豫南罗索线虫感染库蚊、伊蚊和阿蚊的实验研究

试验的伊蚊、库蚊和阿蚊,对豫南罗索线虫均表现敏感,当蚊幼与线幼虫数之比为1:5时,4种伊蚊的感染率均在95％以上;致倦库蚊和三带喙库蚊的感染率分别为98.6％和97.1％,骚扰阿蚊为66.4％。线虫在蚊体内发育良好,感染度亦较高,表明此线虫具有应用前景。     

两种罗索线虫对不同蚊种的自然感染及实验研究

1984年在河南信阳地区发现两种蚊体寄生索线虫,在同一孳生地内生长繁殖,分别寄生于中华按蚊和致倦库蚊及三带喙库蚊等幼虫体内,自然寄生率为5.48％、4.32％、5.82％。通过人工感染试验,感染率均较高,可达61.5％～95.7％。试验证明两者对按蚊和库蚊具有显然不同的生理特性。这两种罗索线虫在稻田、田沟等多种水体内均有孳生,宿主范围广泛,有应用价值。     

稻田放养满江红对蚊虫孳生影响的初步观察

实验室笼内研究表明,容器水面覆盖细绿萍可阻止库蚊在其中产卵,但对中华按蚊产卵无显著作用。1987年在湖南桂东县对放养细绿萍的稻田观察结果,库蚊(主要是三带喙库蚊)幼虫密度明显比对照田为低,而且随着覆盖面积比例扩大而下降率愈大,当覆盖面积达到95％时,平均下降率达78.96％,但对按蚊幼虫密度下降率甚微,这与实验室观察结果相符。在桂东县,养萍稻田每亩可收鲜萍1500-2000公斤,可用作禽畜饲料或其他作物基肥。养萍稻田也可使稻谷增产8％左右。由于养萍既可减少库蚊幼虫孳生,也有较好的经济效益,是在稻田蚊虫综合治理中值得采用的方法之一。     

寄生于三带喙库蚊幼虫的罗索线虫研究

以寄生线虫作蚊虫的生物防制,近十多年来国外研究较多(Roberts,et al.1980);国内近年在安徽、四川、湖北、浙江等地均有报导,对这些寄生线虫的形态、生活史、人工繁殖及田间试验应用等做了不少研究,指出利用寄生线虫对我国蚊虫的防制有很大的潜力。我们于1984年8～10月间在湖南郴州三带喙库蚊(Culex tritaeniorhynchus)     

α-三联噻吩对淡色库蚊血细胞的光敏作用研究

研究了α-三联噻吩(α-T)对淡色库蚊Culex pipiens pallens幼虫血细胞的光敏作用。结果表明,在活体和离体条件下,α-T对淡色库蚊4种主要血细胞的形态延展及增殖均有不同程度的影响,处理后较短的时间内,α-T能促进血细胞的增殖,但随着作用时间的延长,其对血细胞均表现出抑制作用,且抑制程度随α-T浓度升高而逐渐增强。α-T对淡色库蚊不同血细胞的影响具有一定的差异,在处理早期,其对浆血胞(SP)和原血胞(PR)的增殖促进作用较强,而在处理后期,其对粒血胞(GR)和珠血胞(SP)的抑制作用较强,并且改变了淡色库蚊幼虫体内不同血细胞之间的比例,使得GR和SP所占比例逐渐降低。实验还表明,α-T对各种离体血细胞增殖的促进作用均较对活体的弱,且促进时间明显缩短。     

乙型脑炎病毒NS1△63蛋白发酵工艺优化研究

【目的】乙型脑炎病毒NS1蛋白能诱导机体产生保护性免疫,具有开发成亚单位疫苗的潜力。为提高重组蛋白NS1_△63的原核表达量,研究进行发酵条件优化以开发稳定高产的蛋白生产工艺。【方法】采用单因素与PlackettBurman试验对培养基成分进行优化,同时探究诱导条件对发酵的影响,并在5 L发酵罐中进行初步的工艺放大验证。【结果】最佳的培养基成分为乳糖10 g/L、酵母粉19 g/L、蛋白胨25 g/L、磷酸盐37.5 mmol/L、氯化钾1.25 g/L。最佳发酵条件是诱导温度36℃、诱导时间12 h、0.6 mmol/L IPTG、5%接种量。蛋白产量提高到优化前的3.25倍,5 L发酵罐蛋白产量可达3 022.23 mg/L。【结论】研究显著提高了NS1_△63蛋白的原核产量,为该蛋白应用于亚单位疫苗和检测试剂盒的相关研究奠定了基础。     

在进境水果的集装箱中检出三带实蝇

１９９８年９月３日,新会动植物检疫局检疫人员在装载进口水果的集装箱内检获三带实蝇Ｂａｃｔｒｏｃｅｒａ（Ｂａｃｔｒｏｃｅｒａ）ｕｍｂｒｏｓａ（Ｆａｂｒｉｃｉｕｓ）。三带实蝇分布于热带和亚热带地区,危害水果和蔬菜类果实,是我国二类检疫性害虫。由于这是全...     

三裂叶豚草发生规律及综合防控措施研究

对三裂叶豚草生物学特性、传播途径和扩散原因、其密度对作物的影响等进行了研究,筛选出效果好、见效快的药荆20%百草枯水溶剂,并研究提出加强植物检疫、农业防治、天敌控制、化学防治等综合防控措施.     

三种植物精油对致倦库蚊成蚊的熏蒸活性及其混配增效作用

研究了香樟叶、香樟果实、天竺桂叶的水蒸气蒸馏精油对致倦库蚊Culex pipiens quinquefasciatus成蚊的熏蒸活性及其混配增效作用。结果表明:用香樟叶、香樟果实和天竺桂叶精油对致倦库蚊熏蒸20 min后,其24 h的LC50值分别为7.47、4.92和5.70μg/cm3;在设定的熏蒸剂量下,3种精油的半数击倒时间(KT50值)分别为16.62、15.91和16.98 min。将香樟叶精油与天竺桂叶精油以体积比1∶9、3∶7和5∶5混配,其共毒系数分别为152.09、158.20和152.86;将香樟果实精油与天竺桂叶精油以体积比1∶9、5∶5和7:3混配,其共毒系数分别为145.73、146.30和139.79。表明3种植物精油均对致倦库蚊成蚊具有显著的熏蒸活性,将其以适当比例混配后具有增效作用。     

森林健康与森林病虫害科学防控的浅析

森林健康是现代林业的经营理念,本文分析了森林健康与森林病虫害的各种关系,阐述了森林病虫害可持续控制的策略和措施,以促进森林健康的质量,实现森林病虫害的科学防控。     

Lack of cross-resistance to Mtx1 from Bacillus sphaericus in B. sphaericus-resistant Culex quinquefasciatus (Diptera: Culicidae)

The toxicities of Mtx1 toxin against dipteran and lepidopteran species have been evaluated in this study. It was shown that Mtx1 has little or no toxicity to the tested lepidopteran species, but has moderate-level toxicity to Aedes albopictus Skuse (Diptera: Culicidae) and high-level toxicity to both susceptible and binary toxin-resistant Culex quinquefasciatus Say (Diptera: Culicidae). The LC(50) values of Mtx1 against a susceptible C. quinquefasciatus colony SLCq and two resistant colonies RLCq1/C3-41 and RLCq2/IAB59 selected in the laboratory with Bacillus sphaericus (Mayer & Neide) strains C3-41 and IAB59 respectively were 0.508, 0.854 and 0.675 mg L(-1) respectively. The data indicate that Mtx1 has a different mode of action from the binary toxin, and that it could be an alternative toxin to delay or overcome resistance development to binary toxin in C. quinquefasciatus.     

Cloning and characterization of two glutathione S-transferases from pyrethroid-resistant Culex pipiens

BACKGROUND: The Marin strain of Culex pipiens Say is a pyrethroid‐resistant population that was collected in Marin County, California, in 2001 and subsequently maintained in the laboratory under regular permethrin exposure. RESULTS: In this study, two cDNAs, CpGSTd1 and CpGSTd2, encoding glutathione S‐transferase (GST) were cloned from Cx. pipiens Marin. Phylogenetic analysis of the deduced amino acid sequences, CpGSTD1 and CpGSTD2, of these genes indicated that they belong to the Delta class of insect GSTs. The nucleotide and deduced amino acid sequences of CpGSTd1 and CpGSTd2 were 59 and 48% identical respectively. CpGSTD1 and CpGSTD2 were expressed in Escherichia coli and purified by affinity chromatography. The recombinant GSTs exhibited unique selectivity towards the general GST substrates 1‐chloro‐2,4‐dinitrobenzene (CDNB) and 1,2‐dichloro‐4‐nitrobenzene (DCNB), and also differed in their sensitivity to known inhibitors of GSTs. CpGSTD1 exhibited peroxidase activity with cumene hydroperoxide, while CpGSTD2 appeared to lack this activity. CpGSTD1 was able to metabolize 1,1,1‐trichloro‐2,2‐bis(4‐chlorophenyl)ethane (DDT), while DDT metabolism by CpGSTD2 was not detectable. CpGSTD1 and CpGSTD2 showed no detectable metabolism of permethrin. Gene expression of CpGSTd1 and CpGSTd2 in Marin mosquitoes was elevated about twofold in comparison with that found in a pyrethroid‐sensitive mosquito strain. CONCLUSION: The results indicate that CpGSTD1 and CpGSTD2 have unique biochemical characteristics, but they do not appear to play major roles in permethrin resistance in Marin mosquitoes. Copyright © 2012 Society of Chemical Industry     

疫情常态化防控下游客旅游行为意向研究

当前中国应对新冠疫情的主要策略已确定为”外防输入、内防反弹”的常态化防控.疫情中,旅游业及相关行业都受到了严重影响,亟待重振市场信心,稳步恢复.文中通过广泛的网络问卷调查和SPSS23.0初步统计分析,基本把握了疫情常态化防控下中国游客旅游行为意向.研究结果表明:1)游客对常态化防控下旅游公共卫生安全具有清晰理性的认知...     

Attract-and-kill strategy. Laboratory studies on hatched larvae of Culex pipiens

The attract‐and‐kill strategy is a new pest management technique that presupposes the intelligent combination of an attracting agent (e.g. pheromone) and a killing agent (e.g. insecticide). In the present study, the potential combination of the microencapsulated synthetic oviposition pheromone 6‐acetoxy‐5‐hexadecanolide with an insecticide has been tested. Initially, polyurea microcapsules containing 6‐acetoxy‐5‐hexadecanolide, the synthetic mixture of diastereomers of the oviposition pheromone of the mosquito species Culex quinquefasciatus Say (Diptera: Culicidae), were studied. Laboratory bioassays were performed to confirm the bioactivity of the microencapsulated pheromone on the oviposition activity of Culex pipiens L. biotype molestus Førskal (Diptera: Culicidae) with the aim of determining the optimum dose for oviposition response. Its effect was dose dependent, revealing an optimum dose of 300 mg of dried microcapsules. Attractancy over time was also studied. The microencapsulated pheromone was found to be sufficiently attractive to gravid female mosquitoes for a period of 40 days. Finally, the combination of the synthetic pheromone with the control agent temephos showed both an acceptable oviposition activity and sufficient larvicidal effect. Copyright © 2007 Society of Chemical Industry     

Filariasis vector in China: insecticide resistance and population structure of mosquito Culex pipiens complex

Seven field populations of mosquito Culex pipiens complex (Diptera: Culicidae) were collected from four provinces of China. The resistance status of larvae to dichlorvos, parathion, chlorpyrifos, fenobucarb (BPMC) and propoxur were determined by bioassays, disclosing that they were more resistant to organophosphate (moderate or low resistance) than to carbamate (low or no significant resistance) insecticides. Starch gel electrophoresis confirmed the presence and distribution of overproduced esterases B1, A2-B2, A8-B8 and A9-B9, the frequencies of which varied according to their regional origins. Electrophoretic polymorphism at four putatively neutral loci (got-1, got-2, pgi and pgm) showed that the overall genetic differentiation found across all populations was significantly large (Fst = 0.28, P < 10(-4)), and genetic exchange was slightly restricted by distance isolation (P = 0.018).     

辽宁口岸进境原木疫情分析及检疫监管建议

本文对2001～2010年间辽宁口岸进境原木疫情情况进行分析,探讨了进境原木截获有害生物种类特点、疫情年发生规律特点并对其形成原因进行了深入分析。同时,对今后的检疫监管工作提出了相关建议。