After reading last fall about the drastic decline in bumblebee populations in my state, I feared I would not see the black-and-yellow bombers this spring, so I was greatly relieved when they visited my early-blossoming ‘Purple Gem’ and ‘Olga Mezitt’ rhododendrons last week.
There were so many and they moved so fast flitting from flower to flower in search of pollen and nectar that it was hard to get one to stand still long enough to get a good picture.
Female worker bees do the collecting of nectar and pollen. They perform buzz pollination by grabbing the pollen producing part of the plant in their jaws and vibrating their wing muscles to loosen trapped pollen. If you can get one to be still long enough, look closely and you can see the pollen basket or cobicula on its rear legs where it stashes a load of pollen to carry back to the nest. Crops such as tomatoes, peppers, and cranberries bear better fruits if they are buzz pollinated.
What Are Bumblebees
There are about 45 species of bumblebees (Bombus) in the continental US. Unlike most native bees that are solitary, bumblebees are considered social, meaning that, like non-native European honeybees, they live in colonies and share the work of keeping the hive thriving. A typical colony can have 50 to 500 workers but unlike a honeybee hive, they usually nest underground, under clumps of grass, or in hollow trees. Abandoned mouse holes are a favorite since they come come complete with a warm fur lining.
Like most native bees they are considered generalists meaning they feed from a wide range of flowers. Bumblebees make only a small amount of honey, just enough to tide them over a few days of bad weather. They can maintain about a week’s worth of food in their bodies so they need to forage regularly to survive. Early bloomers like fruit trees, pussy willows, and serviceberry are especially necessary to give the newly emerging queens some nourishment as they wake up and start their new colonies. The whole hive, even the old queen, dies off leaving just new, mated queens to start new colonies in the spring. If even one queen dies a whole colony will be lost.
Last year the rusty patched bumblebee (Bombus affinis) was the first bee listed as an endangered species in the continental US and it is thought to be extinct where I live, the last recorded sighting of it being in 1993! According to the Dept. of Agriculture the decline in bumblebee populations can be blamed on the 5 “P’s”—parasites, pests, pathogens, poor nutrition, and pesticides.
Plants Bumblebees Prefer
Gardeners can help by planting flowers and flowering trees and shrubs. Though natives are preferred—such as asters, echinacea, lupines, bee balm, and spring ephemerals—bumblebees are not fussy; anything that produces nectar and pollen works for them. If you plant even a small area or a few containers with flowering plants they will find them.
Plan your garden to have a long season of bloom. Bumblebees fly in cooler temperatures and lower light conditions than other bees making them the first you’ll see in the spring and the last ones flying in the fall. Unfortunately this ability also makes them more vulnerable to agricultural pesticides and herbicides which are usually sprayed in early morning and later in the day to avoid harming honeybees that are active during the middle of the day.
That said, try to eliminate pesticides from your garden. A group of insecticides called neonicotinoids have been shown to have a devastating effect on all types of bees. It is a systemic chemical that can come from pre-treated seeds or sprays applied to bedding plants. The chemical is present in every part of the treated plant—flowers, stems, leaves, etc. Buy organic whenever possible or ask your local nursery to make sure that no systemics were used on the plants you are purchasing.
To provide nesting sites, leave some part of your yard a little wild and brushy. Don’t mow or rake there, and leave some plant stems standing over the winter to give the new queens places to hibernate and spots to establish new colonies in the spring.
See our video showing easy ways to attract bees to the garden for more flowers and food!