Pest Library
Mud Dauber
Mud daubers are slender solitary wasps with long thread-like waists that build mud tubes or clumped mud nests on walls, ceilings, sheds and under eaves. Because they are solitary rather than colony-forming, they defend nothing and almost never sting.
Profile
- Scientific name
- Sceliphron and Trypoxylon spp.
- Identification
- Long thin petiole between thorax and abdomen; black, metallic blue-black or black with yellow markings. Mud nests are the clearest sign.
- Typical size
- Adults about 1 inch.
- Behavior
- Females build and provision cells with paralyzed spiders, then seal them. Adults are not defensive.
- Habitat
- Sheltered walls, ceilings, garages, sheds, under decks and porch overhangs.
- Diet
- Nectar for adults; provisioned spiders feed the larvae.
- Lifecycle
- Cells are provisioned in warm months and adults emerge from the mud nest, leaving round exit holes.
- Why it matters
- Mostly a cosmetic and staining nuisance. Abandoned nests can attract other insects, and mud tubes on a foundation should not be confused with termite mud tubes.
- DIY considerations
- Physical removal and washing is usually all that is needed.
- Professional considerations
- Service removes nests and addresses the spider population supporting them, plus perimeter treatment where nesting is heavy.
Signs of activity
- Mud tubes or lumpy mud nests attached to walls and ceilings
- Round exit holes in older mud nests
- Spider remains and mud debris beneath nest sites
Prevention
- Scrape and wash mud nests off surfaces early in the season
- Reduce spider populations that provide the food supply
- Keep garages and sheds closed during peak building season
Sources
Related information
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