A Cool Good Bug

A Cool Good Bug

Blue Mud Dauber 2With all the media discussion of “bad” insects, like mosquitoes, many of the good guys are forgotten. One that has been very active this summer is the blue mud dauber, Chalybion californicum. These wasps are metallic blue, blue-green or blackish in color with very short narrow waists.  During the summer, female blue mud daubers 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 silk cocoon.  They spend the winter in the nest, emerging the following spring as adults.

 

Blue mud daubers are solitary wasps and not known to be aggressive. When the females have carried water to an old black and yellow mud dauber’s nest, she softens it and remolds it to her needs.  The result is a very lumpy version of the originally smooth nest.  Next she must fill the nest with food for her future offspring.  The blue mud dauber prays on spiders.chalybnest1a

Female-Black-WidowIf orb weavers, lynx or crab spiders are plentiful, the blue mud dauber is able to land on their web without getting entangled and pluck the web to simulate an insect in distress. When the spider rushes to capture its prey, the poor arachnid becomes the victim of the wasp’s paralyzing sting and is quickly flown to the mud nest.  However, the preferred host of the blue mud dauber is the southern black widow. Even without the elaborate web game, this wasp can control a dangerous nuisance.  Once at the nest with her spider victim, the blue mud dauber stores the paralyzed arachnid at the bottom of a mud cell and lays a single egg onto its body.  When the wasp larva hatches it consumes the remaining body of the spider.  With a full belly, the mature larva spins a papery silken cocoon within the mud nest and begins to pupate.  The following spring an adult wasp chews a round hole in the end of the mud cell and exits it’s winter home.muddauber_l-300x226

 

As adults, the blue mud dauber feeds on nectar from flowers and honeydew secreted by insects. Should you encounter a large congregation of this normally solitary wasp, don’t be alarmed.  It is probably just a bunch of male blue mud daubers gathering together to sleep it off, after a heavy day of “drinking.”

 

So, rather than having to cover yourself in DEET just to spend the evening on the patio, brave the heat (with water bottle in hand, of course) and spend the daytime hours watching the blue mud daubers prepare their nest for next year’s young. Maybe the media will pick up on wasp that are reducing black widow populations, rather than the dangers of mosquitoes.

 

Wasps Have a Purpose

Wasps Have a Purpose

Mud dauber, Photo Credit: UF/IFAS Extension

Mud dauber, Photo Credit: UF/IFAS Extension

Paper wasp, Photo Credit: UF/IFAS Extension

Paper wasp, Photo Credit: UF/IFAS Extension

 

I respect the fact that wasps can sting when threatened or disturbed. But I also respect the fact that they are beneficial.

 

Every time I’ve been stung by wasps, I either accidentally disturbed a nest that I didn’t know was there or I intentionally disturbed the nest and paid the price.

 

Paper wasps are common in Florida. They frequently construct and attach their paper-like nests to building eaves or the ceilings of porches. The adults seek out caterpillars, which they sting and paralyze. They then take the caterpillars back to their nest and place them in individual cells as food for the developing larvae.

 

I’ve witnessed the paper wasp as it stings and carries away a caterpillar from my vegetable garden. They are busy insects and are doing us gardeners a favor by reducing the population of caterpillars in our landscapes and gardens.

 

There are other beneficial wasps in Florida. Mud daubers, for example, build their mud-like nests on the sides of buildings close to human activity.

 

The mud dauber is not as aggressive as the paper wasp. It rarely stings people. It stings and paralyzes spiders. The mud dauber lays an egg on each paralyzed spider and seals it inside a chamber in its earthen nest. Upon hatching, the wasp larva feeds on the body of the spider. An emergence hole is made as the young wasp leaves the mud nest.

 

It may not be wise to tolerate all wasp species living in close proximity to your home. Even though yellow jackets, a type of wasp, could be considered beneficial, they are too aggressive and too likely to repeatedly sting to have as close neighbors. I also would be concerned with any type of wasp or bee nest existing in close proximity to individuals with a known allergy to insect stings.

 

Just because an insect has the ability to sting, it’s not all bad. Wasps can serve a beneficial purpose. But you’ll have to decide for yourself how close to you they can build their nests. The front porch may be too close.