Dectes stem-borer, Dectes texanus LeConte, 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.  Management with an insecticide application is difficult, due to the prolonged window of adult activity and protected feeding site of the larvae.  To gain a better understanding of the seasonal occurrence of D. texanus adults, 12 soybean fields in south central Nebraska were sampled regularly for 9 weeks, and infested soybean stems were placed in emergence cages.  Sweep net sampling and emergence data are reported.