摘要: 白背飞虱Sogatella furcifera是重要的水稻害虫，通过取食和传播病毒病对水稻造成严重的危害。因此，开发和利用病原微生物防治白背飞虱具有重要现实意义。本研究从白背飞虱体内分离出1株细菌，命名为HUNAN-1。通过形态学及分子生物学手段对该菌株进行了鉴定，并采用喷雾法测定了该菌株菌液对白背飞虱的室内杀虫活性，同时评估了培养时间和培养基pH值对发酵上清液杀虫活性的影响。结果表明，菌株HUNAN-1为不动杆菌属，单不动杆菌Acinetobacter soli。菌株HUNAN-1对白背飞虱表现出显著的杀虫活性。当浓度为10～9 CFU/mL时，菌液对白背飞虱的校正死亡率达到100%，其LT₅₀为31.523 h,LC₅₀值为2.71×10～6 CFU/mL。菌株HUNAN-1的发酵上清液同样对白背飞虱有较高的致死率，处理72 h后，白背飞虱的死亡率超过80%，并且不同发酵时间和培养基pH值对发酵上清液的杀虫活性无显著影响。综上，菌株HUNAN-1对白背飞虱具有良好的防治潜力，应用前景广阔。

摘要: 本研究从田间采集的菜青虫Pieris rapae L.中肠分离获得可培养的、菌落形态有显著差异的细菌菌落53个。将这些菌落接种至新鲜的LB培养基中培养3 d后，用于浸泡人工饲料并饲喂草地贪夜蛾Spodoptera frugiperda Smith2龄幼虫，其中9株对草地贪夜蛾幼虫展现出一定的胃毒活性。针对杀虫活性最高的一株——克雷伯氏菌Klebsiella pneumoniae A7株进行了进一步的检测，发现其在培养后1 d、2 d和3 d后对草地贪夜蛾2龄幼虫处理96 h的致死率分别为26.39%±11.98%、8.33%±3.73%和56.25%±10.26%，均显著高于对照组试虫的死亡率（P<0.05）。全基因组测序的结果表明，A7基因组总长度为8.55 Mb,GC含量51.78%，可编码8 148个基因，另含有3个质粒，大小分别为190 495 bp、89 806 bp和77 436 bp。进一步的分析结果表明，A7株编码的748种基因中，有214种毒力基因的检出率在70%以上，306种毒力基因的检出率低于50%，其余228种毒力基因的检出率在50%～70%之间；进一步利用VFDB数据库对214种毒力基因检出率在70%以上的基因进行注释，分别注释到13类毒力相关基因。可以观察到A7在16S rDNA系统发育树上与其他克雷伯氏菌属Klebsiella sp.的亲缘关系。本研究报道了一种对草地贪夜蛾幼虫具有杀虫活性的克雷伯氏菌，结合基因组学的分析，为草地贪夜蛾的生物防治提供了依据。

摘要: 蠋蝽Arma chinensis(Fallou)作为一种重要的捕食性天敌，广泛用于多种害虫的防控，但传统的释放方式成本高，时效性差等问题影响了天敌昆虫的使用。如何增值保护天敌，提高生物防治的技术成为关键。储蓄植物具有预防性引入天敌的特点、有助于帮助天敌种群的维持，实现持续控害。本文评价了花生、大豆、豌豆、蚕豆、菜豆5种豆科植物作为蠋蝽的储蓄植物的室内适合度。结果表明：蠋蝽在不同的植株上的偏好率及产卵量存在显著差异（P<0.05），蠋蝽对花生与大豆植株的偏好率均达到20%以上，显著高于其它植株（P<0.05）；在大豆植株上平均产卵量最高达到15.2粒，占所有植株上总产卵量的23.71%，其次是花生植株14粒，占总产卵量的21.84%，两者无明显差异（P > 0.05）；大豆上的孵化率可达到93.78%，与蚕豆、花生相比无显著差异（P >0.05）；而大豆的繁殖系数最高，与其它植株有显著差异（P<0.05）。在无猎物时，蠋蝽在花生和大豆叶片饲养下存活时间最长、存活率最高，可少量发育至成虫。综上所述，初步认为大豆与花生比较适合用来构建蠋蝽储蓄植物系统，而田间构建蠋蝽储蓄植物系统效果还需进一步研究。

摘要: Grasslands are among the world's most threatened ecosystems, and steppe birds face increasing risks from human activities. This study investigates how human impacts affect the distribution and community structure of breeding steppe birds in Inner Mongolia, a biodiversity hotspot in Asia. We conducted standardized point-count surveys across a gradient from intact grasslands to urbanized areas, integrating species occurrence data, functional traits and the Human Footprint Index(HFI). Using Generalized Linear Models(GLMs) and Conditional Random Fields(CRFs), we assessed trait-environment interactions and shifts in species associations. Our results indicate that the HFI significantly affects bird communities. Habitat specialists, such as Mongolian Lark(Melanocorypha mongolica), showed negative responses, whereas generalists like Eurasian Tree Sparrow(Passer montanus) thrived in disturbed areas. Trait-based analysis showed that species with larger body mass and specialized diets were negatively associated with HFI, whereas those linked to human-modified habitats exhibiting strong positive associations. In areas with high human footprint, co-occurrence networks grew more polarized: specialists faced intensified competition, while species with positive HFI responses formed stronger positive associations. CRF models indicated that human activities restructure species interactions, favoring generalists and simplifying community dynamics. These findings highlight the dual role of human impact in supporting some species while threatening specialists, potentially driving biotic homogenization. Our study emphasizes the need for conservation strategies that protect vulnerable species and manage those that thrive in human-altered environments. By linking traits and interactions to human impacts, this study provides a framework for identifying at-risk species and guiding conservation in the Anthropocene.

摘要: Poyang Lake（PYL） and the Yellow River Delta（YRD） are two critical wintering areas for the Siberian Crane（Leucogeranus leucogeranus） along the East Asian–Australasian Flyway in China. Based on nearly two decades of remote sensing and environmental data, this study used the Max Ent model to assess wintering habitat suitability in Poyang Lake（PYL） and the Yellow River Delta（YRD）. Landscape pattern and ecological network（EN） analyses were integrated to examine habitat changes and their impact on Siberian Crane distribution. In PYL, land use/land cover（LULC） change was driven primarily by water level fluctuations, leading to transitions among natural habitat types. In contrast, LULC change in YRD was dominated by anthropogenic activities, with widespread conversion of natural habitats into artificial habitats. In both regions, Siberian Cranes favored wetlands that are food-rich, flat, and minimally disturbed. In PYL, ecological sources were mainly found in sub-lakes of nature reserves and nearby moist areas, averaging 87.42 km². In the YRD, sources were distributed across tidal flats, paddy land, and grasslands, with a larger mean area of 198.37 km². Mann–Kendall tests showed significant trends in PYL, including increased patch density and decreased EN cumulative resilience. The maximum habitat suitability in the YRD significantly declined. Comparative analysis revealed that PYL had significantly higher habitat suitability and EN cumulative resilience, whereas the YRD had larger but more fragmented habitats. By introducing key stepping-stone nodes to optimize the ENs, the connectivity and resilience of PYL's EN were notably enhanced. Although improvements in the YRD were less marked, the optimization scheme still improved the security of the crane migration network. Based on the findings, it is recommended to implement refined water level management in PYL to maintain the stability of sub-lakes and adjacent wetlands, and to strengthen the protection of natural wetlands in the YRD by limiting the expansion of artificial land use, in order to mitigate habitat fragmentation.

摘要: Understanding the fundamental drivers of large-scale species co-occurrence is a critical issue in ecology and conservation research. Here, we assessed foraging guilds, habitat type and disturbances as drivers of bird species co-occurrence in Ghana's Central Region over six months. Birds were sampled in 120 points across six different habitat types(farmland, forest reserve, urban area, coastal savannah, wetland, and mangrove), using the pointcentred count technique. In total, 4060 individuals belonging to 216 species were recorded across all six habitat types. We found that co-occurring species were more similar in their foraging behaviour and habitat association. About 60% of the birds were found to co-occur randomly, 15% co-occurred negatively, and 25% co-occurred positively. Carnivores like the Black Heron(Egretta ardesiaca) and Spur-winged Lapwing(Vanellus spinosus) randomly co-occurred with other guild groups and were dominant in the mangroves and wetlands. Frugivores from forest reserves had only a 25% chance of randomly co-occurring with other birds and about a 60% chance of positively co-occurring with other birds. Our findings suggest that foraging guilds and habitat type are major factors driving bird co-occurrence and community assemblages in this West African suburban region.

摘要: Food abundance and availability constitute fundamental determinants of foraging habitat quality for waterbirds, with high-quality foraging habitats playing a crucial role in supporting the survival and annual life cycle of wintering populations. The ongoing degradation and loss of optimal habitats have forced wintering waterbirds to increasingly rely on alternative foraging sites and modify their behavioral adaptation strategies to cope with food scarcity. The Siberian Crane(Leucogeranus leucogeranus), a large-bodied endangered waterbird species characterized by specialized dietary preferences, demonstrates particular sensitivity to environmental alterations. Faced with diminishing suitable habitats and declining natural food resources, this species has progressively adapted to utilizing artificial habitats, including agricultural landscapes such as paddy fields and lotus ponds, as supplementary wintering foraging grounds to fulfill their energetic requirements. This study examines the hypothesis that Siberian Cranes adapt their foraging behavior through plastic behavioral strategies in artificial habitats under conditions of limited food availability, thereby enhancing population fitness. A comparative analysis of crane foraging behaviors was conducted between mudflats and lotus ponds throughout the 2023–2024 wintering period. This investigation focused on three critical environmental factors: food abundance, food burial depth, and sediment penetrability, examining their influence on foraging patterns across these distinct habitats. The results revealed significant inter-habitat differences: foraging success rates were substantially higher(p < 0.05) and food handling times markedly longer in lotus ponds compared to mudflats, whereas foraging effort and attempt frequency were significantly elevated in mudflat habitats. The superior food availability in lotus ponds facilitated enhanced foraging success rates, enabling cranes to accumulate essential energy reserves for winter survival. However, the deeper burial depth of lotus roots in these habitats required more intensive processing behaviors, including prolonged digging, breaking, and swallowing activities, which consequently increased handling time by approximately 40% and reduced foraging attempts by 25–30% compared to mudflat conditions. These behavioral trade-offs suggest that while lotus ponds provide adequate food resources, their structural characteristics may impose physiological constraints that limit their effectiveness as optimal foraging grounds for Siberian Cranes. These findings offer valuable insights into the behavioral plasticity of wintering Siberian Cranes response to spatial variations in food resource distribution, while contributing to our understanding of the ecological value of lotus roots as alternative winter food sources in artificial wetland ecosystems.

摘要: Bergmann's rule predicts that the larger of two homeotherm species differing only in size would occur at higher latitudes,or in cooler climates than the smaller,because of relative thermoregulatory costs in relation to body mass/surface area ratio.Individual tracking data from two congeneric long-distance migratory northern nesting swan species,Tundra Cygnus columbianus(TS,n=99) and Whooper Swans C.cygnus(WS,61-71% larger mass than TS,n=47) were used to determine their summering and wintering latitudes along similar migration routes and common staging areas along the same flyway.We hypothesised that throughout Arctic and Boreal breeding areas(10℃ in July),summer ambient temperatures mainly exceed the Lower Critical Temperatures(LCT,c.1℃) for both swan species,so the duration of the snow-free summer period will favour smaller body size at highest latitudes,since this constrains the time available to lay,incubate eggs and raise cygnets to fledging.We hypothesised that in contrast,in winter,both species occur in temperatures near to freezing(-3℃ in January),below their respective LCT,so differential thermoregulation demands would constrain TS to winter south of WS.Tracking of individuals showed for the first time that while smaller TS summered significantly north of WS,WS wintered significantly north of TS,with limited overlap in both seasons.We conclude that differences in relative summer distribution of these two closely related migratory herbivores are not to do with latitude per se but are constrained by the time both species require to raise their young to fledging during the short northern summer,when thermoregulation costs are unlikely limiting.In winter,both swan species occur within a climate envelop at or below their respective LCT and smaller TS occurred consistently south of the range of the tracked WS,as predicted by Bergmann's rule.

摘要: Ecological barriers present significant challenges to bird migration by limiting the availability of stopover sites and shelters. The Qinghai-Tibet Plateau, a major migratory barrier located in higher latitude Central Asia, exerts a substantial influence on avian migration patterns. Species traversing such ecological barriers may adopt multiple optimal routes, which can contribute to the formation of migratory divides. From 2018 to 2021, the migration routes of 13 adult Common Cuckoos(Cuculus canorus) breeding in the north of the Qinghai-Tibet Plateau were tracked using satellite transmitters. We found Common Cuckoos have two primary migration routes: western and eastern, respectively following western and eastern edges of the Qinghai-Tibet plateau. The eastern and western routes are likely the optimal routes for the Central Asian Common Cuckoos population to navigate the Qinghai-Tibet Plateau. Furthermore, two individuals exhibited intermediate migration routes, suggesting attempted traverses of the Qinghai-Tibet Plateau, although neither completed the migration. These intermediate routes may indicate migratory behavior influenced by hybridization between eastern and western populations or migratory flexibility. Common Cuckoos exhibit significantly faster migration speed, flight speed, and shorter stopover durations during spring compared to autumn. The observed seasonal differences in migration behavior support birds following time-minimization strategies during spring migration. These results revealed the diverse migration routes of Common Cuckoos shaped by the Qinghai-Tibet Plateau and seasonal variation in migration patterns.

摘要: Understanding migration patterns and spatial connectivity is crucial for conserving long-distance migratory birds. While satellite telemetry has advanced the study of large gulls, Pallas' s Gull(Ichthyaetus ichthyaetus) remains relatively understudied, with limited data on its migration routes and habitat use, particularly in Central Asia. This study integrates 684 ring recoveries(1968–2024) and GPS tracking data to analyze the migration ecology of individuals breeding at Alakol Lake, Kazakhstan. Ring recoveries confirm migratory connectivity across Kazakhstan, Russia, Uzbekistan, Turkmenistan, Iran, and Pakistan, with wintering records as far as India, Kuwait, Bangladesh, and Ethiopia. GPS tracking of a single individual(June 2020–August 2021) revealed a migration route from Alakol Lake to the Arabian Sea, with key stopovers at Zaisan Lake, Balkhash Lake, the Aral Sea, Aydar Lake, and the Amu Darya River. Notably, a post-breeding northward dispersal to Zaisan Lake and southern Russia was identified before the southward migration commenced. These findings highlight the significance of Kazakhstan's lakes as breeding and migratory hubs and the need to protect critical stopover sites in Central Asia. Given increasing anthropogenic pressures on wetland habitats, this research provides essential baseline data for conservation planning and enhances the broader understanding of gull migration ecology.