Like the Foo Fighters song, “this is a call” for your assistance with field data. I am interested in strip trials with aphids in corn from 2011. Did you count aphids in corn and make foliar insecticide applications? If you are willing to share data, I am compiling a larger data set to help answer some basic biology and economic questions about aphids in corn. When do aphids start to build up and how high can the populations reach in corn? When were applications made and were previous applications made in the same year? How many aphids does it take to cause a yield response? Is this number different for drought-stressed field? What is the knockdown efficacy of currently labeled products?
It got pretty bad for corn fields in NE and NW Iowa this year. I saw corn that was grey and covered with aphids, cast skins, and honeydew. Most of the heavy infestations were at the field edge, so scouts could have overestimated populations if they didn't sample throughout the field. This is a difficult task, given it was mid-August!
Some fields had very heavy aphid infestations in corn this year. Aphids were colonizing the stalk, ears and leaves. Photo by Brian Lang.
All this information feeds into developing an economic threshold and sampling plan for future growing seasons. I would really appreciate hearing about your experiences with aphids in corn this summer. Please email (firstname.lastname@example.org) or call (515.294.2847). Thank you!!