Archive
TOO HOT FOR BUMBLES
16/05/2024
In contrast to the redwoods I wrote about last week, it seems bumblebees are suffering because of the hotter temperatures arising from the climate catastrophe. Bees generally are not doing well, so recent research[1] indicating that higher temperature peaks are causing nest failure is worrying.
Bumblebees are adapted to colder climates, and they are vitally important pollinators, critical for many wild and crop plants, so we absolutely do not want to see further decline. The problem is that, in the longer and hotter heat waves we are experiencing these days, bumblebees cannot keep the temperature in their nests low enough to avoid brood mortality. Usually, the worker bees do this by collectively beating their wings to fan and thus cool their nests. In other words, they operate thermoregulation. Indeed, the research considered nests as a “superorganism”, an ecological concept which is frequently overlooked.
[1] Kevan, P.G., Rasmont, P. & Martine, N. (2024). Front. Bee Sci (2) https://doi.org/10.3389/frbee.2024.1351616
After a substantial literature search, the researchers conclude that bumblebee nests need to be kept at a temperature between 28 and 32 degrees Celsius for successful incubation. The bees can’t achieve that if the ambient air is too hot. It is thought that the lethal limit of temperature is c.35oC, above which the brood cannot survive. The researchers point out that this is bad news, especially in North America and Europe and offers one explanation of why bumblebees are declining. We could lose half our bumblebee species because of climate change and habitat destruction.
On our sites, Betts Ecology proscribe pesticides and we provide a rich flora of pollinator-friendly blossoms as well as nesting habitat, but latest data show the adverse effects of the climate catastrophe globally are terrifying, with national and international action frankly pitiful. Awareness and apprehension are growing, but we have a very long way to go, and time is fast running out if indeed it is not already too late.
