Aphid honeydew may be the predominant sugar source for Aphidius parasitoids even in nectar-providing intercrops

The nectar provision hypothesis predicts that the introduction of nectar-producing plants in agroecosystems benefits parasitoid populations field and enhances biological control. Intercropping is a common crop diversification scheme may bring complementary sources for parasitoids increase herbivore pest For instance, intercropping cereals with faba beans introduces usually sugar-devoid systems (i.e. cereal single crops). However, has never been evaluated at scale such systems. To test this hypothesis, we if sugar limiting factor Aphidius triticale crops their feeding activity increases bean-triticale intercrops. patterns were from profiles, using high-performance liquid chromatography (HPLC). In parallel, aphid density parasitism rates estimated edge centre Sugar analyses revealed honeydew was always main source parasitoids, although significant proportion recorded to feed on nectar, did not Besides, intercrops, nor reduced. Thus, our results do support but rather suggest some systems, its effects control are highly context-dependent. They also confirm can be major food which necessarily limited scale.