Selection of flowering plants to enhance the biological control of Tuta absoluta using parasitoids

Abstract

The tomato moth Tuta absoluta is an important pest of tomato crops. To enhance biological control services, our study aims to ascertain the effect of potential insectary plants (Achillea millefolium, Calendula officinalis, Fagopyrum esculentum, Lobularia maritima, Ononis natrix, Sinapis alba, and Tagetes patula) as nutrient-providers to facilitate the installation of T. absoluta parasitoids (Necremnus tutae, Stenomesius nr. japonicus, and Bracon nr. nigricans) without encouraging the pest. Our results showed that different flowers provide different benefits in terms of survival and egg load for different parasitoid species, and that the benefit of these flowers for T. absoluta females was low. Being N. tutae the most abundant and widespread parasitoid, selection of flowers might target this parasitoid. However, the provision of a flower mixture may be more advantageous than selecting only one species because they may contribute to enhance a broader guild of parasitoid wasps.