Aphids In Wheat

We have recently received some reports of noticeable aphid populations in wheat.  The two main aphid species that infest wheat in Ohio are the English grain aphid and the bird cherry-oat aphid.  Infestations of greenbug and corn leaf aphid are rare.  These aphids rarely cause economic injury on wheat from feeding. However, they can transmit several viruses that can severely impact wheat including Barley Yellow Dwarf virus.  Autumn transmission is the greatest concern.  These aphids do not only feed on wheat, but several other grasses that serve as natural sources of viruses.  If wheat is planted too early in the fall, and emerges before the aphids overwinter or stop feeding, they can be early transmitters of viruses.  However, it is not economically feasible to control transmission of barley yellow dwarf virus with insecticides because aphids can transmit the virus within six hours of landing on the plant.  Planting after the Hessian fly-free date is a good method to help minimize fall aphid feeding. 

It is rare for aphid feeding alone to cause economic damage in wheat.  However, it is not unheard of.  The following tables give details of damage, biology, and scouting management.  Key points are a treatment threshold of 12-15 aphids per full tiller in seedling to boot [averaged across 100 tillers], or a more precise scouting method based on presence/absence on tillers (Table 4A).  Some registered foliar insecticides are listed on page 86 of the MSU/OSU Pest Management Guide for Field Crop Insects, a useful biology, scouting, and management guide for the main field crops in Ohio and Michigan. 

https://aginsects.osu.edu/sites/aginsects/files/imce/IPM%20Guide%20FULL%20-%20OSU%20%28002%29.pdf