Development of a pheromone trap monitoring system for orange wheat blossom midge, Sitodiplosis mosellana, in the UK

Field-trapping experiments with synthetic 2,7-nonadiyl dibutyrate, the female-produced sex pheromone of the orange wheat blossom midge, Sitodiplosis mosellana (Géhin), demonstrated that pheromone traps were highly attractive to males and caught very few non-target organisms. Different formulations of pheromone were tested to identify the optimum release rate and dispenser type for use in pheromone traps in the UK. Key findings were that racemic pheromone was as effective as enantiomerically pure (2S,7R)-2,7-nonadiyl dibutyrate, that release rates higher than 0.5 microg day(-1) were not necessary and that the optimal formulation was a 1 mg pheromone loading in a rubber septum. Pheromone traps gave a reliable indication of peak midge emergence, onset of flight and abundance of midges throughout the season. A strong correlation between maximum trap catch and crop infestation levels was obtained.     

黄曲条跳甲药剂敏感性监测方法的比较

应用浸叶法、点滴法和滤纸药膜法对黄曲条跳甲药剂敏感性测定结果的重复间变异系数比较表明,用点滴法测定黄曲条跳甲成虫药剂敏感性的重复性最好,变异系数为6.42%;其次为浸叶法和滤纸药膜法。利用点滴法和浸叶法测定了4个菜区黄曲条跳甲成虫对毒死蜱、丁硫克百威、氯氰菊酯的敏感性,结果表明点滴法和浸叶法测定结果均能一致反映出黄曲条跳甲田间种群的药剂敏感性水平。     

Selection of colour of sticky trap for monitoring adult bean thrips, Caliothrips fasciatus (Thysanoptera: Thripidae)

Adult bean thrips, Caliothrips fasciatus (Pergande), overwintering inside the navel of navel oranges shipped from California to Australia, are an actionable pest for the importing country, i.e. infested lots are fumigated with methyl bromide. Strict quarantine regulations regarding C. fasciatus prompted studies on the best colour sticky trap that might be used to monitor for bean thrips populations in the vicinity of California citrus groves prior to harvesting fruit for export. Preliminary experiments identified the most attractive trap of each of four colours (blue, green, white, yellow) commonly used to sample adult Thysanoptera. Three trials of a field study were conducted, comparing C. fasciatus capture on the best card of each colour using asparagus ferns naturally infested with high levels of this pest. Based on significantly higher catch on green sticky cards, this colour trap is recommended for potential use in California's bean thrips mitigation plan designed to reduce thrips levels on citrus exported to Australia.     

Metapopulation approach for landscape level management of western tarnished plant bug, Lygus hesperus, in Texas (Hemiptera, Miridae)

Insect source-sink dynamics are vital to ecologically intensive pest management. Maintaining sink plant hosts, or "trap crops", and destroying alternate hosts or breeding places adjacent to the field crop are effective pest management strategies for some arthropods. However, determining whether a host acts as a source or a sink is challenging, especially when the pest species is highly mobile and polyphagous. The western tarnished plant bug, Lygus hesperus, is highly polyphagous, and can utilize >300 hosts. Its presence has been documented in 26 roadside weed hosts in the Texas High Plains. Previous studies demonstrated that L. hesperus prefer alfalfa over cotton and several alternate weed hosts. A four-year project involved surveying and sampling for L. hesperus in the agricultural landscapes of several sub-regions of the southwestern United States, including the Texas High Plains. In Texas, geographic information of the landscape vegetation complex was compiled from a 150 km radius in the Texas High Plains. In one study, fifty irrigated cotton fields representing the crop diversity within this region were sampled via sweep-net for 10 weeks. This effort also included sampling of up to six non-cotton insect habitats within a 3 km radius of each field. Seasonal average L. hesperus abundance data were regressed with 27 field characteristics (variables), including habitat-specific land cover, distance between focal cotton fields and non-cotton habitats, longitude, latitude, elevation, habitat heterogeneity index, and several environmental/ecological variables. Significant variables were selected using a stepwise regression at 15% probability rate. A 10-parameter linear model explained 93% of the variation in the data. Major parameters contributing significantly to variation in L. hesperus abundance in cotton were corn and sunflower acreages, focal cotton field distances from several non-cotton hosts, and habitat heterogeneity index. In addition, field marking-and-capture studies were conducted using protein markers and enzyme-linked immunosorbent assays to characterize L. hesperus intercrop movement behavior. The field marking-and-capture approach can be used to study the effects of various crop management practices on L. hesperus intercrop movement and can potentially be applied to other pests and cropping systems.     

佳多虫情测报灯和普通黑光灯对草地螟种群监测与防治效果比较

2004-2006年连续3年应用佳多自动虫情测报灯和传统普通黑光灯对草地螟种群监测和诱杀结果表明,两种诱虫灯均可有效监测草地螟种群动态,自动虫情测报灯对高密度草地螟种群诱杀效果显著,诱蛾量明显高于普通黑光灯的,而普通黑光灯对低密度种群诱杀较为有效。两种灯光诱捕器监测的草地螟种群动态变化趋势基本一致,每天诱蛾数呈极显著相关（r2004=0.973、r2005=0.990和r2006=0.981,p<0.01),但黑光灯下草地螟种群始见期较早而终见期较晚。两种灯下诱捕的草地螟雌蛾数均大于雄蛾数,但灯光诱捕器之间诱捕的草地螟雌雄性比差别不大。     

Integration of partial resistance,plant density and use of fungicide for management of white mould in common bean

In-row plant densities have not been studied for common beans with type II growth habit and contrasting reactions to white mould. Advanced breeding lines with partial resistance or susceptibility to white mould were combined with 4, 7, 10 or 13 plants m⁻¹ and with or without fungicide at a constant between-row spacing of 0.5 m in five sprinkler-irrigated field trials conducted during the autumn–winter season in Brazil. White mould pressures in the trials covered the whole range from zero to moderate/high (46–60% of white mould severity index). In all trials, means of white mould incidence, severity and yield did not vary significantly between 7 and 13 plants m⁻¹ for the partially resistant line, regardless of the fungicide levels. For the susceptible line, 13 plants m⁻¹ increased white mould incidence and severity under moderate disease, regardless of the fungicide levels, and decreased yield compared with 10 plants m⁻¹ when fungicide was applied twice under moderate/high disease pressure. For the susceptible line, 7 or 10 plants m⁻¹ maximized yield in all trials, with or without fungicide applications. The results suggest that the current recommendation of 11–13 plants m⁻¹ could be used for type II beans with partial resistance to white mould in either a conventional or organic system. For susceptible genotypes, 7–10 plants m⁻¹ seems to be the most appropriate in-row plant density. This study may improve the recommendation of in-row plant density for type II beans cultivated under white mould pressure.     

Characteristics of immunofluorescence microscopy and of dilution-plating to detect Pseudomonas syringae pv. phaseolicola in bean seed lots and for risk assessment of field incidence of halo blight

Routine laboratory testing of 710 bean seed lots from various origins forPseudomonas syringae pv. phaseolicola (Psp) with immunofluorescence microscopy (IF) showed that 27.5% of the seed lots (five subsamples of 1000 seeds tested per sample) contained two or more IF-positive cells in a total of 500 microscope fields (magnification 500×). Simultaneously performed dilution-platings of IF-positive subsamples on King's medium B confirmed presence of Psp for one-third of these IF-positive seed lots. The grey area of disagreement between both laboratory tests was studied by comparison of test data and by field trials.The number of IF-positive cells per subsample was positively correlated with isolation and identification of Psp (R=0.85). The detection level of IF was ca. 10² Psp cells per ml of undiluted subsample extract. The detection level of Psp by isolation on King's medium B was variable, being inversely related with the saprophyte to Psp ratio. The high sensitivity of IF was in part due to high percentages of dormant or dead IF-positive cells in the sample extract. Field trials over two years with 10 000 seeds per seed lot, showed disease incidence for 9 of the 22 seed lots. Of ten IF-positive lots with five positive subsamples per sample, nine were positive in the field test plot (the negative lot gave primary infection spots of Psp when used for commercial growing). By isolation, seven of these ten IF-positive lots were positive. Of the five IF-positive lots with two or less positive subsamples, isolation and field trial were both negative. Based on data on seed transmission from literature, field incidence was unlikely for these five samples in a 10 000 seeds field trial. All seven IF-negative lots were negative in the field trial. The value of IF and isolation for indexing bean seed lots for Psp is discussed.This study was carried out at the Centre for Plant Breeding and Reproduction Research (CPRO-DLO), Binnenhaven 1, P.O. Box 16, 6700 AA Wageningen the Netherlands, to which address correspondence should be addressed.     

雷达昆虫学研究进展及应用前景

雷达昆虫学经过近50年的发展,取得一系列的重要成果。本文系统介绍了各类昆虫雷达的体制和功能,总结了相似体制天气雷达与昆虫雷达的主要区别,回顾了各相关国家雷达昆虫学的实践情况,归纳了昆虫雷达建制技术取得的进步,并展望了雷达应用的前景及其今后昆虫雷达建制技术的发展方向,以期促进我国昆虫雷达事业的发展。     

性信息素诱捕器与频振杀虫灯对甜菜夜蛾发生监测作用的比较

通过甜菜夜蛾两种性信息素诱捕器与频振杀虫灯对甜菜夜蛾诱捕效果比较表明,两种性信息素诱捕器与频振式杀虫灯所诱到的成虫消长规律基本一致。通过SAS统计分析,干式性信息素诱捕器、水盆性信息素诱捕器和频振杀虫灯的平均诱虫量变化趋势紧密相关,相关系数分别为r₁=0.950 36,r₂=0.934 55,r₃=0.853 20。但两种性信息素诱捕器的诱蛾量高于频振杀虫灯,干式诱捕器与频振灯诱蛾量差异显著(p<0.05)。