Native carpenter bees are invaluable pollinators – The Santa Rosa Press Democrat


Query: Each time I stroll out into my yard, an aggressive carpenter bee flies in circles round me. I like bees, however I’m afraid of being stung. Is there some method to let this bee know I’m not a risk?

Reply: The bee you describe is a western carpenter bee (Xylocopa californica), a big, shiny, blue-black bee. The males are both being territorial or curious, or each. Their in-your-face behavior might be disconcerting, however their aggressive habits is barely a entrance, as a result of they lack weaponry. Feminine carpenter bees, though they do have a stinger, are shy and retiring and received’t sting until provoked, for instance, by being dealt with.

Menacing habits of the males apart, there’s a lot to love about carpenter bees. They’re vital pollinators of many native crops and a few crop crops, together with blueberries, blackberries, peppers, melons and fervour fruit.

On some flowers, resembling these of tomatoes and eggplants, the females apply “buzz pollination.” They chew into and maintain on to the anther base of the flower — the a part of the stamen that holds the pollen. Then they curl their our bodies right into a “C” form and beat their wings to create vibrations that blast the pollen out of the anther pores and onto a set of bristles, or scopae, on their hind legs. Nevertheless, they do have a fame as “nectar robbers,” generally shirking their pollinator duties by piercing the petals of tubular flowers with their blade-like tongue to get to the nectar.

The females have been described as “businesslike” of their foraging actions, accumulating pollen and nectar and shortly returning to their nests to unload the products. These bee mothers mix the pollen, nectar and saliva right into a dough-like substance known as “bee bread.” In a tunnel she has drilled into wooden together with her mandibles, the feminine shapes the bee bread right into a small pillow with three legs and lays a big single egg on prime of the pillow. There could also be a number of chambers, or brood cells, in every tunnel. She seals every chamber with sawdust left over from development. When it hatches, every younger bee is totally nourished with its personal provide of bee bread because it matures over a interval of months.

Bee tunnels are roughly ½ inch in diameter and initially 6 to 10 inches deep. Over time, carpenter bee tunnels can prolong as much as 10 toes in size. Carpenter bees want untreated softwoods for constructing their nests, particularly redwood, cedar, cypress and pine. They have an inclination to keep away from hardwoods and don’t hassle with painted, varnished or handled wooden.

In case you are involved concerning the harm carpenter bee tunnels might trigger to your private home, you’ll be able to deal with the wooden to discourage tunneling. Deal with exterior wooden to stop the formation of depressions and cracks which could appeal to the bees. If bees are already residing there, wait till the newly emerged adults have left the nest within the late summer time or early fall, after which block the unoccupied tunnels with metal wool or caulk.

You’ll be lucky to come across the valley carpenter bee (Xylocopa varipuncta), often called the “teddy bear bee,” a nonaggressive species of carpenter bee that’s hardly ever present in Sonoma County. This bee is even bigger than the western carpenter bee, and the males are golden brown and furry, with inexperienced eyes.

For extra data, take a look at “Carpenter Bee: Helpful Insect or Pest?” at or the UC IPM Pest Notes for Residence and Backyard: Carpenter Bees at

Contributors to this week’s column have been Janet Bair, Karen Felker and Pat Rosales. The UC Grasp Gardener Program of Sonoma County gives environmentally sustainable, science-based horticultural data to Sonoma County dwelling gardeners. Ship your gardening inquiries to [email protected]. You’ll obtain solutions to your questions both on this newspaper or from our Data Desk. You possibly can contact the Data Desk instantly at 707-565-2608 or [email protected].


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