Kudzu Bug Present Controlled by Fungus
scouted Oct. 7, 2024
- Background
- Soybeans were scouted at the R7 growth stage and areas of dark brown discoloration on the stem were observed. When scouted, groupings of kudzu bugs were observed to be at threshold. A white matted growth was observed on the bodies of the kudzu bugs.
- Conclusion
- This injury was confirmed by a NC State Extension Specialist as damage from Kudzu Bugs. Kudzu bugs tap through the veins of plants to reach the phloem, using piercing sucking mouthparts. Which is why symptomology may look like stem discoloration, or lead to sooty mold on the leaves. Economic threshold for spraying kudzu bugs is five bugs per plant until mid-July, when we switch to a sweep net-based threshold. It is recommended that if an insecticide is needed, it is applied once the migration period is over. Interestingly enough, the white growth observed on the kudzu bugs is caused by fungus Beauveria bassiana. This fungus attacks kudzu bugs and suppresses or almost completely controls infestations.
