By Jim Moore, Entomologist
Being a Bug Wild enthusiast, I have made efforts to attract many of the little bug critters to my yard by landscaping it into a very friendly bug habitat. As a result I have recorded well over 1500 visiting bug species to my 50×150 foot biodiversity hot-spot! One secret is a diverse variety of flowering plants that keep the flowers blooming continually from the earliest spring thaw to the earliest fall frost.
My most abundant and continuous flower visitors are Bumble Bees. My crocus flowers, the first to emerge in the spring, are sure to be visited by solitary queen bumble bees on sunny warm days. When the fall frosts begin, I often find early morning chilled worker bumble bees, clinging to the flowers of the die hard California poppy plants, waiting to warm up their bodies in the sunshine before returning to their colonies with their pollen and nectar.
New bumble bee colonies are established in early spring by a single foundress queen. She usually chooses an underground or sheltered ground based site. She gathers nectar and pollen and stores them in her new home. Eggs are laid, the larvae are kept fed, and eventually female workers emerge and take over the chores and upkeep of the Colony. Colonies may grow to between 50 and 400 individual bees, most of whom are worker bees. In the autumn, drone males and new queens are produced by the colony, which take flight from the colony and mate. The new queens fatten their bodies up by feeding on nectar and pollen, and then find underground sites to hibernate. The workers, drones, and old queens all eventually die with the onset of winters cold.
Bumble bees are very efficient pollinators of many flowering plant species, especially those that have tubular shaped anthers, such as tomato plants. They utilize a unique process called Buzz-pollination, whereby the bumble bee grabs hold of the flower and rapidly move their flight muscles causing a strong buzzing vibration that shakes pollen loose and out of the tubular anthers; a truly beneficial adaptation! NorCal is home to about thirteen Bumble Bee species. The Bumble bee pictured is called the Black-tailed Bumble Bee, species Bombus melanopygus.