These wasps are metallic blue, blue-green or blackish in color. Males 9mm to 13mm (3/8in.-1/2in.) are typically smaller than the females at 20mm to 23mm (3/4in.-7/8in.) Both the males and females share similar body structure in that their waists are short and narrow; both having slight body bristles. The antennae and legs are black for both male and female. The wings of both the males and females are opaque and tinted the same color as the body (Hogue 1974).
Other Physical Features: ectothermic ; bilateral symmetry
This species is found in many different habitat types, anywhere flowers, spiders, nest sites, and a little water may be found (O'Brien 1998).
Terrestrial Biomes: desert or dune ; savanna or grassland ; chaparral ; forest
Adults of this species feed on flower nectar, and possibly pollen. Individual wasps get most of their nutrition while they are larvae, feeding on spiders provided by their mother. Adult females capture orb-weavers (family Araneidae) and comb-footed spiders (family Theridiidae), often including black widow spiders (genus Latrodectus). These wasps capture their prey by paralyzing them with a sting. Some have been observed landing on orb webs and luring the spider out of its retreat, captureing and paralyzing the spider without getting caught in its web and becoming prey itself (Bohart & Menke 1976, Hogue 1974, O'Brien 1998).
Known prey organisms
This list may not be complete but is based on published studies.
Life History and Behavior
We don't know much about courtship or mating in this species. They probably only need to mate once, though may mate more often. "Sleeping" aggregations (see Behavior) may also be part of the mate-finding process (Bohart and Menke 1976).
During the summer, female blue mud wasps build nests by bringing water to abandoned mud nests made by other species of wasps (mainly the genus Sceliphron). They form new mud chambers, stock them with paralyzed spiders and a single egg, then seal the chambers with more mud. Their offspring stay in the chamber, feeding on the spiders, and then pupating in a thin silk cocoon. They spend the winter in the nest, emerging the following spring as adults (Baker and Bambara 1999, Bohart and Menke 1976, O'Brien 1998).
Molecular Biology and Genetics
Statistics of barcoding coverage: Chalybion californicum
Public Records: 3
Specimens with Barcodes: 15
Species With Barcodes: 1
This species is common and widespread throughout North America, and is not considered in need of special conservation efforts.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
Relevance to Humans and Ecosystems
This species sometimes nests around buildings, and may thus be a small nuisance, but its inoffensive habits and use of spiders as prey generally prevent it from being a pest (Bambara and Becker).
This species may help to control the population of black widow spiders (O'Brien 1998).
Blue mud dauber
The blue mud dauber (Chalybion californicum) is a metallic blue species of mud dauber wasp that preys primarily on black widow spiders. It does not build a nest, but uses nests abandoned by other mud dauber wasps. Like other mud daubers, it is rarely aggressive. It is similar in shape and colour to the steel-blue cricket hunter (Chlorion aerarium).
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- M. C. Day (1979). "The species of Hymenoptera described by Linnaeus in the genera Sphex, Chrysis, Vespa, Apis and Mutilla". Biological Journal of the Linnean Society 12 (1): 45–84. doi:10.1111/j.1095-8312.1979.tb00049.x.
- B. M. Drees & J. Jackman (1999). "Mud Daubers". Field Guide to Texas Insects. Texas A&M University.
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