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1.
Abstract

Flue‐cured Virginia (f.c.v.) tobacco grown on deltaic islands or lankas in the Godavari river in Andhra Pradesh, India is subject to heavy infestations of green peach aphid, Myzus persicae Sulz. The relative efficacy of granular formulations of the systemic insecticides phorate, disulfoton, carbofuran, aldicarb and terbufos in controlling the aphid, and their effect on the yield and quality of lanka tobacco have been studied. Aldicarb granules at 1 g/plant and disulfoton at 2 g/plant were found to be the most effective in controlling the aphid, and also resulted in higher yields of green leaf, cured leaf and total bright leaf equivalent (an index of visual quality). Terbufos at 2 g/plant also gave good yields, but was slightly less effective in controlling aphid infestations. Carbofuran at 3 g/plant was the least effective. The chemical quality of f.c.v. tobacco was not affected by the application of granular insecticides to the soil.  相似文献   

2.
Abstract

We developed a procedure for preparing a model for mapping spatially distributed zones of aphid pest (Lipaphis erysimi) outbreaks at a regional level. This study employed near-surface meteorological parameters derived from National Oceanic and Atmospheric Administration (NOAA) Television and Infra-Red Operational Satellites (TIROS) Operational Vertical Sounder (TOVS) data and field observations of disease infestation. The study area comprised three sites representing semi-arid and sub-humid regions of dominant Indian mustard (Brassica juncea L.)-growing regions of India. A model based on TOVS-derived cumulative surface air temperature and minimum specific humidity (SpH) was developed to estimate the date of ‘aphid onset’ (first appearance), date of peak infestation and location of severity with respect to aphid population density. Aphid population growth rate during the linear growth phase between aphid onset to peak was computed using SpH-weighted temperature and dates of sowing of the crop (crop age). Sowing dates of mustard crop, of northwest India, were obtained from spectral growth profiles derived from time series remote sensing (RS) products of the SPOT-4 VEGETATION sensor. Estimated dates of peak aphid infestation and peak population showed a strong match with the observed data. The location of peak aphid population density was depicted in each spatial grid of 25×25 km2 for parts of northwest India. The simulated aphid population build-up and date of peak population density was validated with observed data for an unknown site in the Sriganganager district, Rajasthan state, India. Comparison of predicted dates of attaining peak aphid population with observations showed a deviation of ±7 days. After validation, the regional level model was applied over a large area of a mustard-growing region for varying dates of sowing, surface air temperature and specific humidity, to show the spatial distribution of aphid growing severity zones (population density) and to predict dates of severe aphid infestation (peak population) at each grid level in the region.  相似文献   

3.
Abstract

A method was devised for estimating large populations of cowpea aphid Aphis craccivora Koch (Hemiptera: Aphididae) on cowpea. The densities of the aphid on stem, leaves and pod were first estimated in the laboratory for use in the field later. The densities were estimated in three arbitrary classes of infestation, viz. heavy, medium and low, determined visually based on the intensity of colonization. The densities of the aphid per cm2 on stems were 108.50, 49.77 and 2503, while on pods they were 80.68, 44.46 and 23.20, in the three classes of infestation respectively. The aphid did not show any preference for the thickness of stems whereas young pods were preferred to old pods for colonization. The mean aphid densities on leaflets of topmost leaves were 62.10, 36–35 and 18–50, while on leaflets of top 2nd and 3rd leaves they were 124–60, 69–35 and 38.20, in the three infestation classes respectively. Comparisons made between the aphid densities on different parts of cowpea plant showed that the aphid colonized them in descending order of preference as stem > pod > top most leaf > top 2nd and 3rd leaves.  相似文献   

4.
Abstract

The impact of native natural enemies, supplemented by augmentative releases of the green lacewing, Chrysoperia rufilabris Burmeister (Neuroptera: Chrysopidae), and/or the cecidomyiid, Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae), on the population dynamics of the green apple aphid, Aphis pomi De Geer (Homoptera: Aphididae), was assessed in a series of experiments conducted in north central Washington State, USA. In one trial, C. rufiabris alone was released at a rate of 200 eggs or first instar larvae per tree per week for 6 weeks; in a second experiment, it was released in combination with A. aphidimyza at rates of 400 eggs and 250 pupae respectively per tree per week. In a final trial, A. aphidimyza alone was released at a rate of 200 pupae per tree per week for the duration of the growing season. The dominant native natural enemies in the study area were Chrysopa nigricornis Burmeister, A. aphidimyza. Onus sp. (Hemiptera: Anthocoridae), and various species of Syrphidae, Chamaemyiidae, and Coccinellidae (principally Coccinelle transversoguttata Faldermann and Hippodamia convergens Guerin). Exclusion cage techniques indicated that this native natural enemy complex caused significant mortality of A. pomi. However, no effect of the augmentative release treatments could be demonstrated, and where plant growth was vigorous and aphid populations high, the numerical response of indigenous generalist predators was insufficient to keep A. pomi densities below damaging levels.  相似文献   

5.
BACKGROUND: Two important pests of the sweet pepper, Capsicum annuum, are the peach potato aphid, Myzus persicae, and the glasshouse potato aphid, Aulacorthum solani. Current aphid control measures include the use of biological control agents, i.e. parasitic wasps, but with varying levels of success. One option to increase parasitoid efficiency is to activate plant defence. Therefore, sweet pepper plants were treated with the naturally occurring plant defence activator cis-jasmone, and its impact upon the behaviour and development of aphids and aphid parasitoids was investigated. RESULTS: Growth rate studies revealed that the intrinsic rate of population increase of A. solani and M. persicae on sweet pepper plants treated with cis-jasmone (cJSP) was not affected compared with untreated plants (UnSP), but the positive behavioural response of alate M. persicae towards the volatile organic compounds (VOCs) from UnSP was eliminated by cis-jasmone treatment 48 h previously (cJSP48). In addition, the aphid parasitoid Aphidius ervi preferred VOCs from cJSP48 compared with UnSP, and a significant increase in foraging time was also observed on cJSP. Analysis of VOCs collected from cJSP48 revealed differences compared with UnSP. CONCLUSION: There is evidence that treatment with cis-jasmone has the potential to improve protection of sweet pepper against insect pests. © Crown copyright 2012. Reproduced with permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.  相似文献   

6.
AdultCoccinella septempunctata, a coccinellid predator of the bean aphidAphis fabae Scop., responded to aqueous extract containing kairomones of the prey. The crude aphidextract was topically dropped onto either clean leaves ofVicia faba or clean Petri-dishes. After application of aqueous-extract at different aphid densities, the predator showed variations in the attractivity and searching behaviour in comparisons with control. The variations are summarized as follows: (1) the aqueous-extract of aphids attract or directC. septempunctata adults to the treated vials at all aphid densities. The number of attracted or directed coccinellid adults was directly proportional with aphid concentrations; (2) the predatorC. septempunctata adult intensified its searching behaviour by increasing the total path length walked; (3) the number of turns exhibited is significantly higher as compared with those of control; and (4) the arrested time spent by coccinellid adults with treated plant is much more than that with clean plant at all aphid densities. The present results show that the aphid aqueous-extract contains the active ingredients (kairomone) which induce considerable changes in the searching pattern of the predator coccinellid adults.  相似文献   

7.
Abstract

An experiment was designed to test the efficacy of various insecticides for the control of mustard aphid (Lipaphis erysimi (Kalt)) on mustard (Brassica juncea), variety RL 18 at the Research Farm of the Haryana Agricultural University, Hissar (India). Out of the 13 insecticides tried, each at two levels, it was found that methyldemeton 250 ml and menazon 250 g a.i. gave the maximum control of mustard aphid. Maximum yield of 1111 kg/ha was obtained with methyldemeton 250 ml (a.i./ha) against 360 kg/ha of the control.  相似文献   

8.
为拓展和获取对荻草谷网蚜Sitobion miscanthi表现稳定的小麦抗源,以我国146个小麦品种(系)为材料,利用2020年麦田蚜虫发生严重的机会,采用有蚜株蚜害级别计算抗蚜指数,采用耐蚜值(调查株蚜害级别/千粒重损失率)计算耐蚜指数,以此评估小麦的抗蚜性水平和耐蚜性水平;2022年利用人工辅助接蚜的方法对2020年表现稳定的部分小麦品种(系)的评估结果进行验证。结果显示,在自然感蚜条件下2个试验点6次调查中仅山农116、泉麦31和濮麦116表现稳定的抗蚜性,在人工接蚜时仅郑麦132表现稳定的抗蚜性;中育1220、泰禾麦2号和瑞华1408在自然感蚜时蚜量较低,千粒重损失率低于5.00%,人工接蚜亦表现良好的耐蚜性,表明其兼具耐蚜性和一定的抗蚜性;泰麦601、瑞华592、轮选166和中农麦4007在自然感蚜的高蚜量情况下和人工辅助接蚜时均能保持较低的千粒重损失率(小于15.00%),表明成株期小麦的抗蚜性减弱是一种普遍现象,耐蚜性是比抗蚜性更稳定的遗传特征。  相似文献   

9.

The resistance of ashgourd to the melon-cottonaphid, Aphis gossypii (Glover), and the incidence of aphid-transmitted viral diseases was investigated following recording of aphid numbers and trichome (plant hair) numbers per cm2 of leaf on four parts of the cucurbit, ashgourd, representing four genotypes (Local Sylhet, Local Round, High Female and CQ-10-90). The Local Sylhet genotype was found to have the highest trichome density compared with those of Local Round, High Female, and CQ-10-90 ashgourd genotypes, and was least infested by Aphis gossypii. The percentage of virus-infected plants was also found to be lowest on the Local Sylhet genotype. Aphid numbers were lowest on the terminal and young leaves of ashgourd compared with mature and senescent leaves, due to the higher trichome density in the former leaf categories. Trichome density was found to have a significant negative influence on the number of aphids. Trichomes in ashgourd play a major role by providing a first line defence in reducing aphid infestation, with a subsequent beneficial effect of reducing the incidence of virus.  相似文献   

10.
AdultCoccinella septempunctata, a coccinellid predator of the bean aphidAphis fabae Scop., responded to aqueous extract containing kairomones of the prey. The crude aphidextract was topically dropped onto either clean leaves ofVicia faba or clean Petri-dishes. After application of aqueous-extract at different aphid densities, the predator showed variations in the attractivity and searching behaviour in comparisons with control. The variations are summarized as follows: (1) the aqueous-extract of aphids attract or directC. septempunctata adults to the treated vials at all aphid densities. The number of attracted or directed coccinellid adults was directly proportional with aphid concentrations; (2) the predatorC. septempunctata adult intensified its searching behaviour by increasing the total path length walked; (3) the number of turns exhibited is significantly higher as compared with those of control; and (4) the arrested time spent by coccinellid adults with treated plant is much more than that with clean plant at all aphid densities. The present results show that the aphid aqueous-extract contains the active ingredients (kairomone) which induce considerable changes in the searching pattern of the predator coccinellid adults.  相似文献   

11.
为探究禾谷缢管蚜Rhopalosiphum padi (Linnaeus)水通道蛋白基因RpAQP1的序列特征及其在不同龄期的表达,利用RT-PCR和RACE技术克隆了RpAQP1基因的cDNA全序列,采用生物信息学软件分析了RpAQP1编码蛋白的特性,利用qRT-PCR分析了RpAQP1在不同龄期的表达量。结果显示:禾谷缢管蚜水通道蛋白基因RpAQP1的cDNA全长为1 216 bp,其750 bp的开放阅读框编码250个氨基酸,蛋白分子量为27.36 kD。RpAQP1属于水通道蛋白亚家族DRIP(果蝇内嵌蛋白Drosophila integral protein)的一员,具有6个跨膜区,2个保守的NPA结构单元和1个压缩区域Ar/R;qRT-PCR结果显示,RpAQP1在整个发育历期均有表达,其在2龄若蚜中表达水平最高,是成蚜表达量的1.432倍;在4龄若蚜中表达量最低,为成蚜表达量的0.444倍,显著低于其它龄期,而其余各龄期RpAQP1表达量无显著差异。  相似文献   

12.
BACKGROUND: Black pecan aphid, Melanocallis caryaefoliae (Davis) (Hemiptera: Aphididae), feeding elicits localized chlorotic injury to pecan foliage [Carya illinoinensis (Wangenh.) K Koch] and apparent acceleration of leaf senescence and defoliation. The ability of certain plant growth regulators (PGRs) (forchlorfenuron, gibberellic acid and aviglycine) to prevent M. caryaefoliae from triggering pecan leaf chlorosis and senescence‐like processes was evaluated on two dates in both 2006 and 2007. Treatments were applied to orchard foliage and used in laboratory leaf‐disc bioassays to assess possible reduction in aphid‐elicited chlorosis and concomitant effects on aphid mortality and development. RESULTS: Foliage pretreated with forchlorfenuron + gibberellic acid prior to being challenged with aphids resulted in significantly less aphid‐elicited chlorosis than did control or aviglycine‐treated leaf discs. No PGR affected aphid mortality; however, development time was increased by forchlorfenuron + gibberellic acid in 2006 and by aviglycine + gibberellic acid on one date in 2007. CONCLUSION: Certain PGRs possess the potential for usage on pecan to protect foliar canopies from M. caryaefoliae via changes in the susceptibility of the host leaf to senescence‐like factors being introduced by feeding aphids. This protective effect on host foliage and the associated suppressive effect on development of feeding aphids might also be relevant to pest management programs on other aphid–crop systems in which aphid‐elicited chlorosis and senescence‐like processes can limit profitability. Published 2010 by John Wiley & Sons, Ltd.  相似文献   

13.
A survey of aphid species which colonize or reproduce on wild and cultivated plants in the Arava Valley of Israel was carried out at the end of winter 1986. Thirty-three aphid species were collected on wild plants and 23 in green tile or yellow traps exposed in cultivated plots. Aphids were recorded from 77 plant species in 22 botanical families.Myzus persicae, Aphis craccivora, Brachyunguis harmalae, Acyrthosiphon gossypii andAphis gossypii were present on plants in 19 botanical families. M. persicae was the most frequently trapped aphid species in both green tile and yellow traps. The possible origin of the aphid species found in the desert was considered in view of the ecology and geography of the region. The role of aphid species trapped in the Arava Valley, in the epidemiology of potato virus Y (PVY) and zucchini yellow mosaic virus (ZYMV), is discussed. Publication of the Agricultural Research Organization. No. 2305-E, 1988 series.  相似文献   

14.
The impacts of elevated CO2 and soil water on the population dynamics, adult fecundity and nymphal period of the bird cherry-oat aphidRhopalsiphum padi (Linnaeus) were evaluated in three experiments: (i)Combined effects of CO 2 and soil water on aphid populations. Spring wheat was grown in pots at three CO2 concentrations (350, 550 and 700 ppm) and three soil water levels (40%, 60% and 80% of field water capacity, FWC) in field open-top chambers (OTC) and infested with the bird cherry-oat aphid. Aphid population dynamics were recorded throughout the growing season; at the same time, adult fecundity and duration of the nymphal period were recorded. Chemical composition of spring wheat leaves was also analyzed. (ii)Indirect effects of CO 2 concentrations and soil water on aphid adult fecundity and nymphal period. The experiment was conducted with the leaf discs method in the laboratory. Aphids were reared on leaf discs excised from the treated wheat in OTC with different CO2 and soil water levels. (iii)Direct effects of CO 2 concentrations on aphid adult fecundity and nymphal period. Aphids were reared on leaf discs excised from the wheat grown under natural conditions. The experiment was conducted with the leaf disc method in OTC with the three CO2 concentrations. It was found that the direct effect of CO2 concentration on aphid population parameters was minor. CO2 and soil water affected aphid population indirectly through their effects on wheat characteristics. The aphid population under 550 ppm CO2 was far larger than the one under 350 ppm CO2, whereas the population under 700 ppm CO2 was slightly higher than that under 550 ppm CO2. The largest aphid population was obtained with the 60% soil water treatment, regardless of CO2 treatment. The effects of CO2 concentration on aphid population were, however, not significantly correlated with soil water level. Adult fecundity increased with CO2 concentration, the highest fecundity being achieved under 60% FWC treatments. The nymphal period was not affected by CO2 concentration. The shortest period occurred under 60% FWC. Atmospheric CO2 and soil water had significant effects on the chemical composition of the wheat leaves. Aphid population size was positively correlated with leaf water content, concentrations of soluble proteins, soluble carbohydrates and starch, and negatively correlated with DIMBOA and tannins concentrations. http://www.phytoparasitica.org posting Oct. 20, 2003.  相似文献   

15.
BACKGROUND: Saponins are a class of secondary plant metabolites consisting of a sugar moiety glycosidically linked to a hydrophobic aglycone (sapogenin) that often possess insecticidal activities. Four saponins were selected: two triterpene saponins, Q. saponaria saponins and aescin, and two steroidal saponins, digitonin and diosgenin. Their effects were investigated on an important pest species and a model piercing‐sucking insect, the pea aphid Acyrthosiphon pisum. The triterpene Q. saponaria saponins bark saponin received special attention because of its high activity. Aphids were challenged by oral and contact exposure to demonstrate aphicidal activities, and in choice experiments to support use as a natural deterrent. RESULTS: When aphids were exposed to supplemented artificial diet for 3 days, a strong aphicidal activity was recorded for three of the four saponins, with an LC50 of 0.55 mg mL?1 for Q. saponaria saponins, 0.62 mg mL?1 for aescin and 0.45 mg mL?1 for digitonin. The LT50 values ranged between 1 and 4 days, depending on the dose. For diosgenin, only low toxicity (14%) was scored for concentrations up to 5 mg mL?1. In choice experiments with treated diet, a deterrence index of 0.97 was scored for Q. saponaria saponins at 1 mg mL?1. In contrast, direct contact showed no repellent effect. Spraying of faba bean plants with Q. saponaria saponins resulted in an LC50 of 8.2 mg mL?1. Finally, histological analysis in aphids fed with Q. saponaria saponins demonstrated strong aberrations of the aphid gut epithelium, and exposure of midgut CF‐203 cell lines to Q. saponaria saponins in vitro confirmed the cytotoxic effect. CONCLUSIONS: The present insect experiments provide strong evidence that saponins, as tested here with triterpene Q. saponaria saponins, can be useful as natural aphicides and deterrents. Furthermore, the insect midgut epithelium is suggested to be a primary target of saponin activity.Copyright © 2011 Society of Chemical Industry  相似文献   

16.
不同寄主植物上烟蚜DNA多态性的RAPD-PCR分析   总被引:3,自引:0,他引:3  
用RAPD-PCR技术研究了桃树,油菜和烟草上烟蚜的DNA多态性。结果表明,用相似性指数和Nei的遗传距离及聚类分析对本研究筛选的三个引物OPX-04,POX-06和OPX-19的扩增结果进行比较,除OPX-06的D值聚类可将各寄主植物上的烟蚜分开外,其余均可将样本分为两类,即来自桃树的烟蚜和来自油菜,烟草上的烟虾。  相似文献   

17.
Host plant preference of the Russian wheat aphid Diuraphis noxia (Kurdj.) was studied on 11 cultivars of 9 plant species: winter barley, spring barley, winter wheat, spring wheat, rye, oat, Triticale, canary grass, red millet yellow millet and maize. Seeds of the host plants were sown in a circle near the edge of pots. The host plant choice was evaluated 24 hours after releasing 55 Diuraphis noxia female adults in the middle of each pot. The suitability of different hosts for aphid development was evaluated 2, 7 and 14 days after infestation based on the mean number of Russian wheat aphid individuals per plant. Red millet, yellow millet and maize were chosen by significantly fewer aphids than grain crops. Winter and spring barley were chosen as hosts most frequently, and the progeny production was also the highest on these plants. The growth rate of D. noxia was significantly affected by the host plants and the date of assessment and their interaction.  相似文献   

18.
The aphids Aphis craccivora Koch attack country bean Lablab purpureus L. both in its vegetative and reproductive stages and cause severe damage. To develop an integrated management of aphid powders of black pepper, chili, turmeric, and coriander; oils of mahogany, neem, and eucalyptus; aqueous extracts of neem, basil, and garlic leaves; and water were evaluated in field conditions. The treatments were applied at 7?day intervals and aphid abundance per inflorescence was counted at 24, 48, and 72?h after treatment. All the plant materials reduced aphid abundance and flower infestation, ensuring a higher yield with larger and heavier pods. The neem oil treatment had the lowest abundance of aphid and consequently produced the highest marketable and gross yields. Predatory insects were abundant in the field, but their populations were lower in the treatments than the control. An economic analysis indicated that the highest gross return, net return, adjusted net return, and benefit-cost ratio were obtained from the mahogany oil treatment. The plant materials have insecticidal potential against aphids, and the oils of mahogany and neem showed better performances.  相似文献   

19.
During the spring of 2016, the aphid Myzus mumecola (Matsumura) (Hemiptera: Aphididae) was detected on its preferential host plant, Prunus armeniaca L. (Rosaceae), in Italy. This was the first record of the species in Europe. Several populations of the aphid have been collected in various apricot orchards in Emilia‐Romagna, in the localities of Imola, Campiano, Cesena and Castiglione di Cervia. The species is considered to be an apricot pest in India and East Asia. Details on the morphology, biology and distribution of this aphid species and the damage it causes are given.  相似文献   

20.
广州地区十字花科蔬菜花叶病(主要病毒是芜菁花叶病毒的油菜毒系和芜菁毒系)的越夏寄主,根据11年来的观察特别是1956—1958年间的实地调查结果,主要是小白菜、菜心和西洋菜。在野生植物中曾发现过2株蔊菜和1株荠菜自然感病,说明野生植物不是本病的重要毒源。室内试验结果证明,此病的自然传染媒介为萝卜蚜、桃蚜和普通红蜘蛛。黄条跳(虫甲)、斜纹夜盗蛾和菜粉蝶都不是本病的虫媒,病株的种子不会传病,中国菟丝子也不会传递本病。在带有未腐熟的病菜残体的土里进行直播,长出来的菜苗没有发病的;但是把菜苗移植在这样的土里,会有极小量的植株感病。根据1956年7月至1958年6月,每十日田间调查一次结果:萝卜蚜是广州地区最重要的传病媒介,桃蚜每年只在3—4月间略有发生,作用不大。根据这24个月的田间发病率,萝卜蚜(有翅蚜及无翅蚜)的虫口密度和气候情况,我们认为本地区本病的发生及流行程度主要受降水量和降水天数所影响,并认为可以从降水情况来预测约30日后的病害流行程度。  相似文献   

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