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1.
Pectolinaringenin was isolated from chloroform extract of Clerodendrum phlomidis L. and was evaluated at 12.5 to 100 ppm concentrations for its effects on total protein, esterase and glutathione S-transferase (GST) activities of Earias vittella and Helicoverpa armigera. At 100 ppm, the compound reduced total protein content by 55.75% and 53.01% over control with IC50 values of 74.37 and 212.31 ppm in E. vittella and H. armigera, respectively. At 100 ppm it also reduced GST and esterase enzyme activities in E. vittella by 37.53% and 43.09% over control, with IC50 values of 133.00 and 111.76 ppm, respectively. It also reduced GST and esterase activities in H. armigera by 43.14% and 47.421% over control with IC50 values of 114.38 and 98.78 ppm, respectively. Data were analyzed for their normality using the Shapiro-Wilk test and Levene’s statistics to determine the significant deviation. Pectolinaringenin could be used for the management of agricultural pests.  相似文献   

2.
利用Syntech触角电位仪,测定了甜菜夜蛾雌成虫对艾蒿提取物和4种溶剂(苯、乙酸乙酯、丙酮和乙醇)柱层析馏分的触角反应;利用涂纸法,测定了艾蒿提取物和4种馏分对甜菜夜蛾产卵的忌避特性和抑制特性。结果表明:甜菜夜蛾雌成虫对相同浓度(10 mg/mL)提取物和馏分的触角反应存在很大差异,对丙酮馏分的反应最强烈,电位值为9.632±1.054 mV,其次为乙酸乙酯和苯馏分,以乙醇馏分的反应最弱。提取物和不同馏分对甜菜夜蛾的产卵忌避作用存在很大差异,丙酮馏分、乙酸乙酯馏分和提取物都具有一定的忌避作用,而且随浓度上升而增强,其中以丙酮馏分的忌避作用最强,10 mg/mL的忌避率达到49.0%。不同浓度处理时,都以丙酮馏分和乙酸乙酯馏分的产卵抑制作用最强,且随浓度上升而增强,10 mg/mL的抑制率分别达到72.16%和68.95%;较高浓度(5 mg/mL和10 mg/mL)时,提取物、苯馏分和乙醇馏分也具有一定的产卵抑制作用。  相似文献   

3.
Oviposition deterrents have potential to prevent arthropod pest infestations making the crop habitat less or no favorable for pests to lay eggs and even to settle. In this study, seed oils of maize, safflower, rapeseed and castor oil plant were evaluated in the field between years of 2015 and 2016 for their oviposition deterrent activity against winterform females of pear psylla, Cacopsylla pyri (L.) (Hemiptera: Psyllidae), the most important insect pest of pears in Turkey. All the oils were used at three different concentrations, 1, 1.5 and 2 L/100 L water including 0.01% Tween-20 for a good mixture and applied at the dormant period (just before the first eggs were deposited by overwintered females). Only one application was made each year. Oviposition deterrency was evaluated by counts of eggs deposited by overwintered females of the pest on treated dormant shoots during the sampling times 3, 7, 14, 21 and 28 days after application. The results showed that significant reductions in total numbers of eggs laid by winterform females were observed in all the oil-treated plots compared with the controls sprayed with tap water including Tween-20 (0.01%). Safflower and castor oils exhibited 100% oviposition deterrent activity at all the concentrations during the 3 weeks period in both years. Even after 4 weeks, the deterrency of these oils was higher than 70%. In the control plots, the first eggs were deposited by overwintered females within 3 days after application in both years. These findings suggest that these oils are promising oviposition deterrents against winterform females of C. pyri.  相似文献   

4.
This study evaluated the direct antifungal activity of tiadinil [N-(3-chloro-4-methylphenyl)-4-methyl-1,2,3-thiadiazole-5-carboxamide], a systemic acquired resistance (SAR) inducer and two formulations of thymol (thymol I and thymol II) against Stagonosporopsis citrulli, the causal agent of gummy stem blight (GSB) disease of watermelon. Tiadinil, thymol I and thymol II completely inhibited the mycelial growth of S. citrulli in vitro at ≥?100 ppm. Conidial germination and germ tube elongation were completely inhibited by tiadinil at ≥?2000 ppm and by thymol-based formulations at ≥?100 ppm. A single foliar application of tiadinil at ≥?10 ppm or a single application of thymol I and II at ≥?1 ppm, 48 h before or after pathogen inoculation, significantly reduced disease severity of watermelon seedlings inoculated with 105/ml conidial suspension of S. citrulli, compared to respective nontreated controls. Plants treated with foliar application of tiadinil at ≥?1000 ppm before pathogen inoculation had significantly lower disease severity than plants that received an equivalent drench application. The efficacy of foliar application of tiadinil was affected by concentration and frequency of application. The study suggests direct antifungal activity of tiadinil, indicating a new mode of action of tiadinil against GSB disease of watermelon. The study also demonstrated direct antifungal action of thymol, a formulated active compound of essential oils, against S. citrulli and GSB disease of watermelon.  相似文献   

5.
With the aim of selecting potential botanical insecticides, seven plant extracts (Daphne mucronata (Family: Thymelaeaceae), Tagetes minuta (Asteraceae), Calotropis procera (Apocynaceae), Boenninghausenia albiflora (Rutaceae), Eucalyptus sideroxylon (Myrtaceae), Cinnamomum camphora (Lauraceae) and Isodon rugosus (Lamiaceae)) were screened for their toxic effects against four important agricultural pest insects, each representing a separate insect order; pea aphids of Acyrthosiphon pisum (Hemiptera), fruit flies of Drosophila melanogaster (Diptera), red flour beetles of Tribolium castaneum (Coleoptera), and armyworms of Spodoptera exigua (Lepidoptera). Aphids were the most susceptible insect with 100% mortality observed after 24 h for all the plant extracts tested. Further bioassays with lower concentrations of the plant extracts against aphids, revealed the extracts from I. rugosus (LC50 36 ppm and LC90 102 ppm) and D. mucronata (LC50 126 ppm and LC90 198 ppm) to be the most toxic to aphids. These most active plant extracts were further fractionated into different solvent fractions on polarity basis and their insecticidal activity evaluated. While all the fractions showed considerable mortality in aphids, the most active was the butanol fraction from I. rugosus with an LC50 of 18 ppm and LC90 of 48 ppm. Considering that high mortality was observed in aphids within 24 h of exposure to a very low concentration of the butanol fraction from I. rugosus, we believe this could be exploited and further developed as a potential plant-based insecticide against sucking insect pests, such as aphids.  相似文献   

6.
Aqueous leaf extract of Ricinus communis L (Euphorbiaceae), a cultivated plant in tropical countries, showed excellent insecticidal activity against Callosobruchus chinensis L (Coleoptera: Bruchidae). We have isolated and tested flavonoids as insecticidal and antimicrobial agents. The isolated flavonoids showed potential insecticidal, ovicidal and oviposition deterrent activities against C chinensis L. However, antimicrobial activity against the common microbial infestants of stored pulses, of which C chinensis is a major pest, was found to be insignificant. Two bands having Rf 0.63 and 0.69 were seen on HPTLC plates using mobile phase benzene + ethyl acetate + methanol + formic acid (12 + 4.5 + 2 + 1.5 by volume) as eluant. The Rf values and scanning of the spectrum in the ultraviolet region, showed identity with the flavonoids quercetin and kaempferol. This was further confirmed using HPLC and IR and UV spectrometry. HPLC and HPTLC chromatograms also suggested quercetin to be the major flavonoid present in the hydrolyzed aqueous leaf extract of R communis.  相似文献   

7.
A botanical natural product,AkseBio2, was evaluated under laboratory conditions for its oviposition deterrent, ovicidal and larvicidal (nymphicidal) effects against the pear psyllaCacopsylla pyri (L.) (Hemiptera: Psyllidae). The product exhibited a strong oviposition deterrent effect for winterform and summerform females and caused a reduction in the total number of eggs laid in both choice and no-choice assays. Significant mortalities in freshly laid eggs (0–48 h) and various nymphal stages of the pest were recorded in toxicity assays. At a concentration of 0.1% (formulation), the highest biological activity of the product was recorded against the young (1st and 2nd) nymphal stages (up to 87.4% mortality) in comparison with the other biological stages of the pest. It was less active against the older (3rd-5th) nymphs, causing 62.1% mortality at the same concentration. In assays with non-target organisms, a significant negative effect was not observed. There were no significant changes on treated plants up to 7 days after treatment in any trial, nor was there any phytotoxicity on plant tissue as a result ofAkseBio2 treatments. The results suggest that the product can be used in psylla control instead of synthetic insecticides and may serve as an integrated pest management (IPM) component in pear orchards. http://www.phytoparasitica.org posting July 14, 2004.  相似文献   

8.
20种杀虫剂对草地贪夜蛾的杀卵活性   总被引：2，自引：0，他引：2  
在前期测定14种杀虫剂对草地贪夜蛾杀卵活性的基础上,本文采用浸渍法又测定了20种不同类型杀虫剂的杀卵活性,以期为草地贪夜蛾卵期防治药剂的选择提供更全面的参考。结果表明,所测的20种杀虫剂均具有一定的杀卵活性。在100 mg/L浓度下,溴氰菊酯、高效氯氰菊酯和乙基多杀菌素表现出出色的杀卵活性,能够完全抑制卵的孵化,杀虫双的杀卵活性最差,低于10%。而噻虫胺、氯虫苯甲酰胺、高效氯氟氰菊酯、多杀霉素、联苯菊酯、噻虫啉、氧乐果、噻虫嗪、甲氰菊酯、烯啶虫胺和啶虫脒的杀卵活性相对较好,其校正死亡率在70.95%～98.52%之间,毒死蜱、吡虫啉、辛硫磷、虫螨腈和杀虫单的杀卵活性相对较差,在42.26%～61.51%之间。在10 mg/L浓度下,噻虫胺、乙基多杀菌素和噻虫啉的杀卵活性均在70%以上,而杀虫双、毒死蜱和烯啶虫胺的杀卵活性低于15%。特别是在100 mg/L和10 mg/L浓度下,新烟碱类杀虫剂噻虫胺和噻虫啉对草地贪夜蛾表现出较高的杀卵活性,分别为98.52%、76.91%和89.37%、72.44%。上述药剂在田间对草地贪夜蛾的杀卵效果还有待进一步验证。  相似文献   

9.
Diflubenzuron, 1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)urea, possesses larvicidal and ovicidal activities. On larvae it acts mainly as a stomach poison, yet it sometimes exhibits important contact activity. Though all instars can be controlled, older instars are generally less susceptible than younger ones. Histological inspections of Leptinotarsa decemlineata larvae revealed that after ending exposure to the compound, distortions in newly deposited cuticular layers decreased gradually. Ovicidal effects resulted from direct contact of diflubenzuron with eggs or from contamination of females by contact or feeding. Electron microscopic observations of embryos of Leptinotarsa decemlineata, contaminated via the female, also showed disturbed cuticule formation, suggesting a similar activity of the compound in larvae and in eggs. Spraying the eggs of Leucoptera scitella shows the compound to be mainly ovidical at a rate of 100 mg litre?1, whilst with lower concentrations (10 and 1 mg litre?1) the young larval instar will be killed. The levels of cross-resistance to diflubenzuron as a larvicide are low and the compound can be used effectively in the field against populations that are highly resistant to conventional insecticides. Laboratory and field results, based on larvicidal and ovicidal activities of diflubenzuron, are discussed in respect of species belonging to the Diptera, Lepidoptera, Coleoptera, Acarina (Phyllocoptruta oleivora) and Hemiptera (Eurydema oleraceum and Psylla piri).  相似文献   

10.
We prepared an ethanol extract from Laminaria japonica, and obtained five fractions from the extract using various solvents. We investigated the antibacterial activities of the fractions against Clavibacter michiganensis subsp. sepedonicus (Spieckermann & Kotthoff) Davis et al., the causal agent of bacterial ring rot of potato (BRR). Among all the fractions, the petroleum ether fraction showed the strongest (P?C. michiganensis subsp. sepedonicus. We analyzed the petroleum ether fraction to detect the components with antibacterial activity, and identified 24 compounds. The main constituents of the petroleum ether extract were esters (35.28 %) and acids (44.84 %). Cell membrane permeability assays, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses revealed that the petroleum ether fraction caused drastic ultrastructural changes in the cells of the pathogen. The petroleum ether fraction caused envelope disruption, cell deformation, the separation of the cell wall from the cell membrane, and the formation of vacuoles. These results clearly indicate that the petroleum ether fraction obtained from L. japonica shows strong antibacterial activity against the causal agent of BRR.  相似文献   

11.
Ten genotypes of Asiatic cotton, Gossypium arboreum, viz. C-353, G 17, G 33, AC-3545, LD 491, LD 575, B 11 A, SAG-BLY (Red), Sargosi and LD 694, were screened under epiphytotic conditions against spotted bollworm, Earias vittella, at the cotton farm of the Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, India, and their morphological basis of resistance to spotted bollworm was studied. The plant characters examined were plant color, leaf shape, size and shape of bract, density of gossypol glands, nectaries, hair density and hair length. Hair density was positive (r?=?0.81, P?=?0.005) and significantly correlated with the number of eggs laid by E. vittella, whereas a significantly negative (r?=?–0.66, P?=?0.038) correlation was obtained with gossypol glands. Similarly, correlation of larval population with hair density was significantly positive (r?=?0.68, P?=?0.030) and gossypol glands were negative (r?=?–0.63, P?=?0.050) and significantly correlated with larval population. The R2 values, computed together for multiple regression analysis, indicated that the morphological plant traits, viz., gossypol glands and hair density, cumulatively contributed 67% and 50% variability in the egg and larval population, respectively. Genotype B 11 A, with the lowest egg and larval population, had a high number of gossypol glands, low hair density and smaller bracts and proved to be the best, followed by LD 491. Genotypes with low hair density, smaller bracts and a greater number of gossypol glands are desirable for low oviposition and larval population of E. vittella. These characteristics should be taken into consideration when planning a resistance breeding program against spotted bollworm in arboreum cotton.  相似文献   

12.
The current study involved evaluation of the toxicity of acetone soluble fraction of the ethanol extract of Annona squamosa Linn. seeds on Aedes albopictus (Skuse). Toxicity of fresh sample has been compared with that of solar radiated and heat treated aliquots of the same. Acute toxicity of fresh acetone fraction on adults was evident with LC50 and LC90 values of 15.21 and 60.38 μg/ml, respectively. Larvicidal bioassays recorded LC50 and LC90 values ranging from 0.44 to 5.97 and 1.64-43.36 μg/ml, respectively for different instars. Ovicidal bioassays yielded EC50 and EC90 values of 18.82 and 69.61 μg/ml. The study further revealed ovipositional deterrent and chemosterilant activities of the extract on the target mosquito. Bioassays using solar radiation and heat treated samples of the active fraction have showed toxicity levels similar to those of fresh sample. Chemical analysis of acetone soluble fraction of seed extract of A. squamosa has reveled ethyl oleate and iso-octyl phthalate as major components. Adulticidal, larvicidal, ovicidal, ovipositional deterrent and chemosterilant activities of the fraction on A. albopictus were proved. The investigation further confirmed stability of the active fraction on exposure to solar radiation and high temperature.  相似文献   

13.
为探讨苍耳（Xanthium sibiricum）倍半萜内酯分离物L-Ⅱ (主要成分为4β,5β-环氧苍耳素-1α,4α-内过氧化物) 的活性大小,将其与博落回（Macleaya cordata）总生物碱提取物MacSC （主要成分为血根碱和白屈菜红碱）的活性进行了比较研究。结果显示,两种测试物对试虫均表现较高活性,其中,苍耳倍半萜内酯分离物L-Ⅱ对小菜蛾（Plutella xylostella ）4龄幼虫的选择性拒食中浓度（AFC50）为23.6 mg/L,活性强于博落回生物碱提取物MacSC（111.8 mg/L）;在测试浓度为10 mg/mL时,L-Ⅱ处理组的小菜蛾4龄幼虫仅有4.30%发育为成虫,是对照的6.12%,小菜蛾蛹的羽化率为对照的12.05%,而MacSC的影响相对较低,两值分别为对照的33.89%和56.23%; 在上述测试浓度,L-Ⅱ对桃蚜 （Myzus persicae）和萝卜蚜（Lipaphis erysimi）均有较强的忌避作用,24 h忌避率分别为72.03%和74.47%,而MacSC对桃蚜的忌较效果较低（55.50%）,对萝卜蚜无忌避活性。说明苍耳倍半萜内酯分离物L-Ⅱ对几种试虫的拒食、忌避和生长发育抑制活性均高于博落回总生物碱提取物MacSC。  相似文献   

14.
利用3-(N-甲基-N-甲氧基氨基)-1-芳基-1-丙酮腙与酰氯反应,合成了14个新型N-酰基-3-(N-甲基-N-甲氧基氨基)-1-芳基-1-丙酮腙化合物,其化学结构经1H核磁共振和元素分析确证。初步的生物活性测试结果表明,部分化合物在50 mg/L时对淡色库蚊Culex pipiens pallens的致死率为95%~100%;化合物 c7 在1 000 mg/L时对粘虫Leucania separata Walke 的致死率达100%。  相似文献   

15.

Oviposition deterrent activity of a natural enemy food supplement, Envirofeast, against Ostrinia nubilalis Hubner females was studied in choice and no-choice tests under laboratory conditions. Maize plants treated with Envirofeast at 25-40 g a.i./l had significantly fewer egg masses per leaf and eggs per egg mass laid on them compared with the untreated control plants in both choice and no-choice tests. However, maize plants treated with Envirofeast concentrations of 10-20 g a.i./l did not significantly deter the insect's oviposition. The optimum rate at which Envirofeast could deter oviposition was 25 g a.i./l. Increasing the rate of Envirofeast application from 25 g to 40 g a.i./l did not significantly increase its oviposition deterrent activity against O. nubilalis. However, reducing the rate from 25 to 20 g a.i./l resulted in a significant reduction in the oviposition deterrent activity of Envirofeast. The egg masses laid by O. nubilalis on Envirofeast treated plants were essentially (80%) located on the lower leaf surfaces in contrast to untreated (control) plants where only 40-60% of the egg masses were deposited on the lower leaf surfaces. The egg masses on the Envirofeast-treated plants were found at sites which did not receive sprays, indicating the importance of good spray coverage when the product is used in the field. The study has demonstrated the oviposition deterrent activity of Envirofeast against O. nubilalis on maize and this indicates that Envirofeast may have the potential to be integrated into programmes to assist in the control of O. nubilalis on maize.  相似文献   

16.
Callosobruchus maculatus (F.), a major pest of grain legumes, causes considerable losses worldwide. C. maculatus management relies on synthetic insecticides with their adverse environmental and health concerns. The current study investigated the use of Artocarpus altilis (breadfruit) extracts on contact and fumigant toxicity, repellency and oviposition deterrency of C. maculatus as a management strategy. Fumigant mortality (LC50) of the dry inflorescence extract of A. altilis was 126.65 µL L?1 air at 53.4 h. Fruit extract gave 73.3% repellency at 1000 ppm after 24 h. Percent repellency was dose and time dependent. Green inflorescence extract of A. altilis reduced egg laying with 50% oviposition occurring after 37.78 h at 1000 ppm. We conclude that extracts of leaf, fruit, green and dried inflorescence of A. altilis displayed contact mortality, repellency, deterred oviposition and had fumigant activity toward C. maculatus.  相似文献   

17.
The insecticidal activity of lauric, oleic and linoleic acids against Callosobruchus maculatus on cowpea was investigated in laboratory bioassays. In pre-oviposition grain treatments, it was found that, at dosages between 1.96 and 11.59 kg-lauric acid had no effect on progeny development, while the oily oleic and linoleic acids were active in reducing progeny development. The active fatty acids had no effect on oviposition (in no-choice experiments) or on mortality of adults or larvae that successfully penetrated treated cowpea seeds, and their insecticidal activity, like that of fixed vegetable oils, depended mainly on ovicidal action. When applied to cowpeas in a pure state, oleic acid had an LC50 value of 1.64mlkg?1, which made it approximately 3 and 8 times more toxic against eggs of C. maculatus than groundnut oil and linoleic acid respectively. When the ovicidal activities of the three fatty acids were tested by dipping egg-infested seeds in acetone- based solutions, they were all found to be similarly toxic, lauric, oleic and linoleic acids having LC50, values of 40, 38 and 26 ml litre?1 respectively (with overlapping 95% C.L.). These values made them 2-4 times more toxic than acetone-based solutions of groundnut and traditional coconut oils. The possibility of employing fatty acids in large-scale and traditional small-scale food storage systems is discussed.  相似文献   

18.
The house fly, Musca domestica L., is a widespread pest of intensively reared livestock, where its presence negatively affects growth and productivity through the irritation their activity causes. Furthermore, adult flies mechanically vector a wide range of animal and human pathogens and, as such, pose a health risk to both livestock and people. The development of resistance in M. domestica populations to most of the insecticides used against them, coupled with diminishing product availability in many regions, means that new fly control methods and materials are constantly required. In the present study, a formulation of allicin, a compound derived from garlic cloves, was evaluated against the eggs, larvae and adults of Musca domestica L.. An in-diet LD50 of 134 ppm against larvae was achieved, whilst marked ovicidal activity was also recorded. Adults were similarly affected when exposed directly and indirectly to surface residues of the compound. The results indicate that allicin exhibits potential to be used against filth flies through incorporation into their developmental substrates and, potentially, for the control of other economically important dipteran pests.  相似文献   

19.
The in vitro metabolism of [14C-methoxy] or [32P]azinphosmethyl by subcellular fractions of abdomens from a resistant and a susceptible strain of houseflies was studied. The degradative activity in both strains was associated with the microsomal and soluble fractions and required NADPH and glutathione, respectively. The resistant strain possessed higher activity for both the mixed-function oxidases and the glutathione transferase than the susceptible strain, and both systems appear to be important in the resistance mechanism. The mixed-function oxidases were involved in the oxidative desulfuration as well as the dearylation of azinphosmethyl. A glutathione transferase located in the soluble fraction catalyzed the formation of desmethyl azinphosmethyl and methyl glutathione. This enzyme also demethylated azinphosmethyl oxygen analog. Although the soluble fraction exhibited both glutathione S-alkyltransferase and S-aryltransferase activity against noninsecticidal substrates, no evidence of the transfer of the benzazimide moiety from azinphosmethyl to glutathione was obtained. Sephadex G-100 chromatography of the soluble enzymes revealed a common eluting fraction responsible for both types of transferase activity.  相似文献   

20.
Oviposition deterrents have the potential to prevent insect infestations in agroecosystems. In the present study, the level and duration of this behavioral effect was evaluated against pear psylla,Cacopsylla pyri (L.) (Hemiptera: Psyllidae), a serious pest of pears in Turkey. The activity of four oily substances — cotton seed oil, fish-liver oil, neem oil and summer oil — was tested against winterform and summerform females of the pest in laboratory and field experiments, in order to determine their oviposition deterrency and stability as deterrents. In the laboratory assays, the initial (3 days after treatments) deterrency of all test materials was 100%. While decreases in initial deterrency started after 1 week for neem oil and after 2 weeks for cotton seed oil, fish-liver oil and summer oil exhibited 100% deterrent activity against winterforms, but not summerforms during the 3-week test period. The last two also exhibited strong oviposition deterrent activity for both forms ofC. pyri females in field trials. A significant reduction in the total number of eggs laid was observed in the field plots. Data showed that summer oil and fish-liver oil are the most promising oviposition deterrents against pear psylla females. http://www.phytoparasitica.org posting Sept. 28, 2004.  相似文献   

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