–by Dr. Jeff Whitworth and Dr. Holly Schwarting
Soybeans seem to be growing really well around north central Kansas. As these plants start germinating and growing, however, they provide very attractive hosts for bean leaf beetles.
These soybean pests have been inhabiting alfalfa fields and grassy areas since last fall, waiting for these first soybeans. They are very efficient at finding young, succulent soybeans when the plants start emerging. They are also relatively unique as foliage feeders because they usually chew round and/or oblong holes in the leaves.
These beetles can eat an alarming number of holes in these small plants. However, the young plants are very resilient at overcoming this leaf feeding and so there is normally very little impact on yield. For more information on bean leaf beetle biology, treatment thresholds, and management options please see the following:
Bean Leaf Beetles: https://www.bookstore.ksre.ksu.edu/pubs/MF2824.pdf
Soybean Insect Management Guide: https://www.bookstore.ksre.ksu.edu/pubs/MF743.pdf