The Contribution of Surrounding Margins in the Promotion of Natural Enemies in Mediterranean Apple Orchards

Abstract

(1) Habitat management can enhance beneficial arthropod populations and provide ecosystem services such as biological control. However, the implementation of ecological infrastructures inside orchards has a number of practical limitations. Therefore, planting/growing insectary plants in the margins of orchards should be considered as an alternative approach. (2) Here, we assessed the efficacy of a flower margin composed by four insectary plant species (Achillea millefolium, Lobularia maritima, Moricandia arvensis and Sinapis alba), which was placed on an edge of four Mediterranean apple orchards to attract natural enemies of two apple tree aphids (Dysaphis plantaginea and Eriosoma lanigerum). We also characterized the natural enemies present in the aphid colonies. (3) Our results show that the implementation of a flower margin at the edge of apple orchards attracts predators (Syrphidae, Thysanoptera, Araneae, Heteroptera, Coleoptera) and parasitoids. Parasitoids are the main natural enemies present in aphid colonies in our area. (4) The implementation of the flower margins successfully recruited natural enemy populations, and the presence of parasitoids in the surroundings of the orchards increased the parasitism of D. plantaginea colonies.

Selection of insectary plants for the conservation of biological control agents of aphids and thrips in fruit orchards

“…Regarding parasitoids, Braconidae was the earliest in the season and the most widely distributed (found on more plant species and more samples), with A. matricariae being the most abundant. This is a positive result since this species is by far the main parasitoid species attacking M. persicae and D. plantaginea in the surveyed area (Aparicio et al ., 2019; Rodríguez-Gasol et al ., 2019). Other aphid parasitoids mentioned in these two studies ( A. colemani and A. ervi ) were also found during the present samplings visiting flowers at the border of orchards.…”

“…By contrast, individuals from the Aphelinidae family were detected only in two samples of B. maritima . It is worth noting that A. mali , the main parasitoid of E. lanigerum in the area sampled (Lordan et al ., 2014; Rodríguez-Gasol et al ., 2019), belongs to this family.…”

“…Similarly, measurements were made on the width of the head and the thorax of several natural enemies of aphids and thrips already sighted in the study area (Aparicio et al ., 2019, 2021; Rodríguez-Gasol et al ., 2019), including: Aphidius matricariae Haliday, Aphidius ervi Haliday, Lysiphlebus testaceipes Cresson, (Hymenoptera: Braconidae), Aphelinus abdominalis Dalman, Aphelinus mali Haldemann, (Hymenoptera: Aphelinidae), Aphidoletes aphidimyza Rondani (Diptera: Cecidomyiidae), Orius majusculus Reuter (Hemiptera: Anthocoridae) and Aeolothrips intermedius Bagnall (Thysanoptera: Aeolothripidae). O. majusculus were obtained from the colony kept in the IRTA laboratory.…”

“…The studies by Rodríguez-Gasol et al . (2019) and Aparicio et al . (2019) reported on several species of Braconidae and one of Aphelinidae that parasitized several aphid pests in fruit orchards in the same area as the current study, and on hyperparasitoids from the Pteromalidae, Encyrtidae and Figitidae families.…”

“…By contrast, only one species, Ceranisus menes (Walker) (Hymenoptera: Eulophidae), parasitizes F. occidentalis in Mediterranean agroecosystems, although this species only plays a minor role in thrips control (Loomans, 2006). In Spain, several predatory groups (Coccinellidae, Chrysopidae, Anthocoridae, Syrphidae and Aeolothripidae) have also been recorded from peach and apple orchards (Miñarro et al ., 2005; Davidson et al ., 2014; Rodríguez-Gasol et al ., 2019; Aparicio et al ., 2021).…”