甘肃河西走廊苹果蠹蛾种群遗传分化研究:基于COI基因序列分析

【目的】揭示河西走廊苹果蠹蛾不同地理种群间的联系,分析地理种群间的序列变异、遗传多样性和遗传分化。【方法】采用PCR和基因测序技术,扩增并分析了河西走廊8个地理种群132个苹果蠹蛾个体的线粒体细胞色素氧化酶Ⅰ亚基(COI)基因片段,应用DnaSP 5.10计算单倍型多样性指数(Hd)、核甘酸多样性指数(Pi)和Tajima’s D值,采用ZT软件包进行Mantel检验,分析种群间遗传距离与地理距离的相关性,利用软件Arlequin 3.11计算成对种群间的固定系数(Fst)。【结果】在获得的132条序列中共发现了8个变异位点和5个单倍型,其中3个单倍型为种群共享单倍型。总体单倍型多样性指数为0.578,种群内单倍型多样性为0.000~0.700。各种群的Tajima’s D值中性检验符合中性突变,说明河西走廊苹果蠹蛾在历史上没有出现群体扩张,群体大小稳定。Fst值表明,河西走廊苹果蠹蛾种群间具有一定程度的遗传分化,而各地理种群的遗传距离与地理距离无显著的相关性。【结论】河西走廊苹果蠹蛾遗传多样性较低,且地理种群间有一定程度的遗传分化。     

Efficacy of the pear ester as a monitoring tool for codling moth Cydia pomonella (Lepidoptera: Tortricidae) in New Zealand apple orchards

BACKGROUND: The behavioural response of both sexes of codling moth, Cydia pomonella to the pear-derived kairomone (ethyl (2E,4Z)-2,4-decadienoate), codling moth sex pheromone (E,E-8,10-dodecadien-1-ol), and sex pheromone combined with the pear derived kairomone loaded into red rubber septum were investigated in trapping experiments in New Zealand apple orchards. A range of 0.01-10.0 mg of pheromone loading in rubber septum dispensers was tested and the highest catch of males was in traps baited with 1.0 mg. No dose response in trap catch of males was seen in traps baited with different amounts of pear-derived kairomone (0.01-10.0 mg). RESULTS: The number of females caught was significantly affected by the amount of pear derived kairomone used to bait traps, with the highest catch obtained at 10 mg loading. The attractiveness of sex pheromone was not enhanced by the addition of the kairomone either when used in the same bait or in a separate bait. The mean number of males captured in traps was reduced by 44% when the pheromone and kairomone were combined at ratio of 1:1 (0.1 mg pheromone: 0.1 mg kairomone) in separate sources. CONCLUSION: Kairomone baited traps showed some potential for monitoring the flight activity of female C. pomonella in apple orchards in two locations (Canterbury and Hawke's Bay). However, the number of male moths caught was low as compared to the number of male moths caught in pheromone-baited traps, and therefore the sex pheromone should continue to be used for monitoring male activity.     

Assessment of methoxyfenozide exposure on the sexual attractiveness and responsiveness of adult codling moth, Cydia pomonella L., in small orchard blocks

BACKGROUND: The sexual attractiveness of female and the responsiveness of male codling moth, Cydia pomonella L., exposed to surfaces treated with the ecdysteroid agonist methoxyfenozide were investigated in small orchard block experiments. The main purpose of the study was to determine whether the reported sublethal effects of methoxyfenozide affecting moth behavior also occur under field conditions. RESULTS: Data from the first experiment showed that in some trials untreated females were significantly more attractive to wild males than methoxyfenozide-treated females. The second experiment revealed that some released methoxyfenozide-treated males were not as responsive to calling females as untreated males, and that some untreated females were more attractive to males than methoxyfenozide-treated females. The third experiment revealed that wild males exposed to treated tree surfaces were significantly less responsive to traps than were wild males exposed to untreated trees. However, there were no significant differences in mean recaptures of released males between the untreated and treated orchard blocks. CONCLUSION: Exposure of adult C. pomonella to methoxyfenozide-treated surfaces resulted in a negative impact on male responsiveness to calling females and synthetic pheromone lures. However, the level of impact on the sexual attractiveness of treated females did not appear to be as explicit.     

5种引诱剂田间诱捕苹果蠹蛾效果比较

利用5种引诱剂对苹果蠹蛾在乌鲁木齐地区的消长动态进行监测。结果发现,苹果蠹蛾在乌鲁木齐地区1 a发生2代,还有一个不完整的第3代。对比进口型、聚集+性诱型、普通型、聚集型、加强型5种引诱剂的田间引诱效果,加强型引诱剂最好,整个监测期间,每个诱捕器诱捕到的雄虫总数平均为163.7头,单日最高引诱量达育每只30头;进口型引诱剂效果最差。从粘虫板和诱芯的更换周期等对引诱效果的影响来看,每10 d更换1次粘虫胶的诱捕效果好于30 d更换1次,但诱芯更换周期对引诱效果影响并不明显。     

利用性诱剂监测新疆果树食心害虫的消长动态

[目的]梨小食心虫、桃小食心虫和苹果蠢蛾是新疆果树的主要害虫.研究利用性诱剂监测这3种食心害虫在南北疆不同果园的消长动态,分析其世代发生规律,为梨小食心虫、桃小食心虫和苹果蠢蛾的害虫防治工作提供依据.[方法]利用性诱剂对梨小食心虫、桃小食心虫和苹果蠢蛾开展检测预报.[结果]2009年,梨小食心虫和桃小食心虫年在轮台地区和石河子地区一年分别发生5代、4代.苹果蠢蛾在轮台地区一年发生4代,在石河子地区有少量的出现.在不同地区的不同果园内,诱集到的梨小食心虫、桃小食心虫和苹果蠹蛾是不同的.[结论]果树混栽的果园内,梨小食心虫、桃小食心虫和苹果蠢蛾的发生程度较严重.梨小食心虫、桃小食心虫、苹果蠢蛾存在着世代重叠现象,化学防治的重点应放在第一代幼虫上.     

Pre-harvest survival of codling moth in artificially infested sweet cherry fruits

Prior to the 2009 season, sweet cherry fruits, Prunus avium (L.) L., from North America were required to be fumigated with methyl bromide before being exported to Japan to eliminate possible infestation by codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae). However, based on recent biological research on host status, a new procedure (the “systems approach”) was implemented relying on the cumulative effects of pre- and post-harvest practices to produce pest-free sweet cherry fruits for export. This is an organized process that involves the integration of procedures used in the production, harvest, packaging, and distribution of a commodity which cumulatively meet the requirements for quarantine security. The objective of our study was to provide additional information to support the systems approach for codling moth in sweet cherries fruits. For four seasons, branches with sweet cherry fruits were caged on trees and infested by released ovipositing codling moths into the cages. Fruits were sampled weekly for codling moth individuals at each life stage. Eggs were laid mostly on leaves with the seasonal average numbers per cage ranging from 142 to 617. Populations declined rapidly after egg eclosion, with <1.5% of the original cohort surviving to fifth instars. Even after 8 weeks, none had formed cocoons or pupated. This failure of the codling moth to complete a life cycle under field conditions supports previous life history studies and demonstrates that sweet cherry fruits are inadequate hosts for codling moth.     

光周期和温度对苹果蠹蛾滞育诱导的影响

为探讨光周期和温度对苹果蠹蛾Cydia pomonella滞育诱导的影响,通过人工诱导的方法对其滞育的光周期、温度诱导条件及滞育的敏感光照虫期进行了研究。结果表明:20℃时,光照时间短于12 h,苹果蠹蛾的滞育率可达到100%;25℃时,光周期为L 8∶D 16时滞育率最高,为98.3%;30℃时,光照时间少于10 h,苹果蠹蛾的滞育率可达85%以上。在20、25和30℃条件下,幼虫滞育的临界日长分别为14.21、13.68和13.73 h。苹果蠹蛾对光照反应有2个最敏感时期,即幼虫初孵化阶段和预蛹期阶段,卵期对光照反应不敏感。表明苹果蠹蛾是一种典型的短日照滞育型种类,光周期、温度及其交互作用均对其滞育诱导具有重要影响,其中光周期占主导作用,温度随着光周期起作用,低温对滞育诱导有很好的促进作用。     

迷向防治技术对苹果蠹蛾的田间防治效果

选取甘肃省12个苹果蠹蛾发生县区,研究了迷向防治技术对苹果蠹蛾的防治效果。结果表明:在种群密度较低(平均蛀果率在1%以下)的果园(连片面积17hm~2),采用迷向防治技术,即在诱捕到第1头苹果蠹蛾成虫(4月末5月初)后进行第1次悬挂迷向条(120~150根/hm~2),7月中旬进行第2次补充悬挂,可有效控制苹果蠹蛾为害,成虫诱蛾量和蛀果率分别较对照下降90.8%和92.6%,成虫无明显的诱集高峰;采用迷向防治的果园,增加化学防治次数,对防治效果影响不显著(P0.05)。本研究证实苹果蠹蛾迷向防治技术有较好的防治效果,虽然防治成本相对较高,但减少了环境污染,是未来值得推广的绿色防控技术措施。     

Involvement of a sodium channel mutation in pyrethroid resistance in Cydia pomonella L, and development of a diagnostic test

Populations of the codling moth, Cydia pomonella L (Lepidoptera, Tortricidae) have developed resistance to several classes of insecticide such as benzoylureas, juvenile hormone analogues, ecdysone agonists and pyrethroids, but the corresponding resistance mechanisms have not been extensively studied. Knockdown resistance (kdr) to pyrethroid insecticides has been associated with point mutations in the para sodium channel gene in a great variety of insect pest species. We have studied two susceptible strains (S and Sv) and two resistant strains (Rt and Rv) of C pomonella that exhibited 4- and 80-fold resistance ratios to deltamethrin, respectively. The region of the voltage-dependent sodium channel gene which includes the position where kdr and super-kdr mutations have been found in Musca domestica L was amplified. The kdr mutation, a leucine-to-phenylalanine replacement at position 1014, was found only in the Rv strain. In contrast, the super-kdr mutation, a methionine-to-threonine replacement at position 918, was not detected in any C pomonella strain. These data allowed us to develop a PCR-based diagnostic test (PASA) to monitor the frequency of the kdr mutation in natural populations of C pomonella in order to define appropriate insecticide treatments in orchards.