Soybeans were scouted at the R5 growth stage and intensive defoliation was observed in widespread areas across the field.
Conclusion
This injury was confirmed by a NC State Extension Specialist as damage from Mexican Bean Beetles. Larvae and adults will feed on all parts of the plant, but injury is generally most severe on the foliage. Mexican bean beetles feed on the underside of the leaf and because of this patchy yellow and brown areas can often be visible on the tops of injured leaves. Recommended treatment to control this pest includes applying a pyrethroid insecticide.