Species Chalybion californicum - Common Blue Mud-dauber Wasp

Common Blue Mud Wasp

Common Blue Dirt-dauber Wasp

Nearctic Blue Mud-dauber Wasp (primarily outside of our area, where another member of the genus is "common")

* Note: this species should not be called "the" blue mud-dauber or "the" blue mud wasp as those apply to the entire genus.

Chalybion californicum (de Saussure, 1867)

Pelopoeus califortiicus de Saussure, 1867

Sphex cyanea Fabricius, 1775

Sphex caerulea Linnaeus, 1763

Sphex caeruleus Linnaeus, 1763

10-23 mm

A large, active, blue-black wasp with irridescent blue wings. Frequents flowers for nectar and buildings for nest sites. Compare "Steel-Blue Cricket-hunter Wasp" Chlorion aerarium, which preys on crickets. This is about the same size as Chalybion, and is said to have a longer pedicel (narrow waist between thorax and abdomen). The body of Chalybion looks much more hairy, and more steely-blue, based on specimen photos. Within Chalybion, the darker wings and lack of long white thorax and head pubescence of californicum separate it from zimmermanni males. Separation of females is based on the morphology of the pleuron, which is usually impossible to do from images.

Widespread in North America (1)(2)(3)

Fields with flowers; residential areas

Apr-Oct in NC

Adults take nectar. Larvae feed on spiders.

Females construct mud nests in sheltered areas, often under the eaves of buildings, and provision them with spiders. Sometimes refurbishes the nests of other mud-daubers, such as Sceliphron.

Probable nests:

Here are some females with prey:

Wikipedia

DicoverLife species page (5)

Barcode of Life Data Systems (BOLD)