This week, hundreds of small, brown worm-like creatures have appeared on and inside four out of four homes on one of our courts. These invaders have been tentatively identified as millipedes. The insects have been spotted in large numbers basking in the sun on garage doors and have worked their way into basements. Below is an article on millipedes from the University of Colorado.
Millipedes
The most common millipedes are dark brown and reach 1 to 1 1/2 inches when full grown. They are round and elongated, with many small legs. A common description is "little black worms crawling in the basement windows." When dead or disturbed, they tend to curl into a tight coil.Millipedes do not bite or pose any danger to humans. They feed on rotting organic matter such as leaves and wood and rarely feed on tender green leaves and roots. They spend almost all their time in moist areas, such as under rocks or logs and in lawn thatch.
Movement into houses often is sudden and sporadic. Most millipede movement takes place in September and October and again in midspring. Invasions, usually into cellars, often take place shortly after a period of wet weather and end as suddenly as they start.
Because millipedes require high moisture, they usually die in a home within a day or two. Chronic problems are associated with damp conditions. Measures taken to dry out moist areas usually are sufficient. The hard body of the millipede, however, remains intact for a considerable time after it is dead.
Because millipedes cause no damage in homes other than a minor annoyance, the best way to handle infestations is to wait a few days for the problem to subside, then vacuum the bodies that remain. Remove debris and other favorable habitats from around building foundations to help reduce problems. Seal or caulk openings around the foundation to reduce future millipede problems.
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Figure 2: A common species of millipede found in gardens |
Usually only shaded sides of the home need treatment. Whole yard treatments are unnecessary and not recommended. However, most sod webworm and white grub treatments applied to lawns will also control millipedes.
When millipedes damage garden plants several practices can limit injury. Ripening fruit should be lifted off the soil, on mulch or other surfaces. Fruit that is overly ripe may be left in the garden to divert and concentrate feeding by millipedes. Similarly, millipedes can be concentrated under fruit rinds or moistened newspapers. The millipedes that are found at these sites can then be collected. Garden baits that contain carbaryl (Sevin) may also be used to control millipedes in gardens.
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| Figure 3: Young millipedes in strawberry fruit. (Photo by W. Cranshaw.) | Figure 4: Millipedes curl in defense and when dead. (Photo by W. Cranshaw.) |
