Lobularia maritima as a nutrient-rich floral food source for two parasitoid wasps of Tuta absoluta

Abstract

Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the main pests threatening tomato production worldwide. Since its detection in the Mediterranean basin, it has been the target of research aiming to reduce damage in tomato crops. Current conservation biological control approaches focus on the polyphagous predators Macrolophus pygmaeus (Rambur) and Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae), which are very effective predators of the pest’s eggs but have little effect on T. absoluta larvae. Surveys conducted in northeast of Spain have concluded that the eulophid Necremnus tutae Ribes & Bernardo and the braconid Dolichogenidea gelechiidivoris (Marsh) are the most abundant larval parasitoids. It is well known that adding floral resources near crops can provide high-quality food for natural enemies and thus enhance biological control. Previous studies showed that Lobularia maritima L. (Brassicaceae) flowers are a reliable food source for N. tutae. The present study examines whether the availability of L. maritima flowers positively influences the fitness of D. gelechiidivoris and the biological control of T. absoluta by parasitoids. To study this aspect, the performance of both wasps was evaluated in a simple and complex arena at high and low densities of T. absoluta, respectively. Our results demonstrate that the nectar of L. maritima is a nutrient-rich food source for both N. tutae and D. gelechiidivoris with profound implications on the biological control of T. absoluta in tomatoes.