稻水象甲和稻象甲成虫形态及为害状的主要鉴别特征

<正>稻水象甲Lissorhoptrus oryzophilus Kuschel和稻象甲Echinocnemus squameus Billberg同属鞘翅目(Coleoptera)象虫科(Curculionidae),分别属稻水象属Lissorhoptrus和象甲属Echinocnemus,两者都营水生生活,生活史极为相似,主要为害的农作物也是水稻,且以成虫为害茎叶、幼虫为害根系,都是管状喙口器,造成的为害状相似,虫体大小也差不多,许多     

一种潜在入侵害虫——霜梅蛾蜡蝉

霜梅蛾蜡蝉[Metcalfa pruinosa (Say,1830)]危害多种农作物和重要经济作物,主要分布于北美及欧洲,已被多个国家列为检疫性或限定性有害生物,近年来该害虫已入侵韩国,但在我国尚无分布报道。本文对霜梅蛾蜡蝉的分类地位、地理分布、寄主、形态特征、生物学特性、为害、传播途径和防控措施进行综述,并提出预防建议,以期为口岸检疫鉴定提供参考依据。     

基于线粒体COⅠ基因及形态特征的喜树丛枝植原体主要媒介昆虫种类鉴定

植原体病害是喜树上危害最严重的病害之一,传播喜树植原体病害的主要媒介昆虫是喜树上的一种小绿叶蝉,为进一步分析媒介昆虫传播植原体机制以及植原体在昆虫体内的侵染循环过程,为植原体病害的科学防控提供参考,媒介昆虫的种类及分类地位必须先行明确。通过网捕法采集云南文山喜树上的小绿叶蝉标本,在体视显微镜下根据各龄期外部形态以及雄性外生殖器特征进行种类鉴定,结合PCR扩增线粒体COⅠ基因序列片段进行测序和比对,利用Kimura 2-parameter模型计算出平均遗传距离并用最大似然法构建系统发育树,进一步明确其分类地位,再根据前人制作的属及亚属分类检索表明确其分类地位。共检视并解剖小绿叶蝉雄虫标本100余头,提取20余头DNA进行测序,得到16条709 bp大小的COⅠ基因序列片段,结合NCBI上相关的叶蝉COⅠ序列,建立基因进化树。综合分析其外部形态、雄性外生殖器特征以及COⅠ序列比对,明确了喜树丛枝植原体主要媒介昆虫是拟帕小绿叶蝉Empoasca(Matsumurasca)paraparvipenis Zhanget Liu-CA,分类地位为小绿叶蝉属Empoasca Walsh, 1862,...     

龙牙百合软腐病病菌——米根霉的分离鉴定及杀菌剂室内毒力测定初报

对低温储藏的部分腐烂的龙牙百合种球,进行了病原菌鉴定及致病性研究,并用菌丝生长速率法对10种杀菌剂进行了测定。经形态学和分子生物学鉴定,结果表明,导致龙牙百合种球腐烂的病原菌为米根霉(Rhizopus oryzae)。室内毒力结果显示,10种杀菌剂对米根霉菌丝的抑制效果有很大的差异。其中,1%申嗪霉素悬浮剂、30%己唑醇悬浮剂的抑菌效果较好,相应的EC_(50)分别为6.963、12.765 mg/L;抑菌效果最差是250 g/L嘧菌酯悬浮剂,EC_(50)为158 489.319 mg/L;30%己唑醇悬浮剂抑菌率最高,为100%。     

肾状线虫属种类鉴定和特征描述

本文记述了目前世界上认可的肾状线虫属Rotylenchulus sp.已知的10个种的重要鉴定特征、世界分布和寄主范围。这10个种包括越南肾状线虫R.anamictus,短管肾状线虫R.brevitubulus,北方贝肾状线虫R.borealis,短尾肾状线虫R.clavicaudatus,离异肾状线虫R.leptus,大囊肾状线虫R.macrodoratus,长肾状线虫R.macrosoma,微小肾状线虫R.parvus,肾形肾状线虫R.reniformis,甘蔗肾状线虫R.sacchari。     

中国四省(区)葡萄根围螺旋线虫种类记述

描述了采自陕西、山东、广西、宁夏 4省 (区)葡萄根际的 6种螺旋属线虫 :双宫螺旋线虫(Helicotylenchus dihystera)、外异螺旋线虫 (H exallus)、双角螺旋线虫 (H .digonicus)、H .digitiformis、H .platyurus、H .multicinctus。其中后 4种螺旋线虫均为我国葡萄上的首次报道     

中国4省(区)葡萄根际剑线虫属和针线虫属种类的鉴定

从中国广西、陕西、山东、宁夏4省(区)36个葡萄品种的230份葡萄根际土样中鉴定出4种剑线虫和1种针线虫,分别为Xiphinema americanum,X.insigne,X.hunaniese,X.elongatum和Paratylenchus audriellus. ,其中X.elongatum为葡萄上的新记录种;P.audriellus在中国属首次记录,葡萄为其新寄主植物。     

茶树叶斑病病原菌可可毛色二孢菌的鉴定

The tea leaf disease, which led to a large loss of production and decrease of quality, was found in the tea region in Huishui county, Guizhou province. Some strains were isolated from the diseased samples, and the representative strains fulfilled Koch’s postulate. Then the isolates were further identified as Lasiodiplodia theobromae based on morphological characters and phylogenetic analysis with internal transcribed spacer (ITS) and elongation factor 1-α (EF-1α) regions. The results showed that the pathogen of the leaf disease occurred in Huishui county, Guizhou province was L. theobromae.     

茶树叶斑病病原菌可可毛色二孢菌的鉴定

<正>可可毛色二孢菌(Lasiodiplodia theobromae Pat. Griffon Maubl.)属葡萄座腔菌属(Botryosphaeria)病原菌的无性型,其有性型为Botryosphaeria rhodina(Berk. M.A. Curtis)Arx[1,2]。该病原菌可导致热带、亚热带地区的植物发生病害,如葡萄树干溃疡和顶梢枯死[3],春芋叶斑病[4],橄榄溃疡病[5]等。叶斑病是茶树的一类重要病害。近年来,不     

贵州省余庆县茶褐枯病病原菌的鉴定

为鉴定引起茶褐枯病的病原菌,本研究对病原菌进行分离、纯化和培养,通过柯赫氏法则验证菌株的致病性,并观察病原菌的形态特征,依据病原菌rDNA-ITS、ACT、CAL和TUB2基因进行多基因系统发育分析。结果显示:病原菌分生孢子呈淡蓝色,表面光滑,无隔膜,圆柱状,两端钝或向底部变窄,水滴状斑点,大小为(11.7~29.5)μm×(3.9~7.7)μm,平均为(19.4±4.4)μm×(5.4±0.8)μm,分生孢子梗形成于气生菌丝上,透明,具有隔膜;附着胞为棒状等不规则形状,颜色呈棕色到深棕色,单生。基于病原菌形态学鉴定和多基因系统发育分析结果,将病原菌确定为山茶刺盘孢Colletotrichum camelliae。     

苯醚甲环唑在茶叶中的残留量及其在茶汤中的浸出动态研究

采用气相色谱-电子捕获检测器(GC-ECD)对田间采集的茶叶样品中的苯醚甲环唑残留量进行了测定,同时对泡茶后茶汤中苯醚甲环唑的浸出动态进行了研究。结果表明:苯醚甲环唑10%水分散粒剂分别按有效成分100和150 mg/kg于茶叶炭疽病发生初期施药2~3次,距末次施药后间隔5 d采样,成茶中苯醚甲环唑的残留量低于最大残留限量(MRL)值10.0 mg/kg;茶汤中苯醚甲环唑残留量及浸出率随冲泡次数的增加逐渐下降,4次冲泡的总浸出率为19.6% ~21.8%,人体摄入的苯醚甲环唑残留量占每日允许摄入量(ADI)的9.0%。     

茶扁叶蝉 Chanohirata theae (Matsumura)的生物学特性

茶扁叶蝉Chanohirata theae(Matsumura)近年来在贵州部分茶园中偶有发生甚或暴发成灾,为了解这一害虫的生物学特性,通过室内饲养和野外调查对其形态特征、生活史、发育历期、生活习性等进行了研究。结果显示:茶扁叶蝉在贵州一年发生2代,第一代发生于4月上旬至9月下旬,第二代发生于7月中旬至翌年5月中旬;若虫共5龄,以5龄若虫在茶树中下部叶片上越冬;发育历期受温度影响明显,温度越高发育速率越快,第一代卵期(23.42d)明显长于第二代(15.73d),相反,第一代若虫历期(56.33d)明显短于第二代(218.28d);成、若虫均喜静伏于叶片正面取食,交配多于白天进行,雌成虫一般由叶片正面将卵产入叶肉组织内;成虫具较强的趋光、趋黄的特性。建议于成虫盛期悬挂黄板或开灯诱杀,于若虫1~2龄盛期施药进行防治。     

Identification of tea foliar diseases and pest damage under practical field conditions using a convolutional neural network

Lesions of tea (Camellia sinensis) leaves are detrimental to the growth of tea crops. Their adverse effects include further disease of tea leaves and a direct reduction in yield and profit. Therefore, early detection and on-site monitoring of tea leaf lesions are necessary for effective management to control infections and prevent further yield loss. In this study, 1,822 images of tea leaves with lesions caused by three diseases (brown blight, Colletotrichum camelliae; blister blight, Exobasidium vexans; and algal leaf spot, Cephaleuros virescens) and four pests (leaf miner, Tropicomyia theae; tea thrip, Scirtothrips dorsalis; tea leaf roller, Homona magnanima; and tea mosquito bug, Helopeltis fasciaticollis) were collected from northern and central Taiwan. A faster region-based convolutional neural network (Faster R-CNN) was then trained to detect the locations of the lesions on the leaves and to identify the causes of the lesions. The trained Faster R-CNN detector achieved a precision of 77.5%, recall of 70.6%, an F1 score of 73.91%, and a mean average precision of 66.02%. An overall accuracy of 89.4% was obtained for identification of the seven classes of tea diseases and pests. The developed detector could assist tea farmers in identifying the causes of lesions in real time.     

北亚脉扁蜂形态特征和生物学特性

为明确李树上新纪录害虫北亚脉扁蜂Neurotoma sibirica的生物学特性,通过田间调查和室内饲养观察,记述该虫的形态特征、生活史及生物学特性。结果表明,北亚脉扁蜂在吉林省吉林市1年发生1代,以老熟幼虫在树下5~15 cm深的土层中做土室越冬。每年4月中旬幼虫开始化蛹,5月上旬成虫羽化出土,5月中旬为成虫盛期,成虫产卵从5月上旬持续到5月下旬,单雌产卵量为13~43粒,卵期5~9 d。6月上旬为北亚脉扁蜂幼虫为害盛期,幼虫为6龄或7龄,幼虫期14~21 d,6月中、下旬老熟幼虫陆续入土越冬。北亚脉扁蜂幼虫在李、紫叶李、杏、榆叶梅4种寄主上均可完成发育,在自然条件下李树受害率可达100%,紫叶李树受害率为40%,杏树受害率为20%。北亚脉扁蜂天敌有龟纹瓢虫Propylea japonica、异色瓢虫Harmonia axyridis、斯马蜂Polistes snelleni、日本弓背蚁Camponotus japonicus、2种姬蜂及1种病原菌。     

Identification and characterization of Pyrenophora species causing leaf spot on oat (Avena sativa) in western China

Drechslera leaf spot (DLS) is a serious leaf disease of oats chiefly caused by Pyrenophora chaetomioides in the main oat-producing areas of the world. However, other species of Pyrenophora that may cause DLS have not been investigated in China. From 2018 to 2020, a total of 256 strains of Pyrenophora were isolated from nine oat-producing areas in three provinces in western China. Using a combination of morphological characteristics and phylogenetic analysis of the rDNA internal transcribed spacer (ITS), 28S ribosomal RNA gene (LSU), RNA polymerase second largest subunit region (RPB2), and glyceraldehyde-3-phosphate dehydrogenase region (GAPDH), 66% of the isolates were identified as P. chaetomioides and 34% of isolates belonged to P. avenicola. Pathogenicity tests confirmed that P. avenicola also infected oat and caused DLS, but it was less virulent than P. chaetomioides. From our survey, DLS caused by P. avenicola generally occurred in warm areas at lower altitude and the annual average temperature was above 0°C (Huan and Zhenyuan county in Gansu, Huize county in Yunnan), compared to high-altitude areas (Tianzhu county, Shandan county, Haiyan county). The combination of optimal and maximal temperature indicated that P. avenicola had greater tolerance to high temperature, which was also an important factor for its distribution on oats. Precise identification and understanding of virulence, distribution, and occurrence of these pathogens has significance for control of oat DLS in the future.     

黏虫和劳氏黏虫形态特征比较

黏虫和劳氏黏虫往往混合发生,给小麦、玉米和水稻等造成严重的产量损失。本文从卵、幼虫、蛹和成虫4个虫态分别描述了这两种黏虫在形态特征上的差异。两种黏虫卵无差异。低龄幼虫中黏虫刚毛基部的毛片色深,2龄幼虫前胸背板上各条背线较明显;劳氏黏虫毛片色浅,2龄幼虫各背线不明显。高龄幼虫中黏虫头部有"八字纹",气门近圆形,气门筛黑色有光泽;劳氏黏虫头部除"八字纹"外唇基还有一黑褐色斑,气门椭圆形,气门筛黄褐色。黏虫蛹腹部背面5~7节有刻点,臀棘着生近于平行;劳氏黏虫蛹4~7节有刻点,臀棘呈"八"字形。黏虫成虫前翅有环纹、肾形纹,劳氏黏虫则无。本研究旨为两种黏虫的田间调查提供技术支撑。