By STACY CAMPBELL
Cottonwood Extension Dist. Ag Agent
Agriculture producers should be scouting their grain sorghum fields now due to insects being detected in fields.
Chinch bug activity
Chinch bug populations continue to increase dramatically throughout much of Kansas. Adults are still active, mating, and ovipositing (laying eggs) in both the developing heads and around the base of plants. There are also large numbers of nymphs, mainly feeding in and around the base of plants, but some are on the developing kernels. There is really nothing that can be done about controlling second generation chinch bugs on large plants, it is difficult for contact insecticides to reach them because of their habit of hiding behind leaf sheaths.
“Headworm” activity
‘Headworms’, both fall armyworms and corn earworms, are showing up in many fields. On August 6th, there were all different sizes of larvae detected in milo heads in north central Kansas, according to Whitworth. Many fields are in the reproductive stages, so these ‘headworms’ will continue to be problematic in any field that is in the flowering to soft dough stage. Past research has indicted that ‘headworms’ may cause approximately 5% loss/worm/head. It is important to sample in a timely manner to detect these pests while they are still small, before most of the feeding damage has been done.
Corn leaf aphid activity
Corn leaf aphids (CLA) continue to cause considerable concern throughout north central Kansas as these populations are still very widespread and become more apparent as the heads start to extend out of the whorl. However, there are many beneficials present as well. CLA should have little to no negative impact on plant development or yield other than potentially a few individual plants.
Sugar Cane Aphid
Sugar Cane Aphids (SCA) have been confirmed in Barton Co. as well as other counties in the state. The numbers of SCA found in Barton Co. in fields is at a low numbers. It is important that you start scouting your milo fields at least weekly for the SCA. There are also a good number of beneficial insects in the milo fields, so it is hopeful that the aphids will not build-up to damaging levels.
myFields
If you would like to sign up to myFields which is a Multi-state monitoring effort using myfields.info to track SCA and to give you other insect information relative to Kansas. You can track county movement by visiting themyFields distribution map, or sign up for an account to receive an email alert when SCA has been detected in your area. There is other agronomy and insect related information on this sight and it is being updated on a regular basis with production information.
For more information relative to sorghum insect management, please see the 2018 Sorghum Insect Management Guide: https://www.bookstore.ksre.ksu.edu/pubs/mf742.pdf