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1.
黑蝇Simulium damnosum sensu lato是由多个姊妹种组成的复合体,这些种在生态学和盘尾丝虫病的传播方面各不相同。本文对奥孙河沿线的尼日利亚西南部森林区域的黑蝇S. damnosum s.l.复合体的组成以及成虫的形态学特征进行了研究。本研究所用的黑蝇S. damnosum s.l.成虫标本来源于奥孙河沿线的3个区,分别是Osun Eleja, Osun Ogbere和Osun Budepo。标本采集通过人体诱捕的方式,采集时间从2008年2月至2009年6月上午7:00到下午6:00,每两周采集1次。通过观察成虫的翅毛簇(wing tufts)和其他形态特征,对其进行分类研究。结果表明:存在同域分布的森林种和稀树草原种。在奥孙河沿线3个区内,森林种为优势种,占总捕获量的99.18%,而稀树草原种仅占0.82%;森林种和稀树草原种在多度上存在显著差异(P<0.05)。所捕获的所有稀树草原种的翅毛簇均为灰白色,而捕获的森林种的翅毛簇颜色存在显著差异(P<0.05)。为了更清楚地揭示该地区黑蝇S. damnosum s.l.的物种组成,建议进行更深入的研究。  相似文献   

2.
赤眼蜂属一新种记述(膜翅目:赤眼蜂科)   总被引:1,自引:0,他引:1  
在陕西省采集赤眼蜂中,发现一新种,现记述如下。模式标本保存于陕西省植物保护研究所生物防治研究室。稻苞虫赤眼蜂 Trichogramma parnarae Huo,新种 图1-4 雄:成虫体长0.95毫米,头宽0.29毫米。胸部褐色,中胸盾片及小盾片色稍深,腹部黑色。触角毛最长的为鞭节最宽处的1.7倍,前翅臀角缘毛为翅宽的1/9。雄性外  相似文献   

3.
为探讨小兴安岭凉水自然保护区森林生态系统中地表鞘翅目成虫群落对不同人为干扰梯度的响应,于2015年7月、8月和10月分别对轻度干扰[原始阔叶红松林(KY)和谷地云冷杉林(YL)]、中度干扰[阔叶红松择伐林(ZF)和次生白桦林(BH)]及重度干扰[落叶松人工林(RL)和红松人工林(RHS)]的6个林型进行取样调查。结果表明:(1)整个采样周期共捕获地表鞘翅目成虫879只,隶属9科44物种;其中轻度干扰生境共捕获6科29种251只(KY捕获5科21种150只,YL捕获4科20种101只),中度干扰生境捕获6科27种276只(ZF捕获3科20种144只,BH捕获6科23种132只),重度干扰生境捕获6科29种352只(RL捕获4科22种232只,RHS捕获5科17种120只)。(2)7月和8月步甲科和葬甲科占据数量优势,10月步甲科和葬甲科成虫数量明显减少而隐翅虫科数量占优势;不同林型及不同干扰梯度地表鞘翅目成虫物种总数和总个体数于7、8、10月均表现为下降趋势,且群落多样性也呈不同程度下降。(3)林型和月份对地表鞘翅目成虫群落结构具有显著影响,干扰梯度对群落结构无显著影响;6个林型之间地表鞘翅目成虫个体数量具有显著差异,但在物种组成上无显著差异;不同干扰梯度间地表鞘翅目成虫个体数、物种数无显著差异,且随干扰梯度变化没有明显的梯度性规律;相似性系数和聚类分析表明,属于同一干扰梯度的两个林型没有表现出高度的相似性。本研究表明干扰梯度不是决定各林型间地表鞘翅目成虫群落多样性存在差异的主要原因,凉水森林生态系统地表鞘翅目成虫对不同干扰梯度的响应不符合中度干扰假说,林型和时间则是影响地表鞘翅目成虫群落组成的显著因素,本实验为地表生物多样性保护和森林生态系统管理提供数据支撑。  相似文献   

4.
记述了树甲属Strongylium 5新种:棕黑树甲S.brunneum sp.nov.,凹翅树甲S.sulcielytrum sp.nov.,四斑树甲S.quadrimaculatum sp nov.,暗红树甲S.fuscum sp.nov.,缘毛树甲S.pilimarginum sp.nov..模式标本保存在河北大学博物馆.  相似文献   

5.
赵仲苓 《昆虫学报》1987,(2):212-213
本文记述盗毒蛾属(Porthasia Stephens)一新种。模式标本保存于中国科学院动物研究所。 小盗毒蛾Porthesia pulchella sp.nov.(图1) 本新种与盗毒蛾(Porthasia similis Fueszly)相似,但不同在于:头部、胸部和腹部白色混有黑棕色,肛毛簇白色;前翅白色,三角形,在中室M_3脉起点上方、翅顶角和外缘稀  相似文献   

6.
蔡荣权 《昆虫学报》1984,(2):211-214
本文发表刺蛾科一新属和两个新种。新种模式标本保存在中国科学院动物研究所。 副纹刺蛾属Paroxyplax新属 下唇须中等大小,稍向上弯伸不过额;雄蛾触角长双栉形,触角干末端1/4生有一簇长的鳞毛,乍看似变粗大,雌蛾触角丝形;胸腹部粗壮,披毛浓厚,翅基片基部有一竖起成角形的毛簇,后胸背中央和腹背基部中央具毛簇,足披浓密长毛,后足胫节有两对距;前翅前缘内半部直,外半部微拱,翅尖尖,外缘与后缘分界处不明显,呈弧形曲,脉序与斜纹刺  相似文献   

7.
利用扫描电子显微镜对3种隐翅虫成虫的下颚须和下唇须外部形态进行观察,结果表明,3种隐翅虫成虫的下颚须、下唇须末节感器变化较大。梭毒隐翅虫Paederus fuscipes Curtis下颚须末节有毛形感器、刚毛形感器、柱形感器、感器簇和板形感器,其中柱形感器、感器簇和板形感器在其它昆虫下颚须中未见报道,下唇须末节有锥形感器。闪蓝束毛隐翅虫Dianous coeruleotinctus Puthz和瘦突眼隐翅虫Stenus tenuipes Sharp下颚须、下唇须末节较光滑,仅闪蓝束毛隐翅虫下颚须末节有孔状结构。此外,文中还探讨了这些感器的功能及在分类学上的意义。  相似文献   

8.
记述采自陕西太白山巴山木竹上的带纹竹飞虱种团1新种,太白山竹飞虱Bambusiphaga taibaishana sp.nov.,编制了该种团的分种检索表,提供了成虫照片及外生殖器特征图.太白山竹飞虱,新种Bambusiphaga taibaishana sp.nov.(图1~21)新种与B.fascia Huang & Tian,1980近似,区别在于新种尾节有1个腹中突(后者无腹中突);雌性成虫前翅中部无弧形带纹(后者前翅中部有1条斜向的黑褐色弧形带纹);阳茎端部有2个突起(后者端部无突起).模式标本保存在西北农林科技大学昆虫博物馆(NWAFU).正模♂,陕西太白山,2011-08-15.海拔1 430m,秦道正、刘婷婷采.副模:13♂♂,4♀♀,采集信息同正模.词源:新种种名源自模式标本采集地(陕西太白山).  相似文献   

9.
2003年8月中旬在晋陕接壤地带进行医学昆虫调查时,在山西永济境内普救寺花园内采集到若干蠓类,经分类研究,发现1毛蠓新种,命名为普寺毛蠓Dasyhelea pusi Yu and Yan sp.nov.,本文描述了该新种两性成虫的形态特征.模式标本收藏于医学昆虫标本馆.  相似文献   

10.
对采自尼日利亚南部城市阿贝奥库塔冈比亚按蚊复合体Anopheles gambiae complex的形态特征进行了研究。依据2005年8月至2006年7月灯诱捕获的364个冈比亚按蚊复合体标本,分别对它们的触角、翅、喙、前足、中足和后足6个部位的长度进行了测量,对月平均值进行回归分析,同时利用差异系数(co-efficient of difference,CD)进行近缘分析。分析显示,各特征的长度平均值雨季大于旱季,但是回归分析表明长度变化与季节不显著相关(P>0.05)。差异系数分析结果表明,仅触角长度和翅长显示此复合体为两个不同的种群(CD>1.28),而其他特征值表明为同一种群。因此,该研究结果提示触角长度及翅长对冈比亚按蚊复合体近缘种的区分有重要参考价值。  相似文献   

11.
Microfilariae (mff) of the savanna and forest strains of Onchocerca volvulus (Leuckart) were injected intrathoracically into adult females of Simulium damnosum Theobald sensu stricto, S.sirbanum Vajime & Dunbar, S.squamosum Enderlein and S.mengense Vajime & Dunbar. Nine days post infection (pi) 27-29% of the savanna mff and 31-38% of the forest strain had developed to third-stage larvae (L3), irrespective of the fly species, size or injection dose (5, 10 or 15 mff). Savanna flies supported the development of forest O.volvulus better than forest flies, in contrast to the results after per os infections. Therefore, in these four species of the S.damnosum complex from Cameroon, the peritrophic membrane is considered to be the main factor limiting the success rate of microfilarial development following the ingestion of blood infections, while the fly's haemolymph and intracellular environment play minor roles.  相似文献   

12.
1. Resistance of some populations of the Simulium damnosum complex to temephos (100-fold at the LC50 level), with degrees of cross-resistance to chlorphoxim (14-fold) and other organophosphate insecticides, follows intensive larvicidal control of S. damnosum s.l. in West African river systems since 1975 by the WHO Onchocerciasis Control Programme. 2. Larvae of at least three sibling species of the S. damnosum complex have become organophosphate-resistant: these are the forest species S. sanctipauli Vajime & Dunbar and the savanna species S. sirbanum V. & D. and S. damnosum Theobald sensu stricto. 3. Organophosphate-resistant S. damnosum s.l. larvae show increased susceptibility to some organochlorine and pyrethroid insecticides, especially to permethrin (up to 11-fold) and OMS 3002 (up to 17-fold), as compared with organophosphate-susceptible populations. 4. This differential susceptibility is reflected by increased pyrethroid efficacy in operational use for river treatments against organophosphate-resistant field populations of S. damnosum s.l. larvae. Treatment of 100 km of the lower Bandama River in 1985 showed that permethrin at the highly selective dosage of 10 min exposure to 0.01 mg/l caused reversion towards organophosphate-susceptibility of the target population of S. sanctipauli. This effect was less pronounced when the Comoe River was treated at the lower dosage of 0.005 mg/l for 10 min. 5. To overcome temephos-resistance, it is proposed that the most rational usage of currently available larvicides would involve the following annual sequence of treatments: Bacillus thuringiensis serotype H-14 when river discharge is below 75 m3/s; chlorphoxim for about eight weekly treatment cycles after river discharge rises; permethrin (or alternative pyrethroid) for up to six treatment cycles--this should eliminate any incipient selection for chlorphoxim-resistance; resume chlorphoxim (or perhaps carbosulfan) treatments until river discharge falls below 75 m3/s permitting resumed use of B.t. H-14.  相似文献   

13.
In Ivory Coast, treatments against black flies larva are interrupted since December 1998 and these flies are back everywhere in abundance. They are now a severe source of discomfort, so it is therefore very important to propose to rural populations a personal protection method against their bites. This article is about the individual attraction of fly boys on the efficiency of lotions and creams of the different repellents (coconut, palm nut, gobi). Our works were carried out in savanna zone (Niakaramandougou) and in forest zone (Soubré) in Ivory Coast. The methodology consisted in capturing black flies on volunteers whose legs were rubbed with repellent. Coconut, palm nut and gobi formulas (lotions and creams) were tested on Simulium damnosum s.l. During each session, which lasted from 07:00 am to 12:00 and from 03:00 pm to 06:00 pm, one person without repellent was used as a control person. The results show that the least efficient repellent (gobi) ensures nonetheless a reduction of 90% of the number of bites that an individual would have received if he was not protected by the repellent. Experimentations allows to say that for a given repellent and formulas (lotion and cream), there is no significant difference between the number of Simulium damnosum s. l. bites received by fly boys.  相似文献   

14.
Abstract .During the decade from 1984 to 1993, nine species of the Simulium damnosum complex of blackflies (Diptera: Simuliidae) were identified from the area covered by the Onchocerciasis Control Programme. These were S. damnosum s.s., S. dieguerense, S. konkourense, S. leonense, S. sanctipauli, S. sirbanum, S. soubrense, S. squamosum, and S. yahense. Some of these species were found to consist of two chromosomal variant populations. These were S. konkourense‘Konkouré' and ‘Menankaya' forms, S. sanctipauli sensu stricto and‘Djodji' form, S. soubrense‘Chute Milo' and ‘Beffa' forms. The distribution of these twelve cytological taxa was assessed in relation to the two main vegetation zones of West Africa (forest and savanna), topography, river size and other factors. The range of each species was influenced by seasonal climatic changes in wind movement and river water level. The most widely distributed species were S. sirbanum and S. damnosum s.s., associated with savanna areas, recorded from all river basins. Simulium dieguerense was restricted mainly to Western Mali on the Rivers Bafing and Bakoye in the Senegal River basin. Simulium squamosum was identified from rivers draining mountainous areas in both the forest and savanna zones. Simulium yahense was found in small permanent rivers along a wide forested band parallel to the coast and was absent from the plains of Togo and Benin. Members of the S. sanctipauli subcomplex had restricted distributions except for S. sanctipauli s.s., which was widespread in large rivers of the forest zone from Sierra Leone to the Volta Lake in Ghana. Simulium soubrense‘Beffa' form occurred in Togo and Benin, S. soubrense‘Chutes Milo' form in Guinea, both ‘Konkouré' and ‘Menankaya' forms of S. konkourense occurred predominantly in Guinea and S. leonense in Sierra Leone. The relevance of the distribution maps and the importance of the data bank to vector control larvicidal operations are discussed.  相似文献   

15.
The drosophilids of a gallery forest in the Brazilian savanna were investigated to identify the temporal and vertical patterns in the community structure of these insects. Twelve monthly collections were performed (December 2007 to November 2008) in three vertical strata of the forest (0, 4 and 8 m heights) using 30 traps baited with fermented banana. The drosophilid assemblage was composed of 61 species (7,623 individuals), experienced temporal fluctuations and was vertically stratified. Both the diversity and abundance of the flies were very low during the dry season, a time when the assemblages were dominated by the exotic species Drosophila simulans, whereas the community showed an increased abundance and richness of neotropical species and showed vertical stratification in the wet season. Rare species were found primarily at the ground level (flies usually associated with neotropical forests) or in the canopy, which harbors species currently associated with open vegetation, little-studied neotropical species and most likely several new species. These changes, which reflect drosophilid adaptations to different environments, involve a shifting of the ecological niches occupied by the flies in the forest over time. This process of change is termed niche construction. Thus, we conclude that this complex and dynamic community structure, which is related to the interaction of several environmental factors associated with different forest environments, contributes to the high diversity of gallery forests in the Brazilian savanna.  相似文献   

16.
Questions: Has fire suppression relaxed barriers to the exchange of species between savanna and forest? Do all species or a subset of species participate in this exchange? Would current vegetation structure persist if fire suppression were to cease? Location: A gallery forest edge in the Cerrado region of central Brazil that burned only once in the past 35 years. Methods: Density of tree seedlings, saplings and adults, leaf area index (LAI), tree basal area and diameter were surveyed in 12, 10 m × 70 m transects centred on and perpendicular to the forest–savanna boundary. Community composition was assessed using non‐metric multi‐dimensional scaling (NMDS). Results: Basal area and LAI declined substantially from forest to savanna, with an associated shift in species composition. Savanna tree species were nearly absent in the forest, but accounted for the majority of stems in the savanna. In contrast, forest species comprised 14% of adults and more than one‐third of juveniles in the savanna. Despite the high diversity of trees (85 species) in the forest, five species play a particularly large role in this initial phase of forest expansion. Reintroduction of fire, however, would result in widespread topkill of juveniles and the majority of adult forest trees, thereby interrupting the succession towards forest. Conclusions: After 35 years during which the site burned only once, the savanna still remains dominated by savanna species. Nevertheless, the dominance of forest juveniles in border and savanna tree communities suggests that with a continued policy of fire suppression, the forest will continue to expand.  相似文献   

17.
The vertical distribution of blood‐feeding flies in two temperate forests in the southeastern U.S.A. was determined by placing 15 Centers for Disease Control and Prevention miniature light traps (12 CO2‐baited, three unbaited controls), without lights, at three heights (1.5 m, 5.0 m, 10.0 m). More than 6550 haematophagous flies, representing 49 species in four families, were collected. Eighteen species were taken almost exclusively (90–100%) at 1.5 m or 10.0 m, and the mean number of flies per trap differed significantly with height for another six species. Five species exhibited shifts in vertical distribution between the two forests, indicating that forest structure could influence the height of host searching. Most (52.5%) mammalophilic flies were collected at 1.5 m, whereas most (56.4%) ornithophilic flies were taken at 10.0 m, suggesting that host associations influence vertical distributions. The significant differences in the composition of haematophagous fly populations among forest strata emphasize the importance of trap placement in vector surveillance and of understanding the ecological relationships of blood‐feeding flies.  相似文献   

18.
Aim To analyse the effects of forest fragmentation on ant communities in an Amazonian landscape that has been fragmented for over a century. Location The region surrounding the village of Alter do Chão in the Brazilian Amazonian state of Pará (2°30′ S, 54°57′ W). Methods Collection of ants and measurements of tree density were performed along transects established in eight sites in continuous forest and in 24 forest fragments surrounded by savanna vegetation. Data on size, perimeter, and degree of isolation (distance to continuous forest and distance to nearest area of forest > 5 ha) of each fragment were obtained from a georeferenced Landsat image of the study area. Results There were significant differences in species richness and composition between fragments and continuous forest, and these differences were not related to intersite variation in vegetation structure (tree density). Fragments supported fewer ant species per plot, and these species tended to represent a nested subset of those found in continuous forests. Fragments had significantly fewer rare species and fewer ant genera. However, fragments and continuous forest had similar numbers of species that also occur in the savanna matrix (i.e. that are not forest specialists). Multiple linear regression analyses indicated that species richness and composition in the fragments are significantly affected by fragment area, but not by fragment shape and degree of isolation. More species were found in larger fragments. Main conclusions Forest fragmentation influences the organization of ant communities in Amazonian savanna/forest landscapes. Forest fragments harboured, on average, 85% of the species found in continuous forest. That these fragments, despite their long history of isolation, support a relatively large complement of the species found in continuous forest is surprising, especially given that in some recently fragmented landscapes the proportion of species surviving in the fragments is lower. Differences in inter‐fragment distance and type of matrix between Alter do Chão and these other landscapes may be involved. The fact that fragments at Alter do Chão are surrounded by a natural (rather than an anthropogenic) habitat, and that most of them are less than 300 m from another forest area, may have helped to ameliorate the adverse effects of forest fragmentation.  相似文献   

19.
Vegetation mosaics of grassland/savanna and forest can be found in tropical and subtropical regions of the world, as in southern Brazil, where climate conditions are suitable for forest. Changes in intensity or frequency of disturbances could enable woody species encroachment in grassland communities; however, the processes are related to site conditions and life history of pioneer species. In this paper, we study transition patterns of forest to grassland in the absence of grazing, but under different site conditions related to aspect (landscape position) and time since the last burn. Data are based on shrub and tree species composition and soil variables at forest–grassland boundaries. We found 119 woody species of 42 families along transects of 27 m into the forest and 31.5 m into the grassland. Gradients from forest to grassland were analysed as compositional trajectories in ordination space and differences in the spatial patterns depicted between distinct site aspects. The time since the last fire did not influence these patterns. Inside the forest, tree species diversity was significantly higher close to the edge, independent of the density of individuals. Two main mechanisms may promote forest expansion into the grassland. First, a gradual tree encroachment near the edge and, second, a mechanism linked to the recruitment of isolated pioneer trees within the grassland matrix, most frequently near rocky outcrops, where a decrease in grass biomass leads to low-intensity fires. Despite vegetation patterns at boundaries differing according to aspect, the most important explanatory factor was the distance from the forest border, not just by itself, but with all correlated parameters that are changing along the gradient.  相似文献   

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