生防放线菌Fq24代谢产物对朱砂叶螨的生物活性

菌株Fq24是从健康番茄植株分离得到的一株植物内生放线菌.为了研究它对朱砂叶螨生物活性的影响,通过萃取、柱层析、气相色谱-质谱(GC-MS)等技术对Fq24代谢产物中的杀螨活性物质进行了分离和结构鉴定,并采用玻片浸渍法和叶片残毒法测定了这些代谢产物的生物活性.结果表明:石油醚萃取物对朱砂叶螨具有较强的触杀和产卵忌避作用.触杀作用的LC50为52.57 mg·L-1,产卵忌避作用的ODC50为43.18 mg·L-1.经GC-MS分析,流份S11的主要化学成分为棕榈酸甲酯,分子式为C17H34O2,是代谢产物中的杀螨活性物质之一.质量浓度为5 mg·mL-1的棕榈酸甲酯对雌成螨的24h校正死亡率为78.3％,对雌成螨24h产卵驱避率为81.6％.     

东莨菪内酯对朱砂叶螨的驱避和产卵抑制活性

本研究采用叶碟浸渍法测定了东莨菪内酯对朱砂叶螨Tetranychus cinnabarinus(Biosduvals)雌成螨的触杀活性,采用选择性的半叶法测定了驱避活性,同时采用非选择性的全叶法测定了产卵抑制活性。结果表明,东莨菪内酯对朱砂叶螨雌成螨具有较好的触杀活性,采用叶碟浸渍法处理48h后的LC50为0.297mg·mL-1,LC30为0.105mg·mL-1,LC10为0.023mg·mL-1。采用LC50、LC30和LC103个浓度的东莨菪内酯处理雌成螨后,发现东莨菪内酯对雌成螨没有表现出明显的驱避活性,处理区和对照区24h和48h的着螨率均为50%左右;采用LC50和LC102个浓度处理雌成螨后表现出了一定的产卵抑制活性,平均产卵抑制率分别为23.02%和13.23%,而LC30对雌成螨的产卵量表现出了促进作用,平均产卵抑制率为-8.25%,这可能是由于毒物兴奋效应所致。本研究旨在为东莨菪内酯的进一步开发和应用奠定理论基础。     

双去甲氧基姜黄素对朱砂叶螨的生物活性及作用方式

在室温26℃±1℃、湿度60%～80%、光照14 h条件下,测定了天然植物活性成分双去甲氧基姜黄素对重要植食性害螨朱砂叶螨各螨态的触杀和熏蒸活性,对幼螨、若螨、成螨的驱避活性,以及对雌成螨的产卵抑制活性.采用玻片浸渍法测得双去甲氧基姜黄素对朱砂叶螨雌成螨48 h的LCso为0.433 mg·mL-1.在0.883 mg·mL-1(LC70)的浓度下,双去甲氧基姜黄素对朱砂叶螨不同螨态触杀活性的大小依次为幼螨＞若螨＞成螨＞卵,其中对幼螨24h和48 h的校正死亡率分别为60.0%和83.3%;对朱砂叶螨各螨态的熏蒸作用不明显,024h和48 h的校正死亡率均小于3%;对幼螨、若螨以及成螨均表现出较强的驱避作用,其中对幼螨的效果最好,不同处理时间的驱避率均在85%以上,其次是若螨,对成螨的驱避性相对较差,72 h的驱避率仅为47.8%.同时对雌成螨有明显的产卵抑制作用,处理后120 h产卵抑制率达到89.3%.表明双去甲氧基姜黄素对朱砂叶螨的主要作用方式为触杀、驱避和产卵抑制作用.     

辣椒碱对烟粉虱的生物活性及生长发育和生殖力的影响

在实验室条件下研究了辣椒碱对烟粉虱的生物活性及生长发育和生殖力的影响.结果表明:辣椒碱对烟粉虱各虫态均有杀虫活性,且随辣椒碱浓度的增大活性增强;辣椒碱浸叶法/浸虫法处理对烟粉虱成虫、卵和若虫的毒力(LC50分别为3525.79、1603.29和1526.27mg·L-1))均高于内吸法处理(LC50分别为5360.04、2359.19和5897.43 mg.L-1),两种处理方法下辣椒碱对烟粉虱卵的毒力均明显高于对成虫的毒力;2000和4000 mg·L-1浓度辣椒碱对烟粉虱成虫具有明显的拒食作用,烟粉虱在该两种浓度辣椒碱处理过的棉花叶上取食24 h的蜜露分泌量均显著低于取食非处理棉花叶后的蜜露分泌量;辣椒碱各试验浓度对烟粉虱成虫均表现出较强的产卵忌避作用,当辣椒碱处理浓度达4000 mg·L-1时,对烟粉虱的选择性产卵忌避率和非选择性产卵忌避率分别高达94.2％和83.0％.500、1000和2000 mg·L-1辣椒碱浸渍处理对烟粉虱存活卵和若虫的发育历期、成虫羽化率均没有影响,但辣椒碱4000mg·L-1处理明显延长烟粉虱若虫发育历期、降低成虫羽化率.不同浓度辣椒碱处理均明显抑制烟粉虱生殖力,且这种抑制作用随辣椒碱浓度的增大而增强.     

Oviposition deterrents for the Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae) from fly faeces extracts

After oviposition, females of the Mediterranean fruit fly Ceratitis capitata Wiedemann deposit a host-marking pheromone on the fruit surface that deters oviposition by conspecifics. Methanolic extracts of fruit fly faeces elicit a similar deterrent effect. The results of laboratory and field experiments using raw methanolic extracts of C. capitata faeces as an oviposition deterrent are reported. Laboratory bioassays revealed a significant positive relationship between concentration of faeces and the inhibition of oviposition responses by C. capitata. Treatment of halves of coffee bushes with methanolic extracts containing 0.1, 1.0 and 10 mg faeces ml(-1) resulted in a significant reduction of infestation only at the highest concentration (P=0.03). Treatment of blocks of coffee bushes with an extract of 10 mg faeces ml(-1) resulted in an 84% reduction in infestation by C. capitata in sprayed plants and a 56% reduction in adjacent untreated coffee bushes surrounding treated plots, probably due to the deterrent effect of host-marking pheromone on fly oviposition. We conclude that faeces contain oviposition deterrent substances that effectively reduce fruit infestations by C. capitata, suggesting a clear potential for the use of this infochemical in integrated management programmes targeted at this pest.     

鱼藤酮对松墨天牛产卵和取食行为的影响

为探索松墨天牛防治的新方法,实验了鱼藤酮对松墨天牛产卵和取食行为的影响及鱼藤酮对松墨天牛5龄幼虫的触杀作用。结果表明,鱼藤酮对松墨天牛具有显著的产卵忌避作用和成虫取食的干扰作用。产卵忌避作用和拒食作用随鱼藤酮浓度的增大而增强,处理浓度为1 000 mg/L时,鱼藤酮对成虫的产卵忌避率为75.63 %,处理后12 h松墨天牛的选择性和非选择性拒食率分别为72.91%和69.50%。鱼藤酮对松墨天牛5龄幼虫的触杀作用不明显。因此,利用鱼藤酮防治松墨天牛,一方面可以通过抑制其取食减少松材线虫的传播;另一方面通过忌避产卵可减少下代虫口。     

Studies of Aedes aegypti (Diptera: Culicidae) ovipositional responses to newly identified semiochemicals from conspecific eggs

Abstract  The chemical factors influencing the selection of oviposition site by gravid females of various mosquito species have been the subject of numerous investigations. Recent studies have revealed this behaviour to be controlled by semiochemicals. Here we report studies on semiochemicals of egg origin and their effect on the ovipositional behaviour of Aedes aegypti. The compounds present in egg extracts of Ae. aegypti mosquitoes were isolated and identified by gas chromatography-mass spectrometry. They were then evaluated for their effect on ovipositional behaviour against gravid females of Ae. aegypti mosquitoes at different concentrations. Gravid female Ae. aegypti were found to be sensitive to all the identified compounds: 6-hexanolactone, methyl dodecanoate, dodecanoic acid, methyl tetradecanoate, tetradecanoic acid, methyl (Z)-9-hexadecenoate, methyl hexadecanoate (Z)-9-hexadecenoic acid, hexadecanoic acid, methyl (Z)-9-octadecenoate, methyl octadecanoate (Z)-9-octadecenoic acid and octadecanoic acid. Among them, dodecanoic and (Z)-9-hexadecenoic acids showed significant positive ovipositional response at different concentrations whereas all the esters showed deterrent/repellent ovipositional effect.     

植物内生放线菌Lj20的鉴定及其抗真菌物质的合成

[目的]菌株Li20是从辣椒植株根部分离得到的一株有抗真菌活性的植物内生放线菌.为了进一步开发利用这一放线菌,对其进行了鉴定及抗菌活性物质的研究.[方法]根据Lj20的形态特征、培养特征、生理生化特征、细胞壁组分和16s rDNA序列对其进行鉴定.结合GC-MS分析,合成了代谢产物中所含的抗真菌活性物质,并用菌丝生长抑制法测定其生物活性.[结果]Lj20菌株属于链霉菌属,与娄彻氏链霉菌(Streptomyces rochei)极为相似.代谢产物中含有2,6-二叔丁基对甲酚和3,5-二叔丁基-4-羟基-苯甲醚.两种化合物对番茄灰霉病菌的EC<,50>值分别为237.04 mg/L和186.48 mg/L.[结论]菌株Li20鉴定为娄彻氏链霉菌(Streptomyces rochei).2,6-二叔丁基对甲和3,5-二叔丁基-4-羟基-苯甲醚对番茄灰霉病菌都有较强的抑制作用.     

Anthelmintic profile of methyl 5(6)-(4-methylpiperidin-1-yl) carbonylbenzimidazole-2-carbamate in experimental helminthiases

Biological evaluation of methyl 5(6)-(4-methylpiperidin-1-yl) carbonylbenzimidazole-2-carbamate against Ancylostoma ceylanicum, Nippostrongylus brasiliensis, Syphacia obvelata, Hymenolepis nana, H. diminuta and Cysticercus fasciolaris in experimental animals is reported. The compound (mg/kg) causes 100% elimination of A. ceylanicum (25 x 1), N. brasiliensis (100 x 1), S. obvelata (50 x 1), H. nana (250 x 3) and C. fasciolaris (50 x 10). It was also effective against the developing larvae (L3, L4 and L5) of A. ceylanicum at a single oral dose of 100 mg/kg. Another study indicated that the compound elicits 100% response within 32 hr of drug administration. The drug is well tolerated and LD50 is greater than 4500 mg/kg.     

Specialist deterrent chemoreceptors enable Pieris caterpillars to discriminate between chemically different deterrents

Pieris butterflies (Lepidoptera: Pieridae) are specialist herbivores of cruciferous plants. They exploit glucosinolates, secondary plant metabolites chemotaxonomically characteristic for this plant family, as token stimuli. In addition to particular glucosinolates, some genera of the Cruciferae contain cardenolides, steroidal allelochemicals that act as potent feeding and oviposition deterrents to several Pieris species. We investigated the sensory mechanisms by which these compounds are perceived in larvae. Pieris caterpillars and many other lepidopterous species are endowed with so-called generalist deterrent receptors, that respond to a broad spectrum of secondary plant substances. In Pieris caterpillars we found a second type of deterrent chemoreceptor in maxillary styloconic taste sensilla. This neuron is very sensitive to cardenolides (threshold 0.1–0.3 M). The generalist deterrent receptor also responds to these substances but its threshold lies at 50–100× higher concentrations. In behavioural preference experiments Pieris brassicae L. caterpillars preferred cardenolide-treated cabbage leaf discs when confronted with a choice between them and a deterrent substance that does not occur in the Brassicaceae. The cardenolides acted as potent deterrents when offered against untreated cabbage leaf discs. This demonstrates that the balance of activity elicited in the two types of deterrent chemoreceptors determines the behavioural decision.     

Oviposition and feeding behavior of the maize borer,Chilo partellus,in response to eight essential oil allelochemicals

Eight essential oil compounds were evaluated against the maize borer, Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae), to determine their influence on oviposition and feeding behavior. Thymol was the most active compound against C. partellus when evaluated as an oviposition deterrent (ODI₅₀ = 1.36 mg ml^?1), an ovicide (LC₅₀ = 2.06 mg ml^?1), or a feeding deterrent (FI₅₀ = 141.8 μg cm^?2) in laboratory experiments. The results corroborated with greenhouse experiments, in which egg laying on maize plants was inhibited significantly when the treatment was 15 times the concentration used in the laboratory experiments. However, there was neither any correlation between oviposition deterrence and feeding inhibition, nor between oviposition deterrence and ovicidal action. Apparently, toxicity per se or ovicidal action does not play any role in choice of oviposition in C. partellus. This was more obvious when the efficacy of compounds was compared in greenhouse experiments where ODI values and number of eggs laid on the treated leaves did not differ significantly in choice and no‐choice situations. Apparently, toxicity plays an important role in predicting host plant choice, but behavioral response in terms of oviposition preference is independent of toxic action, particularly for non‐host toxins. Thus, the same compounds affecting oviposition behavior on the one hand and having ovicidal or feeding deterrent properties on the other could be useful in field situations in any area‐wide integrated pest management model.     

东莨菪内酯与双脱甲氧基姜黄素对朱砂叶螨毒力的温度效应

为明确植物性杀螨活性物质东莨菪内酯与双脱甲氧基姜黄素对朱砂叶螨Tetranychus cinnabarinus雌成螨毒力的温度效应, 采用玻片浸渍法测定了两者不同温度下的杀螨活性。结果表明： 在8～26℃的温度范围内, 东莨菪内酯和双脱甲氧基姜黄素对朱砂叶螨雌成螨的毒力呈正温度系数; 在26～34℃的温度范围内两者对朱砂叶螨雌成螨的毒力呈负温度系数。其中26℃下东莨菪内酯和双脱甲氧基姜黄素表现出较好杀螨活性, 处理后48 h的致死中浓度(LC₅₀)分别为0.1884和0.3376 mg/mL; 23℃下的毒力次之。致死中浓度(y)与温度(x)关系的拟合方程为： 东莨菪内酯: y₁= 0.006x₁²-0.278x₁+3.403; 双脱甲氧基姜黄素: y₂=0.007x₂²-0.354x₂+4.826。对y求最小值得出, 东莨菪内酯和双脱甲氧基姜黄素对朱砂叶螨雌成螨的最高毒力温度分别为23.2℃和25.3℃, LC₅₀分别为0.1828和0.3504 mg/mL。据此认为, 在一定的温度范围内, 随着温度的升高, 这两种植物性杀螨活性物质对朱砂叶螨的毒力与温度先呈正相关, 到达最佳毒力温度后再呈负相关。     

木鳖子提取物对朱砂叶螨的触杀活性

测定了木鳖子提取物对朱砂叶螨的触杀活性。用甲醇、氯仿、石油醚3种不同极性的溶剂提取,石油醚提取率最高为30.79%,且对朱砂叶螨成螨和卵的触杀活性均高于其他两种溶剂的提取物,24 h校正死亡率分别为77.52%和72.04%。用甲醇对石油醚提取物萃取,发现甲醇萃取物活性明显高于石油醚部分,对成螨和卵处理24 h后的校正死亡率分别为89.60%和74.65%,产卵抑制率为62.74%,驱避率为58.23%。柱层析对甲醇萃取物进行分离得到10种组分,组分5活性最高,浓度为2 mg/mL时,24 h校正死亡率为86.15%。用薄层层析和气相色谱质谱联用仪分别检测组分5纯度和主成分,初步确定活性成分为α-菠菜甾醇。     

Acaricidal activities of extracts of Kochia scoparia against Tetranychus urticae, Tetranychus cinnabarinus, and Tetranychus viennensis (Acari: Tetranychidae)

Extracts of an annual herbaceous plant, Kochia scoparia (L.) Schrad (Macrophomina), were bioassayed to determine their acaricidal activities against Tetranychus urticae Koch, Tetranychus cinnabarinus (Boisduval), and Tetranychus viennensis Zacher (Acari: Tetranychidae) in the laboratory. Extracts had both contact and systemic toxicity to these mites. Three solvents were tested for preparing crude extracts: petroleum ether, chloroform, and methanol. Methanol was the most effective solvent, extracting 3.11-4.53% of the acaricide. Petroleum ether was the least effective solvent, extracting 1.25-1.54%. However, extracts with chloroform resulted in the highest mite mortality (78.86%), and ultrasound-assisted extraction required the least time (10 min). Concentrated extracts were prepared using chloroform, methyl acetate, or distilled water as a solvent. Mite mortalities from the concentrated extracts by methyl acetate or distilled water were significantly lower than those by chloroform. The mean lethal concentrations (LC50) of the extracts by chloroform, methyl acetate, and distilled water to the mites were 0.71 +/- 0.06, 2.08 +/- 0.16 and 8.75 +/- 0.062 mg/ml, respectively. After liquid chromatography and thin layer chromatography, the concentrated extracts by chloroform were separated into seven groups of isolated fractions and tested for acaricidal activity.     

枣飞象对枣树植物挥发物的EAG和行为反应

【目的】枣飞象Scythropus yasumatsui是枣树Zizyphus jujuba主要害虫。近年来,在陕西和山西枣区暴发成灾,造成了严重的经济和生态损失。本研究旨在明确枣树挥发性物质在枣飞象成虫化学通讯中的作用,为该虫植物源引诱剂开发和研制提供基础资料。【方法】利用顶空吸附法收集5个枣树品种(木枣、狗头枣、赞皇枣、骏枣和酸枣)的枣芽挥发物,采用气质联用(GC-MS)进行化学指纹谱的鉴定和分析;随后分别利用触角电位(electroantennogram, EAG)仪和Y型嗅觉仪测定枣飞象成虫对17种枣树挥发性物质的EAG和行为反应。【结果】5个品种枣树的枣芽中共鉴定出挥发性物质6类26种,包括9种萜烯类、6种酯类、4种醇类、4种烷类、2种醛类和1种酚类;不同品种枣芽挥发性物质种类和含量具有差异。EAG试验结果表明,枣飞象成虫对测试的17种枣树挥发性物质的EAG反应相对值有明显差异。枣飞象成虫对D-柠檬烯、正十三烷、正十四烷、正十五烷、壬醛、棕榈酸甲酯、油酸甲酯7种挥发性物质的EAG反应较强。当挥发性物质浓度为0.1~100 μg/μL时,随着浓度增加,枣飞象成虫的EAG反应相对值先增加后下降,刺激浓度为50 μg/μL时EAG反应相对值达到最大。50 μg/μL浓度下,枣飞象雌成虫对棕榈酸甲酯和壬醛EAG反应相对值分别为3.84和3.67,雄成虫对棕榈酸甲酯和壬醛EAG反应相对值分别为3.47和3.21,极显著高于对其他挥发性物质的EAG反应相对值。行为反应结果表明,枣飞象雌雄成虫对棕榈酸甲酯和壬醛有明显趋向性, 选择率均大于65%,雄成虫对十五烷有明显趋向性,雌雄成虫对其他供试的物质无明显趋向性。【结论】棕榈酸甲酯和壬醛对枣飞象雌雄成虫均有明显吸引作用,十五烷对雄成虫有明显吸引作用。结果提示棕榈酸甲酯和壬醛可能与枣飞象对不同品种枣树偏好性选择密切相关。     

姜黄素类化合物对朱砂叶螨的生物活性

分别用玻片浸渍法和叶片浸渍法测定了从姜黄中分离的姜黄素(curcumin,CCM)、去甲氧基姜黄素(demethoxycurcumin,DMC)和双去甲氧基姜黄素(bisdemethoxycurcumin,BDMC) 3种天然姜黄素类化合物对朱砂叶螨Tetranychus cinnabarinus Boisduval的成螨、若螨、卵的触杀活性以及对成螨产卵的抑制作用。结果表明：3种化合物对朱砂叶螨的生物活性大小依次为BDMC>DMC>CCM。3种化合物对朱砂叶螨成螨触杀活性最高者为BDMC,处理24 h和48 h其LC₅₀分别为1.18和0.51 mg/mL。对若螨触杀活性的大体趋势与对成螨的相同,其中处理48 h,BDMC对若螨的LC₅₀最小,为2.48 mg/mL。3种化合物对朱砂叶螨卵的触杀毒力也同样表现为BDMC>DMC>CCM。3种单体化合物都表现出一定的对朱砂叶螨雌成螨的产卵抑制作用。对姜黄素类化合物构效关系的初步研究,明确了甲氧基在姜黄素模板上对杀螨活性的贡献,对于开发具经济价值的叶螨类杀螨剂或者筛选先导化合物模板,具有一定的参考价值。     

Natural oviposition-deterring chemicals in female cotton bollworm, Helicoverpa armigera (Hubner)

Observation of the oviposition behavior of cotton bollworm demonstrated the existence of substances that can act as oviposition deterrents. The scales, abdomens and tarsi of the moths, the most likely carrier, were extracted for the substances. An acetone extract exhibiting an oviposition deterrent effect was analyzed using gas chromatography and combined gas chromatography-mass spectroscopy. Three components, 4-methyl-4-hydroxyl-pentanone-2, hexadecanoic acid and (Z)-9-octadecenoic acid, were identified, being present in the ratio 1:2:2. Experiments with synthetic mixtures indicated that a mixture of equal amounts of the two organic acids exhibited similar repellent and deterrent activity to a synthetic mixture of all three components. It is concluded that the natural oviposition-deterring pheromone is a mixture of hexadecanoic acid and (Z)-9-octadecenoic acid.     

葫芦素B对美洲斑潜蝇成虫产卵和取食的抑制作用研究

美洲斑潜蝇是严重危害瓜、豆类蔬菜的世界性害虫之一,主要以幼虫潜伏在叶表皮下的叶肉组织中为害,给防治带来很大困难。本研究测定了葫芦素B对美洲斑潜蝇成虫产卵和取食的抑制作用。在非选择性试验中,当葫芦素B使用浓度为500~2000 mg/L时,对美洲斑潜蝇成虫的产卵抑制率达31.2~69.9%,对美洲斑潜蝇成虫的取食抑制率达61.7~64.9%;在选择性试验中,葫芦素B使用浓度达1000~2000 mg/L时,对美洲斑潜蝇成虫的产卵抑制率和取食抑制率分别为54.8~71.1%和57.2~65.2%;研究结果表明:利用葫芦素B可有效地抑制美洲斑潜蝇成虫的产卵和取食,减轻其幼虫的为害,为安全、有效地控制美洲斑潜蝇提供了一条新途径。     

黄蒿挥发油对蚊虫的毒杀活性及其化学成分

采用培养板浸液法和三角瓶药膜法研究了黄蒿挥发油对蚊虫幼虫和成虫的毒杀效果,采用GC MS-DS联用分析了其化学成分.结果表明,挥发油对淡色库蚊幼虫和成虫具有较高的作用效果,且作用速度较快.对幼虫处理后2 d的LC₅₀值约为12.5 mg·L^-1.综合毒力测定显示,挥发油对成虫具有明显的击倒和致死作用,1 μg·cm^-2和10 μg·cm^-2剂量24 h致死率分别为70%和100%.黄蒿含挥发油0.38％,共鉴定出38种化合物,检出物占总质量87.53％,其中萜烯类12种,占45.04％,为黄蒿挥发油的主要成分.     

Isolation and identification of acaricidal compounds in Inula japonica (Asteraceae)

We identified acaricidal compounds in Inula japonica Thunberg (Asteraceae) that were effective against carmine spider mite, Tetranychus cinnabarinus (Boisduval). Petroleum-ether extracts from I. japonica were toxic to T. cinnabarinus, with a 50% lethal concentration (LC50) value of 1.18 mg/ml. Silica gel column chromatography was used to separate the acaricidal components. Seventeen of 38 fraction groups had mite mortality rates >50%, nine fraction groups had rates >60%, and three fraction groups had rates >80% at 2 mg/ml. The major volatile compounds in the bioactive fraction groups were identified by gas chromatography-mass spectroscopy, and beta-sitosterol (1), stigmasterol (2), lupeol (3), and alpha-amyrin (4) were identified and determined to have acaricidal activity against T. cinnabarinus in vitro.