals a change in the phenology of northern Europe Culicoides or simply is an adaptive response that manifests during warmer episodes, thus heightening periodically the incursive potential of midge‐borne arboviruses, remains to be clarified. Culicoides duddingstoni Kettle & Lawson, C. grisescens Edwards, C. maritimus Kieffer, C. pallidicornis Kieffer and C. riethi Kieffer are new records for the biting midge fauna of the Netherlands. It is suggested that C. punctatus (Meigen) be added to the European list of vector Culicoides.  相似文献   

9.
    
Culicoides (Diptera: Ceratopogonidae) are vectors of pathogens that affect wildlife, livestock and, occasionally, humans. Culicoides imicola (Kieffer, 1913) is considered to be the main vector of the pathogens that cause bluetongue disease (BT) and African horse sickness (AHS) in southern Europe. The study of blood‐feeding patterns in Culicoides is an essential step towards understanding the epidemiology of these pathogens. Molecular tools that increase the accuracy and sensitivity of traditional methods have been developed to identify the hosts of potential insect vectors. However, to the present group's knowledge, molecular studies that identify the hosts of C. imicola in Europe are lacking. The present study genetically characterizes the barcoding region of C. imicola trapped on farms in southern Spain and identifies its vertebrate hosts in the area. The report also reviews available information on the blood‐feeding patterns of C. imicola worldwide. Culicoides imicola from Spain feed on blood of six mammals that include species known to be hosts of the BT and AHS viruses. This study provides evidence of the importance of livestock as sources of bloodmeals for C. imicola and the relevance of this species in the transmission of BT and AHS viruses in Europe.  相似文献   

10.
    
The emergence of bluetongue disease in Europe has led several countries to rapidly establish large-scale entomological surveys of its vectors, which are midges belonging to the genus Culicoides Latreille, 1809 (Diptera: Ceratopogonidae). These surveys have largely been based on the use of Onderstepoort-type blacklight traps. However, the range of attraction of the traps and the spatial dependence of the samples they provide are unknown, which somewhat complicates subsequent analyses. This paper investigates spatial interaction between Onderstepoort-type blacklight traps based on catches at a central trap placed close to two traps set in consecutive on/off modes. The spatial interaction is inferred from the drop in the number of midges collected in the central trap when nearby traps positioned at 50 m, 100 m or 200 m are turned on. The results showed a significant spatial interaction between traps separated by 50 m for female Culicoides obsoletus/Culicoides scoticus and Culicoides dewulfi. No significant interaction was found for female Culicoides of other species, for male Culicoides, or for traps spaced at ≥100 m. Based on the experimental design geometry and on simple assumptions on the distribution of Culicoides midges in the neighbourhood of the traps, the paper also presents a method to infer the range of attraction of the traps.  相似文献   

11.
Symbiotic interactions are often context-dependent. We explored how different habitats have modified the symbiosis between the grass Festuca rubra and the endophyte Epichloë festucae. We grew endophytic and endophyte-free grasses originating from subarctic meadows and open river banks in a growth chamber with a hemiparasitic plant (Rhinanthus minor) and a competitor (Achillea millefolium), representing typical plant-plant interactions in meadows. Grasses from meadows were more adapted to plant species interactions than river bank grasses, and the presence of the endophyte strengthened this difference further. Endophyte-infected meadow grasses did not suffer from the hemiparasite, but the endophyte decreased the tolerance of the river bank grasses to the hemiparasite. Endophytic river bank grasses invested more than meadow grasses in vegetative spread. These results suggest differentiation of grass-endophyte symbiota between the habitats, and underline the context dependency of species interactions as well as the role of symbionts in the habitat adaptation of plants.  相似文献   

12.
    
Options for control of northern root-knot nematode (NRKN, Meloidogyne hapla) on vegetables are very limited currently. In this study, we characterized the parasitism of Myrothecium verrucaria strain X-16, a new nematophagous fungus, on NRKN at the stages of eggs, J2, and adult females and evaluated its biocontrol efficacy in the greenhouse. Strain X-16 produced conidia that geminated and invaded in 80 h after in contact with eggs, causing the shrinkage and depression of egg shell and blastocolysis of the embryo. The strain also attacked 2nd-stage juveniles by producing developing surface networks of hyphae on the nematode body wall. Strain X-16 attacked adult females by producing dense networks of hyphae on the nematode body wall in 120 h. Strain X-16 had lethal effects (22–71% mortality) against NRKN J2 at the concentration as low as 3.1 × 107 conidia/ml and with the incubation treatment time as short as 24 h. The lethal effects linearly increased with the increase of conidial concentration, with the estimated LC50 values as low as 1.0 × 108 conidia/ml. Soil treatments with strain X-16 at 1%, 2% or 4% (wt/wt) induced significant reductions in J2 nematode counts in 100 g of dry soil, Pf/Pi ratios and root-know index in cucumber in the greenhouse evaluations. These studies are the first to demonstrate that M. verrucaria is able to parasitize NRKN and strain X-16 can be a potential biocontrol agent for management of NRKN.  相似文献   

13.
14.
    
Four isolates of the entomopathogenic fungus Metarhizium anisopliae were tested for their potential to control the biting midge Culicoides brevitarsis, the principal vector of bluetongue virus in Australia. Adult C. brevitarsis died three to eight days after walking on paper substrate treated with 0.7 g/m2 conidia of any of the isolates, indicating that M. anisopliae has potential as a surface treatment or topical application control strategy. Incorporation of the fungus into freshly excreted cattle dung at rates of between 0.25 and 1 g conidia/kg reduced the emergence of adult midges by up to 98.5% compared to untreated dung indicating that M. anisopliae has the potential to control C. brevitarsis larvae in cattle dung. Three of the isolates produced similar mortality rates on adult and immature C. brevitarsis while the fourth isolate produced lower, but still significant, mortality rates on adult and immature stages.  相似文献   

15.
Minimal concentrations of oxygen are limiting factors for limnic biocenoses. It should therefore be possible to use biocenose structure to infer minimal oxygen concentrations that have occured, provided the tolerance of the organisms concerned is known. A simple apparatus used to measure LC50 of oxygen for aquatic insect larvae with tracheal gills is described. Lethal concentrations found in some Ephemeroptera differ between species. Usually, they are strongly temperature dependent. In the species so far studied, confidence intervals are very small and suggest that such insect larvae could be used as bioindicators of minimal oxygen concentrations (even of short term ones), especially in thermically stable waters.  相似文献   

16.
The use of particles for the construction of tubes by a community of stream-dwelling midge (Chironomidae) larvae was investigated. It was shown that the particles present in the larval tubes occurred in the same proportions as those present on the surfaces of stones in the stream. Small particles were principally of detritus, medium-sized particles mainly of detritus and diatoms, and a a variety of types of particles, including filamentous algae and sand grains, occurred in the large size category. The absence of particle selection in the field was reflected in laboratory experiments. It is suggested that competition for suitable available space in which to build tubes and the quantity of building material are likely to be of more significance to the larval community in upland streams than particle size or type.  相似文献   

17.
The density of midge larvae (Chironomidae), which dominate the stone-surface fauna (81.3 ± 4.9% of the community by number) in an upland stream in northeast England is regulated by the amount of particulate material available. The amount of material depends on the deposition of suspended particles and on epilithic algal growth. Spates, characteristic of this type of stream, result in scouring and denudation of rock surfaces, preventing the build-up of epilithic material and limiting larval densities by regulating the availability of food and tube-building material. Detritus is the main type of particle in suspension throughout the year (66 ± 6%); detritus and diatoms the chief epilithic kind (65 ± 4 and 29 ± 4% respectively). The probable effects of flow amelioration, resulting from the formation of the proposed Kielder Reservoir are discussed.  相似文献   

18.
Larvae of two midge species, Chironomus pulcher and Chironomus imicola normally occur in different puddles of rain-water; C. pulcher in shaded and C. imicola in sunny ones. When the sun/shade signal is unclear, both species can coexist for most of each rainy season. Yet, in the laboratory, C. pulcher shows total competitive exclusion of C. imicola. The puzzle is resolved by experiments and observations which suggest that some naturally occurring puddles possess characteristics not present in laboratory pools. These include a spatial refuge (deep water) and separate shaded and sunny parts. Both variables are normally found only in larger puddles, so coexistence is a function of patch size. On its own, each variable is a necessary but not a sufficient condition for coexistence.  相似文献   

19.
    
Compared to non-flying nest-dwelling ectoparasites, the biology of most species of flying ectoparasites and its potential impact on avian hosts is poorly known and rarely, if ever, reported. In this study we explore for the first time the factors that may affect biting midge (Diptera: Ceratopogonidae) and black fly (Diptera: Simuliidae) abundances in the nest cavity of a bird, the hole-nesting blue tit Cyanistes caeruleus, and report their effects on adults and nestlings during reproduction. The abundance of biting midges was positively associated with nest mass, parental provisioning effort and abundance of blowflies and black flies, while negatively associated with nestling condition. Furthermore, a medication treatment to reduce blood parasitaemias in adult birds revealed that biting midges were more abundant in nests of females whose blood parasitaemias were experimentally reduced. This finding would be in accordance with these insect vectors attacking preferentially uninfected or less infected hosts to increase their own survival. The abundance of black flies in the population was lower than that of biting midges and increased in nests with later hatching dates. No significant effect of black fly abundance on adult or nestling condition was detected. Blood-sucking flying insects may impose specific, particular selection pressures on their hosts and more research is needed to better understand these host–parasite associations.  相似文献   

20.
  1. Spatial patterns of parasitism of eumenid wasps Anterhynchium flavomarginatum and Orancistrocerus drewseni by the miltogrammine fly Amobia distorta were studied in Kyoto, Japan during 1980–1984.
  2. In generations of low (<5%) and medium (5–20%) parasitism, percent parasitism per shed (the habitat of the hosts) increased as a function of host density. Conversely, in generations of high (>20%) parasitism, percent parasitism was rather constant over different host densities.
  3. The spatial distributions of adult miltogrammine flies among sheds were censused in generations of low and medium parasitism. The frequency of observations of adult miltogrammine flies was higher at sheds of higher host density (aggregative behavioral response), but on the other hand, the adult miltogrammine flies distributed in an underdispersed (or regular) manner in relation to other conspecifics.
  4. The spatially density independent relationship between host density and percent parasitism in generations of high parasitism was explained in relation to parasitoid dispersal from patches of high parasitoid density.
  相似文献   

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