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Monday, August 3, 2020

Bumblebee Nests by Vicky Spelman


Bumblebee Nest
Photo: Vicky Spelman

What about those giants in the yard – the bumblebees?  I was fortunate enough to discover a bumblebee nest in my yard - hidden and nestled in behind some railroad ties. Look at the orange colored pollen baskets on either side of the hind legs. 

Carrying Pollen to the Nest
Photo: Vicky Spelman


Incoming with pollen and outgoing to collect more pollen
Photo: Vicky Spelman

<<Bumblebees are large, charismatic insects, but to understand them, one must know about their natural history. All bumblebees, like butterflies have four life stages: egg, larva, pupa, and adult. They also live in colonies.

Each newly reared future queen overwinters by burrowing into soft ground or other safe place. In the early spring, this young queen seeks out a place to establish a nest. She will build wax pots, collect pollen and nectar to feed to her offspring, and start laying eggs. When her daughters emerge, they will be the worker caste that continues to forage for pollen and rear offspring. The queen will stay in the hive and lay eggs. Later in the summer, the colony will start producing new queens for next summer and males. In the fall, all but the newly emerged and mated queens will die. The following year, the cycle will repeat.

Bumblebee visiting penstemon
Photo: Vicky SpelmanBlog

Like other bees, bumblebees visit flowers for pollen and nectar. Nectar serves as a food source for both the adults (males and females including queens and workers) and their offspring. Pollen is collected by females as a protein source for their offspring. Pollination occurs in the process, but is not the goal of the bee. While all bumblebees have fairly long tongues, some also have elongated faces that allow them to gather nectar from flowers with long corolla tubes, such as delphiniums. Bumble bees are also known to buzz pollinate certain types of flowers including tomatoes and blueberries. After landing on these flowers, they buzz their wings at a frequency that shakes the pollen out of the anthers. Unlike drone honey bees, male bumblebees are not restricted to their colonies and are often observed on flowers. Incidentally, only the female (queen and worker) bees can sting.>>

Bumblebee Nest
Courtesy Iowa State University

<<Nesting sites are often abandoned rodent burrows in the ground, but they may be a matted grass hummock, or even a hole in a tree trunk, eave, or bird houses.>>
Bumblebee Nest
Courtesy Utah State University

To see find out more about Colorado bumblebees: CSU-Bumblebees