Soybeans were scouted at the V9 growth stage and areas of snapping of stems was observed. These soybeans were planted into a terminated cover crop of cereal rye in early May.
Conclusion
This injury was confirmed by an NC State Extension Specialist as damage from Threecornered Alfalfa Hoppers. Weakening and breaking of soybean stems as well as lodging are symptoms associated with damage from threecornered alfalfa hoppers. We have seen issues in recent years of threecornered alfalfa hopper injury behind cover crops, most often when cover crop mixtures were used. In this environment, the damage from the insect occurred in weeks prior to the scouting date. The injury observed now is from thunderstorms the morning of scouting. The high winds aided in breaking the already weakened stems. Continued scouting is recommended in this environment.