Increasing the biodiversity of agroecosystems can increase populations of natural enemies that are useful for pest control. Orchards often have a low diversity of plant species, which is not conducive to maintaining ecosystem functions and services. However, additional flowering plants could provide natural enemies with beneficial resources. To assess the ability of flowering plants to attract predators and increase the biological control of Aphis spiraecola Patch, we established individual plots of three different flowering plant species with sequential bloom periods between the rows of apple orchard. These plants attracted predators such as Coccinellidae, Syrphidae, and Chrysopidae when flowering. The density of predators on trees in the three flowering plant plots was significantly higher than that in the control, whereas the density of aphids on trees in Orychophragmus violaceus (L.) O. E. Schulz (Rhoeadales: Brassicaceae) and Cnidium monnieri (Linn.) Cuss. (Apiales: Apiaceae) plots were significantly lower than that in control. The density of aphids on trees in Calendula officinalis L. (Asterales: Asteraceae) plots was significantly lower than in other plots at second peak period. There was a significant negative correlation between the population of aphids and predators on trees at peak of aphids. Cage exclusion tests showed that the biocontrol services index (BSI) of O. violaceus was highest (32.7%) on 24 May, and the BSI of C. monnieri was highest (47.6%) on 7 June. Our results suggest that the temporal combination of different flowering plants could provide useful effective biocontrol to management pest in orchard.

中文翻译：

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苹果园三种不同开花植物对蚜虫（半翅目：蚜科）的生物防治

增加农业生态系统的生物多样性可以增加对害虫防治有用的天敌数量。果园的植物物种多样性往往较低，不利于维持生态系统功能和服务。然而，额外的开花植物可以为天敌提供有益的资源。为了评估开花植物吸引捕食者的能力并增加对 Aphis spiraecola Patch 的生物控制，我们在苹果园行之间建立了三种不同开花植物物种的单独地块，并具有连续的开花期。这些植物在开花时吸引了捕食者，如 Coccinellidae、Syrphidae 和 Chrysopidae。三个开花植物样地的树上捕食者密度显着高于对照，而在 Orychophragmus violaceus (L.) OE Schulz (Rhoeadales: Brassicaceae) 和 Cnidium monnieri (Linn.) Cuss 中的蚜虫密度。（Apiales：伞形科）地块显着低于对照。在第二高峰期，金盏花（Asterales：菊科）地块上的蚜虫密度显着低于其他地块。蚜虫数量与蚜虫高峰期树上天敌数量呈显着负相关。笼舍排除试验结果表明，紫罗非鱼的生防服务指数（BSI）在5月24日最高（32.7%），而虎耳草的BSI在6月7日最高（47.6%）。我们的研究结果表明，不同开花植物的时间组合可以为果园害虫管理提供有用的有效生物防治。