The X. californica species of carpenter bee is 3/4-1 inch long and both sexes can be mostly metallic green or blue with grayish/dusky wings. The male’s pronotum has orange, yellow or white hairs and its 1st abdominal segment has whitish hairs. The X. tabaniformis is about 1/2-5/8 inches long and both sexes are black. The male’s head has yellow and white hairs mixed with black hairs. These bees do resemble bumble bees, but of course with the exception of the different coloration.
These particular bees nest in incense cedar and redwoods. Male carpenter bees tend to be territorial and often become aggressive when humans approach. The bee will hover a short distance in front of the face or buzz one’s head. Since males have no stinger, these actions are merely show. The female does have a potent sting, but is rarely used.
Mature colonies are moderate to large, apparently composed of up to several thousand workers and only one queen. If mounds are present, they range up to 8-10 inches in diameter. Developmental time ranges any where from 59 to 127 days. Reproductives are present in the colony from midsummer to autumn. Mating occurs in the nest before swarming happens. Swarming occurs July through September any may be composed of males and females. Queens burrow into a chamber and usually doesn’t lay any eggs until the following spring. Queens can live more than 10 years.
Xyloccopa Californica Cresson