At this time of year, bumblebee queens are a familiar sight rummaging on spring flowers. After surviving in hibernating winter, they need to build up important energy stores before laying their eggs. Access to flower-rich habitats from spring through to summer is key to the survival of successive generations of the bees, according to the largest study if its kind. Scientists have found that bumblebees need flowers within a short distance of their colony. Bumblebees are among the most important insect pollinators, yet they are declining globally. Dr. Carvell, an ecologist said, “Until now, aspects of the lifecycle of bumblebees have remained a mystery.”
“Our research was looking to resolve some of these mysteries and in particular to try and look at how the structure of habitats across a landscape, or the availability of flowers for the bees, affected this one key aspect of their life cycle, which was the survival of their families between years,” she said. The study, which took place in rural Buckinghamshire, is the first to path the effects of the surrounding landscape on wild bumblebees, from one generation to the next. Researchers at the UK’s Center for Hydrology and Ecology sampled DNA from bumblebees of three different species. They reconstructed the family tree of hundreds of families of wild bumble bees across a large area of farmland.
They were capable of matching queen bumblebees to their sisters and daughters, to look at survival from one year to the next. Even small increases in the amount of flowering plants through the summer and spring could have a big effect, raising the survival rate of queen bumblebees by up to four times.
“These are particularly important to getting colonies started in the spring and seeing them live through to be successful into the next generation.” The scientists found that as little as 1 to 2% of flower-rich habitat in a landscape, or even a park or a garden, was enough to have a significant impact on populations of wild bumblebees.
Bumblebees are social insects who love to live in colonies. When the queens emerge in early spring, having spent the winter hibernating alone, they go out to place a nest and in search of food. Each queen first forms its own nest, lays its eggs, and produces a few hundred daughter workers. Towards the end of the season, new queens and males hatch, which emerge from the nest to go in search of a mate. Only fertilized queens go on to hibernate, after feeding heavily on pollen and nectar to build up fat stores.