Agriculture & Natural Resources

IPM – Sorghum Insect Thresholds


Growth Stage
Whorl to boot
Head emergence to soft dough
Grasshoppers 5-8 per sq. yd.  
Greenbug aphid 10-40 per plant 50-100 per plant 500 per plant
Cornleaf aphid   1000 per plant and plant dying  
European corn borer   50% infested plants 50% infested plants
Fall armyworm   80% plants infested with 1 worm50% plants infested with 2 or more 2 per head
Corn earworm     2 per head
Sorghum midge     1 per head
Sorghum webworm     3 per head