Chemical constituents and fumigant toxicity of essential oil from Carum copticum against two stored product beetles

Plant secondary metabolites play an important role in plant-insect interactions and therefore such compounds may have insecticidal or antifeedant activity against insects. Carum copticum C. B. Clarke （Apiaceae） is one of these plants that have medicinal effects on humans. The chemical composition of the essential oil from dry seeds of C. copticum was studied by gas chromatography （GC） and gas chromatography mass spectrometry （GC-MS）. Thymol （41.34%）,α-terpinolene （17.46%） and ρ-cymene （11.76%） were found to be the major constituents of the oil. In fumigant toxicity tests with the essential oil against adults of Sitophilus oryzae （L.） and Tribolium castaneum （Herbst） at 27 ±1℃ and 60% ± 5% RH, it was observed that S. oryzae （LC50 = 0.91 μL/L） were significantly susceptible than T. castaneum （LC50 = 33.14 μL/L）. The mortalities of the insect species reached 100% at concentrations higher than 185.2 μL/L and 12-h exposure time. The findings indicate the strong insecticidal activity of C. copticum oil and its potential role as a fumigant for storedproduct insects.     

Biological activity of two juvenoids and two ecdysteroids against three stored product insects

The insecticidal activity of juvenile hormone agonists methoprene and pyriproxyfen, and the ecdysone agonists RH-5849 and tebufenozide was evaluated against susceptible and actellic-resistant strains of Tribolium castaneum and susceptible strains of Rhyzopertha dominica and Sitophilus oryzae. Concentrations ranging from 0.1 to 20 ppm of the analogues were mixed in the food medium to which the tested insects were exposed. The results showed that all these compounds could affect the development of the tested species to differing extents but had no effect on the mortality of parental adults. The two JH analogues did not prolong the life span of R. dominica and S. oryzae, but very greatly extended that of T. castaneum. The extension led to the production of giant larvae and failure to pupate. Actellic-resistant strain of T. castaneum showed some cross-resistance to methoprene and pyriproxyfen, but not to RH-5849 and tebufenozide. Pyriproxyfen was the most effective compound among the four IGRs; a concentration of 0.1 ppm could completely inhibit the F(1) adult occurrence of both S- and R-strains of T. castaneum and its LC(90)s for controlling R. dominica and S. oryzae were 0.1 and 1.2 ppm, respectively. Methoprene was highly effective against R. dominica, but less active on S. oryzae. RH-5849 could achieve almost complete control of F(1) adults of T. castaneum and R. dominica at 10 ppm, but was less potent on S. oryzae. Tebufenozide appeared to be much less active on these three species compared with the other three compounds. The percentage reductions of F(1) adults for S- and R-strains of T. castaneum at a concentration of 20 ppm were 80 and 99%, respectively.     

椿叶花椒果实精油对两种蚊虫的生物活性及成分分析

为筛选环保型的植物源灭蚊活性物质, 研究了椿叶花椒 Zanthoxylum ailanthoides 果实精油对白纹伊蚊Aedes albopictus和致倦库蚊Culex pipiens quinquefasciatus成蚊的熏杀活性, 并测试了精油对这两种蚊幼虫的毒杀效果。此外, 采用GC-MS分析了该精油的化学成分。 结果表明：在102.145 μg·cm^-3熏杀剂量下, 精油对白纹伊蚊和致倦库蚊成蚊的KT50值分别为2.788和3.505 min, 24 h致死率分别为100%和97.53%。该精油对白纹伊蚊和致倦库蚊4龄幼虫的LC50值分别为45.237和20.759 mg·L^-1。从椿叶花椒果实精油中共鉴定出14种化合物, 其中2-十一酮为主要成分, 相对含量为89.86%。结果说明椿叶花椒果实精油对两种蚊虫均有明显的杀虫活性, 具有开发成植物源灭蚊剂的潜力。     

不同居群山苍子果实精油和柠檬醛含量及其与地理-气候因子的相关性

采用水蒸气蒸馏法和气相色谱技术对取自浙江富阳、贵州毕节和织金、湖南永州、福建永安和建瓯、云南景东、四川长宁、江西安远和分宜10个居群的山苍子[ Litsea cubeba (Lour.) Pers.]果实精油含量和柠檬醛含量进行测定,并分析了果实精油含量和柠檬醛含量与地理-气候因子的相关性;在此基础上对供试居群进行了聚类分析.测定结果表明:各居群的果实精油含量和柠檬醛含量差异显著,精油含量均值为3.60％,变异系数(CV)为1.54％～10.46％;柠檬醛含量均值为3.52％,CV为24.78％ ～40.54％;云南景东居群精油含量最高(4.56％)、江西分宜居群最低(3.14％);福建永安居群柠檬醛含量最高(7.01％)、贵州毕节居群最低(1.85％),且柠檬醛含量的表型分化系数为57.87％,说明居群间柠檬醛含量的变异幅度大于精油含量,且居群间柠檬醛含量的变异程度大于居群内.相关性分析结果显示:山苍子果实精油含量与经度和7月均温呈极显著负相关,与年降雨量呈显著负相关,与海拔呈极显著正相关;柠檬醛含量与经度和年降雨量分别呈显著和极显著正相关,说明精油含量随经度增大而降低,且受环境水分和温度变化的影响较大;而柠檬醛含量随经度增大而提高,并明显受生境中水分条件的调节.聚类分析结果表明:在欧氏距离15处,供试的10个山苍子居群主要分成3类,根据地理位置大体可划分为西南部和东南部2个种质类型,其中福建永安居群较为特殊.研究结果表明:不同居群山苍子果实精油含量和柠檬醛含量差异与遗传特性、地理分布和生境气候条件均有一定的相关性.     

Synergistic repellent activity of hot and cool thermal-sense compounds against two stored product insect pests

The repellent activities of one hot thermal-sense compound, vanillyl butyl ether (VBE), and two cool thermal-sense compounds, menthoxypropanediol (MPD) and (?)-isopulegol (IPG), against two stored product insects, Tribolium confusum and Liposcelis bostrychophila, were investigated. Such thermal-sense compounds affect mammals through transient receptor potential (TRP) channels, and both types of agonists (VBE and menthol) exhibited mutually inhibitory effects on mammalian TRPV1 and TRPM8 channels. Each compound exhibited repellent activity against both T. confusum and L. bostrychophila in a dose-dependent manner. Furthermore, synergistic effects were observed between VBE and MPD or IPG. The composition of TRP channels is different between mammals and insects. These results suggest that the use of thermal-sense compounds might serve as an alternative to essential oils in stored products protection.     

Bioactivity of two major constituents isolated from the essential oil of Artemisia judaica L

The essential oil of Artemisia judaica L., grown on Sinai Peninsula of Egypt, was extracted via hydrodistillation. Chromatographic separation on repeated silica gel columns led to isolate two compounds namely piperitone and trans-ethyl cinnamate. Insecticidal, antifeedant and antifungal properties of the isolated compounds were examined. Both compounds showed pronounced insecticidal and antifeedant activity against the third instar larvae of Spodoptera littoralis (Boisd). trans-Ethyl cinnamate (LD₅₀ = 0.37 μg/larva) was more toxic than piperitone (LD₅₀ = 0.68 μg/larva). The two isolated compounds revealed antifeedant activity in a concentration dependent manner, with complete feeding inhibition at a concentration of 1000 μg/ml. When tested for antifungal activity against four plant pathogenic fungi, the isolated compounds exhibited a moderate to high activity.     

Fumigant toxicity of essential oil of Mugwort (Artemisia vulgaris L.) against three major stored product beetles

Application of plants essential oil for the evaluation of their fumigant toxicity and insecticidal properties is the goal of many researches. In this study, aerial parts of Artemisia vulgaris L. were subjected to hydrodistillation using a Clevenger-type apparatus, and the chemical composition of the volatile oils was studied by gas chromatography–mass spectrometry. Alpha-Pinene (23.56) was the main component of the essential oil. Insecticidal activity of the oil was evaluated against Tribolium castaneum (Herbst), Callosobruchus maculatus (F.) and Rhizopertha dominica (F.) after 24, 48 and 72 h. After 24-h exposure time, C. maculatus was more susceptible (LC₅₀ = 52.47 μl/l air) and T. castaneum was more tolerant (LC₅₀ = 279.86 μl/l air) than other species. LT₅₀ values were indicated using highest concentration of LC₅₀ tests for three species. In general, mortality increased as the doses of essential oil and exposure time increased. These results proposed that A. vulgaris oil might have potential as a control agent against T. castaneum, R. dominica and especially C. maculates in storages.     

Bioactivities of black cumin essential oil and its main terpenes from Tunisia

Ex vivo antioxidant, anti-inflammatory, anticancer and antibacterial activities of the essential oil from Tunisian Nigella sativa seeds and its main terpenes (p-cymene, γ-terpinene, thymoquinone, β-pinene, carvacrol, terpinen-4-ol and longifolene) were determined. The essential oil exhibited strong ex vivo antioxidant activity, inhibiting DCFH oxidation with an IC₅₀ of 1.0 µg/ml, and high anti-inflammatory activity, inhibiting NO radical excretion with an IC₅₀ value of 6.3 µg/ml. Thymoquinone was found to be the most active to decrease DCFH oxidation and NO excretion. The oil was found to significantly inhibit the growth of A-549 and DLD-1 cancer cell lines (IC₅₀ values of 43.0 and 46.0 µg/ml, respectively) and to exert antibacterial activity against Staphylococcus aureus and Escherichia coli with IC₅₀ values of 12.0 and 62.0 µg/ml. The anticancer and antibacterial activities could be mainly due to the action of thymoquinone and longifolene.     

我国仓储昆虫研究和防治的回顾与展望

与人类生活和经济发展密切相关的各类农产品,在其储藏期间和加工过程中常遭受仓储昆虫的严重为害。至今全世界已记载的仓储昆虫和螨类约500种,我国有383种,其中仓储昆虫242种,螨类141种。昆虫和螨类二者在储藏物中的栖境、食性和危害性基本相似,因此常通称为仓储害虫。它们多数潜藏在仓库、厂房、贷栈、商店、居室、图书馆、档案馆等处,为害储藏粮食、油料、动植物食品、中药材、烟草、棉、麻、丝、皮毛、呢料、图书、档案、纸质文物、竹木及其制品、电缆、塑料以及进出口贸易中的检疫商品等,造成很大损失。如粮油储藏期每年因虫害损…     

龙柏精油对小菜蛾的生物活性

龙柏精油对小菜蛾Plutella xylostella(L.)的室内生物活性测定结果表明,熏蒸作用是龙柏精油对小菜蛾的主要作用方式,熏蒸实验中当龙柏精油浓度为5.00 mg/L2、.50 mg/L时,处理后48 h小菜蛾2龄幼虫的校正死亡率分别为92.33%、80.29%。龙柏精油对小菜蛾具有较强的非选择性拒食作用和产卵忌避作用,但由于精油的挥发性效果不持久。当龙柏精油浓度为5.00 mg/L和2.50 mg/L时,24 h小菜蛾的产卵忌避率分别为80.45%和77.42%;而48 h则降为72.30%和61.79%。当龙柏精油浓度为5.00,2.50和1.25 mg/L时,24 h的非选择性拒食率分别为86.70,74.36和70.93%,48 h的非选择性拒食率分别降为82.36,71.40和60.40%。龙柏精油对小菜蛾具有一定的触杀活性,当龙柏精油浓度为5.00 mg/L时效果最好,24 h和48 h的校正死亡率分别为60.00%和76.67%。     

山苍子叶内生真菌的纯化与鉴定

本研究选用PDA培养基,通过组织块分离法从山苍子叶中分离得到两株内生真菌。对照真菌鉴定手册,根据菌株和菌丝体形态学特征,并给合ITS区段的碱基序列分析,鉴定两株内生分别属于顶孢霉属和芒果球座菌属。     

Antileishmanial activity of essential oil from Chenopodium ambrosioides and its main components against experimental cutaneous leishmaniasis in BALB/c mice

Chenopodium ambrosioides have been used during centuries by native people to treat parasitic diseases.Aims of the studyTo compare the in vivo anti-leishmanial activity of the essential oil (EO) from C. ambrosioides and its major components (ascaridole, carvacrol and caryophyllene oxide).Materials and methodsAnti-leishmanial effect was evaluated in BALB/c mice infected with Leishmania amazonensis and treated with the EO, main compounds and artificial mix of pure components by intralesional route at 30 mg/kg every 4 days during 14 days. Diseases progression and parasite burden in infected tissues were determined.ResultsEO prevented lesion development compared (p < 0.05) with untreated animals and treated with vehicle. In addition, the efficacy of EO was also statistically superior (p < 0.05) compared with the glucantime-treated animals. No potential effects were observed with pure components treatment. Mix of pure compounds cause death of animals after 3 days of treatment.ConclusionsOur results demonstrate the superiority of EO against experimental cutaneous leishmaniasis caused by L. amazonensis.     

竹叶花椒果实精油对两种蚊虫的毒杀活性研究

采用浸液法测试了竹叶花椒果实的水蒸汽蒸馏精油对白纹伊蚊和致倦库蚊幼虫的毒杀效果,并用三角瓶密闭熏蒸法研究了精油对这两种成蚊的熏杀活性;此外,采用GC-MS分析了该精油的化学成分。研究结果:(1)精油对白纹伊蚊和致倦库蚊的Ⅰ、Ⅱ、Ⅲ、Ⅳ龄期幼虫及蛹的LC50值分别为25.634/61.472、31.763/76.431、52.356/110.172、258.497/121.884和198.263/162.048mg.L-1;(2)精油对白纹伊蚊和致倦库蚊成蚊的LC50值分别为24.957和29.517μg.cm-3;(3)在147.52μg.cm-3熏杀剂量下,精油对白纹伊蚊和致倦库蚊成蚊的KT50值分别为3.493和2.993min,24h致死率均为100%;(4)共鉴定出18种化合物,其中萜烯类10种,占精油总量的67.122%,为竹叶花椒果实精油的主要成分。竹叶花椒果实精油对白纹伊蚊和致倦库蚊均有明显的致死作用,且作用速度快,具有开发为植物源杀蚊剂的潜力。     

Toxicity of propylene oxide at low pressure against life stages of four species of stored product insects

The relative toxicity of propylene oxide (PPO) at a low pressure of 100 mm Hg to four species of stored product insect at 30 degrees C over a 4-h exposure period was investigated. PPO at 100 mm Hg was toxic to all four species tested: Tribolium castaneum (Herbst), Plodia interpunctella (Hübner), Ephestia cautella (Wlk.), and Oryzaephilus surinamensis (L.). There were differences in susceptibility between the life stages of the tested insect species. Mortality tests on all life stages of the insects resulted in LD99 values ranging from 4.7 to 26.1 mg/liter. The pupal stage of E. cautella, O. surinamensis, and T. castaneum was the most tolerant stage with LD99 values of 14.4, 26.1, and 25.7 mg/liter, respectively. For P. interpunctella, the egg stage was most tolerant, with a LD99 value of 15.3 mg/liter. Generally, PPO at 100 mm Hg was more toxic to P. interpunctella and E. cautella than to O. surinamensis and T. castaneum. A 99% mortality of all life stages of the tested species was achieved at a concentrations x time product of 104.4 mg h/liter. These findings indicate that a combination of PPO with low pressure can render the fumigant a potential alternative to methyl bromide for rapid disinfestation of commodities.     

Chemical Composition and Antibacterial Activity of Essential Oils from Different Parts of Litsea cubeba

The composition of the essential oils obtained by hydrodistillation of different parts of Litsea cubeba, including roots, stems, leaves, alabastra (flower buds), flowers, and fruits, were investigated by GC (RI) and GC/MS. The antimicrobial activity of the oils was assessed with disc diffusion and microbroth dilution assays. The results showed large variations in the composition among the different oils. The major components in the oils from roots and fruits, from stems, leaves, and alabastra, and from flowers were citral B (neral), β‐phellandrene, and β‐terpinene, respectively. The inhibition zone (DD) and MIC values for the bacterial strains tested, which were all sensitive to the essential oil of L. cubeba, were in the range of 10.1–35.0 mm and 100–1000 μg/ml, respectively. Hence, the oils of the various parts showed moderate activity against the tested bacteria. This investigation showed that the antibacterial activity of L. cubeba was attributed to the essential oils, thus they can be a potential medicinal resource.     

紫茎泽兰提取物对四种储粮害虫的杀虫活性

紫茎泽兰提取物对米象、玉米象、绿豆象和蚕豆象等 4种储粮害虫成虫具有强烈的熏杀活性 ,用 4 4.4 4mg L的浓度熏蒸处理 4 8小时后 ,每种成虫死亡率均达到 1 0 0 .0 0 %。熏蒸毒力测定结果表明 ,紫茎泽兰提取物对上述 4种成虫 2 4小时的LC50 分别为 1 4 .65,1 2 .80 ,2 5.0 7和 1 2 .2 0mg L ,4 8小时的LC50 分别为 1 1 .79,9.67,1 3 .2 9和 9.76mg L。     

A film technique for the biological evaluation of pyrethrum-in-oil insecticides for use against stored product insects in warehouses

There is need for a technique whereby a given insecticidal preparation can be compared with a standard containing 0.8% (w/v) pyrethrin 1 in a heavy white oil and pronounced biologically equal or inferior to the standard within known and reasonable limits. A film method was investigated, Tribolium castaneum beetles being used as the test insects.
Numerous factors which may influence the kill achieved are discussed. The results of preliminary work, planned to help in the standardization of some of these factors, are summarized.
Several materials were tested to ascertain their suitability for reception of the insecticidal film and, as thin greaseproof paper showed promise, its possibilities were explored. Although 0.3 % pyrethrin I could be distinguished from 0.4%, 0.5% could not be distinguished from 0.8%, and the results throughout were very heterogeneous.
Woven Nylon proved more satisfactory, since the test just failed to establish a significant difference between 0.6 and 0.8% pyrethrin 1. The origin of a pink coloration of the substrate, when T. castaneum beetles were confined on Nylon sprayed with pyrethrum in oil, was investigated.
Whatman filter paper no. 544 proved the best substrate, and a comparative test on it will distinguish 0.65% pyrethrin 1 from the standard 0.8%; the limit could probably be raised to 0.7%.
The influence of several factors on the homogeneity of the results was investigated, and the importance was shown of allowing beetles time to recover from the mechanical shock inherent in the method of counting into batches.
Directions are given for carrying out the film technique for comparing preparations of relatively high pyrethrin content. The method does not measure the direct spray or fumigant action of the insecticide.
The technique described is compared with the Peet-Grady method for evaluating liquid household insecticides of low pyrethrin content. A simplified, but less accurate, design for the test is indicated.     

Bioactivity of fenchone and Plectranthus glandulosus oil against Prostephanus truncatus and two strains of Sitophilus zeamais

The toxic, repellent and reproduction inhibitory effects of Plectranthus glandulosus essential oil and one of its major compounds, fenchone, were evaluated against adult Prostephanus truncatus (Horn) and for two strains of Sitophilus zeamais Motschulsky from Cameroon and Germany. Maize grains were coated with the oil at 0, 10, 20, 40 and 80 μl/40 g grain and fenchone at 0, 20, 40, 80 and 120 μl/40 g grain. Mortality was assessed over a 7‐day period, followed by the determination of F₁ progeny production. The repellence of the two products was evaluated at five rates (0.5, 1, 3, 5, 10 μl/half disc) in a choice bioassay on filter paper. The oil and fenchone caused significant dose‐dependent mortality to the three insects, with the oil achieving 100% and 90% mortality for the two S. zeamais strains and P. truncatus, respectively, within 1 day of exposure at the dosage of 80 μl/40 g grain. The insects were less susceptible to fenchone compared with the crude oil. The German strain of S. zeamais was susceptible to the oil than the Cameroonian strain. At the dosage of 20 μl/40 g grain, S. zeamais F₁ progeny emergency was completely inhibited by the oil, while 80 μl/40 g grain treatment with fenchone prevented also insect emergence. Plectranthus glandulosus oil generally evoked a maximum per cent repellency of 100% for the three insects, but fenchone caused 55–60% to S. zeamais and 80% to P. truncatus. These results suggest that fenchone, though a major constituent of P. glandulosus oil, may only be a minor component of its bioactivity.