Effect of formic acid treatment on Apis mellifera foraging behavior using nanopore metabarcoding technologies

The Western honeybee (Apis mellifera) is a crucial contributor to worldwide agriculture and ecological health but is experiencing wide population declines linked to Varroa mite infection. Formic Acid (FA) has been increasingly used to control for Varroa, yet its effects on A. mellifera hives, particularly their foraging preferences, remain unclear. In this study, we used a combination of pollen DNA metabarcoding with real-time nanopore sequencing to assess how FA treatment influences A. mellifera foraging preferences. DNA sequencing was performed on pollen samples from six University of Utah campus honeybee hives (n = 6) separated into FA and control treatments. Samples were collected before, during, and after FA application. We amplified trnL, a chloroplast DNA region useful for plant identification using portable sequencers from Oxford Nanopore Technologies (ONT). We detected a significant difference in foraging composition between FA-treated and placebo-treated hives at the end of the experiment. Control hives foraged from a more diverse array of plant genera. We also found individual hives to have unique foraging preferences independent of treatment. These findings suggest that FA treatment is associated with detectable differences in A. mellifera foraging behavior. The magnitude of FA impact, however, on hive foraging repertoire remains unclear. Pollen DNA metabarcoding with nanopore technology is an effective method for analyzing bee foraging patterns and holds significant potential for advancing ecological research on pollination health.