Conservation-Mud Daubers – wasps I can live with. By: Kevin Williams, Grundy County Conservation Director
Well, the wasps are flying around my garage door again building this year building nests. Normally, I work hard at eliminating any that take up residence so close to regularly used doors and windows in my home or shop. These are an exception because I find these ones fascinating and relatively harmless. The thought for the subject today came as my wife was “alerting” me to the man-killing wasp that was flying around the garage door. As it turned out, the wasp was a member of the mud dauber family. These are probably the most docile of wasps and difficult to provoke enough to sting you. I did some research into this interesting group of wasps to see how many species there are here and a bit of their life history. I found them fascinating and while I have talked about them before, I believe their story is worth sharing. Iowa has three species of wasps known as mud daubers. They include the larger black organ pipe mud dauber, the black and yellow mud dauber, and the blue mud dauber. The latter is a beautiful metallic blue and happens to be the one that was flying around our doorway. They are all solitary as opposed to the more familiar colonial paper wasps that sometimes make nests under our eves. They have stingers but they don’t aggressively defend their nests. People are seldom stung by mud daubers. Their stingers are used primarily to anesthetize their prey which is usually small spiders. Spiders are typically caught as they rush out thinking the wasp is prey caught in their web. The hunter thus becomes the hunted. The live, but paralyzed, prey is placed into mud nest chambers where it becomes food for larval wasps. I found it interesting that the adult wasps feed only on flower nectar. Each chamber receives a single egg. The larva that hatch consume the spiders before becoming a pupa. Although two generations may emerge in a summer, no adults survive the winter. They overwinter as pupa in their mud nests. Organ pipe mud daubers build nests that are typically vertical, side-by-side mud tubes on a sheltered wall. They get their name because the tubes resemble organ pipes. Black and yellow mud daubers build layered nests of mud tubes that may be smoothed over on the outside in somewhat the shape and size of a lemon. And Blue mud daubers are the least industrious of all and don’t build their own nests. Instead, they remodel the old nests of the other mud daubers. Extremely efficient use of time and energy. And personally, as my wife and kids can tell you, I am all about reusing and repurposing items. As you go about your business around you house and yard, should you encounter a mud dauber nest, think about their life history before you choose to knock it down and smash it.