Mathews Clarissa R, Bottrell Dale G, Brown Mark W
Department of Entomology, University of Maryland, 4112 Plant Sciences Building, College Park, MD 20742, USA.
Environ Entomol. 2011 Feb;40(1):42-51. doi: 10.1603/EN10161.
Extrafloral nectaries (EFNs) are reported to benefit some plants when ants (Hymenoptera: Formicidae) use their secretions and fend off herbivores, but in some cases resulting competitive interactions may reduce biological control of specific herbivores. This research examined the interactions between ants and other natural enemies associated with the EFNs of peach [Prunus persica (L.) Batcsh] and the implications for biological control of a key pest, the oriental fruit moth [Grapholita molesta (Busck)]. Studies using sentinel G. molesta placed on peach trees ('Lovell' cultivar) with EFNs present and absent revealed that several natural enemy groups associated with the EFNs contribute to reductions in G. molesta eggs, larvae, and pupae in peach orchards. Ants on trees with EFNs antagonized the G. molesta egg parasitoid Trichogramma minutum (Riley), but the ants were crucial in reducing G. molesta in both the larval and pupal stages. Overall, individual trees with EFNs experienced higher ant and other (nonant) natural enemy densities and subsequent pest reductions, as compared with trees without EFNs. However, the implications of EFN-natural enemy-pest interactions to orchard-level biological control will likely depend on local G. molesta population dynamics.
据报道，当蚂蚁（膜翅目：蚁科）利用花外蜜腺（EFNs）的分泌物并抵御食草动物时，花外蜜腺对一些植物有益，但在某些情况下，由此产生的竞争相互作用可能会降低对特定食草动物的生物防治效果。本研究调查了与桃树[Prunus persica (L.) Batcsh]花外蜜腺相关的蚂蚁与其他天敌之间的相互作用，以及对一种关键害虫——东方果实蛾[Grapholita molesta (Busck)]生物防治的影响。在有和没有花外蜜腺的桃树上（‘Lovell’品种）放置东方果实蛾哨兵进行的研究表明，与花外蜜腺相关的几个天敌群体有助于减少桃园中东方果实蛾的卵、幼虫和蛹。有花外蜜腺的树上的蚂蚁会对抗东方果实蛾的卵寄生蜂微小赤眼蜂（Trichogramma minutum (Riley)），但蚂蚁在减少东方果实蛾幼虫和蛹阶段的数量方面至关重要。总体而言，与没有花外蜜腺的树相比，有花外蜜腺的单株树的蚂蚁和其他（非蚂蚁）天敌密度更高，随后害虫数量减少。然而，花外蜜腺 - 天敌 - 害虫相互作用对果园水平生物防治的影响可能取决于当地东方果实蛾的种群动态。
