Agronomic Crop Insect Scouting

David Owens, Extension Entomologist,

Begin scouting this week for sugarcane aphid and corn earworm. So far we have not yet detected white sugarcane aphids from the 5 fields we have been looking at. There are two other aphid species that get into sorghum – the yellow sugarcane aphid and the corn leaf aphid. I almost think of both as beneficial to give natural enemies something to feed on. Yellow sugarcane aphids are bright yellow and larger than the white sugarcane aphid. Corn leaf aphids sometimes build up in large numbers on the flag leaf at head emergence, but populations typically crash soon after. For corn earworm, sample fields by shaking 50 heads into a small bucket to dislodge the worms.

Bean leaf beetle counts seem to have slightly decreased from last week, as have Dectes. Two spotted spider mites continue to be active in and around fields, although in some locations fungal pathogens are starting to work on the mites. Fungal infected mites look like small brown puffballs. Green cloverworm are increasing in some fields, and low numbers of soybean looper have been reported. Begin scouting for corn earworm – our usual August flight should be starting soon.