–by Jeff Whitworth — Field Crops
Wheat aphids, primarily bird cherry oat but with a few greenbugs mixed in, have been migrating into Kansas, especially the southern parts, over the last couple of weeks. Sampling a couple dozen fields throughout the central part of the state, however, over the last week (from I-35 to Hwy 77 west to east and from Hwy 24 north to Hwy 56 on the south) yielded very few aphids but also very few beneficials-which makes sense. However, in one field we did find one aphid — just as the only lady beetle we found in that field also found it and promptly gobbled it up (see fig 3). Most wheat was at least at the jointing stage. If aphid migrations increase significantly in the next couple of weeks, coupled with the lack of beneficials, these aphid populations could explode and thus cause some stress to the developing wheat. Thus, monitoring should continue — but please remember it takes approximately 20+ aphids/tiller throughout the field, with very few beneficials, to actually cause a negative effect on yield. Also, please remember adding an insecticide to an application of a fungicide to kill any insect pests, “just in case” is never a good idea.
