Mating disruption barriers in pome fruit for improved control of oriental fruit moth Grapholita molesta Busck (Lep., Tortricidae) in stone fruit under mating disruption

Oriental fruit moth (OFM) Grapholita molesta Busck (Lep., Tortricidae) is a very important pest in commercial orchards in Victoria, Australia. Pheromone‐mediated mating disruption (MD) applied in stone fruit orchards successfully controlled OFM populations for many years, but damage to shoot tips and fruit at the edge of peach blocks located adjacent to pear blocks under insecticide treatments has become problematic. To improve protection of stone fruit against edge damage and outbreaks of OFM, all orchards were treated with sex pheromone dispensers for MD on an area‐wide basis. Area‐wide MD treatment, including all pome and stone fruit orchards in a discrete area, successfully controlled edge infestations of OFM, but was expensive. To reduce the cost of OFM control, sex pheromone dispensers for MD were applied as barrier treatments to 54–60 m of neighbouring pears adjacent to peaches under MD. Detailed monitoring of the OFM population, shoot tip and fruit damage assessments indicated that application of MD barriers on pears during two consecutive seasons provided sufficient control of OFM on peaches. This MD barrier treatment was able to reduce the number of OFM caught in all experimental peach blocks, with damage to shoot tips and fruit giving similar results to MD treatment of the whole neighbouring pear block. Extending the MD treatment area for 54–60 m into the neighbouring pear block significantly reduced the edge damage in MD‐treated peaches in the first season and almost eliminated OFM damage in the second season.     

Distribution of the oriental fruit moth Grapholita molesta Busck (Lep., Tortricidae) infestation on newly planted peaches before and during 2 years of mating disruption

Abstract:  Oriental fruit moth (OFM) Grapholita molesta Busck (Lep., Tortricidae) is one of the most important pests of commercial stone fruit orchards in the Goulburn-Murray Valley region of Victoria, Australia. OFM populations have been successfully controlled by the use of the mating disruption (MD) technique for many years, but damage to shoot tips and fruit has now started to increase. The most severe damage under MD is found at the edge of peach blocks, adjacent to the pear blocks under insecticide treatment. In 1997–98, OFM infestation levels were examined in a newly planted peach block surrounded by older peaches, pears, apples and pasture. The infestation distribution was followed up for four consecutive years. No treatments were used against OFM for the first 2 years in the newly planted peaches, but in years 3 and 4 the whole block was treated with MD. At the end of year 2, shoot tip damage was randomly distributed throughout the newly planted peach block with no 'edge effect'. After MD was applied in year 3, the damage was confined to the edges of the block adjacent to insecticide-sprayed apples and pears. No 'edge effect' was detected along the border with an older peach block treated with MD or on the border with pasture. Extending the MD treated area for 25–30 m into the neighbouring apples and pears in year 4 reduced the 'edge effect'.     

梨小食心虫化学通信中的信息物质

梨小食心虫Grapholitha molesta Busck是我国北方果区发生的重要害虫。当前对该虫的防治主要依赖化学农药, 但引起的害虫抗药性、 杀伤天敌和环境污染等问题非常严重。食心虫自身的信息素、 寄主/非寄主的他感化学物质对于调节其配偶选择和寄主定位起着至关重要的作用, 基于信息化学物质的害虫管理策略为果园食心虫的治理提供了新的途径。本文综述了国内外有关梨小食心虫化学信息物质研究进展, 包括雌蛾释放的性信息素组分及对雄、 雌两性的引诱, 雄蛾释放的信息素, 利用性信息素的迷向研究, 寄主植物挥发性引诱物质的鉴定和筛选, 以及梨小食心虫寄主转换机制等方面的研究现状和存在的问题。具体来说, 雌蛾的性信息素包括顺-8-十二碳烯醋酸酯、反-8-十二碳烯醋酸酯、顺-8-十二碳烯-1-醇和十二碳-1-醇, 各个组分的比例在地理种群间存在变异。在室内, 通过行为试验证实两种醋酸酯对雄蛾的引诱是必不可少的, 微量的顺-8-十二碳烯-1-醇对二元组分起到增效作用。在田间, 上述3种物质组成的诱芯具有较强的活性; 由此开发的性信息素迷向技术（人工迷向丝、 可喷施的微胶囊和蜡滴）被用于梨小食心虫交配干扰, 取得了很好的效果。梨小食心虫最主要的寄主植物桃梢挥发物包括22种化合物, 其中绿叶挥发物占到50%, 行为生测证实6~8个碳原子的物质是主要的活性化合物。顺-3-己烯丁酸酯、顺-3-己烯醇、反-2-己烯醛、苯甲醛和苯甲腈的五组分混合物, 其引诱力与天然桃梢挥发物相当。通过钙成像试验证实, 尽管苯甲腈在桃梢天然挥发物中仅占0.14%, 但雌蛾对含有该物质的混合物有显著趋性, 该物质对梨小食心虫成功识别寄主具有重要意义。最后对梨小食心虫信息化学物质下一步的研究和应用前景进行了探讨。     

Mapping of pachytene bivalents of female codling moth Cydia pomonella (Linnaeus) (Lep., Tortricidae)

Spread pachytene nuclei of codling moth Cydia pomonella (Linnaeus) (Lep., Tortricidae) females of a Syrian strain (SY) were used to investigate chromomere patterns of chromosome bivalents and determine their length. The karyotype of female codling moths consists of 28 chromosome bivalents, of which seven are clearly distinguishable using chromosome length and the number and size of the chromomeres in the pachytene stage. One autosome bivalent has two nucleolar organizing regions (NORs) that are located at the opposite ends of the chromosome and appear as distinct structural landmarks. In female codling moths, the WZ sex chromosome bivalent was easily identified in pachytene oocytes according to the heterochromatic thread of the W chromosome. This study contributed to the knowledge and identification of pachytene chromosomes of female codling moths.     

Behavioral observations of codling moth, Cydia pomonella, in orchards permeated with synthetic pheromone

Mating disruption of codling moth, Cydia pomonella, was studied in apple orchards treated with the main pheromone compound codlemone, (E,E)-8,10-dodecadienol, and a blend of codlemone and codlemone acetate, (E,E)-8,10-dodecadienyl acetate, a strong pheromone antagonist. Codlemone alone and the pheromone/antagonist-blend had a similar effect on the behavior of males emerging into air-permeated orchards. Male flights within tree canopy and upwind orientation along tree rows were strongly enhanced by both formulations, compared to untreated plots. However, the codlemone/codlemone acetate-blend increased the rate of cross-wind and downwind flights within the orchard, compared to codlemone alone. The major difference between these two formulations was that males from nearby, untreated orchards were attracted towards orchards treated with codlemone, but not towards treatments with codlemone/codlemone acetate. Additional tests were done with an equilibrium blend of codlemone and its geometric isomers. Aerial pheromone concentrations in the orchards were recorded by the field electroantennogram technique. Decreasing pheromone concentrations towards the upper part of the tree canopy, together with the stimulation of male flight activity by synthetic pheromone explains failures to control codling moth at high population densities with current dispenser formulations.     

Reduction of the response to sex pheromone in the oriental fruit moth,Grapholita molesta (Lepidoptera: Tortricidae) following successive pheromonal exposures

The effects of prior pheromonal experience upon the pheromone- mediated upwind flight response was examined in the oriental fruit moth, Grapholita molesta(Busck) (Lepidoptera: Tortricidae). Adult male G. molestawere subjected to a parallel series of staggered and repeated pheromonal exposures in a sustained-flight wind tunnel. Levels of response to pheromone in male G. molestasignificantly decreased in a (a) rectilinear function with increased ages of individuals, (b) logarithmic function of successive trials, and (c) steeper logarithmic function of successive trials with increased dosage of sex pheromone. The baseline levels of responding were not affected by either the (a) dosage of sex pheromone, (b) posteclosion ages of individuals for their initial exposures once the main effect of age itself was estimated, (c) elapsed time in hours between trials, or (d) discrete days of testing as integral intervals, disregarding hours within days.     

不同剂型迷向剂处理对苹果蠹蛾控制效果比较

【背景】苹果蠹蛾是我国重要的检疫性害虫,目前从新疆迅速向东部扩散。苹果蠹蛾性信息素胶条迷向剂对防控苹果蠹蛾高效、安全,但成本较高。【方法】2013年在宁夏中卫市常乐镇马路滩村果园使用3种不同剂型的迷向剂对苹果蠹蛾进行了防治试验,每个处理果园面积3.3 hm~2,分别使用性诱剂处理后,用诱捕器监测处理后的诱蛾量,在生长期调查果实为害率,比较防治效果。【结果】通过整个生长季诱捕器监测,悬挂点以900个·hm~(-2)双层处理,胶条迷向剂在开花前处理1次,整个生长季处理区中心部位没有监测到苹果蠹蛾成虫;透明塑管迷向剂分别在开花前和6月底处理2次,整个生长季中心部位平均每个诱捕器诱到3.3头雄蛾;膏体迷向剂分别在开花前和6月底处理2次,整个生长季中心部位平均每个诱捕器诱到12头雄蛾。在6月下旬和果实采收前进行果实为害率调查,胶条迷向剂区平均蛀果率分别为0和0.56%,透明塑管迷向剂区蛀果率分别为0.89%和1.38%,膏体迷向剂处理区蛀果率分别为0.79%和1.38%。常规农药防治区2个时期蛀果率分别为1.44%和3.13%。【结论与意义】综合考虑防治效果和使用成本,在虫口密度高、效益高的果园可以使用胶条迷向剂,膏体迷向剂和透明塑管迷向剂只有在虫口密度较低的情况下使用。     

梨小食心虫性诱剂附加农药诱杀器的设计

通过田间对梨小食心虫雄蛾着陆行为观察,设计出4种诱杀器,其中双翼式和台式最适于雄蛾降落。诱杀器的材料以PVC塑板为好。涂在诱杀器上的缓释型菊酯农药,开始对雄蛾有较强的忌避作用,但在田间暴露10天后,雄蛾着陆率可在80％以上,让雄蛾接触在田间暴露的药膜5秒左右,开始雄蛾可在10分钟内被击倒,当药膜在田间暴露80天后,仍可击倒雄蛾,所以这种性诱剂加农药的诱杀器有可能用来防治梨小食心虫或其它小型害虫。     

Evaluation of extended-season mating disruption of the Oriental fruit moth Grapholita molesta (Busck) (Lep., Tortricidae) in apples

Abstract:  Oriental fruit moth Grapholita molesta (Busck) (Lep., Tortricidae) has recently become a key pest of apples throughout the eastern USA. Pheromone-mediated mating disruption of Oriental fruit moth was successfully used in North Carolina apple orchards in the past few years. However, low levels of late-season fruit damage occurred in some orchards treated in late May with hand-applied pheromone dispensers because of inadequate dispenser longevity. To investigate alternative pheromone application schedules for extended mating disruption control, the following pheromone treatments were compared with conventional insecticides in Henderson County (NC) in 2002: late May application of hand-applied dispensers; late June application of hand-applied dispensers; late May application of hand-applied dispensers supplemented with a late August application of sprayable pheromone dispensers; late May application of hand-applied dispensers which have a longer activity period; and conventional insecticides as a control. All treatments were sprayed with an insecticide at petal fall in late April for thinning and for control of the first generation Oriental fruit moth adults. Pheromone trap catches were significantly reduced in all mating disruption blocks compared with conventional insecticide blocks. Among pheromone treatments, the highest trap captures were recorded in the delayed hand-applied dispenser treatment in June before treatment. However, the mean percentage fruit damage did not vary with timing of application of hand-applied dispensers and the type of pheromone dispenser used. Clearly, the combination of each mating disruption treatment with insecticide application against first generation Oriental fruit moth was as effective as the conventional insecticide treatment under moderate population pressure.     

Attract and kill for codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) control in Syria

The possibility of controlling the codling moth Cydia pomonella (Linnaeus) using an attract and kill approach as an alternative to chemical sprays with contact insecticides was investigated in widely separated orchards. The results of a 4‐year study have shown that, using an attract and kill approach, three applications/season kept infestation rates in treated orchards below the economic injury level except in one with a too high codling moth population density. The mean number of male codling moths/trap/week in attract and kill‐treated orchards was much lower in comparison with control orchards which were treated with the usual cover sprays of insecticides. The results also showed that the efficacy of attract and kill under orchard conditions decreased with time and the relationship between time effect and codling moth death rate was very strong. These data indicate that the attract and kill technique applied at a rate of three application per season resulted in good control of codling moth in well managed orchards in Syria.     

Isolation of microsatellite loci in the codling moth,Cydia pomonella (Lepidoptera: Tortricidae)

Cydia pomonella L. is an important insect pest of pome fruits worldwide. We have isolated and characterized 17 microsatellite loci from the enriched genomic libraries constructed using a biotin/streptavidin capture protocol. Among these loci, 11 were scored polymorphic when 50 individuals from a laboratory population were screened. Their alleles numbered two to four, with the observed heterozygosity (H_O) ranging from 0.114 to 0.404. Successful amplification was obtained for all these loci when the designed primers were tested, showing the promise of use in genetic mapping and population studies.     

苹果蠹蛾性信息素缓释剂的控害效果

2010年在甘肃、宁夏、黑龙江3地对苹果蠹蛾Cydia pomonella(L.)性信息素缓释剂(购自澳大利亚Bioglobal公司;性信息素含量为0.16g/根)对苹果蠹蛾的迷向防治效果进行了试验;观察了不同生态区设置不同缓释剂密度的防治效果和持效期。结果表明,在低虫口密度下,在不同生态区每公顷悬挂660、990和1320根性信息素迷向丝,均能取得较好的防治效果;在越冬代活动前处理,基本上可以控制整个生长期苹果蠹蛾对果实的为害。在新侵入的低密度果园,通过诱蛾监测、调查蛀果和树干绑诱虫带等验证方法,初步证明使用该性信息素缓释剂处理1年可以达到铲除的效果。依据本研究结果,结合防治成本,在苹果蠹蛾发生地区,采用660根/hm2的悬挂密度使用进口性信息素缓释剂处理果园可以达到良好的防治效果。     

梨小食心虫生物防治研究进展

梨小食心虫Grapholita molesta(Busck)是世界性分布的果树主要害虫之一,可危害多种果树。多年来,过度依赖化学农药防治梨小食心虫效果并不理想,且杀伤天敌、污染环境、导致农药残留。利用自然天敌防治梨小食心虫高效、无毒、无污染,符合当前社会对环保的要求。本文结合前人工作,从病原微生物、寄生性天敌、捕食性天敌、性信息素、化学信息物质等方面,综述了梨小食心虫生物防治的研究进展,并对其应用前景进行了展望。     

生物源农药在苹果蠹蛾防治中的应用

苹果蠹蛾是世界性检疫害虫,对我国苹果优势产区构成了巨大威胁。长期依赖化学防治使该虫抗性问题变得十分严峻。为了保障食品安全,以环境友好的生物源农药替代化学农药已成为当前苹果蠹蛾防治的热点。本文对国内外现有的生物源农药,如寄生蜂、不育昆虫、颗粒体病毒、病原线虫、Bt、病原真菌、微孢子虫、性信息素、斑蝥素、多杀菌素等,在苹果蠹蛾防治中的最新应用及其存在的问题进行论述,讨论了生物源农药凭借其种类多、来源广且在用药时期上选择性强等特点,在该虫综合治理中的重要地位及面临的挑战。     

苹果蠹蛾性信息素的研究和应用进展

苹果蠹蛾Cydia pomonella (L.)是我国重要的检疫害虫, 在我国仅分布于新疆和甘肃以西局部地区, 但一直保持向我国东部扩张的趋势。在国际上, 利用性信息素监测和迷向防治苹果蠹蛾已经成为一种切实可行并广泛应用的害虫管理技术。本文综述了苹果蠹蛾性信息素的成分鉴定、人工合成和应用情况的研究进展, 指出了目前存在的问题和应用前景, 以期为我国苹果蠹蛾的防控策略的研究和应用提供参考。     

Laboratory and field experiments towards the development of an attract and kill strategy for the control of the codling moth, Cydia pomonella

A viscous formulation based on castor oil containing the pyrethroid insecticide cyfluthrin and E8, E10-dodecadienol, the main component of the codling moth sex pheromone, (Cydia pomonellaL.: Tortricidae, Olethreutinae) was developed. The insecticidal performance of the formulation was evaluated in the laboratory using a tarsal-contact bioassay. The pheromone dosage required to attract male moths to the formulation was determined in behavioural tests performed in a wind tunnel. The efficacy of formulations applied to seedlings of the host plant was further investigated in glasshouse experiments conducted with male moths in small wire-gauze cages. The laboratory tests resulted in a formulation for preliminary field trials containing 4% cyfluthrin and 0.1% pheromone. During the 1995 growing season, experiments were conducted in apple orchards at three locations in Germany. The formulation was first applied to the bark of apple trees (Malus domestica) in mid May and then again in late July. A good level of control, comparable with a spray treatment using the insect growth regulator Alsystin was achieved. The potential of the attract and kill strategy, combining selective attraction of a pest species with the efficacy associated with a pyrethroid insecticide treatment, as a means of controlling the codling moth in commercial apple growing, is discussed.     

The morphology and development of Nosema carpocapsae,a microsporidian pathogen of the codling moth,Cydia pomonella (Lepidoptera: Tortricidae) in New Zealand

The morphology of Nosema carpocapsae and its development in experimentally infected codling moth larvae are described. Spherical uninucleate meronts were the first stages. Nuclear division produced binucleate meronts which were the most abundant vegetative stage, although additional uninucleate and a few tetranucleate meronts were also observed at this time. All meronts were spherical and ranged from 2.8 to 5.8 μm in diameter. Uninucleate and binucleate fusiform sporonts then appeared followed by some tetranucleate and dividing forms. Oval sporoblasts developed after these and did not divide before maturing into spores. Sporonts were approximately 5.0 to 7.9 × 2.4 to 3.0 μm. Spores developed in all host tissues except the nervous tissue. The binucleate spores showed considerable variation in spore size, 2.4 to 3.9 × 1.3 to 3.1 μm (alcohol fixed, Giemsa stained). The polar filament was usually coiled 11 times (range 9 to 13) at an angle of 53° to the long axis of the spore. Its maximum observed length was 75 μm.     

Comparative analysis of peach and pear fruit volatiles attractive to the oriental fruit moth,Cydia molesta

Cydia molesta is an important pest of peach and pear fruits late in growing season. We identified and quantified volatiles from immature and mature fruits of peach and pear using gas chromatography-mass spectrometry. Antennally, active compounds were identified by gas chromatography-electroantennogram detection and were further tested in the field. Consistent electroantennographic activity was obtained for nine compounds from headspace collections of the mature fruits of two peach and two pear varieties. Esters were the major components, but qualitative and quantitative differences were found among four odor profiles. Blends mimicking pear fruit volatiles were more attractive to both sexes than blends mimicking peach fruit volatiles in both orchards. Our finding indicated that mixtures mimicking peach and pear fruit volatiles attracted both females and males of C. molesta, and these host volatiles may also be involved in the host switch behavior from peach to pear in mid-late season.