In a temperate, seasonal climate bees spend winter in diapause. They usually overwinter as prepupae (that is, as a larva that ate everything it could and is ready for pupation) or, more rarely, as adults. I often hear from people who have bee hotels in their gardens, or who breed red mason bees as a hobby, that they are afraid that their bees will freeze in winter. They want to put them somewhere in a sheltered and warm place to help them survive. Actually, it’s a very bad idea. The bee species native to the seasonal environment are not only adapted to survive low temperatures. They may simply need them! The red mason bee, one of the best studied solitary bee species, can endure about -30°C (-22°F) but constant temperature of about a dozen Celsius degrees can cause trouble. When kept in a room temperature, the red mason bees may emerge in the middle of winter or die in the cocoon. It sometimes happens when a female built her nest inside a house, or the nest was brought home, either accidentally or purposefully (in an attempt to ‘keep the bees warm’).
Bringing the nests home for winter is not the biggest threat for overwintering bees. More disturbing is the climate change, manifesting itself with higher mean temperatures, but also warmer and shorter winters.

This post was published on Instagram in cooperation with The Pollinator Academy. I’m happy to be involved in this initiative. If you are interested to learn about pollinators, in particular bees, hoverflies and butterflies, and recognizing them, check out the PA website!










