Other Common Names
Males informally called 'teddy bear' bees (UC, Davis)
Synonyms and other taxonomic changes
Author: Patton 1879
Xylocopa brasilianorum varipuncta
14 spp. (in five subgenera) (1)
18-26 mm (Largest bees in CA)
Their eggs are the largest of all insect eggs. The Valley carpenter bee egg can be 15mm long. (UC, Davis)
Female is black with brassy reflections, perhaps.
Male is a striking tawny brown.
Apparently, no other Xylocopa are so sexually dimorphic.
Western US: CA-TX / plus Baja California, Mexico.
Valleys and foothills with deciduous trees such as oaks.
Carpenter bees overwinter as adults in the tunnels and emerge in the spring. (UC, Davis)
May emerge earlier than X. californica?
Adults presumably take some pollen, like others of the genus. Due to their large size, carpenter bees cannot enter tubelike blossoms such as sage, so they slit the base of corolla, a practice known as "stealing the nectar" (without pollinating the flower). (UC, Davis). The Hosts section on its Discover Life species page
lists known floral associations based on specimen records and images.
Carpenter bees tunnel through wood to make their nests, carving with their mandibles, but they don't ingest the wood. Only the females excavate the tunnels, which average six to 10 inches in depth.
The males are territorial and can be quite aggressive. They hover and lie in wait for passing females.
To build their nests, the females select telephone poles, fences, decks, railings, eaves, siding, outdoor furniture and tree trunks. They prefer bare, unpainted or weathered wood, especially redwood, cedar, cypress and pine. They generally avoid painted or pressure-treated wood. (UC, Davis)
John S. Ascher pointed out that the species name is varipuncta
. This is the spelling on Nearctica, ITIS, as well in Charles Hogue's Insects of the Los Angeles Basin
Powell and Hogue, p. 352--describes sexual dimorphism (3)
--Walter Ebeling, Univ. California. Discussion and illustrations showing sexual dimorphism.