Chalybion californicum
In 3 days ~30% in a week ~60%
Chalybion californicum, the Nearctic blue mud-dauber wasp or common blue mud-dauber wasp of North America, is a metallic blue species of mud dauber wasp formally described by Henri Louis Frédéric de Saussure in 1867. It is not normally aggressive towards humans. It is similar in shape and color to the steel-blue cricket hunter (Chlorion aerarium). Like other types of wasps, males do not have an ovipositor, and therefore cannot sting.
It is ranged from northern Mexico to southern Canada, including most of the United States. It has also been introduced to regions including Hawaii, Bermuda, Croatia, and other European countries. Females can build their own nests, but often refurbish nests abandoned by other wasps and bees, particularly those of Sceliphron caementarium, removing any spiders captured by S. caementarium and the larva, replacing it with an egg of its own and freshly caught spiders. They go through multiple generations in a year.
This species is most famous for its predation of black widow spiders. Adults feed on the nectar of flowers, which powers their flight. They pollinate some common wildflowers... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Everglades National Park | 🇺🇸 United States |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Montreal | 🇨🇦 Canada | |
| 2 | Chicago | 🇺🇸 United States | |
| 3 | Toronto | 🇨🇦 Canada | |
| 4 | New York City | 🇺🇸 United States | |
| 5 | Detroit | 🇺🇸 United States | |
| 6 | Baltimore | 🇺🇸 United States | |
| 7 | Boston | 🇺🇸 United States | |
| 8 | Vancouver | 🇨🇦 Canada | |
| 9 | Portland | 🇺🇸 United States | |
| 10 | Washington | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Common Blue Mud-Dauber Wasp sighting in Everglades National Park on a given day, based on 50 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 85th most-seen of the 496 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 60%, if each day is a fresh chance.
March–April and June
In those months about 20% of wildlife watchers report a Common Blue Mud-Dauber Wasp in Everglades National Park on a given day, against under 5% in September and November–February, the lowest months.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Common Blue Mud-Dauber Wasp sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Only Everglades National Park, in our data
Everglades National Park is the only park on Wallace's Line with enough records to rate Common Blue Mud-Dauber Wasp sightings: about 10% of wildlife watchers there report one on a given day.
Same family: Sphecidae
The closest relatives of the Common Blue Mud-Dauber Wasp that you can see in Everglades National Park (family Sphecidae, Thread-waisted Wasps) are Yellow-Legged Mud-Dauber Wasp (about 10%), Jamaican Digger Wasp (about 10%) and Great Golden Digger Wasp (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Common Blue Mud-Dauber Wasp is recorded against all the insects logged in Everglades National Park (50 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
