Sorghum webworm larvae

Worms in Sorghum

We received a sorghum head sample today from Dinwiddie County with sorghum webworm (see image on right).  This is a known pest of sorghum and we have seen them before, but because of their smaller size compared to other head worm species, the threshold is an average of 5 per head across the field.  To date, we have never seen nearly this many in any field, but this is a pest that should be scouted for.  We are also seeing a very large number of fall armyworm moths in our pheromone traps here at the Tidewater Center.  Fall armyworm is another sorghum head pest (see the image below), along with corn earworm, and the threshold for these species is an average of 2 per head.  We recommend scouting sorghum fields until heads have hardened seeds.  If fall armyworm is found in threshold numbers and a treatment is needed, pyrethroids will not do the job.  The best results will be with non-pyrethroids like Belt, Prevathon or Besiege.

fall armyworm larvae