Rapeseed (Brassica napus) is an important source of nectar and pollen for honey bees, but it may also hide some problems.

A recent study conducted in Argentina and published in the Journal of Apicultural Research showed that colonies foraging on rapeseed were stronger than colonies kept in areas without this crop. Colonies foraging on rapeseed had more brood, workers, and stored food, but they also showed a higher level of Varroa infestation, probably due to the greater amount of brood.

Regarding other health parameters, colonies foraging on rapeseed had lower Nosema infestation levels and similar levels of viral infection compared with colonies kept in areas without rapeseed.

Rapeseed appears to be a very good resource for colony development and honey production. However, we now know that it is important to pay particular attention to Varroa mites after colonies have foraged on this crop.

Go to the scientific paper here.