784 © The Author(s) 2021. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com. Horticultural Entomology Can Insectary Plants Enhance the Presence of Natural Enemies of the Green Peach Aphid (Hemiptera: Aphididae) in Mediterranean Peach Orchards? Yahana Aparicio, 1 Jordi Riudavets, 1, Rosa Gabarra, 1 Nuria Agustí, 1 Neus Rodríguez-Gasol, 2,3 Georgina Alins, 2 Anabel Blasco-Moreno, 4 and Judit Arnó 1,5, 1 Sustainable Plant Protection Programme, IRTA, 08348 Cabrils, Barcelona, Spain, 2 Fruit Production Programme, IRTA Fruitcentre, 25003 Lleida, Spain, 3 Present address: Department of Ecology, Swedish University of Agricultural Sciences, Uppsala 75007, Sweden, 4 Servei d’Estadística Aplicada, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Valles, Barcelona, Spain, and 5 Corresponding author, e-mail: judit.arno@irta.cat Subject Editor: Anne Nielsen Received 5 August 2020; Editorial decision 25 November 2020 Abstract Conservation biological control could be an alternative to insecticides for the management of the aphid Myzus persicae (Sulzer). To develop sustainable strategies for M. persicae control in peach orchards in the Mediterranean, a 2-yr feld experiment was conducted to identify the key predators of the aphid; to determine whether the proximity of insectary plants boost natural enemies of M. persicae in comparison to the resi- dent vegetation; and whether selected insectary plants enhance natural enemy populations in the margins of peach orchards. Aphidoletes aphidimyza Rondani (Diptera: Cecidomyiidae) and Episyrphus balteatus De Geer (Diptera: Syrphidae) were the most abundant predators found among sentinel aphid colonies, accounting for 57% and 26%, respectively. Samplings during 2015 yielded twice as many hoverfies in M. persicae sentinel plants close to the insectary plants as those close to the resident vegetation. The abundance of other natural enemies in sentinel plants, depending on their proximity to the insectary plants, was not signifcantly different in either of the 2 yr. Hoverfies hovered more often over the insectary plants than over the resident vegetation and landed signifcantly more often on Lobularia maritima (L.) Desv., Moricandia arvensis (L.) DC., and Sinapis alba L. (Brassicales: Brassicaceae) than on Achillea millefollium L. (Asterales: Compositae). Parasitoids were signifcantly more abundant in L. maritima and A. millefollium. The vicinity of selected insectary plants to peach orchards could improve the presence of hoverfies, which might beneft the biological control of M. persicae. Key words: conservation biological control, agroecological infrastructure, insectary plant, parasitoid, predator Peach, Prunus persica [L.] Batsch (Rosales: Rosaceae), is an im- portant crop in Europe, the second worldwide producer after China. Within Europe, Spain is a lead producer, with 30% of total European production (FAO 2017). Catalonia comprises 24% of the total Spanish production, mostly in the province of Lleida, where 20,000 ha are dedicated to this crop (MAPA 2017). The green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), is one of the most important pests of peach, one of its primary hosts. Although to our knowledge there has been no formal evaluation of yield loss in peach production due to this aphid spe- cies, it has been acknowledged as a very injurious pest (Dedryver et al. 2010). Damages to peach include leaf twisting, pitting and discolored fruits, and the vectoring of important viruses, such as plum pox, also known as sharka (Penvern et al. 2010, Barbagallo et al. 2017). Aphids in peach crops have usually been managed with insecti- cide sprays (Barbagallo et al. 2017). However, the use of pesticides is a growing social concern due to the risks that these products pose to human health and to the environment. Additionally, M. persicae resistance to numerous active substances, such as pyrethroids, neonicotinoids, organophosphates, and carbamates, often renders many insecticide treatments ineffective (Foster et al. 2011). Therefore, it is urgent to develop alternative aphid management strategies that are more sustainable and socially acceptable. In this scenario, bio- logical control, more specifcally conservation biological control, could be a good tool to reduce the use of insecticides in peach crops (Dedryver et al. 2010, Penvern et al. 2010). Conservation biological control relies on modifying the environment or existing practices to protect and enhance specifc natural enemies or other organisms to reduce the effect of pests on crops (Eilenberg et al. 2001). Aphid natural enemies belong to different taxonomic groups from entomopathogenic organisms to parasitoids and also in- clude several specialist and generalist predators. Among these Journal of Economic Entomology, 114(2), 2021, 784–793 doi: 10.1093/jee/toaa298 Advance Access Publication Date: 22 January 2021 Research Downloaded from https://academic.oup.com/jee/article/114/2/784/6106236 by guest on 19 November 2023