辽细辛精油对淡色库蚊的杀伤作用

采用浸渍法和三角瓶法,测定了辽细辛精油对淡色库蚊幼虫的毒杀作用,对蚊成虫的熏蒸、触杀作用。结果表明,辽细辛精油对淡色库蚊幼虫有较强的毒杀作用,24h的LC50为25.047mg/L,LC90为31.994mg/L;对成虫有较好的熏蒸作用,LC50和LC90分别为69.354mg/L和140.33mg/L,KT50和KT90分别为19.329min和52.848min。     

五种伞形科中草药乙醇提取物对淡色库蚊的控制作用

研究了5种伞形科植物蛇床、防风、当归、紫花前胡和白芷对淡色库蚊幼虫和成虫的生物活性，采用浸渍法测定了样品乙醇提取物对蚊幼虫的杀伤作用，采用三角瓶法测定了样品乙醇提取物对蚊成虫的熏蒸作用。结果表明，5种伞形科中草药的乙醇粗提物对淡色库蚊幼虫和成虫的杀伤效应不同：蛇床子的乙醇粗提物对淡色库蚊幼虫的毒杀效果最佳（24h的LC90为49．886mg／L），白芷的乙醇粗提物对淡色库蚊成虫的熏蒸效果最佳（KT90为23．271min）。     

茚酮肟醚衍生物的合成与生物活性

通过傅－克反应及环化、肟化、成醚等反应,合成了10个未见文献报道的茚酮肟醚类化合物,其结构均经1H NMR、IR、LC/MS及元素分析确证。初步生物活性测试结果表明,所合成的化合物具有明显的杀菌活性或杀虫活性,如在100 mg/L时,化合物 V1 对小麦白粉病菌Erysiphe graminis 的抑制率为 95.6%, V5 对粘虫Mythimna separata的致死率为100%。     

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。     

致卷库蚊引诱产卵信息素的合成及其生物活性

对淡色库蚊产卵信息素 (5R, 6S)-6-乙酰氧基-5-十六内酯40年来的研究进展进行了综述,包括信息素的发现、平面结构和立体结构确定、立体异构体的生物活性、化学合成、作用靶标蛋白及应用研究等,旨在推进昆虫信息素在中国媒介害虫防治方面的应用。     

松油烯-4-醇对淡色库蚊的熏蒸毒力及对其Na+ ,K+ -ATP酶的抑制作用

为进一步探讨杀虫植物砂地柏Sabina vulgaris Ant.精油中主要杀虫活性成分—松油烯-4-醇(terpinen-4-ol)对卫生害虫的生物活性,测定了该物质对淡色库蚊Culex pipiens Pallens及其Na+,K+-ATP酶活性的影响。结果表明:松油烯-4-醇对淡色库蚊具有较强的熏蒸作用,其LC50值为6.79 mg/L, 在LC80剂量下其击倒中时(KT50)为6.92 min;淡色库蚊Na+,K+-ATP酶活性测定的最佳反应条件为pH值7.42、温度35.5℃、底物浓度0.7 mmol/L;离体和活体情况下,松油烯-4-醇均可显著抑制淡色库蚊Na+,K+-ATP酶的活性,其I50值为32.02 μg/mL。Na+,K+-ATP酶可能是松油烯-4-醇对淡色库蚊的杀虫作用靶标。     

麻黄和细辛挥发油的抗真菌作用

从植物中寻找杀菌抑菌活性物质是开发无公害新农药的一条有效途径。近年来,作者从药用植物中筛选出一批对植物病原真菌有较强抑制作用的挥发油,并对麻黄油和细辛油的抑菌活性作了较细致的研究。     

15种昆虫生长调节剂对库蚊幼虫的杀虫活性

浸渍法表明,定虫隆、氟幼脲是试验杀虫剂中对尖音库蚊淡色亚种幼虫杀虫活性最高的.定虫隆、氟幼脲、氟虫脲、氟铃脲、农梦特舜口除虫脲的杀虫活性分别是抑食肼的2 740倍、2 100倍、1 763倍、1 283倍、1 229倍和573倍.     

六种植物精油对家蝇的熏蒸及触杀毒力测定

测定了6种植物精油对家蝇的熏蒸及触杀作用。结果表明,6种精油均对家蝇有较强的熏蒸活性,且表现出一定的触杀活性。熏蒸毒力次序为:黄樟油(LC50＝1.7695 μL/L)＞八角叶油(1.8930 μL/L)＞肉桂油(5.8074 μL/L)＞留兰香油(6.2123 μL/L)＞香茅油(6.5801 μL/L)＞薄荷素油(9.4500 μL/L);触杀活性较好的为黄樟油,其次为 留兰香油、香茅油和薄荷素油,而八角叶油和肉桂油对家蝇的触杀作用较差。     

家蝇免疫血淋巴对几种动,植物病原菌的抑菌作用

针刺损伤诱导的家蝇三龄幼虫免疫血淋巴对几种动、植物病原菌具有抗菌活性。同时、未经诱导的家蝇幼虫血淋巴也具有抗菌活性，但外源诱导能衡旺增强抗菌物质的活性，家蝇的免疫血淋巴中的抗菌物质具有热稳定性和耐冷冻贮藏的特性。     

Effect of a mixture of iprobenfos and malathion on the development of malathion resistance in the mosquito Culex pipiens pallens Coq

A malathion-resistant (RM) strain of Culex pipiens pallens Coq was obtained by successively selecting a field population with malathion in the laboratory. The synergistic effect of iprobenfos on malathion toxicity and alpha-naphthyl acetate (alpha-NA) esterase assay revealed that malathion resistance in the RM strain was associated with increased alpha-NA esterase activity and the synergism was mainly due to the inhibition by iprobenfos of this activity. There was no difference in alpha-NA esterase activity between the larvae and female adults in the susceptible (S) strain, but the activity in the adults was 13-fold higher than in the larvae of the RM strain. To understand the effect of the application of a mixture of iprobenfos and malathion on the evolution of malathion resistance, an artificial strain (Syn) was generated by mixing the RM and S strains with 0.1 frequency of the malathion-resistant individuals. The offspring of the Syn strain were divided into two sub-strains, Rm and Rm+ibp, which were successively treated with, respectively, malathion alone and malathion + iprobenfos (1:2) at LC70. In the mixture, the fungicide iprobenfos acted as a synergist of malathion. After treatment for 10 generations, the resistance level to malathion was 317.4-fold for the Rm sub-strain, whereas for the Rm+ibp sub-strain it was only 38.9-fold, compared with the Syn strain. Similar results were obtained by measurement of alpha-NA esterase activity from both larvae and female adults. The alpha-NA esterase activities in larvae and female adults at F10 generation were 2.6- and 10.9-fold from the Rm+ibp sub-strain and 5.7- and 98.5-fold from the Rm sub-strain, respectively, compared with the Syn strain. The above results suggested that iprobenfos, although it cannot completely stop or prevent the onset of malathion resistance, could dramatically delay its evolution.     

新型肟醚化合物杀叶蝉活性的CoMFA研究

用比较分子力场分析(CoMFA)方法对28个间苯氧基苄醇肟醚和30个联苯苄醇肟醚化合物杀叶蝉Nephotettix cincticeps活性的定量构效关系进行了研究。分别研究了上述两类化合物及其综合的QSAR模型,3种QSAR模型都表明肟苯环对位取代基是影响化合物杀叶蝉活性的主要因素,其体积和电性增加有利于提高化合物的杀叶蝉活性。比较3种模型,还发现综合模型为最佳预测模型,其交叉验证系数R2cv=0.628,非交叉验证的相关系数R2=0.971,标准偏差SE=0.109,F=133.84。用此模型预测了检验组10个化合物的 -lgLC50,结果满意。所得QSAR模型可为进一步合成更高活性的化合物提供指导。     

Culex pipiens pallens: identification of genes differentially expressed in deltamethrin-resistant and -susceptible strains

Insecticide-resistance is a major obstacle to controlling insect vectors of microorganisms that cause human diseases. Identification of genes associated with resistance to insecticides has been a valuable tool for understanding mechanisms underlying resistance to commonly used insecticides such as deltamethrin. To identify such genes, we used suppression subtractive hybridization to obtain 809 differentially expressed clones in deltamethrin resistant versus susceptible laboratory strains of Culex pipiens pallens. Using cDNA microarrays and reverse Northern blots, a subset of 16 clones was confirmed to have greater than 3-fold difference in expression levels. Within this subset, we identified 2 clones uniquely expressed in the deltamethrin-resistant strain, eight clones exhibiting higher expression in the resistant strain and six in the susceptible strain. Of these 16 clones, 13 clones have sequence homology to known genes, such as ribosomal RNA, ribosome proteins, trypsin, and chymotrypsin-like proteins. Our data suggests resistance to deltamethrin may be a polygenic phenotype.     

Cytochrome P450 monooxygenase-mediated neonicotinoid resistance in the house fly Musca domestica L

Neonicotinoids play an essential role in the control of house flies Musca domestica. The development of neonicotinoid resistance was found in two field populations. 766b was 130- and 140-fold resistant to imidacloprid and 17- and 28-fold resistant to thiamethoxam in males and females, respectively. 791a was 22- and 20-fold resistant to imidacloprid and 9- and 23-fold resistant to thiamethoxam in males and females, respectively. Imidacloprid selection of 791a increased imidacloprid resistance to 75- and 150-fold in males and females, respectively, whereas selection with thiamethoxam had minimum impact. Neonicotinoid resistance was in all cases suppressed by PBO. The cytochrome P450 genes CYP6A1, CYP6D1 and CYP6D3 were constitutively over-expressed in resistant strains and CYP6D1 and CYP6D3 differentially expressed between sexes. The highest level of CYP6A1 expression was observed in both gender of the imidacloprid-selected strain after neonicotinoid exposure. CYP6D1 expression was increased after neonicotinoid exposure in resistant males. CYP6D3 expression was induced in both sexes upon neonicotinoid exposure but significantly higher in females.     

芸香科三种植物精油对家蝇的熏杀活性及其混配增效作用

用水蒸汽蒸馏法从岭南花椒Zanthoxylum austrosinense果实、椿叶花椒Zanthoxylum ailanthoides果实和四数九里香Murraya hunanensis叶中提取植物精油,采用三角瓶密闭熏蒸法测试3种精油对家蝇的熏杀、击倒作用及其混配增效作用。3种植物精油对家蝇的6 h熏杀LC₅₀值分别为岭南花椒果实精油 7.55 μg/cm³、椿叶花椒果实精油11.08 μg/cm³、四数九里香叶精油11.41 μg/cm³;在熏蒸浓度均为10 μL/345 mL时精油对家蝇的熏蒸击倒效果KT₅₀分别为岭南花椒果实精油16.80 min、椿叶花椒果实精油24.69 min、四数九里香叶精油23.33 min。将岭南花椒果实精油与椿叶花椒果实精油以体积比7：3和9：1混配,其共毒系数分别为130.00和136.08;将岭南花椒果实精油与四数九里香叶精油以体积比9：1混配,其共毒系数为123.71。研究结果表明,3种植物精油对家蝇均有熏杀、击倒作用,其中岭南花椒果实精油与椿叶花椒果实精油或四数九里香叶精油以适当比例混配后具有增效作用,可利用其开发高效环保的植物源灭蝇剂。     

Characterization of imidacloprid resistance in the housefly Musca domestica (Diptera: Muscidae)

In recent years, imidacloprid was introduced to control the housefly in China and it was documented that the housefly indeed showed signs of resistance to imidacloprid somewhere but not in China. Therefore, a housefly population collected from filed (IFS) was selected continuously with imidacloprid to establish the resistant strain (IRS) and the basic characteristics were investigated in this study. After continuous selection over 21 generations, the resistance ratio increased from 9.01 to 140, and different levels of cross-resistance were developed to beta-cypermethrin, chlorpyrifos, chlorfenapyr, acetamiprid and azamethiphos in the IRS strain. The realized heritability of resistance was 0.10. The synergistic ratios for IRS pretreated with DEF, DEM and PBO were 1.68, 1.52 and 2.53, and the corresponding ones for IFS were 3.17, 1.87 and 2.67, respectively. Synergistic and biochemical assays suggested that the cytochrome P450 may play an important role in the imidacloprid resistance comparing with GSTs- and carboxylesterases-mediated detoxification in the IRS strain, and there might be additional mechanisms (e.g. reduced target-site sensitivity) contributed to imidacloprid resistance in the IRS strain.