Agroecosystems provide habitats, food, and water for many pollinators and insects, but they are also heavily exposed to threats from the widespread use of pesticides and fertilizers. Managed honeybees and wild bees encounter pesticides in vineyards by collecting morning dew from vine leaves and accessing sugars from grapes, particularly during dry periods. This study assessed the toxicological effects of the commercial fungicide formulations Fantic FNCWG^® and Ramedit combi^®, both individually and in combination, on honeybees. Using a multi-biomarker approach, we evaluated neurotoxicity, metabolic disturbances, phase II detoxification processes, and immune system function. Our findings revealed that commercial fungicide mixtures with multiple active ingredients affect bees differently than single active compounds. Biomarker responses highlighted how these complex mixtures disrupt various enzymatic pathways; including immune function; altering critical enzyme kinetics involved in detoxification and potentially impairing essential bee functions. This study emphasizes the need for more comprehensive research into the sublethal effects of commercial pesticides, particularly those used in vineyards, which are understudied compared to pesticides used in orchards.

The global pollinator decline is linked to intensive farming and the high use of plant protection products (PPPs), necessitating risk assessment and mitigation. This study investigates the potential negative impacts of agricultural practices on pollinator health, specifically focusing on the effects of PPPs used in viticulture on the honey bee, Apis mellifera, despite grapevines’ lack of reliance on bee pollination. The beehives sampled were from two farms with vineyards under different management regimes: one transitioning from conventional to organic practices and an organic–biodynamic site with pollinator mitigation measures. Sampling was conducted during three phases, pre-, during, and post-PPP application, to evaluate biomarkers of neurotoxicity (AChE), detoxification enzymes (CaE, GST), metabolic stress (ALP), and immune markers (Lys, PO, proPO). Comparison between the organic–biodynamic farm and the transitioning one revealed a pattern suggesting significant neurotoxic effects in the transitioning farm characterised by a trend of decreased AChE activity during treatments and the subsequent induction of GST post exposure. Crucially, both PO and proPO were induced post treatment, but with a lower PO/proPO ratio compared to previous seasons, suggesting inefficient proPO activation and potentially weakened immune competence that could favour pathogen proliferation. Bee health appeared to deteriorate most at the transitioning farm post treatment, while the biodynamic site remained relatively stable; these differences are likely associated with legacy residues and drift, exacerbated by overwintering stress and summer heat. Given the specific environmental and management characteristics of these two farms, the results provide an indicative comparison of how different agronomic approaches may influence bee health. Moreover, these results support the multi-biomarker approach for detecting potential PPP impacts, suggesting that organic transitions and mitigation strategies could play a role in pollinator conservation.