–by Dr. Jeff Whitworth and Dr. Holly Davis
Alfalfa seems to be growing very well and many fields around north central Kansas have finally dried out enough to swath and remove the hay from the field. However, potato leafhoppers continue to migrate into the state and will continue to for about another month. Most are still adults and have been/are now depositing eggs in stems and the tiny nymphs are just starting to emerge. Thus, potato leafhopper feeding will become more evident as “hopper burn”, the yellowing of leaves which can reduce the health of the plants and the nutritive value of the foliage. Therefore, if fields were just recently cut, or will be in the near future, while potato leafhoppers are still migrating into the state, they will be very vulnerable to potato leafhopper feeding damage.
Pea aphids are still plentiful throughout alfalfa fields in north central Kansas. Populations should not reach treatable levels this late in the year, and they are a good host for many beneficial insects.
For more information regarding these and other alfalfa pests, please see the KSU Alfalfa Insect Management Guide: https://www.bookstore.ksre.ksu.edu/pubs/mf809.pdf