Pest Alert! White-margined burrower bug
Within one week, Extension Entomology has received insect identification requests from Districts 8 and 11 for a small, dark insect appearing by the thousands and covering structures and plants. The insect can be present in high numbers in fields, woodlands, lawns, and gardens. This is Sehirus cinctus, the white-margined burrower bug, a true bug that occasionally has outbreak years in parts of Texas. The nymphs (immature stages) have a red and black coloration, and the adults are black with a lighter tint along the outside of the body. Here is an article from a past outbreak: https://citybugs.tamu.edu/2011/05/04/the-mother-bug/ . The article is correct that the problem will go away in time and not recur for many years. However, if clients must spray something, then a synthetic pyrethroid insecticide would be a good choice (but don’t expose pets or people): https://citybugs.tamu.edu/factsheets/ipm/ent-6003/. Pyrethroids are readily available at home and garden stores and are labeled for use on lawns and landscapes. A pyrethroid insecticide will kill the insects over the course of a few hours of exposure, but it won’t really make a dent in future generations.
Many photos of the white-margined burrower bug can be seen here: https://bugguide.net/node/view/6982/bgimage . According to BugGuide, adults are common on lawn weeds such as Henbit and Purple Dead-nettle, as well as on leaves and flowers of many species of herbaceous plants.
Article by: Dr. Pat Porter