About Bumble Bees
Bumblebees belong to the family Apidae in the genus Bombus. There are more than 250 species of bumblebees, most of which live in the Northern Hemisphere with a few species in New Zealand and Tasmania. They are social insects that live in colonies of usually less than 50 bees. All bumblebees are covered in soft short hairs called pile that make them look fuzzy. While they are usually banded in black and yellow they can also have orange or red markings or be entirely black.
To really know if you are looking at a bumblebee you need to look at the hind leg. A female bumblebee’s hind leg has a shiny concave place, called a corbicula that is bare though surrounded by fringe. It’s used to carry pollen. Other large fuzzy bees hind legs are completely hairy and the pollen is carried between the leg hairs.
Throughout most of their range young bumblebee queens mate with males in autumn and then the males all die and the queen goes into diapause. Diapause is like hibernation but they aren’t just sleeping through winter. Instead, the development of the eggs in the queen is delayed and won’t begin again till spring. At that time the queen wakes up and finds the perfect place for her colony. Then she builds wax pots for food and stretchy wax cells that she lays fertilized eggs in. The eggs hatch into larvae and the wax cells expand as the larvae grow. The queen works hard gathering pollen and nectar from spring flowers both for herself and for the larvae. She chews a little hole in the wax cells and regurgitates nectar into them. The larvae need both nectar and pollen to grow properly. How the bumblebee larvae gets the pollen depends on the species; some put pollen in the brood cell before the egg is laid and some feed it to the larvae in the same way as the nectar. The larvae go through 4 stages, called instars, and become larger with each stage. Then they spin cocoons inside the wax cell and become pupae. The pupae develop into adult female workers and soon the queen will have helpers feeding the young, cleaning the colony, and doing other jobs very much like honey bees. From egg to adult bee can take 5 weeks during which only the queen is able to find food, build the colony and feed and care for the larvae. When autumn approaches new queens will be raised as well as male drones. Male bees are created from eggs called haploid eggs that were not fertilized the year before. Haploid eggs can be laid by any of the worker bees although the first males are usually sons of the queen. The only function of the male drones is to mate with new queens and they are often driven away from the hive by the worker bees as soon as they are mature. New queens leave the colony as well. Away from the colony they will overnight inside flowers or small holes and live off nectar and pollen. Once she is fertilized, sometimes more than once, the young queen finds a place to settle down for the winter. Meanwhile, back at the colony the old queen dies having done her part to reproduce her species.
Bumblebees and People
Bumblebees are used more and more to pollinate greenhouse crops not to mention many wild flowers and trees. Sometimes, the bees don’t even have to land on the flower. Their buzzing alone loosens the pollen and sets it drifting through the green house.
Now that we know how useful bumblebees are we are also aware they are disappearing. There are 30 species of bumblebees worldwide that are known to either be endangered or that are thought to be extinct due to habitat loss or pesticides.
While you may not want them colonizing your yard you can still help bumblebees survive by planting your yard with a variety of flowers that will bloom from early spring to early autumn. Bumblebees love most garden flowers and herbs as well as flowering bushes and brambles like blackberry and raspberry.
Unlike a honey bee’s stinger, bumblebees have a smooth stinger and are able to sting several times. Fortunately, most bumblebees are calm and are unlikely to attack people unless the colony is threatened. To be sure these beneficial insects aren’t troubled by human activity it’s a good idea to keep your yard clear of brush, flat objects like board and stones as well as pipes and hoses as they like to nest under and in these things.
The bumblebee’s distinctive buzz is caused by the bee’s flight muscles which vibrate to keep them warm as well as to get them airborne.
In the mid 20th century, an urban legend started that claimed the laws of aerodynamics proved bumblebees shouldn’t be able to flight due to the small wing to body size ratio.
Bumblebees don’t have ears. We know they can feel vibrations on the ground or on plants but we don’t know if they can sense sounds in the air.