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1.
Extracts of neem (Azadirachta indica A. Juss) seed kernels prepared from various solvents affected the behavior and fecundity of the carmine spider mite,Tetranychus cinnabarinus (Boisd.). Bean leaf discs freshly sprayed with different concentrations of the extracts strongly repelled the females from the treated leaves and egg-laying was reduced. On the basis of EC 50s for both parameters, the order of effectiveness of the extracts was pentane > chloroform >n-butanol > acetone > methanol > H2 0 (inactive). The activity decreased with increasing dielectric constant of the extracting solvent. The chloroform and butanol extracts in the original solvents were phytotoxic. Bean leaf discs 7 days after spraying with the pentane and acetone extracts, still caused mortality and reduction in fecundity of adult females, but no repellency. The acetone and the pentane extracts sprayed directly on adult female mites on bean leaf discs, caused repellency and reduction of fecundity and also mortality of adults. 相似文献
2.
Graeme Jones Colin A. M. Campbell Barry J. Pye Sangita P. Maniar Alan Mudd 《Pest management science》1996,47(2):165-169
Colupulone, the main component of the beta-acid fraction of hop extracts, was shown to repel the two-spotted spider mite Tetranychus urticae Koch from the surface of plant leaves. The total beta-acid fraction was found more effective in repelling the mites and reducing the number of eggs laid than colupulone at equivalent concentrations, suggesting that other components of the extract have repellent and oviposition-deterring effects. 相似文献
3.
Crude ethanolic seed extracts ofAnnona muricata, A. squamosa (Annonaceae),Lansium domesticum andSandoricum koetjape (Meliaceae) collected from different locations and years in Maluku, Indonesia, were screened for inhibition of larval growth
against the polyphagous lepidopteranSpodoptera litura (Noctuidae). Extracts ofA. squamosa were significantly more active (20-fold) than those ofA. muricata. A. squamosa collected from Namlea yielded the extracts with the greatest inhibitory activity. There were significant differences among
locations for bothA. squamosa andA. muricata but not forL. domesticum andS. koetjape. Extracts ofA. squamosa, collected from Namlea, inhibited larval growth in a dose-dependent manner, with a dietary EC50 (effective concentration to inhibit growth by 50% relative to controls) of 191.7 ppm fresh weight. Extracts ofA. squamosa collected from individual trees in Namlea also varied in growth inhibitory effect againstS. litura andTrichoplusia ni larvae. This species is a candidate for development of a botanical insecticide for local use in Indonesia.
http://www.phytoparasitica.org posting Dec. 1, 2003. 相似文献
4.
Ageratum conyzoides L. is an annual herb in the tropics and subtropics whose extracts are known to possess pharmacological and biocidal activity.
We report on the bioactivity of a secondary metabolite (a chromene) isolated from the shoots ofA. conyzoides against some plant pathogenic fungi. Organic solvent extracts from the shoots were tested for antifungal activity against
the plant pathogenic fungiRhizoctonia solani, Sclerotium rolfsii, Botryodiplodia theobromae, Phomopsis theae andFusarium species growingin vitro on potato dextrose agar medium. The cruden-hexane extract completely inhibited the growth ofR. solani andS. rolfsii. Then-hexane extract was chromatographed over a column of silica gel followed by activity-guided fractionation to give an antifungal
principle. Structure elucidation by detailed analysis of1H,13C NMR and mass spectroscopy identified the active compound as precocene II. The growth ofR. solani andS. rolfsii was completely inhibited by precocene II at a concentration of 80–100 ppm. The sclerotia ofR. solani andS. rolfsii were also completely suppressed by 150 ppm of precocene II. Sub-culture of these inhibited fungi onto precocene II-free medium
restored growth of the fungus, indicating that precocene II is fungistatic. Crude or refined extracts fromA. conyzoides offer the possibility of biocontrol of plant pathogenic fungi.
http://www.phytoparasitica.org posting Feb. 11, 2004. 相似文献
5.
The biology ofLixus bardanae (F.) (Coleoptera: Curculionidae) on curly dock (Rumex crispus L.) in northeastern Anatolia (Bayburt, Erzurum and Kars Provinces), Turkey, was studied during the years 2000 and 2001.L. bardanae completes one generation in a year, overwintering as an adult. It feeds on leaves of the host plant. Females lay eggs individually
into stems and the young larvae create galleries in stems while feeding. Pupation occurs inside stems in cells fashioned from
frass. In late September, adults move into soil and overwinter in an upright position around the roots of the host plant.
Infestation levels were found to range between 34% and 84%. Two parasitoids,Exeristes roborator F. andEndromopoda phragmitidis Perve (Hymenoptera: Ichneumonidae), were reared fromL. bardanae.
http://www.phytoparasitica.org posting Dec. 21, 2003. 相似文献
6.
Extracts from two plants from Ethiopia,Withania somnifera andAcacia seyal, were evaluated for their potential as natural biopesticides and to study their mode of action. Methanolic extracts of these
plants were testedin vivo on citrus fruit for their efficacy to controlPenicillium digitatum when applied on wounded or unwounded fruit surfaces. Relative to the control, 70% and 75% of wound — inoculated fruit did
not develop decay symptoms for up to 21 days of storage at 25°C and >85% r.h. An increase in cell wall-bound phenolics was
evident in wounded fruit treated with plant extracts and inoculated with a spore suspension ofP. digitatum. Scanning electron microscopy revealed deposition of crystalline plant material sticking to the pathogen and around the wound
site. The application of the plant extracts increased the epiphytic background total microbial population but decreased diversity.
http://www.phytoparasitica.org posting May 7, 2007. 相似文献
7.
BACKGROUND: Transovarial transport is defined as the passage of chemicals from the maternal body to eggs within the ovaries. Little is known about the effects of transovarial transport on non‐target species. This study evaluates etoxazole (a transovarial acaricidal compound) on a terrestrial trophic web consisting of a ubiquitous phytophagous mite, Tetranychus urticae Koch, and three species of predatory mites. RESULTS: Predatory mite females that consumed eggs laid by etoxazole‐treated T. urticae also produced infertile eggs. There was a negative relationship between the proportion of etoxazole‐treated T. urticae females and the instantaneous rate of predatory mite increase at the population level (r2 = 0.86). Reduced fertility of etoxazole‐treated T. urticae females continued for 18 days following application. Eggs laid by etoxazole‐treated T. urticae females remained toxic to predatory mite females for 42 days after treatment. CONCLUSIONS: Transovarial transport could lead to magnification in the ecosystem by enhancing both bioavailability and movement of an active ingredient. The potential for enhancement of residual activity by terrestrial organisms and its significance once reaching the food web should be taken into account for new classes of acaricides and insecticides. Copyright © 2012 Society of Chemical Industry 相似文献
8.
BACKGROUND: Spinosad is a biopesticide widely used for control of Frankliniella occidentalis (Pergande). It is reported to be non‐toxic to several predatory mite species used for the biological control of thrips. Predatory mites Typhlodromips montdorensis (Schicha), Neoseiulus cucumeris (Oudemans) and Hypoaspis miles (Berlese) have been used for control of F. occidentalis. This study investigated the impact of direct and residual toxicity of spinosad on F. occidentalis and predatory mites. The repellency of spinosad residues to these predatory mites was also investigated. RESULTS: Direct contact to spinosad effectively reduced the number of F. occidentalis adults and larvae, causing > 96% mortality. Spinosad residues aged 2–96 h were also toxic to F. occidentalis. Direct exposure to spinosad resulted in > 90% mortality of all three mite species. Thresholds for the residual toxicity (contact) of spinosad (LT25) were estimated as 4.2, 3.2 and 5.8 days for T. montdorensis, N. cucumeris and H. miles respectively. When mites were simultaneously exposed to spinosad residues and fed spinosad‐intoxicated thrips larvae, toxicity increased. Residual thresholds were re‐estimated as 5.4, 3.9 and 6.1 days for T. montdorensis, N. cucumeris and H. miles respectively. Residues aged 2–48 h repelled T. montdorensis and H. miles, and residues aged 2–24 h repelled N. cucumeris. CONCLUSION: Predatory mites can be safely released 6 days after spinosad is applied for the management of F. occidentalis. Copyright © 2011 Society of Chemical Industry 相似文献
9.
S. Ekesi 《Phytoparasitica》2000,28(4):305-310
The effect of volatiles and aqueous extracts of black pepper,Piper guineense; neem seed,Azadirachta indica; garlic bulb,Allium sativum; and onion bulb,Allium cepa on egg viability ofMaruca vitrata Fab. (Lepidoptera: Pyralidae) andClavigralla tomentosicollis Stål (Heteroptera: Coreidae) was evaluated in laboratory experiments. Compared with the other treatments, volatiles of black pepper and garlic bulb were superior in reducing hatch of freshly laid (12-h-old) eggs of both species of insects. Volatiles of onion bulb and neem seed had no effect on egg hatch. When aqueous extracts of the various plant materials were tested at 5%, 10% and 15%, extracts of black pepper, neem seed and garlic bulb caused a severe reduction in egg hatch, with black pepper and garlic bulb providing the highest reduction at all concentrations tested in both insects. When black pepper and garlic bulb were compared at 5% for their activity in relation to egg age, the effect of black pepper decreased with increasing egg age but the performance of garlic was consistent across the various age groups tested in both insects. This result is indicative of the potential of using these plant materials and especially garlic for the management ofM. vitrata andC. tomentosicollis. 相似文献
10.
A study was carried out at the Natural Park of Montesinho, NE Portugal, in order to evaluate the effect of different pine
species (Pinus pinaster Ait.,P. nigra Arn. andP. sylvestris L.) onThaumetopoea pityocampa populations. The structure of the egg batches, the impact of the egg parasitoids on natural mortality of the pest and the
species of parasitoids present, as well as their emergence dynamics, were analyzed. The length of the egg batches varied among
pine species with the longest ones onP. nigra. The mean number of eggs per batch differed betweenP. sylvestris and the two other hosts studied, with fewer eggs per batch on the first. No differences were found in the size of eggs among
pine species. The egg mortality varied between 25.8% and 33.0%, with no differences among hosts. Parasitism was the main cause
of death.Baryscapus servadeii (Mercet.) was the most abundant parasitoid species, followed byOoencyrtus pityocampae (Dom.) andTrichogramma embryophagum Htg.B. servadeii dominated in the egg batches collected fromP. pinaster andP. nigra, whereasO. pityocampae was most frequent onP. sylvestris. The emergence ofB. servadeii started in the middle of March and continued until August, with the emergence peak at the end of May. The emergence ofO. pityocampae started at the end of April and continued throughout September, with maximum values in June.
http://www.phytoparasitica.org posting Sept. 20, 2006. 相似文献
11.
为明确植物源活性物质姜黄素对朱砂叶螨Tetranychus cinnabarinus的杀螨作用机理,克隆并分析了6条朱砂叶螨几丁质酶基因(TcCHTs)的cDNA序列,利用RT-qPCR技术,测定了不同发育阶段的螨体内几丁质酶基因表达的情况,同时研究了姜黄素作用下几丁质酶基因表达的变化。结果表明:6条几丁质酶基因(TcCHIT1、TcCHIT2、TcCHIT3、TcCHT4、TcCHT5和TcCHT6)有不同的结构域,预测其蛋白质分子质量分别为60.80、69.03、104.32、59.75、45.63和49.05 kDa,等电点分别为5.44、8.65、6.23、6.07、6.12和8.27。6条基因的表达量均为幼螨和若螨时期显著高于卵和成螨时期。不同浓度姜黄素处理朱砂叶螨若螨24 h后,6条基因的表达量均有不同程度下调,其中TcCHIT1和TcCHT5的下调更为显著。研究结果表明,姜黄素对朱砂叶螨的杀螨作用机制之一可能是通过抑制几丁质酶的活性,进而影响几丁质的降解过程,最终因螨体壁受损而导致螨不能正常生长发育。 相似文献
12.
Eltayeb A. Elhag 《国际虫害防治杂志》2013,59(2):109-113
Extracts from nine plant materials were tested in choice and no-choice tests as oviposition deterrents for cowpea bruchid, Callosobruchus maculatus (F.) on chickpea, Cicer arietinum L. Seed treatment with 0.1% crude extract of materials resulted in a significant reduction in ovipositional preference of the bruchid. The highest repellency was found in Rhazya stricta leaves (82%), Azadirachta indica seeds (76.8%), Heliotropium bacciferum aerial parts (59.2%) and citrus peels (58.6%). Progeny production was significantly reduced: only 11.5, 11.9, 12.4, 13.4 and 14.8% of the eggs deposited reached adulthood in R. stricta, neem seeds, Piper nigrum, citrus peels and H. bacciferum, respectively. F1 females laid significantly fewer eggs in response to R. stricta, neem seeds, Eugenia caryophyllata cloves, H. bacciferum, citrus peels and P. nigrum. Percentage reduction in F2 progeny ranged between 71.4% with R. stricta-treated seeds and 24.5% in the P. nigrum treatment. 相似文献
13.
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
14.
Apolygus lucorum (Meyer-Dür) (Hemiptera: Miridae) is an important pest on cotton, fruit trees, tea and many other crops in China. Its small eggs are often laid inside plant tissues, making them difficult to detect and survey. In this study, the stalks of 20 plant species were assessed for use as oviposition traps for A. lucorum under field conditions in 2013, 2014 and 2017. During 2013–2014, A. lucorum adults laid eggs in the stalks of all plant species tested. When honey was added to bundles of stalks, the numbers of A. lucorum eggs laid in the stalks increased 1.79- to 44.00-fold compared with the stalks of the same plants without honey added. In general, the plant stalks of cotton Gossypium hirsutum L. and scandent hop Humulus scandens (Lour) Merr. attracted a great number of eggs among all plant species tested. In 2017, a positive correlation was found between the number of A. lucorum eggs laid in cotton plant stalks and A. lucorum adults in the corresponding field plots. Oviposition traps using cotton plant stalks provide a simple and practical method for monitoring the egg-laying dynamics of A. lucorum under field conditions. 相似文献
15.
Studies were carried out on the egg material ofTraumatocampa ispartaensis Doganlar & Avcı (Lep.: Notodontidae) collected onCedrus libani A. Rich. A total of 95 egg-batches were sampled over two annual generations ofTr. ispartaensis. The number of eggs in each egg-batch varied between 39 and 245 and the length of the batches varied between 7 and 36 mm.
The mean number of eggs per batch was found to be 119 and 122 in 1999 and 2000, respectively. Based on field data the oviposition
period continued from mid August to mid September. The mean hatching rate of the host was found to be 85.8% and 88.9%, whereas
the impact of egg parasitoids accounted for 11.3% and 7.4%, respectively in the 2 years.Ooencyrtus pityocampae (Mercet) was observed as the most abundant egg parasitoid, followed byOoencyrtus sp. nearmasii (Mercet) andTrichogramma brassicae Bezdenko. Based on the emergence dynamics of the egg parasitoids in the laboratory, it seems thatO. pityocampae emerged mainly in June whereasO. sp. nearmasii andT. brassicae emerged mainly in May.
http://www.phytoparasitica.org posting Feb. 3, 2003. 相似文献
16.
The effects of Neemgard, an acaricidal and fungicidal formulation obtained from neem (Azadirachta indica) seed kernels, on the phytophagous miteTetranychus cinnabarinus, the predacious mitePhytoseiulus persimilis, and the predatory spiderChiracanthium mildei, were investigated in laboratory experiments. Neemgard was highly toxic toT. cinnabarinus but had no toxic effect onC. mildei orP. persimilis. Another neem formulation—the insecticidal Neemix 45—caused conspicuous repellency, but no mortality, inT. cinnabarinus. 相似文献
17.
The species composition and seasonal cycle ofTetranychus urticae Koch (two-spotted spider mite) andEotetranychus uncatus Garman (garman spider mite; the two species were evaluated together),Amphitetranychus viennensis (Zacher) (hawthom red spider nite),Panonychus ulni (Koch) (European red mite),Bryobia rubrioculus (Scheuten) (brown mite) (Acari Tetranychidae),Cenopalpus pulcher Can and Fanz. (flat scarlet mite) (Tenuipalpidae) and their natural enemies (Phytoseiidae and Stigmaeidae family members)
were compared in two apple orchards during the years 2000 to 2002 in Tokat, Turkey. One orchard was pesticide-free, and the
other was sprayed. Surveys were carried out once a week from April to November and the differences in the dominant species
of spider mites and phytoseiid mites between the two orchards were recorded. In the sprayed orchard, the dominant phytophagous
mites wereA. vienensis andP. ulmi whereas in the unsprayed orchardE uncatus andC pulcher were abundant. It was found that the predatory mites were able to control spider mites in the unsprayed orchard, but the
population level was not adequate to control them in the sprayed orchard, presumably due to the excessive use of pesticides. 相似文献
18.
Kontsedalov S Gottlieb Y Ishaaya I Nauen R Horowitz R Ghanim M 《Pest management science》2009,65(1):5-13
BACKGROUND: Spiromesifen is a novel insecticidal/acaricidal compound derived from spirocyclic tetronic acids that acts effectively against whiteflies and mites via inhibition of acetyl‐CoA‐carboxylase, a lipid metabolism enzyme. The effects of spiromesifen on the developmental stages of the whitefly Bemisia tabaci (Gennadius) were studied under laboratory conditions to generate baseline action thresholds for field evaluations of the compound. RESULTS: Adult B. tabaci mortality rate after spiromesifen treatment (5 mg L?1) was 40%. Treatment with 0.5 mg L?1 reduced fecundity per female by more than 80%, and fertility was almost nil. LC50 for eggs was 2.6 mg L?1, and for first instar 0.5 mg L?1. Scanning electron microscopy revealed that eggs laid by treated adult females had an abnormally perforated chorion, and females were unable to complete oviposition. Light and fluorescent microscopy showed significantly smaller eggs following treatment, and smaller, abnormally formed and improperly localized bacteriomes in eggs and nymphs. The number of ovarioles counted in females treated with 5 mg L?1 was significantly reduced. Spiromesifen showed no cross‐resistance with other commonly used insecticides from different chemical groups, and resistance monitoring in Israel showed no development of field resistance to this insecticide after 1 year of use. CONCLUSION: The strong effect on juvenile stages of B. tabaci with a unique mode of action and the absence of cross‐resistance with major commonly used insecticides from different chemical groups suggest the use of spiromesifen in pest and resistance management programmes. Copyright © 2008 Society of Chemical Industry 相似文献
19.
1960—1961年在北京对棉蚜、桃蚜、棉红蜘蛛及山楂红蜘蛛进行的田间药效试验表明:(1)乐果对两种蚜虫及两种红蜘蛛的速效或残效均接近或超过E-1059,在食用作物上的残毒期较短(7日),使用范围也较广。(2)马拉硫磷的杀蚜效力也较好,但不如乐果,杀螨效力不强。(3)三硫磷粗制原油的杀螨效力很突出:对棉红蜘蛛的速、残效接近或超出 E-1059,显著超过甲基 E-1059和马拉硫磷;对山楂红蜘蛛的速、残效也接近 E-1059,对两种红蜘蛛的残效都比较持久,但杀蚜效力较差,远不如乐果。(4)AC-3741也具有高度的杀螨效力,对棉红蜘蛛的毒杀效力超出甲基 E-1059和马拉硫磷,残效也较好。 相似文献
20.
A novel and versatile method is described for measuring the contact activity of acaricides against spider mites. The microimmersion (MI) bioassay involves drawing batches of 25 mites into small pipette tips under vacuum, immersing them for 30 s in 35 μ1 of a test solution, and then confining the treated subjects on clean foliage in holding cells. Evaluations of amitraz, bifenthrin, chlorpyrifos and dicofol against susceptible strains of Tetranychus urticae Koch showed the MI bioassay to be equally applicable to formulated and technical acaricides (the latter dissolved in acetone + distilled water; 20 + 80 by volume), and to give LC50 values that corresponded well with those from a conventional residual bioassay. The most important difference between bioassay methods was the consistently greater slope of probit lines from MI tests. Results were not highly sensitive to varying the immersion period between 15 and 60 s, and low control mortality was observed with ethanol or acetone concentrations of up to 500 ml litre?1, and surfactant concentrations of up to 10 g litre?1. The potential of this method for assessing the relative toxicity of both fast- and slow-acting acaricides, screening small quantities of experimental compounds for acaricidal activity, and improving the laboratory procedure for selection and characterization of acaricide resistance is discussed. 相似文献