The Life Cycle of Lestes viridis (Odonata: Lestidae) in Two Seasonal Streams of the Sierra Morena Mountains (Southern Spain)

The life cycle of the zygopteran odonate Lestes viridis in two seasonal streams in the Sierra Morena Mountains is inferred from size-frequency analyses of handnet samples of larvae and records of presence and reproductive activity of adults during three consecutive years. The egg stage (duration 5–6 months) overwinters, larval development is brief (6–8 weeks) and adults undergo a protracted, prereproductive, summer diapause (up to 3 months) before mating and ovipositing in late September, about one week after the first appreciable fall of rain, but before surface water reappears in the streams after having been absent for about four months during the hot, dry summer. Comparison between this life cycle and those of more northerly populations reveals a latitude-correlated cline in phenology resembling that found in some other northern hemisphere odonates that, like L. viridis, maintain an obligatorily univoltine life cycle at different latitudes.     

红裸须摇蚊幼虫肠道可培养细菌多样性及耐受重金属功能初步研究

红裸须摇蚊Propsilocerus akamusi为华北地区常见耐污种,广泛分布于各种水体中。本研究采用传统培养法对4龄红裸须摇蚊幼虫肠道内细菌种类进行分离,利用16S rRNA基因序列分析比对,结合菌落形态、系统进化分析等方法进一步鉴定菌株种类,同时探究可培养菌株对重金属（铜、镍）的耐受情况。结果表明,红裸须摇蚊幼虫在重金属铜暴露下的24 h-LC50、48 h-LC50、72 h-LC50、96 h-LC50分别为6304.86、403.59、29.33以及14.43 mmol/L,在重金属镍暴露下的24 h-LC50、48 h-LC50、72 h-LC50、96 h-LC50分别为339.52、182.18、102.59以及60.94 mmol/L。利用LB、NA、BHI、MC 4种培养基,从幼虫肠道分离纯化到16种不同遗传型细菌,分属2门 9科16属,其中优势菌门为变形菌门Proteobacteria。另外,丛毛单胞菌科Comamonadaceae丛毛单胞菌属Comamonas丛毛单胞菌Comamonas sp.对重金属铜和镍有良好耐受性。通过研究红裸须摇蚊幼虫肠道可培养细菌群落组成以及重金属胁迫下摇蚊幼虫肠道细菌群落生长情况,可为水生昆虫肠道菌群资源库的开发提供了一定的思路,也可为筛选出具备重金属代谢功能的细菌资源奠定基础。     

红裸须摇蚊幼虫生物标志物系统对苯酚的响应

以红裸须摇蚊4龄幼虫为对象,测定了苯酚对摇蚊幼虫急性毒性、体质量、化蛹率及体内保护酶和解毒酶活性的影响.结果表明:苯酚对摇蚊4龄幼虫6、24、48、72和96 h半致死浓度LC50分别为222.52、134.86、67.74、47.39和35.76 mg.L-1;亚致死剂量苯酚(0.4、4和40 mg.L-1)处理降低摇蚊4龄幼虫干湿质量和化蛹率;摇蚊4龄幼虫暴露于苯酚液72 h,过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、谷胱甘肽S转-移酶(GST)和羧酸酯酶(CarE)均对苯酚暴露做出响应,且随着浓度增加和暴露时间的延长呈现一定的剂量-时间效应,而摇蚊体内酸性磷酸酯酶(ACP)和碱性磷酸酯酶(ALP)对苯酚暴露响应较迟钝,仅高浓度(40 mg.L-1)长时间(48 h和72 h)的胁迫才会产生显著抑制作用.表明摇蚊体质量、化蛹率和CAT、SOD、GST、CarE可作为监测苯酚水体污染的生物标志物.     

The Pupa and Larva of Propsilocerus taihuensis (Wen,Zhou & Rong) (Diptera: Chironomidae), with Complete Keys to all Immatures of the Genus Propsilocerus

The pupa and larva of Propsilocerus taihuensis (Wen, Zhou & Rong, 1994) are described for the first time. Both are close to P. akamusi (Tokunaga). The phylogenetic argumentation of the genus outlined in Sæther and Wang (1996) is confirmed. Revised keys to larvae and pupae of the genus are given. The main morphological characters of the different species of the genus are compared in tables.     

利福平对红裸须摇蚊幼虫肠道微生物群落结构及功能的潜在影响北大核心

【目的】摇蚊是水生生态系统中重要的昆虫种类之一,其肠道微生物与个体生长发育、环境适应等过程密切相关,本研究旨在探究抗生素处理对摇蚊幼虫肠道微生物群落结构及功能的潜在影响。【方法】利用16S rRNA基因扩增子测序技术对利福平处理的红裸须摇蚊(Propsilocerus akamusi)幼虫肠道内容物中的菌群进行分析和比较,应用Tax4Fun法对其肠道菌群功能进行预测。【结果】利福平处理能够改变红裸须摇蚊幼虫肠道群落结构和多样性,宿主肠道菌群中拟杆菌门(Bacteroidota)(P<0.05)以及脱铁杆菌门(Deferribacterota)(P<0.001)的相对丰度显著上升,而变形菌门(Proteobacteria)与厚壁菌门(Firmicutes)相对丰度有所下降。在属水平上,利福平处理使耶尔森菌属(Yersinia)、假单胞菌属(Pseudomonas)、脱硫弧菌属(Desulfovibrio)的相对丰度有所降低,其中脱硫弧菌属(Desulfovibrio)显著降低。与此同时,共线性网络分析表明利福平处理后细菌群落稳定性大幅下降,菌种之间关联性显著减弱。通过京都基因与基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)通路注释预测出红裸须摇蚊幼虫肠道菌群基因与基因信息处理、新陈代谢、人类疾病等功能相关,利福平处理可以使肠道菌群基因的抗药性功能显著上升,而内分泌和代谢疾病功能显著下降。【结论】研究结果揭示了抗生素利福平对红裸须摇蚊幼虫肠道细菌群落结构及功能的潜在影响,为进一步探索摇蚊肠道菌群发挥的必要作用奠定理论基础。