Kansas State University


Extension Entomology

Alfalfa – Pest Update

–by Dr. Jeff Whitworth, Dr. Holly Schwarting & J.R. Ewing

Cool, wet weather continues to dominate the state. This has allowed the alfalfa weevil adults to remain in the alfalfa fields. As they remain in fields they are feeding in/on terminals and the new foliage. However, they don’t feed anywhere near as much as the larvae, plus there aren’t near as many so, the feeding really is negligible. However, they do cause concern and their feeding on the new foliage and “barking” of the stems can slow regrowth if they remain in fields. Swathing alone will not eliminate the adults if the weather continues to be only in the 80’s for daytime highs.


AW adult barking

The first potato leafhoppers of the summer were detected in north central Kansas on 19 May. This is a little earlier than usual but fits right in with the unusualness of this spring.

Pea aphid populations have been steadily increasing the past couple of weeks. However, sampling some of the same alfalfa fields on 19 May indicated the aphid populations have reduced relatively dramatically. There are many larval and adult lady beetles in these fields and they can even be readily observed feeding on the aphids. So, these beneficials really seem to be helping with aphid control.

lady beetle larvae w aphid

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