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Blue Mud Wasp

Common Name: Blue Mud Wasp.

Scientific Name: Chalybion Californium.

What to look for?  An impressive and beautiful wasp! The male Blue Mud Wasp can be identified by its metallic blue sheen and its narrow petiole (“waist” between thorax and abdomen). The antennae and legs are black for both male and female. The wings are opaque and tinted the same color as the body.

Where can they be found at Carillon Stonegate Pond? The Blue Mud Wasp will be active here from May to September. Look for them flying around the water’s edge and your flower garden. They will often perch on tips of the plants surrounding our ponds and in our gardens.

How big are they? Large! The male Blue Mud Wasp averages approximately one-half of one inch in length. The female Blue Mud Dauber Wasp is slightly larger, averaging approximately three-fourths of one inch in length.

What are their flight patterns? The Blue Mud Wasp is an active flier and can fly forwards, backwards and hover for a while.

How else do they behave? The Blue Mud Wasp is able to land on a spider web without getting entangled and will pluck the web to simulate an insect in distress. The Blue Mud Wasp uses its sting to immobilize spiders in preparing a meal for its developing young. While the Blue Mud Wasp has the ability to sting us, it is rarely aggressive.

What’s for dinner? Nectar and spiders – depending on their point in life cycle! The Blue Mud Wasp feeds on nectar and is a pollinator of some common wildflowers.  While the adults feed on flowers, they feed their developing larvae high protein foods like spiders. Also, did you say to yourself while lounging on your patio that you had not seen any black widow spiders? You can give thanks to the Blue Mud Wasp which the primary predator of the black widow spider!

Where do they take up residence? The Blue Mud Wasp’s range extends from northern Mexico to Southern Canada. It is quite common in Illinois and the Great Lakes region.

When and where do they breed and nest? A unique behavior of the Blue Mud Wasp is how it builds - or steals - its nest. During the summer, females build nests by bringing water to abandoned mud nests made by other species of mud dauber wasps.  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 pupate in a thin, white silky cocoon.  They spend the winter in the nest, emerging the following spring as adults. These nests can often be found in the shadow of buildings or bridges. There can be several generations of wasps in a year.

Where do they migrate? Blue Mud Wasps do not migrate.

Do they make any interesting sounds? No.

Interesting Facts About the Blue Mud Wasp:

  • The life cycle of the Blue Mud Wasp has four stages of development: egg, larva, pupa and adult.

  • Primary predator of the black widow spider – this is why you do not see black widow spiders while enjoying your outdoor patio!

  • While the Blue Mud Wasp has the ability to sting us, it is rarely aggressive so no need to be afraid.

  • Each spring a new generation appears as an adult wasp chews a round hole in the end of the mud cell and exits its winter home.

For more information on the Blue Mud Wasp and sources of information used in this blog (these are the several of the sources that I am using to learn as I blog), please visit U.S. Forest Service, University of Michigan Animal Diversity, University of California and University of Florida

The Carillon at Stonegate community is very fortunate to have a variety of wetland, forest and prairie environments conducive to a variety of birds and other wildlife, insects and plants. Our community and the Kane County Forest Preserve do an exceptional job in maintaining this natural environment – both for the benefit of the birds and wildlife and for our residents to enjoy.


Take a hike and see what you can find – and identify!

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