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

Abstract

This study evaluated the potential of flowering plant species naturally occurring to promote the conservation and early establishment of key natural enemies of aphids and thrips in apple and peach orchards. Flowering plants present in the North East of Spain, a main fruit production area in Europe, were sampled to determine their flowering period and to identify potential natural enemies present on each plant species. Thirty-six plant species were found blooming from early March to late May and provided an array of flowers that might ensure food resources for natural enemies. Among them, six species – Eruca vesicaria (L.) Cav., Cardaria draba (L.) Desv., Euphorbia serrata (L.) S.G. Gmel., Malva sylvestris L., Anacyclus clavatus (Desf.) Pers. and Diplotaxis erucoides (L.) DC. – hosted a high diversity of potential natural enemies of aphids and thrips. Their blooming started early in the season and lasted for several sampling weeks and they were widely distributed. Moreover, they had available nectar even in those species with protected nectaries. Therefore, these plant species can be considered as promising candidates for inclusion in the ecological infrastructure designed for fruit orchards in the study area to promote the conservation of the biological control agents of aphids and thrips.

Flower strips increase the control of rosy apple aphids after parasitoid releases in an apple orchard

“…Using or facilitating the presence of early bloom annual and perennial plants such as Alliaria petiolata, Anthriscus sylvestris, Bellis perennis, Capsella bursa-pastoris, Cardamine pratensis, Diplotaxis erucoides, Euphorbia helioscopia, Euphorbia serrata, Primula spp., Senecio vulgaris, Sinapis arvensis, Veronica persica, etc. should be given priority in orchards to provide early habitats and resources (Denis et al, 2021;Dib et al, 2012;Santos et al, 2018). Aphidius matricariae, Ephedrus sp.…”

“…Aphidius matricariae, Ephedrus sp. and other Braconidae have been reported to be among the first beneficial arthropods to colonize the aphid colonies, and may therefore highly benefit from early flowering plant species in the orchard (Denis et al, 2021;Rodríguez-Gasol et al, 2019).…”

“…Flower strips or margins have been shown to enhance the efficiency and abundance of both released and naturally present natural enemies of apple pests such as Braconidae , Syrphidae , Anthocoridae , Mymaridae , Chrysopidae , Aranae and Coccinellidae (Denis et al, 2021; Dib et al, 2012; Irvin et al, 2006; Rodríguez‐Gasol et al, 2019; Zhang et al, 2022). This is mainly achieved by providing food sources (nectar and pollen), shelters and overwintering sites, and sometimes alternative hosts and prey, to natural enemies (Albrecht et al, 2020; Langer et al, 2004; Pfiffner & Wyss, 2003).…”

“…Although challenging to establish, perennial flower strips in the alleyways, as done in our study, are likely to boost interactions between the crop and the flower strip biotic compartments, as opposed to flower strips sown at the edge of orchards (Cahenzli et al, 2019), but the efficiency may depend on the age and the composition of the flower strip (Albrecht et al, 2020). Using or facilitating the presence of early bloom annual and perennial plants such as Alliaria petiolata , Anthriscus sylvestris , Bellis perennis , Capsella bursa‐pastoris , Cardamine pratensis , Diplotaxis erucoides , Euphorbia helioscopia , Euphorbia serrata , Primula spp., Senecio vulgaris , Sinapis arvensis , Veronica persica , and so forth should be given priority in orchards to provide early habitats and resources (Denis et al, 2021; Dib et al, 2012; Santos et al, 2018). In our study, the flower strips were germinating and flowering throughout the monitoring sessions.…”

“…A cocktail (combined use) of two solitary parasitoid species, Aphidius matricariae Haliday and Ephedrus cerasicola Starý ( Hymenoptera : Braconidae : Aphidiinae ), was developed in previous projects to control D. plantaginea in apple orchards (Boivin et al, 2012; Dumont et al, 2011; Ferrais et al, 2022; Nicolas et al, 2013). Both parasitoid species can benefit from pollen and/or floral nectar in terms of longevity and parasitism capacity (Araj et al, 2006; Bianchi & Wäckers, 2008; Denis et al, 2021). Parasitoid cocktails are used in inundative biological control strategies in several crop systems because each species can complement the others on their host spectrum, on activity timing, and on behavioural and physiological specificities (Boivin et al, 2012).…”