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1.
The effects of host-plant volatiles (HPVs) on male oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), and response to sex pheromone trap were studied in a pear orchard. Two HPVs compounds, (Z)-3-hexenyl acetate and 1-undecanol, combined with sex pheromone of G. molesta in traps were tested. The results showed that most of the male moths were captured in the traps baited with the sex pheromone combined with these two HPVs compounds than by the pheromone alone. Also, more males were captured by the trap containing pheromone plus (Z)-3-hexenyl acetate than by the one containing 1-undecanol. It appeared that these HPVs act as sex pheromone synergists to enhance the attraction of male G. molestato pheromone traps, since males were not captured in the traps baited only with (Z)-3-hexenyl acetate and/or 1-undecanol.  相似文献   

2.
A series of novel 6-(1,2,4-triazol-4-yl) chromone and -1-thiochromone (benzo[b]thiazin-4-one) derivatives was obtained by cyclisation via thiosemicarbazides which were prepared by reaction of hydrazines and the corresponding isothiocyanates. Their fungicidal activity was evaluated against the rice blast fungus Pyricularia oryzae. Of this series, 2,5,8-trimethyl-6-(1-propyl-5-thioxo-3-trifluoromethyl-1,2,4-triazol-4-yl) chromone, 6-(1-butyl-5-thioxo-3-trifluoromethyl-1,2,4-triazol-4-yl)-2,5,8-trimethylchromone, 6-(1-hexyl-3-methyl-5-thioxo-1,2,4-triazol-4-yl)-2,5,8-trimethylchromone and 6-(1-allyl-5-thioxo-3-trifluoromethyl-1,2,4-triazol-4-yl)-2,5,8-trimethylchromone were highly active (pEC50>6·0). Structure–activity relationship studies using the capacity factor k′ as a hydrophobicity index suggested that the log k′ optimum for 2,5,8-trimethyl-chromone and -1-thiochromone derivatives was around 1·0, equivalent to a log Pow value of c. 4·4. © 1998 SCI  相似文献   

3.
BACKGROUND: The swede midge, Contarinia nasturtii Kieffer, is a serious pest in crucifers. Its pheromone is a blend of (2S,9S)‐diacetoxyundecane, (2S,10S)‐diacetoxyundecane and (2S)‐acetoxyundecane. The pheromone is used in monitoring traps, and this study examines possible ways to optimise the traps. RESULTS: Two dispenser types were compared: polyethylene dispensers and cotton dispensers. Polyethylene dispensers attracted male C. nasturtii for more than 6 weeks, whereas cotton dispensers were attractive for only 2 weeks. All three pheromone components were important for attraction of male midges in the field. The importance of the stereoisomeric compositions of the pheromone compounds was also tested—both in the wind tunnel and in the field. In the case of 2,9‐diacetoxyundecane and 2‐acetoxyundecane, the non‐natural stereoisomers did not inhibit male C. nasturtii attraction, whereas one or both of the stereoisomers of 2,10‐diacetoxyundecane did. CONCLUSION: Pheromone traps with the synthetic pheromone in a 1:2:0.02 ratio emitted from PE dispensers were highly effective and long lasting. As the mixture of stereoisomers of 2,10‐diacetoxyundecane strongly inhibited attraction of male C. nasturtii while those of 2,9‐diacetoxyundecane and 2‐acetoxyundecane did not have any inhibitory effect, it is possible to produce traps that are effective and long lasting but cheaper to produce and maintain. Copyright © 2009 Society of Chemical Industry  相似文献   

4.
Abstract

Two species of Cryptophlebia found in Hawaii's macadamia orchards are active in different parts of a tree canopy. C. illepida (Butler) males were mostly caught in traps hung 1·5 m to 9.1 m from the ground; whereas C. ombrodelta (Lower) males were caught from 9.1 m to 15.2 m. A plastic, cylindrical sticky trap caught equal numbers of C. illepida males as Pherocon 1C traps but more than delta traps. A synthetic pheromone blend of 93% (Z)‐8‐dodecenyl acetate, 4% (E)‐8‐dodecenyl acetate, 1% (Z)‐8‐dodecenol, and 2% (2)‐7‐dedecenyl acetate attracted more males than other blends. No significant differences were detected between the two Cryptophlebia species in their response to the four‐component pheromone blend when traps were hung 4.6 m from the ground.  相似文献   

5.
The attract‐and‐kill strategy is a new pest management technique that presupposes the intelligent combination of an attracting agent (e.g. pheromone) and a killing agent (e.g. insecticide). In the present study, the potential combination of the microencapsulated synthetic oviposition pheromone 6‐acetoxy‐5‐hexadecanolide with an insecticide has been tested. Initially, polyurea microcapsules containing 6‐acetoxy‐5‐hexadecanolide, the synthetic mixture of diastereomers of the oviposition pheromone of the mosquito species Culex quinquefasciatus Say (Diptera: Culicidae), were studied. Laboratory bioassays were performed to confirm the bioactivity of the microencapsulated pheromone on the oviposition activity of Culex pipiens L. biotype molestus Førskal (Diptera: Culicidae) with the aim of determining the optimum dose for oviposition response. Its effect was dose dependent, revealing an optimum dose of 300 mg of dried microcapsules. Attractancy over time was also studied. The microencapsulated pheromone was found to be sufficiently attractive to gravid female mosquitoes for a period of 40 days. Finally, the combination of the synthetic pheromone with the control agent temephos showed both an acceptable oviposition activity and sufficient larvicidal effect. Copyright © 2007 Society of Chemical Industry  相似文献   

6.
The electrophysiological activity of some halogenated analogues of the major component of the sex pheromone of the corn stalk borer Sesamia nonagrioides Lef. (1) is presented. The analogues comprise a series of fluoro-, chloro- and bromoacetate analogues 4 – 10 as well as trifluoromethyl ketone 11. The fluoro derivatives 4 – 6 displayed remarkable electro-antennogram (EAG) intrinsic activities in comparison with the parent acetate 1, while the remaining analogues elicited significantly lower response. The compounds have also been tested as inhibitors of the sex pheromone perception in EAG and in the field. In the laboratory. fluoro analogues 4 – 6 were better inhibitors than chloro derivatives 7 – 9 , which in turn behaved similarly to the bromoacetate 10 . Trifluoromethyl ketone 11, however, was a poor inhibitor of the pheromone action. In the field, baits of mixtures of compounds 5 – 11 with the corn stalk borer pheromone in 10 :1 ratio inhibited the concomitant attraction of the clover cutworm moth Scotogramma irifolii Rott., while the difluoro analogue 5, trichloroacetate 9 and trifluoromethyl ketone 11 also diminished the number of catches of the armyworm Mythimna unipuncta Haw. The monofluoroacetate 4. trifluoro analogue 6 and bromo derivative 10 significantly disrupted the pheromone action of the corn borer, whereas trifluoromethyl ketone 11 synergistically increased the number of males attracted to the pheromone trap alone. Addition of 11 to baits containing the corn borer pheromone caught S. nonagrioides selectively with regard to the other habitat-sharing species M. unipuncta and S. trifolii.  相似文献   

7.
The synthetic female sex pheromone ofPrays citri, (Z)-7-tetradecenal, proved to be highly attractive to male moths in the field when released from a variety of dispensers in five different designs of sticky trap. When the pheromone was released from impregnated polyethylene vials, a wide range of initial loadings from 10 μg to 20 mg was attractive, and loadings of 40 μg and above were more attractive than a virgin female moth. Initial loadings of 0.5 mg and 1.0 mg remained attractive for at least five months in the field. Release rates of pheromone from the polyethylene vials under constant laboratory conditions were measured for two different initial loadings. Other isomers of the pheromone and a pheromone ‘mimic’, (Z)-5-dodecenyl formate, were unattractive to male moths and did not affect the attractiveness of the synthetic pheromone or of a virgin female moth.  相似文献   

8.
Metconazole, (1RS, 5RS; 1RS, 5SR)-5-(4-chlorobenzyl)-2,2-dimethyl-1-(1H-1,2,4-triazol-1-ylmethyl)cyclopentanol, is a highly active fungicide, in particular controlling seed-borne and foliar diseases of cereals, such as wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). In order to maximize its foliar activity, an experimental survey of some types of surfactants and an emulsifiable oil was undertaken. Two types of metconazole formulation were investigated using a biological assay involving the therapeutic control of two diseases (Erysiphe graminis DC f. sp. tritici Marchal and Leptosphaeria nodorum Muell.) of wheat. Enhancements of activity by ?Genapol’? C12/C14 alcohol ethoxylates of an emulsifiable concentrate (ECM) formulation of metconazole were approximately three- to four-fold. For its, initially, less active suspension concentrate (SCM) formulation, enhancements were around 35-fold, so that with these adjuvants the two formulations were of similar activity. The enhancement ability of these ?Genapol’? surfactants was optimal at lower (5–10 moles) ethylene oxide content. These analogues induced marginally better enhancements of activity than members of a range of nonylphenol ethoxylates (?Arkopal’?), and emulsifiable paraffinic/naphthenic oil (HVI 60E) and a castor oil ethoxylate (?Atlas’? G1281) but were equivalent to a similar series of alcohol ethoxylates (?Dobanol’?) from another source. Varying the alkyl chain length between C9-C11 and C14-C15 in the ?Dobanol’? series had little effect on their high enhancements of metconazole activity. It was determined from trials varying the application rate of the best alcohol ethoxylates that application rates of 1–1.5 kg ha?1 were required for maximum activity. This implied the use of high adjuvant/metconazole ratios in one-pack adjuvant-containing formulations. A range of soluble liquid (SL) formulations were prepared with either ?Dobanol’? 23–6.5 or ?Dobanol’? 91-6/metconazole ratios varying from 5:1 to 15:1. There were found to be highly active and were recommended for field testing.  相似文献   

9.
An experimental trial of integrated pest management against Tuta absoluta (Meyrick) based on mass trapping with a density of 32 traps per hectare was conducted in a 5 ha open‐field tomato crop. During this trial, the efficiency of three brands of sex pheromone dispenser commercialized in Tunisia was tested. The ‘superdosed’ pheromone lure type TUA‐Optima® (Russell IPM, Deeside, Flintshire, CH5 2LA, United Kingdom) loaded with 0.8 mg of synthetic pheromone was more attractive to males of T. absoluta, and these lures should be used with high populations. Standard lures Pherodis® and TUA‐500® containing 0.5 mg of pheromone were less attractive, and can be used in open‐field tomato crops with lower populations of T. absoluta. An assessment of the susceptibility of crop borders to T. absoluta, based on data collected from traps, revealed that levels of adult T. absoluta were similar between borders with either tomato or cereal crops. Particular attention should thus be paid to crop borders even when not adjacent to other tomato crops.  相似文献   

10.
Mosquitoes of the genus Culex, e.g. Culex quinquefasciatus, release a volatile pheromone from their eggs that induces gravid females to oviposit around the pheromone source. Enantioselective synthesis by the Sharpless epoxidation method and chiral gas chromatography showed the major pheromone component to be (?)-(5R,6S)-6-acetoxy-5-hexadecanolide. Shortening the alkyl chain resulted in a loss of behavioural activity, whereas perfluorination of the alkyl chain or substitution of the acetoxy groups with the trifluoroacetoxy group gave active analogues. A simple large scale synthesis was devised to provide material for a fìeld trial. The pheromone, formulated in effervescent tablets, was used to concentrate oviposition in specific breeding sites where the larvae were controlled with a juvenoid-type insecticide.  相似文献   

11.
A series of novel 4,5-dihydropyrazole-5-thiones (DHPs) was synthesised by treating the corresponding dihydropyrazolones with ‘Lawesson’s reagent and evaluated for miticidal activity against two-spotted spider mites (Tetranychus urticae Koch). Of these, 3-(4-chlorophenyl)-4,4-dimethyl-1-phenyl-4,5-dihydropyrazole-5-thione, 3-(4-chlorophenyl)-4-ethyl-4-methyl-1-phenyl-4,5-dihydropyrazole-5-thione, 3-(4-chlorophenyl)-1-phenyl-4,5-dihydropyrazole-5-thione-4-spirocyclopentane and 4,4-dimethyl-1-phenyl-3-(4-trifluoromethyl-phenyl)-4,5-dihydropyrazole-5-thione were highly active (pEC50>4·0) and were more effective than the miticide dicofol (pEC50=3·879), which has traditionally been used for the control of phytophagous mites. Structure–activity relationship (SAR) studies were performed on each position of the pyrazole ring of DHPs. The results indicated that the unsubstituted phenyl, 4-substituted phenyl and thioxo groups on the 1-, 3- and 5-positions of DHPs respectively were required for activity. Quantitative SAR studies using physicochemical parameters of substituents and the capacity factor k′ as a hydrophobicity index suggested that: (a) the activities of all types of DHPs examined were mainly dominated by hydrophobicity, (b) the bulkiness of 4-substituents of the 3-phenyl ring favoured the activity and (c) the log k′ optimum for all DHPs was 1·675, equivalent to a log Pow value of c. 5·0.  相似文献   

12.
为深入了解国内暗黑鳃金龟Holotrichia parallela Motschulsky种群的性信息素组分及其田间引诱效果,采用气质联用技术对其雌性信息素进行了分离鉴定,利用标记-回捕技术测试了5 h内暗黑鳃金龟的扩散距离,并在此基础上测试了诱捕器颜色、离地高度、密度、单诱芯性信息素含量等对田间诱虫效果的影响。结果表明：L-异亮氨酸甲酯和（R）-（-）-芳樟醇为国内青岛种群暗黑鳃金龟雌虫性信息素的主要组分,两者含量比为7：1;暗黑鳃金龟5 h扩散距离可达400 m以上,平均扩散距离为55.9 m,扩散距离在20~60 m的个体占总虫数的77.5%;黄色诱捕器对该虫的引诱效果显著优于黑色和绿色;诱捕器离地2 m引诱到的试虫数目显著高于1、1.5、2.5和3 m;单个诱芯性信息素含量360 mg引诱效果最好,显著高于180 mg及以下浓度;诱捕器间隔20~60 m防治效果较好,结合使用成本和试虫扩散距离,间距60 m最优。  相似文献   

13.
（反,反）－８,１０－十二碳双烯醛（Ｅ８,Ｅ１０－１２：Ａｌｄ）是槐小卷蛾性信息素的次要活性组分。单组分Ｅ８,Ｅ１０－１２：Ａｌｄ对槐小卷雄蛾没有引诱作用,但作为增效剂,在性信息素两个主要成分中加入Ｅ８,Ｅ１０－１２：Ａｌｄ能显著提高林间诱蛾活性,３个组分的最佳活性配比为２∶３∶１。  相似文献   

14.
BACKGROUND: Field trapping experiments were conducted to evaluate the attractiveness of five different pheromone blends as well as the impact of trap design on attractiveness towards cocoa mirids, Sahlbergella singularis Hagl. and Distantiella theobroma (Dist.), in Cameroon. RESULTS: A total of 361 adults of S. singularis (359 males and two females) were caught. The highest numbers of mirids were found in traps with pheromone blends that combined a monoester and a diester, compared with traps with the diester or the monoester individually and control traps with no pheromone. Rectangular traps caught significantly more mirids compared with delta traps. The mean number of 5.1 mirids trap?1 year?1 caught in rectangular traps was significantly higher compared with the 1.8 mirids trap?1 year?1 for the delta traps. CONCLUSION: The data revealed that rectangular traps containing pheromone blends combining both the monoester and the diester have a good potential to lure and trap adult males of S. singularis on cocoa farms. The pheromone blends used were specific for S. singularis, and the use of pheromone traps appears to be a promising strategy for incorporation into integrated pest management strategies for the monitoring or even the control of S. singularis in cocoa plantations. Copyright © 2011 Society of Chemical Industry  相似文献   

15.
The efficacy of microencapsulated sprayable pheromone was evaluated at different application rates and intervals for mating disruption of the oriental fruit moth,Grapholita molesta (Busck), in apple orchards during 2002. The following treatments were arranged in a randomized complete block design with three replications: (i) a low rate of pheromone (6.2 g a.i. ha−1) applied at 14-day intervals, (ii) a medium rate of pheromone (12.4 g a.i. ha−1) applied at 28-day intervals, (iii) a high rate of pheromone (24.7 g a.i. ha−1) applied at 28- day intervals, and (iv) a non-pheromone control (insecticides only). The combination of a single insecticide application against first generationG. molesta at petal fall with one pheromone application each for the second, third and fourth generations at 12.4–24.7 g a.i. ha−1 successfully controlled low populations. Pheromone-treated blocks. had significantly lower trap catches than those in the insecticide-treated control blocks. Among pheromone treatments, significantly more moths were caught in the 6.2 g compared with the 12.4 and 24.7 g rates. Fruit damage was <1% at harvest and there were no significant differences among treatments. Low rate frequent applications of sprayable formulation appeared to be effective under low pest pressure but efficacy declined with increasing populations. Further studies are needed to demonstrate the effectiveness of this approach under higher pest pressure. http://www.phytoparasitica.org posting July 13, 2005.  相似文献   

16.
A series of pyridylcarbamates showed high potency against cucumber gray mould (Botrytis cinerea Pers.). The most potent compound, propargyl-N-(6-ethyl-5-iodo-2-pyridyl)carbamate was effective against an isolate sensitive to benzimidazole and dicarboximide fungicides as well as against an isolate resistant to both types of compound. QSAR analyses and molecular modelling studies were carried out to investigate the structural requirements for highly active compounds and the structural feature of the binding site of each strain. Significantly different QSAR equations were obtained only for substituents at the 6-position of the pyridine ring. An ethyl-sized pocket or an ethyl terminal recognition was suggested in the case of the sensitive or resistant isolate respectively. These results could explain the phenomenon of negatively correlated cross-resistance between benzimidazoles and N-phenylcarbamate fungicides. Substituent effects at the 5- or 2-position were governed by steric factors. Substituent effects at the 3-position were explained by steric hindrance or by conformational effects. The propargyl-substituted compound above was the most desirable one from the viewpoint of QSAR.  相似文献   

17.
为确定粘虫Mythimna separata(Walker)雌蛾的性信息素特征成分及其不同配比的室内引诱效果,采用气相色谱-质谱和气相色谱-触角电位联用技术检测了雌蛾性腺浸提液,并利用Y型嗅觉仪测定了粘虫雄蛾对不同配比性信息素特征成分的选择反应。结果显示,从粘虫的求偶雌蛾性腺浸提液中可分离到顺-11-十六碳烯醛、十六碳醛和顺-11-十六碳烯醇3种特征成分,在色谱柱中的保留时间依次为15.82、16.06和17.27 min,含量分别为3.37、1.83和0.10 ng,比例约为34∶18∶1。无论是天然存在于雌蛾性腺还是人工合成的顺-11-十六碳烯醛均能够激发雄蛾的电生理反应。顺-11-十六碳烯醛、十六碳醛和顺-11-十六碳烯醇不同配比对雄蛾表现出不同的引诱活性,最大引诱率达87%,极显著高于对照溶剂石蜡油对雄蛾的引诱率。表明顺-11-十六碳烯醛、十六碳醛和顺-11-十六碳烯醇为中国粘虫种群的雌蛾性信息素特征成分,且其不同配比对雄蛾有不同的引诱活性。  相似文献   

18.
The knockdown and contact killing actions of various pyrethroids were compared using Blattella germanica and Periplaneta americana. A wide range of knockdown activity was found; 5-benzyl-3-furylmethyl (1R)-cis-3-(dihydro-2-oxo-3-thienylidenemethyl)-2,2-dimethylcyclopropanecarboxylate (RU 15525) acted fastest, more rapidly than pyrethrins, against B. germanica as well as having a low LD50 value. Topical application and direct spray tests showed that (S)-α-cyano-3-phenoxybenzyl (1R)-cir-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropanecarboxylate (NRDC 161) was more active as a killing agent, by an order of magnitude, than cismethrin, the next most active compound, and also had considerable knockdown activity. Piperonyl butoxide generally had little synergist effect. Female P. americana were over three times more tolerant than males to a range of insecticides applied topically. Residual knockdown action in the WHO resistance test was observed to provide baseline data. There was little overlap in speed of action between pyrethroids and other insecticides among the compounds tested.  相似文献   

19.
BACKGROUND: Sex pheromones of the potato tuber moths Phthorimaea operculella (Zeller) and Symmetrischema tangolias (Gyen) are ideal tools to monitor pest flight activity but are not used as means of control. The aim of the present study was to test the suitability of an attract‐and‐kill strategy consisting of pure pheromones and the contact insecticide cyfluthrin as the active ingredient, formulated with plant oils and ultraviolet absorbers, and applied in droplet sizes of 100 µL. RESULTS: Cyfluthrin at a concentration of 5 g L?1 resulted in the highest and fastest killing of males after 48 h, with a 100% mortality after 3–4 days. In contrast, control males survived for 13 days. In olfactometer experiments, the pheromone concentration of 0.5 g L?1 was significantly most attractive against eight virgin females. At controlled conditions (20 °C), no reduction in efficacy of the attract‐and‐kill formulation was observed for a minimum period of 36 days, whereas under natural environmental conditions the efficacy reduced gradually after day 6 of exposure. The longer the droplet was exposed, the longer was the time to reach 100% mortality of males. CONCLUSIONS: Compared with attract‐and‐kill studies for other pest species, the results are promising as a means of achieving highly effective control of potato tuber moths under field conditions. Copyright © 2010 Society of Chemical Industry  相似文献   

20.
The effects of field aging (0–28 days) and pheromone loading rate on the longevity of red rubber septa loaded with the sex pheromone blend of the oriental fruit mothGrapholita molesta (Busck), were evaluated in North Carolina apple orchards in 2002. Separate field tests examined the influence of trap height and pheromone loading rate of rubber septa on trap catches of adultG. molesta males in an abandoned orchard. The loss of the major pheromone component, (Z)-8-dodecenyl acetate (Z8–12:OAc), from red rubber septa over a 4-week period exhibited a relatively constant release rate with 30, 100 and 300 μg pheromone. Trap catch was significantly higher in pheromone traps placed in the upper canopy than in those in the lower canopy. Pheromone traps baited with 100μg lures caught more moths compared with those loaded with 300 μg. There was no apparent relationship between pheromone trap catch and septa age, with trap catch appearing to be primarily a function ofG. molesta population density. http://www.phytoparasitica.org posting May 14, 2006.  相似文献   

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