三带喙库蚊产卵至吸血时距的观察

在蚊虫生殖营养周期的研究中,有关血液消化时间问题,国内外已有报告(щленова,1938;谭璟宪等,1959;Yajima,1973)。但对产卵至吸血的间隔时间(下简称“时距”)的研究甚少。1965年何桂铭等报告采用,летинова方法观察中华按坟Anopheles hyrcanus sinensis Wiedemann时距的结果。我们在三带喙库蚊Culex tritaeniorhynchus Giles时距的观察中,发现用卵巢小管三个收缩期难于判断准确的产卵时刻。鉴于此,进行了三带喙库蚊卵巢管收缩过程的实验观察,试图对其收缩期的划分予以修订,并用时应用于野外观察。     

应用豫南罗索线虫防制稻田内三带喙库蚊的效果观察

自1986年以来,作者曾在四川的成都、峨眉和云南的昆明等地多次进行了豫南罗索线虫(Romanomermis yunanensis)寄生前期幼虫现场释放试验,结果表明豫南罗索线虫对自然孳生地内的三带喙库蚊、纹腿库蚊和白纹伊蚊等有较好的防制作用。为了解豫南罗索线虫在我国不同地区的应用效果,1991年7月,又选择黄河以北的河南省武陟县进行现场试验,现将     

三带喙库蚊生殖滞育与其体内脂肪酸变化的关系

本文报道1986年—1988年用气相色谱法对不同生殖状态与不同季节采自上海等地野外的三带喙库蚊Culex tritaeniorhynchus脂肪酸组分及其变化的分析结果.经研究发现雌蚊体内有23—43种脂肪酸,其中棕榈油酸、棕榈酸、油酸及硬脂酸为主要组分,其次为亚油酸、豆蔻酸及花生酸等.不同生殖状态蚊间豆蔻酸与油酸及硬脂酸等具有一定的差异.野外蚊体内脂肪酸组分比实验室蚊少,不同季节的野外蚊体脂肪酸具有明显变化.另外,两种提取脂肪酸的方法比较表明,酸水解法有利于提取长链脂肪酸,碱水解法则有利于提取短链脂肪酸.     

温度与光照对三带喙库蚊自育性影响的初步观察

三带喙库蚊Culex tritaeniorhynchus Giles为流行性日本乙型脑炎痫毒的重要媒介,对其自育性的研究有助于媒介生物学的研究。关于蚊虫自育性国外已育较多报告(Laurence,1964;Spielman,1971;Trpis,1977)。近年来,我国也发现白纹伊蚊Aedes albopictus Skuse(崔可伦,1982)与东乡伊蚊     

不同温度对三带喙库蚊卵的保存及不同食料对幼虫发育的影响

用不同温度对三带喙库蚊卵的保存进行了试验,发现蚊卵在10℃条件下仅可保存两天,而2℃、5℃、11℃以上等其他温度均不宜保存．因此证实该蚊卵不能在任何温度下作长时间保存。通过实验观察了以6种不同配方的食料饲养三带喙库蚊幼虫,结果显示用鱼粉、面粉、酵母粉组合成的6号组食料经综合分析优于其他组食料。进一步说明动物蛋白的种类、配比对蚊幼虫的存活、健康关系极大。     

应用豫南罗索线虫防制峨眉稻田内三带喙库蚊的研究

应用豫南罗索线虫防制峨眉稻田内三带喙库蚊的研究薛群力,宋锦章,彭玉芳,唐登明,王绪勇成都军区军事医学研究所成都６１００６１华西医科大学寄生虫学教研室豫南罗索线虫（Ｒｏｍａｎｏｍｅｒｍｉｓｙｕｎａｎｅｎｓｉｓ）已被证实对多种库蚊、伊蚊、脉毛蚊和少数按蚊...     

抗有机磷三带喙库蚊的酯酶研究

本文主要利用聚丙烯酰胺凝胶电泳及离体酶学技术研究抗有机磷三带喙库蚊(Culex tritaeniorhynchus Giles)与各种水解酶系的关系.结果表明:三带喙库蚊抗性品系的羧酸酯酶活性明显高于敏感品系.此外,酯酶同功酶谱显示抗性品系有一染色很深的高活性羧酸酯酶带E₄,而胆碱酸酶活性测定结果表明抗性与敏感品系无明显差异.因此本实验证明,该蚊对有机磷杀虫剂之所以产生高度抗性.其主要原因与羧酸酯酶的活力增加有关.这和我们生物测定结果完全一致.     

三带喙库蚊幼期实验种群动态的模拟研究

根据温度和三带喙库蚊(Culex trttaentorhynchus Giles)幼期发育的关系,以及不同恒温下幼期各龄发育速率变异系数基本恒定,用多群体发育速率累积法建立了幼期实验种群动态的模拟模型.模型对实验种群动态的模拟结果和实际观察值是一致的,并可用来估测在野外研究中难以得到的种群参数.     

实验感染的三带喙库蚊和来亨鸡体内西尼罗病毒的分离与鉴定

采用C6/36细胞培养分离活病毒、间接免疫荧光染色检测病毒抗原、RT-PCR扩增病毒基因片段和PCR产物测序等方法,对实验感染的三带喙库蚊Culex tritaeniorhynchus和来亨鸡血液样本中的西尼罗病毒进行分离和鉴定。结果表明,接种实验感染蚊虫研磨液和来亨鸡血液样本的C6/36细胞出现细胞融合、空泡形成的病变效应; 用西尼罗病毒抗血清进行间接免疫荧光染色,感染病毒的细胞呈现黄绿色荧光,为阳性反应; 采用3对不同引物的RT- PCR体系扩增分别出现预期的408 bp、498 bp和559 bp的基因片段,序列测定证实扩增序列与实验所用毒株相应的基因序列基本相同。从而证实实验感染三带喙库蚊和来亨鸡体血液内的西尼罗病毒与实验感染所用的西尼罗病毒Chin-01株一致。     

印度雕蚀菌对三带喙库蚊幼虫生活力的影响

三带喙库蚊幼虫为印度雕蚀菌的寄生宿主,自然界中2—4龄幼虫均可感染印度雕蚀菌,感染后幼虫体肿胀,活动缓慢,对外界抵抗力降低,各龄幼虫虽可蜕皮,但在蜕皮过程中即行死亡。幼虫存活时间各为:2龄的5天;3龄的4—11天;4龄的4—9天,死亡率达100%。印度雕蚀菌的初生孢子囊和休眠孢子囊不同,可充满于幼虫的血腔,二型孢子囊的数量以前者为多,死亡虫体中多为成熟孢子囊,囊内可见有成熟而极为活跃的,带有鞭毛的游动孢子。经1—2小时,成熟游动孢子破囊而出,游动于水体中。 病态蚊幼主要滋生于有机物质丰富,水质清澈的秧稻田中。连续3年观察,其滋生地多为固定而局限,未发现与三带喙库蚊滋生同一地的中华按蚊和它种蚊虫的感染。     

三带喙库蚊不同地理株间蚊体脂肪酸和单糖的比较

本文报道1986—1988年用气相色谱法对乙型脑炎媒介的三带喙库蚊Culex tritacniorhynchus Giles北京、上海、广州、广西和场州地理株脂肪酸和单糖的比较研究结果.结果显示,实验室养殖的不同地理株之间脂肪酸和单糖具有一定的差异;野外采获蚊虫的脂肪酸和单糖组分及含量也具有一定的差异,而且野外蚊虫比实验室养殖蚊虫的脂肪酸与单糖含量及组分为少.北京株与上海株和扬州株蚊虫脂肪酸组分基本相似,广州株与广西株间基本相似.实验数据经系统聚类分析表明,五株蚊间脂肪酸具有差异,结果与上述基本相似.     

Comparison of the efficacy of CO2‐baited and unbaited light traps,gravid traps,backpack aspirators,and sweep net collections for sampling mosquitoes infected with Japanese encephalitis virus

Two field studies were conducted to determine the efficacy of mosquito collection methods for species composition, species abundance, and Japanese encephalitis virus infection rates in Taiwan. Traps evaluated included John W. Hock (JH) model UD black light traps, JH model 1012 new standard miniature CDC light traps, JH model 1712 CDC gravid traps, and Taiwan‐made Pest‐O‐Lite light traps. Backpack aspirators and sweep nets were also used to collect the resting population. Culex tritaeniorhynchus in all studies and Mansonia uniformis in the Taipei areas were the two most abundance species collected. Dry ice‐baited UD black light traps were effective in regard to species diversity, species abundance, and Japanese encephalitis virus infection rates. The unbaited Pest‐O‐Lite light traps collected significantly more female mosquitoes than the UD black light traps but performed similarly with regard to species diversity and male mosquito collection. Most mosquitoes collected by Pest‐O‐Lite light traps were dried and not suitable for virus detection. Dry ice‐baited CDC light traps collected significantly fewer mosquitoes than other light traps. Although CO₂‐baited UD black light traps with octenol attracted more mosquitoes, no statistical significance was found compared to CO₂‐baited UD black light traps without octenol. Japanese encephalitis viruses were isolated from half of the positive pools in UD black light traps and CDC light traps.     

Evaluation of neem, Azadirachta indica, with and without water management, for the control of culicine mosquito larvae in rice-fields

Applications of neem, Azadirachta indica (Meliaceae), to rice-fields were evaluated with the dual objective of controlling the culicine mosquito vectors of Japanese encephalitis virus (JEV) and enhancing the grain yield. Since crude neem products deteriorate under improper storage conditions, a laboratory bioassay was developed to screen neem cake powder against mosquito larvae, Culex quinquefasciatus. Only samples of neem giving over 90% bioassay mortality were used in field trials. When good quality neem cake powder was applied at the dose of 500 kg/ha, either alone or coated over urea, there was a striking reduction in the abundance of late instar culicine larvae and pupae. Only fourteen pupae were obtained over a period of 13 weeks in neem cake powder treated plots, and four in those treated with neem coated urea, compared with 101 in control plots. Both treatments were significantly less than the control, but on par with one another. In another field trial, neem cake coated urea was tested at 500 and 250 kg neem/ha in combination with water management practices. No reduction in efficacy was noted at the lower dose. Larval abundance in plots under water management alone did not differ significantly from the controls, but was significantly reduced when water management was combined with neem products. Two stable formulations, 'Neemrich-I' (lipid rich) and 'Neemrich-II' (azadirachtin rich), also gave good suppression of immature culicines. All the treatments with neem also gave higher grain yield than the control.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of the water fern Azolla microphylla for mosquito population management in the rice-land agro-ecosystem of south India

The floating water fern Azolla microphylla Kaulfess was evaluated as a biocontrol agent against mosquitoes breeding in rice fields in Tamil Nadu, South India. Anopheles subpictus Grassi, Culex pseudovishnui Colless and Culex tritaeniorhynchus Giles were the predominant species of mosquitoes, with peak densities of late instar larvae and pupae occurring during the second week after transplantation of rice seedlings of short-term (c. 80 days from transplantation to harvest) or medium-term (c. 95 days) varieties. Immature mosquito populations were reduced by mats of Azolla microphylla covering more than 80% of the water surface. However, since 80% coverage by Azolla was achieved only 13-14 days after rice transplantation, its usefulness for mosquito control was limited. Azolla may have a greater potential in an integrated control programme, or in areas where long-term varieties of rice are predominantly grown.     

Historical review and surveillance of Japanese encephalitis, Republic of Korea, 2002–2004

Japanese encephalitis virus (JEV), transmitted by culicine mosquitoes, is endemic throughout much of South‐East Asia, extending to the Korean Peninsula. The zoonotic cycle is from large water birds to culicine mosquitoes, with swine as an amplifying host and man as an incidental host. Culex tritaeniorhynchus, the primary JEV vector in the Republic of Korea, populations peak in late August through to early September when most cases of Japanese encephalitis (JE) are reported. Cx. tritaeniorhynchus were observed near the Demilitarized Zone in each of the years that mosquitoes were assayed for JEV. Each year that vector mosquitoes were assayed for JEV, minimum field infection rates (number of JEV positive mosquites/1000 Cx. tritaeniorhynchus assayed) ranged from 0.31 to 3.27. The epidemiology of JE has been recorded in Korea for more than half a century, from 1949 to 2005. During a major epidemic in 1949, there were 5616 cases and 2729 deaths reported, with levels persisting near epidemic levels of 1000 cases annually thereafter until 1969. Following the introduction and government mandated mass immunization in 1971, JE decreased dramatically. Since 1984, 0–6 cases of JE have been reported each year. However, continued evidence of mosquitoes positive for JEV indicates that JE continues to be a civilian and military health threat to immunocompromised persons in Korea, as well as non‐immune US soldiers, civilians and their family members.