Landscape - Millipedes

Homeowners often are concerned when they see millipedes coming into their house and landscape professionals may be called upon to deal with millipedes in a landscape. The following is information on millipedes.

Millipedes are long, many segmented creatures that use their two pairs of legs per body segment to move with deliberate determination. There are several species in Delaware so we can see a variety of shapes and colors. Millipedes can be very abundant in forest litter, grass, thatch, and in mulched areas. These places provide them with the food and dampness that they prefer. Usually, millipedes stay out of sight unless abundant rainfall or some other event, such as the mating season, puts them on the move.

While harmless and in fact, helpful recyclers, millipedes generally are not welcomed with enthusiasm. They often invade crawl spaces, damp basements and first floors of houses at ground level. Common points of entry include door thresholds (especially at the base of sliding glass doors), expansion joints, and through the voids of concrete block walls. Frequent sightings of these pests indoors usually mean that there are large numbers breeding on the outside in the lawn, or beneath mulch, leaf litter or debris close to the foundation. Because of their moisture requirement, they do not survive indoors more than a few days unless there are very moist or damp conditions.

MILLIPEDE MANAGEMENT

Minimize moisture & remove hiding places - The most effective, long-term measure for reducing entry of millipedes (and many other pests) is to minimize moisture and hiding places, especially near the foundation. Leaves, grass clippings, heavy accumulations of mulch, boards, stones, boxes, and similar items laying on the ground beside the foundation should be removed, since these often attract and harbor pests. Items that cannot be removed should be elevated off the ground.

Seal cracks and openings in the outside foundation wall, and around the bottoms of doors and basement windows. Install tight-fitting door sweeps or thresholds at the base of all exterior entry doors, and apply caulk along the bottom outside edge and sides of door thresholds. Seal expansion joints where outdoor patios, sunrooms and sidewalks abut the foundation. Expansion joints and gaps should also be scaled along the bottom of basement walls on the interior to reduce entry of pests and moisture from outdoors.

Exterior applications, in the form of barrier sprays, may help to reduce inward invasion when applied outdoors, along the bottom of exterior doors, around crawl space entrances, foundation vents and utility openings, and up underneath siding. It also may be useful to treat along the ground beside the foundation in mulch and ornamental plant beds, and a few feet up the base of the foundation wall. Heavy accumulations of mulch and leaf litter should first be raked back to expose pest hiding areas. Insecticide treatment may also be warranted along the interior foundation walls of damp crawl spaces and unfinished basements. There is no benefit from treating indoors. Millipedes that do get inside will not find what they need to survive.

Reprinted from "MILLIPEDES ON THE MOVE" By Lee Townsend and Mike Potter in the July 14, 2008 edition of the Kentucky Pest News from the University of Kentucky, College of Agriculture.