Secrets of bee hotels

Saturday, August 8, 2015

Urbanites of all sorts have taken to building "bee hotels" for the "pollinator" bees that don't produce honey but, as Maclean's notes in its June 1 issue, not all is going well with these artificial nesting sites. Researchers tracked 200 bee hotels in Toronto over three years and found that wasps occupied three quarters of them.

The advice? Put the bee hotel where a northeast sun hits it. Bees like warmth in the morning. More than four storeys high and introduced bees abandon them. Ground level is better. Make the holes into the rooms big enough for larger females. Furthermore, parasites resulted in heavy losses and no solutions were offered.

Another researcher told Maclean's the problem may be with the city itself. It's just not conducive to bees and he says the same rules don't apply in orchards. "At their worst, bee hotels may act as population sinks for bees through facilitating the increase of parasites and diseases as a result of functional responses to unnaturally high nest densities and nesting site entrances set up in two-dimensions rather than in the more three dimensional arrangement found in nature."

The study's authors don't advocate quitting, just doing more research on what does work. "We advocate for due diligence on the part of retailers and promoters of bee hotels to avoid 'bee-washing' . . . as applied to potentially misleading claims for augmentation of native and wild bee populations."

The study on bee hotels can be found at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0122126 BF