White margined burrower bugs are 1/8 to 1/4 inch long insects with sucking mouthparts. The adult is glossy black with a thin gray line around the edge of the body (Figure 1). The smaller nymphs, immature stages, are orange/red and black (Figure 2). Both stages crawl quickly over and under surface residue and can accumulate in soil cracks and crevices. Large numbers can be present in crop fields and landscapes but there is no cause for concern.
Adult burrower bugs overwinter in the soil. Females lay eggs in April for the single generation produced each year. Nymphs and adults feed on seeds of purple dead nettle so they will be abundant wherever seeds of this plant are present.
There is no indication that burrowing bugs cause any injury to crops, but densities of several dozen of these bright insects per square foot can raise concern. In some cases, migrating burrowing bugs have covered the sides of buildings. They can be accidental invaders in lawns, and occasionally may enter houses. Insecticidal soap, Sevin, or products like Ortho Bug B Gon, or Bayer Advanced Garden Lawn and Garden Multi-Insect Killer may be used for control.
By Lee Townsend, Extension Entomologist