(Horticulture) Pheromone of Apple Sawfly: New Tool for Management of a Re-emerging Pest

苹果锯蝇（Hoplocampa testudinea）是危害商品苹果树的害虫。成虫在春天从土里钻出来交配。雌性被苹果花吸引并产卵。一旦幼虫孵化，它们沿着幼小的水果表面觅食，造成带状疤痕，降低水果的品质。如果幼虫进入果实，它们会在每个苹果簇中钻出3-4个果实，形成粘稠的棕色杂草，使果实掉落或滞销。在未喷洒农药或有机果园，苹果锯蝇可造成高达90%的作物损失；即使在较低的损害水平下，分类滞销水果的成本对种植者来说也是一种损失。有机种植者没有有效的方法来控制苹果锯蝇，除了去除侵染的嫩枝，这是高度劳动密集型的，仍然导致产量损失。在传统的果园里，苹果锯蝇以前是用广谱杀虫剂来对付其他害虫的。其中大部分现在已经被撤回，苹果锯蝇甚至在喷洒过杀虫剂的果园里重新出现，成为一个问题。此外，应避免在开花期间喷洒，因为这可能影响传粉昆虫，并破坏种植者使用的病虫害综合管理方案。雌性锯蝇用远距离性信息素吸引雄性。如果苹果锯蝇的性信息素成分的化学结构可以被识别和合成，这些可以用来帮助减少这种害虫造成的损害。用信息素诱捕可以有效地检测苹果锯蝇的存在，并更有效地采取防治措施。信息素还可以通过大量诱捕和干扰交配等方法来控制苹果锯蝇。这些方法已被用于对付其他害虫，其中信息素已被确定。信息素是无毒的天然产物，对目标害虫有特异性，对其他动物和植物没有影响，而且它们的活性非常小。该项目的合作伙伴此前曾试图鉴定苹果锯蝇的性信息素，但由于难以获得足够的活昆虫来进行这项工作，因此未能成功。苹果锯蝇每年只有一代，没有已知的实验室培养方法。这个短期项目将汇集学术和商业合作伙伴，共同努力克服这一限制。种植者合作伙伴的知识和设备将被用来定位以前被苹果锯蝇侵染的果园。学术和商业伙伴将共同努力，开发从土壤中分离幼虫和蛹的方法，然后收集和处理更大的土壤样本。将幼虫和蛹饲养至成虫，并开始信息素鉴定过程。虽然本项目不太可能完全完成，但研究结果将为今后苹果锯蝇的信息素鉴定和利用开发提供坚实的基础。还将利用这个机会建立一个陷阱网络，监测成年锯蝇并评估造成的损害，提供关于这种害虫的分布和物候的新数据。该项目的学术合作伙伴是格林威治大学自然资源研究所，该研究所在昆虫信息素的鉴定和应用方面拥有50多年的经验，以及英国领先的水果研究机构NIAB East Malling。商业合作伙伴包括Russell IPM，他们已经生产并销售了150多种昆虫信息素；Avalon Ltd和Agrovista，这两个农学组织定期为英国种植者提供害虫控制方面的建议；还有Mole End和Rudford Farms，这两个有机苹果种植者遭受了严重的苹果saw蝇危害。我们还得到了Delphy和PCFruit的支持，这两家分别位于荷兰和比利时的领先水果研发组织热衷于寻找管理苹果锯蝇的新解决方案。

Apple sawfly, Hoplocampa testudinea, is a damaging pest of commercial apple trees. Adults emerge from the soil in spring and mate. Females are attracted to apple blossoms and lay eggs. Once the larvae hatch, they feed along the surface of young fruits causing ribbon-like scars which downgrade fruit. If the larvae enter the fruit, they tunnel in 3-4 fruits per apple cluster creating a sticky brown frass, making fruits drop or be unmarketable. In unsprayed or organic orchards apple sawfly can cause up to 90% crop loss; even at lower damage levels the costs of sorting the unmarketable fruit are a loss to the grower. Organic growers have no effective means for controlling apple sawfly other than removing infested shoots which is highly labour-intensive and still results in yield loss. In conventional orchards, apple sawfly has previously been controlled using broad-spectrum insecticides against other pests. The majority of these have now been withdrawn and apple sawfly is re-emerging as a problem even in sprayed orchards. Furthermore, spraying during flowering is to be avoided as this may impact pollinating insects and disrupt integrated pest and disease management programmes used by growers.Female sawflies attract males using long-range sex pheromones. If the chemical structures of the components of the sex pheromone of apple sawfly could be identified and synthesised, these could be used to help reduce the damage caused by this pest. Traps baited with the pheromone can be used to detect the presence of apple sawfly and apply control methods more efficiently. The pheromone might also be used to control apple sawfly by approaches such as mass trapping and mating disruption. These approaches have been used against other insect pests where the pheromone has been identified. The pheromones are non-toxic natural products, specific for the target pest and without effect on other animals and plants, and they are active in very small amounts.The project partners have previously attempted to identify the sex pheromone of apple sawfly, but have been unsuccessful due to difficulties in obtaining sufficient live insects for the work. Apple sawfly has only one generation per year and there are no known methods for laboratory culture. This short project will bring together academic and commercial partners in a concerted attempt to overcome this constraint. The knowledge and facilities of the grower partners will be used to locate orchards previously infested with apple sawfly. The academic and commercial partners will work together to develop methods for isolation of larvae and pupae from the soil and then will collect and process larger soil samples. The larvae and pupae will be reared through to adults and the process of pheromone identification will be started. It is unlikely that this will be fully completed within this project, but the results will provide a firm basis for identification of the pheromone and development of its use for management of apple sawfly in future projects. The opportunity will also be taken to set up a network of traps for monitoring adult sawfly and assess the damage caused, providing new data on the distribution and phenology of this pest.Academic partners in this project are the Natural Resources Institute, University of Greenwich, which has over 50 years of experience in identification and application of insect pheromones, and NIAB East Malling, the leading UK fruit research institute. Commercial partners are Russell IPM who already produce and sell more than 150 insect pheromones, Avalon Ltd and Agrovista, two agronomy groups who regularly advise UK growers on pest control, and Mole End and Rudford Farms, two organic apple growers who experience significant apple sawfly damage. We also have support from Delphy and PCFruit, leading fruit research and development organisations in The Netherlands and Belgium, respectively, which are keen to find new solutions to managing apple sawfly.