川东地区白背飞虱迁入种群虫源地分布与降落机制

【目的】本研究旨在确定四川达州白背飞虱Sogatella furcifera(Horváth)迁入虫源地及其降落机制,以期为川东地区白背飞虱预警和有效防控提供依据。【方法】运用大气质点轨迹分析平台HYSPLIT4.8对1991-2013年达州灯下白背飞虱主要迁入高峰日进行轨迹模拟,并运用气象图形处理软件Grads对主要迁入高峰日进行气象背景分析。【结果】达州白背飞虱主要在6-7月迁入,7月份是迁入高峰期。6月虫源主要来自广西西北、中部地区;7月虫源主要来自贵州中西部、北部,广西西北部和云南东北部也可提供部分虫源。【结论】四川达州白背飞虱迁入虫源主要来自贵州大部,部分来自云南东北部和广西西北部。由于气候条件和地形胁迫引起的降水、垂直气流和风向切变是白背飞虱大规模集中降落的主要原因。     

Development of fine and coarse roots of Thuja occidentalis `Brabant' in non-irrigated and drip irrigated field plots

Aboveground dry mass, total root dry mass and root length density of the fine roots of Thuja occidentalis `Brabant' were determined under non- and drip-irrigated field conditions. Two-dimensional diffusion parameters for dynamic root growth were estimated based on dry mass production of the fine roots and the concept of the convective-diffusion model of cylindrical root growth and proliferation. Drip irrigation increased above-ground dry mass and the shoot:root ratio compared with no irrigation. Dry mass of the coarse roots increased as well due to drip irrigation. No effect on total or fine root dry mass was found. Drip irrigation increased root length densities in the top 0.1 m but not significantly. However, drip irrigation decreased root proliferation in depth by 27%, whereas proliferation in the horizontal direction was not altered. Measured root length densities were overestimated by 6–21% by the model (0.68 < R ² < 0.92).     

An Examination of Scale-Dependent Resource Use by Eastern Hognose Snakes in Southcentral New Hampshire

ABSTRACT The decline of many snake populations is attributable to habitat loss, and knowledge of habitat use is critical to their conservation. Resource characteristics (e.g., relative availability of different habitat types, soils, and slopes) within a landscape are scale-dependent and may not be equal across multiple spatial scales. Thus, it is important to identify the relevant spatial scales at which resource selection occurs. We conducted a radiotelemetry study of eastern hognose snake (Heterodon platirhinos) home range size and resource use at different hierarchical spatial scales. We present the results for 8 snakes radiotracked during a 2-year study at New Boston Air Force Station (NBAFS) in southern New Hampshire, USA, where the species is listed by the state as endangered. Mean home range size (minimum convex polygon) at NBAFS (51.7 ± 14.7 ha) was similar to that reported in other parts of the species’ range. Radiotracked snakes exhibited different patterns of resource use at different spatial scales. At the landscape scale (selection of locations within the landscape), snakes overutilized old-field and forest edge habitats and underutilized forested habitats and wetlands relative to availability. At this scale, snakes also overutilized areas containing sandy loam soils and areas with lower slope (mean slope = 5.2% at snake locations vs. 6.7% at random locations). We failed to detect some of these patterns of resource use at the home range scale (i.e., within the home range). Our ability to detect resource selection by the snakes only at the landscape scale is likely the result of greater heterogeneity in macrohabitat features at the broader landscape scale. From a management perspective, future studies of habitat selection for rare species should include measurement of available habitat at spatial scales larger than the home range. We suggest that the maintenance of open early successional habitats as a component of forested landscapes will be critical for the persistence of eastern hognose snake populations in the northeastern United States.     

Short- and long-term diets of the threatened longhorned pygmy devil ray,Mobula eregoodoo determined using stable isotopes

Most mobulids are listed as near threatened to endangered. Nonetheless, effective conservation measures are hindered by knowledge gaps in their ecology and behaviour. In particular, few studies have assessed diets and trophic ecologies that could inform methods to avoid fishing mortality. Here, a shortfall in data for the longhorned pygmy devil ray, Mobula eregoodoo was addressed by describing temporal variability in dietary preferences using stable isotope analysis. During summer and autumn in 2017, five bather-protection gillnets were deployed off eastern Australia (29° S, 153.5° E). From the catches of these gillnets, 35 adult M. eregoodoo had liver, muscle and stomach contents sampled to determine δ¹³C and δ¹⁵N profiles. Analyses revealed that surface zooplankton and zooplanktivorous teleosts were important dietary components across short- and long-term temporal scales. Large quantities of undigested sandy sprat, Hyperlophus vittatus, in the stomachs of some specimens unequivocally confirm feeding on teleosts. A narrow isotopic niche and minimal isotopic overlap with reef manta rays, Mobula alfredi from the same geographic region in eastern Australia implies M. eregoodoo has unique and highly specialised resource use relative to other mobulids in the area. The species is clearly vulnerable to capture during inshore migrations, presumably where they feed on shallow-water shoaling teleosts. Female M. eregoodoo likely have a low annual reproductive output, so population recoveries from fishing-induced declines are likely to be slow. Measures to reduce the by catch of M. eregoodoo in local bather-protection gillnets, and artisanal fisheries more broadly, should be given priority.     

甘肃东乡几种早中新世哺乳动物化石

本文记述了在甘肃东乡椒子沟发现的几种早中新世哺乳动物化石:Gomphotherium sp、Dzungariotheriura orgosense、Rhinocerotidae gen. indet.和Paraentelodon macrognathus sp. nov.,着重讨论了全北区猪齿兽类的系统关系。根据化石的性质判断,东乡椒子沟化石点的地质时代应与欧洲Burdigalian早期,亦即MN_3相当或稍早。笔者将原定为上新世临夏组的第一、二岩性段划出,命名为椒子沟组,其时代为早中新世。     

甘肃鼢鼠哈氏腺组织结构及其抗氧化能力

为探讨甘肃鼢鼠(Myospalax cansus)哈氏腺的结构特征及其在低氧应激下的抗氧化能力,用组织解剖学方法观察甘肃鼢鼠哈氏腺整体及其显微结构,分光光度计测定哈氏腺低氧应激前、后超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽还原酶(GR)活性及丙二醛(MDA)含量。结果显示,甘肃鼢鼠哈氏腺肥大,包围在眼周,位于颧骨下的颞窝,为管泡状腺体,由柱状细胞构成,依胞质中分泌物含量分为厚细胞和薄细胞。常氧下,甘肃鼢鼠超氧化物歧化酶和过氧化氢酶活性显著高于SD大鼠(Rattus norvegicus),但谷胱甘肽还原酶活性显著低于SD大鼠;在低氧应激4 h后,甘肃鼢鼠超氧化物歧化酶和过氧化氢酶活性迅速升高,显著高于SD大鼠,谷胱甘肽还原酶的活性在低氧2、4和6 h无显著性变化,但均显著低于SD大鼠;在低氧8 h后,甘肃鼢鼠谷胱甘肽还原酶的活性较低氧2~6 h显著升高。甘肃鼢鼠丙二醛含量在常氧和低氧应激中均显著低于SD大鼠。结果说明,甘肃鼢鼠在低氧应激后,哈氏腺通过提高抗氧化酶超氧化物歧化酶和过氧化氢酶活性,清除低氧诱导产生的多余自由基,谷胱甘肽还原酶在抗氧化中不起主要作用。地下鼠甘肃鼢鼠抗氧化模式与地面鼠明显不同。     

Use of pheromone mimic to cause the disintegration and collapse of colonies of tent caterpillars (Malacosoma spp.)

The disruption of the trail-based communication system of eastern tent caterpillars (ETC) ( Malacosoma americanum ) and forest tent caterpillars (FTC) ( M. disstria ) by spraying host trees with a trail pheromone mimic caused the disintegration and collapse of young colonies. A 1-ppm formulation of 5β-cholestan-3-one or a control formulation was sprayed on trees either before or after eclosion of the caterpillars in the spring. For pre-eclosion trials, an average of 92% of the FTC colonies on control trees, but only 17% of colonies on treated trees consisted of viable, cohesive aggregates when survival was assessed 5–23 days post-spray. The remaining colonies had either completely disappeared or were reduced to small, disintegrated fragments. For the ETC, 100% of colonies on control trees and an average of 12% of colonies on treated trees consisted of cohesive aggregates inhabiting tents when survival was assessed 3–41 days post-spray. The remaining colonies were completely destroyed, reduced to scattered individuals, or to small, disintegrated, shelter-less fragments. For post-eclosion trials with the FTC in which colonies were sprayed during their first or second larval stadium, an average of 63% of individuals in control groups but only 7% in treatment groups were still on the sprayed trees 5–18 days post-spray. For the ETC, colonies were largely unaffected when trees were not sprayed until after the caterpillars had eclosed and established tents. For all trials, the loss of individuals on treated trees was largely attributable to the inability of dispersed and isolated first or second instar caterpillars to maintain secure purchase, causing them to fall from trees and perish. To our knowledge, this is the first study to investigate the potential of manipulating populations of pest species by interfering with a trail-based, chemical communication system.     

甘肃黄芪属药用植物资源

目的:调查甘肃省黄芪属药用植物资源,为该属植物资源的开发利用提供科学依据.方法:深入甘肃各地进行实地调查、采集标本和分类鉴定,并查阅和核对主要标本馆的腊叶标本.结果:初步研究,甘肃省有13种1亚种药用黄芪属植物,记述了它们在省内的分布、生境和药用价值,并编制了检索表.结论:甘肃黄芪属植物资源丰富,有待进一步研究,开发利用.     

甘肃省蚜虫类物种多样性研究

在已有标本采集记录和资料的基础上,从分类阶元、寄主植物、寄生部位、动物地理区系的角度探讨了甘肃省蚜虫类的物种多样性。结果表明甘肃省蚜虫种类丰富,已知9科90属220种;分布在华北区、蒙新区、青藏区、华中区和西南区,其中华北区、蒙新区和青藏区的种类最为丰富,因此甘肃省蚜虫区系以古北界成分为主;寄主植物种类繁多,已知有46科111属;寄生部位多样化,以叶片和茎为主要为害部位。另外就甘肃省所处地理位置的特殊性,初步讨论了在不同地理区划交界处物种生物多样性所受的影响。