As we've reported in some previous issues of the Bulletin, burrower bugs have been observed in many cornfields and soybean fields, especially in southern Illinois. Mark Hoard, IPM educator, Mount Vernon Extension Center, and Ron Hines, senior research specialist, Dixon Springs Agricultural Center, have received numerous calls regarding large densities of burrower bugs in corn and soybeans. In some soybean fields, impressive numbers (10 to 15 per plant) of these bugs were "crawling all over" the foliage of soybean plants. These observations caused considerable alarm, especially in those fields where yellowing plants were not growing very well. As it turns out, many of the fields in which plants were showing signs of stress also were infested with grape colaspis.|
The scientific name of burrower bugs is Sehirus cinctus cinctus. Most burrower bugs are observed as nymphs and adults below the soil surface. Most of their existence is spent feeding on roots. Adults also are often found on the foliage of plants. Female burrower bugs are known to provide maternal care to their young. Female burrower bugs deposit their eggs into tiny holes in the soil. The females remain on top of their eggs until hatch occurs. The story gets more interesting. Female burrower bugs bring seeds to their offspring to consume for a short while. The species of burrower bugs reported most often this spring prefers mints to feed on. According to Ron Hines, many of the fields with the greatest infestations were heavily infested with weeds this spring, such as henbit, purple deadnettle, and horsenettle. These weeds are becoming increasingly common in southern Illinois no-till fields according to Ron Hines. It is quite likely that the increase in burrower bug densities may be directly linked to an increase in weed seed densities of these hosts.
Bottom line is that it is very unlikely that burrower bugs are creating any plant damage to corn and soybean plants. In fact, they are most likely doing producers a favor by feeding on weed seeds. This saga points out an excellent IPM principle: the proper identification of an insect, weed, or plant disease is crucial before implementing any potential management strategy.
We thank Dr. Jay E. McPherson, Southern Illinois University, for providing much of the life cycle information on burrower bugs.--Mike Gray