–by Dr. Jeff Whitworth and Dr. Holly Schwarting
Fields sampled three weeks ago had relatively large numbers of potato leafhoppers, i.e. 20+/20 sweeps. These fields were swathed approximately two weeks ago and averaged 2 potato leafhoppers/20 sweeps, below the treatment threshold. Thus, timely swathing can be very beneficial in managing potato leafhoppers, without use of an insecticide application.
— by Dr. Jeff Whitworth and Dr. Holly Schwarting
Potato leafhoppers continue to be very common in many uncut alfalfa fields. In one field, which was actually flowering, there were more than 40 potato leafhoppers/20 sweeps which exceeds the treatments threshold. Please see the Alfalfa Insect Management Guide for more information on treatment thresholds: http://www.bookstore.ksre.ksu.edu/pubs/mf809.pdf.
This field has serious ‘hopper burn’ already, but timely swathing should alleviate leafhopper pressure.
Another field that was swathed about 3 weeks ago, and at that time had about the same level of potato leafhopper infestation as the above pictured field, has only a trace level of potato leafhoppers now (1 potato leafhopper/20 sweeps).