Worms in the Basement

Millipedes are often seen in damp, dark rooms indoors.

Basements are dark and damp, making them the perfect place for infestations of moisture-loving pests. Most worms enter basements through cracks in windows or under doors that don't have tight-fitting thresholds.

Types

Millipedes are nuisance pests that often migrate indoors when the weather changes in spring and fall. These pests have segmented bodies that reach up to 1 1/2 inches in length at maturity. Millipedes are dark brown or black and curl into a tight ball when frightened. These insects require damp, moist areas to thrive, making basements a primary choice of this nuisance pest. Fly larvae are often found in basements as well. Cluster fly larvae are formed as parasites in earthworms and often seek dark, damp places to live until they pupate into adult flies. Fruit fly larvae are often abundant in basements, especially in homes where people store food items or garbage items in their basements. These larvae are wormlike maggots that are found near infested, rotting food.

Effects

Millipedes are harmless and don't bite or sting humans, though they occasionally migrate indoors at a rate that's a nuisance for homeowners. Cluster fly and fruit fly larvae don't bite or sting humans, but can become abundant in basements where fermented foods or drinks are stored. Cluster flies and their larvae are also found in attics and little-used rooms inside homes. Fruit flies and their larvae multiply rapidly, since each adult female lays approximately 500 eggs that can complete their life cycle in as little as 1 week.

Cultural Control

Millipedes aren't dangerous and don't cause damage to fabrics or clothes through feeding, so control isn't necessary unless infestations are large. Sweep or vacuum millipedes from your basement, or pick them up and discard them. Fly larvae are best controlled by removing all hiding places where adults can lay their eggs. Remove all food and drink items stored in your basement, such as wine or beer. Keep your recycling bins and garbage cans outdoors instead of in your basement, to keep flies from laying eggs in these areas. Eliminating excess moisture and food sources from your basement will help control pests. Placing a dehumidifier in your basement will help reduce the humidity, making it less desirable for moisture-loving worms.

Chemical Control

Heavy outdoor infestations of millipedes may require insecticides to prevent them from migrating indoors. Spray insecticides with active ingredients such as bifenthrin, permethrin or cyfluthrin around your home, especially on the shady side. Keeping cluster flies and fruit flies from coming indoors to hibernate is the key to controlling infestations of those pests. Basements and attics are favorite rooms for these flies to lay their eggs, so be sure to keep screens tear-free, and caulk any cracks and crevices that the adult flies could use to gain entry. Spraying diazinon or malathion around your basement, attic and closets may help keep flies and their larvae out.

References

• Colorado State University Extension; Millipedes, Centipedes and Sowbugs; W.S. Cranshaw; May 12, 2010
• University of Kentucky College of Agriculture; Cluster Flies, Face Flies and Blow Flies In Homes; Mike Potter; January 1994
• University of Kentucky College of Agriculture; Fruit Flies; Michael F. Potter; January 1994