稻秆潜蝇预测预报技术探讨

笔者通过两年的田间定点系统观察和幼虫发育进度剥查，初步提出稻秆潜蝇的短期预测和长期预测方法。短期预测田间各代幼虫发生期，采用幼虫发育进度剥查定化蛹高峰期与查被害株长出正常新叶株率与化蛹率的相关性回归预测法，准确性较高。用当年第2代幼虫成蛹有效量，可对预测翌年发生轻、重作长期预测的重要依据。     

甘肃古浪豌豆潜叶蝇的发生与防治

豌豆潜叶蝇 [Ｃｈｒｏｍａｔｏｍｙｉａｈｏｒｔｉｃｏｌａ (Ｇｏｕｒｅａｕ) ]属双翅目 ,潜蝇科 ,俗名夹叶虫 ,是古浪县豌豆上的常发性害虫 ,每年都有不同程度的发生 ,尤以 2 0 0 2年为重 ,此虫遍及古浪县油菜、豌豆所有田块 ,虫株率达10 0 % ,虫叶率 6 6 .7% ,百株虫量高达 12 32 0头 ,百叶有虫 10 70头。豌豆潜叶蝇的发生 ,严重影响该县 0 .8万ｈｍ2 豌豆的正常生长 ,受害豌豆田轻者减产 10 %～2 0 % ,重者达 4 0 %以上 ,甚至绝收。为减轻该虫危害 ,确保古浪县优质小杂粮基地建设 ,笔者在多年的防治工作中 ,对其发生与防治进行了专题调查…     

蔬菜潜叶蝇综合防治技术

蔬菜潜叶蝇的为害严重影响蔬菜品质,降低蔬菜产量。根据棚室及露地蔬菜潜叶蝇发生的特点,分析影响蔬菜潜叶蝇发生的因素,并采取有效的防治技术措施。     

山区稻秆潜蝇的发生规律及防治措施

稻秆潜蝇是寿宁县中稻的主要害虫之一。通过多年的田间观察与调查,基本掌握了该虫在本地的分布情况、为害特性、发生规律,并提出一套行之有效的测报方法和综合防治方法。     

小麦潜叶蝇呈加重发生趋势

小麦潜叶蝇一直是小麦上的次要害虫,常在局部区域偏轻发生,损失较小,对其发生规律、趋势预报和大田防治都没有引起足够重视.但近年来,北京、天津、河北、山东、河南华北麦区和陕西、甘肃、宁夏等地的西北麦区小麦潜叶蝇呈加重发生态势,发生面积扩大,危害程度加重,已对这些地区的小麦生产构成较大威胁.据初步统计,2003年华北麦区和西北麦区小麦潜叶蝇发生面积达266.7万/hm2.     

京郊蔬菜上潜叶蝇种群动态调查

通过黄卡监测和田间取样调查明确,京郊蔬菜潜叶蝇有美洲斑潜蝇、南美斑潜蝇、番茄斑潜蝇、豌豆彩潜蝇和葱斑潜蝇５种。它们的主要发生期豌豆彩潜蝇为４月底～６月中、下旬,番茄斑潜蝇为５月中旬～７月上旬及９月上、中旬～１０月中旬,南美斑潜蝇为６月中、下旬～７月下旬,美洲斑潜蝇为７月中～１０月初,葱斑潜蝇仅在５、６月发现极少量。     

蔬菜上11种潜叶蝇的鉴别

蔬菜上１１种潜叶蝇的鉴别雷仲仁王音问锦曾（中国农业科学院植物保护研究所北京１０００９４）近年蔬菜上潜叶蝇为害日趋严重，几乎各种蔬菜包括叶菜、番茄、土豆、瓜类都被害，并造成毁产事例。为害蔬菜的潜叶蝇种类很多，不同虫种为害习性不同，防治方法也不同，有些为...     

为害蔬菜和观赏植物的美国三叶草潜叶蝇

1977年欧洲很多国家都初次报道了起源于美国的一种蔬菜和观赏植物的危险性害虫——美国三叶草潜叶蝇Liriomyza trifolii(Burgess)(双翅目:潜蝉科),异名为L. allivora Frick, L. phascolunulata Frost.这种小型蝇类在欧洲称作美国蛇形潜叶蝇、菊花潜叶蝇、大丁草潜叶蝇,或     

稻秆潜蝇的发生危害与防治

稻秆潜蝇(Chlorops oryzae Matsumura)又称稻秆蝇、稻钻心蝇、双尾虫, 属双翅目,黄潜叶蝇科.自20世纪80年代中期在浙南山区发生危害以来, 一直是山区单季水稻的主要害虫.     

A temperature and leaf wetness duration-based model for prediction of gray leaf spot of perennial ryegrass turf

ABSTRACT Gray leaf spot is a serious disease of perennial ryegrass (Lolium perenne), causing severe epidemics in golf course fairways. The effects of temperature and leaf wetness duration on the development of gray leaf spot of perennial ryegrass turf were evaluated in controlled environment chambers. Six-week-old Legacy II ryegrass plants were inoculated with an aqueous conidial suspension of Pyricularia grisea (approximately 8 x 10(4) conidia per ml of water) and subjected to four different temperatures (20, 24, 28, and 32 degrees C) and 12 leaf wetness durations (3 to 36 h at 3-h intervals). Three days after inoculation, gray leaf spot developed on plants at all temperatures and leaf wetness durations. Disease incidence (percent leaf blades symptomatic) and severity (index 0 to 10; 0 = leaf blades asymptomatic, 10 = >90% leaf area necrotic) were assessed 7 days after inoculation. There were significant effects ( alpha = 0.0001) of temperature and leaf wetness duration on disease incidence and severity, and there were significant interactions ( alpha = 0.0001) between them. Among the four temperatures tested, 28 degrees C was most favorable to gray leaf spot development. Disease incidence and severity increased with increased leaf wetness duration at all temperatures. A shorter leaf wetness duration was required for disease development under warmer temperatures. Analysis of variance with orthogonal polynomial contrasts and regression analyses were used to determine the functional relationships among temperature and leaf wetness duration and gray leaf spot incidence and severity. Significant effects were included in a regression model that described the relationship. The polynomial model included linear, quadratic, and cubic terms for temperature and leaf wetness duration effects. The adjusted coefficients of determination for the fitted model for disease incidence and severity were 0.84 and 0.87, respectively. The predictive model may be used as part of an integrated gray leaf spot forecasting system for perennial ryegrass turf.     

Analysis of genetic and virulence variability of Stemphylium lycopersici associated with leaf spot of vegetable crops

Stemphylium lycopersici (Enjoji) W. Yamam was initially described from tomato and has been reported to infect different hosts worldwide. Sequence analyses of the internal transcribed spacer (ITS) regions 1 and 2, including 5.8S rDNA (ITS-5.8S rDNA) and glyceraldehyde-3-phosphate dehydrogenase (gpd) gene, random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR), as well as virulence studies were conducted to analyze 46?S. lycopersici isolates. Stemphylium lycopersici isolates used in this study were obtained from diseased tomato (Solanum lycopersicum L.), eggplant (Solanum melongena L.), pepper (Capsicum annuum L.) and lettuce (Lactuca sativa L.) from major vegetable growing regions of Malaysia, including the three states of Pahang, Johor and Selangor between 2011 and 2012. Phylogenetic analysis of a combined dataset of the ITS-5.8S rDNA and gpd regions indicated that all isolates were clustered in the sub-cluster that comprised S. lycopersici, and were distinguished from other Stemphylium species. Cluster analyses using the UPGMA method for both RAPD and ISSR markers grouped S. lycopersici isolates into three main clusters with similarity index values of 67 and 68 %. The genetic diversity data confirmed that isolates of S. lycopersici are in concordance to host plants, and not geographical origin of the isolates. All S. lycopersici isolates were pathogenic on their original host plants and showed leaf spot symptoms; however, virulence variability was observed among the isolates. In cross-inoculation assays, the representative isolates were able to cause leaf spot symptoms on eggplant, pepper, lettuce and tomato, but not on cabbage.     

广西香蕉真菌性叶斑病病原菌种群结构分析

2009年2-3月对广西香蕉主产区真菌性叶斑病病原进行抽样鉴定。结果显示,广西香蕉真菌性叶斑病病原至少有10种,主要病原为Cordana musae,分布广,检出率为56.77%~92.19%;Corynespora cassiicola和Deightoniella torulosa为次,两种病原菌均主要集中在南宁地区,检出率分别为32.34%和22.61%;叶斑病类型以单一病原侵染为主,检出率为78.13%~92.19%;复合侵染的叶斑病类型以2种病原共同侵染居多。     

晚稻细菌性条斑病发病程度模糊预测

挑选与晚稻细菌性条斑病发病程度相关性好、超前性好的气象因子（雨日数、相对湿度、温湿系数）作为预报因子,应用模糊综合分析法,建立了晚稻细菌性条斑病发病程度的中期预测模型,经回测,历史拟合率为88．9％,对2007年试用,预报结果与实际相符。     

Regression and artificial neural network modeling for the prediction of gray leaf spot of maize

ABSTRACT Regression and artificial neural network (ANN) modeling approaches were combined to develop models to predict the severity of gray leaf spot of maize, caused by Cercospora zeae-maydis. In all, 329 cases consisting of environmental, cultural, and location-specific variables were collected for field plots in Iowa between 1998 and 2002. Disease severity on the ear leaf at the dough to dent plant growth stage was used as the response variable. Correlation and regression analyses were performed to select potentially useful predictor variables. Predictors from the best 9 of 80 regression models were used to develop ANN models. A random sample of 60% of the cases was used to train the networks, and 20% each for testing and validation. Model performance was evaluated based on coefficient of determination (R(2)) and mean square error (MSE) for the validation data set. The best models had R(2) ranging from 0.70 to 0.75 and MSE ranging from 174.7 to 202.8. The most useful predictor variables were hours of daily temperatures between 22 and 30 degrees C (85.50 to 230.50 h) and hours of nightly relative humidity >/=90% (122 to 330 h) for the period between growth stages V4 and V12, mean nightly temperature (65.26 to 76.56 degrees C) for the period between growth stages V12 and R2, longitude (90.08 to 95.14 degrees W), maize residue on the soil surface (0 to 100%), planting date (in day of the year; 112 to 182), and gray leaf spot resistance rating (2 to 7; based on a 1-to-9 scale, where 1 = most susceptible to 9 = most resistant).     

Environmental fate of mineral,vegetable and transesterified vegetable oils

Vegetable oils, synthetic esters (including transesterified oils) and mineral oils are the main classes of oil used in pesticide formulations. Biodegradation is a major route for the removal of oils from soil systems. Most of the oils used in pesticide formulations are degraded substantially in the laboratory tests that are used to assess aquatic biodegradability. The susceptibility of different oils to biodegradation can be explained in terms of the metabolic capacity of common microorganisms. Fewer soil biodegradability tests have been carried out with oils, but the available data suggest that the mode of degradation is not very different from that in aquatic systems. Supplements of inorganic nutrients (in particular nitrogen) are needed to stimulate microbial activity in soils containing the high concentrations of oil that can be encountered in the event of a spill. However, oils are applied at such low rates in pesticide form illations (maximum of 5g oil m^? soil) that nutrient availability is unlikely to affect the rate of biodegradation in the field.     

Techniques to estimate relative leaf area and cover of weeds in crops for yield loss prediction

Destructive measurements to collect input data for models that predict yield loss from relative leaf area of weeds can be laborious. Alternative methods were tested in seven field experiments with sugar beet or spring wheat. Weeds with different morphologies showed the same linear relationships between relative leaf area, meas ured destructively, and cover, assessed by means of a frame, until 3 or 4 weeks after crop emer gence. At later growth stages, differences in weed morphology resulted in different relationships. Visual estimates of weed cover corresponded only roughly with cover assessments with a frame. The possibility of estimating relative leaf area of weeds with a reflectance technique was tested, assuming that for early growth stages the leaf area index of weeds can be considered as additional to that of the crop. In spring wheat, relative leaf areas of Sinapis alba L., sown at different times and densities, correlated well with characteristics based on infra-red reflectance. In sugar beet, these relationships were not as distinct. Techniques d'estimation de la surface foliaire relative et de la couverture des mauvaises herbes dans les cultures, en vue de prédictions de pertes en rendement Des prélèvements destructifs peuvent alimenter en données les modèles qui prédisent les pertes de rendement à partir de la surface foliaire relative des mauvaises herbes, mais ils sont exigeants en temps. Des méthodes alternatives ont été testées lors de sept expériences au champ dans de la betterave ou du blé de printemps. Jusqu'à trois ou quatre semaines après la levée de la culture, des mauvaises herbes possédant différentes morphologies montraient les mêmes relations linéaires entre d'une part la surface foliaire relative mesurée de manière destructive et d'autre part la couverture mesurée grâce à une grille. Aux stades de croissance ultérieurs, du fait des différences morphologiques entre les mauvaises herbes, les relations étaient différentes. Les estimations visuelles de la couverture en mauvaises herbes ne correspondaient qu'approximativement aux mesures de couverture effectuées au moyen de la grille. La possibilité d'estimer la surface foliaire relative des mauvaises herbes avec une technique de réflectance a étéévaluée, en supposant que, aux stades de croissance initiaux, l'indice de surface foliaire des mauvaises herbes peut être considéré comme additif de celui de la culture. Dans le blé de printemps, les surfaces foliaires relatives de Sinapis alba L., semées à différentes époques et à différentes densités, étaient bien corrélées avec des caractéristiques basées sur la réflectance infra-rouge. Dans la betterave à sucre, ces relations n'étaient pas aussi claires. Bestimmung der relativen Blattfläche und des Deckungsgrads von Unkräutern zur Prognose von Ertragsverlusten Die destruktive Gewinnung von Daten der relativen Blattfläche von Unkräutern für Modelle zur Vorhersage von Ertragsverlusten sind arbeitsaufwendig. Alternative Methoden wurden in 7 Versuchen in Zuckerrübe und Sommerweizen untersucht. Morphologisch unterschiedliche Unkräuter zeigten bis zu 3 oder 4 Wochen nach dem Auflaufen der Kulturpflanzen dieselben linearen Beziehungen zwischen der destruktiv gemessenen relativen Blattfläche und dem mittels eines Rahmens bestimmten Deckungsgrad. In späteren Entwicklungsstadien führten die morphologischen Unterschiede zu verschiedenen Verhältnissen. Bonituren des Unkrautdeckungsgrads entsprachen nur grob den mit dem Rahmen ermittelten Deckungswerten. Die Bestimmung der relativen Blattfläche der Unkräuter durch Messung der Lichtreflexion wurde geprüft, wobei angenommen werden kann, daß sich in den frühen Entwicklungsstadien der Blattflächenindex der Unkräuter mit dem der Kulturpflanzen summiert. Im Sommerweizen war die relative Blattfläche von zu verschiedenen Zeiten und in unterschiedlicher Dichte gesätem Sinapis alba L. mit den Daten der Infrarotreflexion gut korreliert, auf den Zuckerrübenflächen nicht so genau.     

Investigations on the interaction between the apple leaf miner Stigmella malella and its parasite Cirrospilus vittatus in the netherlands

Investigations during 1967 in a part of an experimental orchard where no insecticides were applied, showed that parasitism of larvae of the first generation ofStigmella malella byCirrospilus vittatus, which is by far the most numerous parasite of this leaf miner in The Netherlands, was low and that parasitism of larvae of the second generation was much higher. It is concluded that the capacity of increase of the parasite is much larger than that of its host and that the parasite is an important potential factor in the natural control of the leaf miner. The factors that may be responsible for the discrepancy between the high population density of the parasite in autumn and the low density in spring are discussed.Samenvatting Cirrosspilus vittatus is in Nederland verreweg de talrijkste parasiet van de appelbladmineerderStigmella malella (Tabel 1).In de proefboomgaard Thedinghsweert bij Tiel werd het verloop van de populatiedichtheid van de imagines van mineerder en parasiet (Fig. 1) en van de mineerderrupsen, benevens hun parasitering (Fig. 2), gedurende 1967 wekelijks nagegaan. Het bleek dat de tweede generatie van de mineerderrupsen, hoewel veel talrijker dan de eerste, voor een veel hoger percentage beparasiteerd werd. Daaruit wordt geconcludeerd dat de vermeerderingscapaciteit van de parasiet belangrijk groter moet zijn dan die van haar gastheer en dat de parasiet een belangrijke potentiële factor is in de natuurlijke beheersing van de mineerderpopulatie.De factoren die verantwoordelijk kunnen zijn voor het grote verschil in de populatiedichtheid van de parasiet aan het einde en aan het begin van het seizoen, worden besproken.     

Development of weather-based prediction models for leaf rust in wheat in the Indo-Gangetic plains of India

Weather based prediction models for leaf rust were developed using disease severity and weather data recorded at four locations viz. Ludhiana, Kanpur, Faizabad and Sabour of the All India Wheat and Barley Improvement Project. Weeks 7–9 of the crop growing season at Ludhiana, Faizabad and Sabour and weeks 10–12 at Kanpur were identified as critical periods for relating weather variables to disease. Highly significant correlation coefficients were found between disease severity and a greater number of weather variables in these critical 3-week periods than at other times. The correlation coefficients were greatest for the Humid Thermal Ratio (HTR), Maximum Temperature (MXT) and Special Humid Thermal Ratio (SHTR), and these three weather variables were selected as predictor variables. Linear regressions with these predictor variables (individually) during the critical periods, and a multiple regression with MXT and relative humidity (RH), serve as four disease prediction models, with sufficient lead-time to take control measures. Validation of these prediction models with independent disease severity data showed that the regression equation with MXT (Model-1) was the best among the prediction models, with four out of six simulations matching observed disease severity classes and also having lowest residual sum of squares (SSE) value of 2727. Models 4 (multiple regression), 2 (HTR) and 3 (SHTR) with SSE values of 2881, 3092 and 3732, respectively are in order of decreasing accuracy of prediction. The model using MXT can be used to predict the disease severity in the Indo-Gangetic Plains and provide the basis for efficient disease control.     

薏苡叶枯病和叶斑病调查与病原鉴定

对福建省龙岩市新罗区薏苡叶部病害进行了调查。用组织分离法,PSA平板培养经纯化后作病原鉴定,在其上发现了两种病害:薏苡叶斑病为一种新病害,病原鉴定为薏苡尾孢(Cercospora sp.);薏苡叶枯病为福建省首次记录,其病原为薏苡平脐蠕孢(Bipolaris coicis)。