Dectes stem borer, Dectes texanus Leconte, (Coleoptera: Cerambycidae) in Nebraska soybeans

The Dectes stem borer, Dectes texanus Leconte, has caused significant injury to south central Nebraska soybean fields in recent years.  D. texanus adults emerge over an extended period during the growing season, and oviposit in soybean petioles.  Larvae feed within the main stem until mature, tunnel down to the base of the plant, and girdle the stem.  While physiological yield loss from feeding is usually negligible, severe economic injury may occur when girdled soybean plants lodge late in the season, causing harvest difficulties.  Proper timing of foliar insecticides to control the adult stage is not well understood and cost effective sampling plans to assess beetle densities for pest management decisions have not been developed.  Twelve fields in south central Nebraska were regularly sampled with a sweep net for 9 weeks.  Results are reported.