nest density. Predators X. californica does not have many predators, but in the southwest of Northern America, the ladder-backed woodpecker, Dendrocopos scalaria, has been observed to attack their nests. And the bee fly, Anthrax simson, is a parasite of their nests There are reports of the honey bee, Apis mellifera, having negative effects on X. californica populations. The carpenter bees are attracted to the floral scents of the honey produced by the honey bees; X. californica may come near or inside their hives and get attacked by the hive resulting in the death of the carpenter bee. Disease The fungus Ascosphaera apis is generally found in the larva of the European honey bee, Apis mellifera, causing the larva to be mummified. It has also been found in X. californica, except the infected larva does not look the same as the honey bee's; they develop spore cysts beneath the larval integument. X. californica are not the natural hosts of this fungus, but they may be infected if they visit the same plants as other infected honey bees. Subspecies The species has three named subspecies, defined solely by coloration and geography: X. c. arizonensis Cresson, 1879 X. c. californica Cresson, 1864 X. c. diamesa Hurd, 1954 Gallery References External links Discoverlife.org: Photo gallery of Xylocopa californica (Western Carpenter Bee) — with list of host plants. BugGuide.Net: Xylocopa californica — Western Carpenter Bee — images. Hymenoptera of North America Insects of Mexico Insects of the United States Fauna of California Fauna of the Southwestern United States Fauna of the California chaparral and woodlands Fauna of the Great Basin Fauna of the Mojave Desert Natural history of the Central Valley (California) Xylocopinae Insects described in 1864 Taxa named by Ezra Townsend Cresson