
25 Jun Scouting for Potato Leafhoppers
Now is the time to scout for potato leafhoppers in alfalfa, especially newly seeded stands.
Pay special attention to new spring seedings of alfalfa. Young plants are more susceptible to damage from potato leafhoppers because small plants have not yet fully developed the all-important tap root. The tap root stores energy for rapid plant recovery after cutting, as well as recovery from other insults and injuries that alfalfa plants need to overcome, including damage from potato leafhoppers.
Potato leafhoppers are small insects that overwinter in land areas around the Gulf of Mexico. Their annual summer migration northward is dependent on storm fronts coming up from the gulf, so timing and intensity of infestation can vary from year to year. Typical symptoms of leafhopper damage are yellowing and stunting, but the damage is already done by the time you observe symptoms. Therefore its important to be aware of leafhoppers when scouting your fields. If leafhoppers are detected, use a sweep net and make leafhopper counts to help you make decisions about economic thresholds for control with a labeled insecticide application. A general rule of thumb is that economic thresholds are reached when the number of leafhoppers per ten sweeps approaches the height of alfalfa in inches. As an example, if your field averages eight leafhoppers per ten sweeps, your field would be at or above the threshold for control in alfalfa that is less than eight inches tall.
SW525LHTM is a superb alfalfa seed choice for high resistance to potato leafhoppers, when you want to take the worry out of leafhopper control in alfalfa. SW525LHTM is the obvious choice if you don’t plan to spray, or even if you’ve had difficulty obtaining timely pesticide application and control of leafhoppers in the past. SW525LHTM contains the latest fall dormancy five leafhopper resistant germplasm for high yield and winterhardiness.
S&W’s alfalfa breeders have been improving the yield, overall disease and pest resistance of leafhopper resistant alfalfa germplasm for nearly thirty years, ever since leafhopper resistant germplasm was first introduced into commercial fall-dormant germplasm.
You can take advantage of that strong breeding improvement when you plant Alfalfa Partners brand SW525LHTM. Plant SW525LHTM for a highly productive agronomic combination of high yield, high resistance to leafhoppers, winterhardiness, and overall disease resistance including phytophthora and multi-race Aphanomyces resistance.
For more background on SW525LH, see the Alfalfa Partners video and product profile here: https://alfalfapartners.com/sw525lh/
Photo taken by: Frank Peairs, Colorado State University, Bugwood.org
For more information about scouting for potato leafhoppers in alfalfa, including insect photos and economic thresholds:
https://extension.psu.edu/potato-leafhopper-on-alfalfa
https://aginsects.osu.edu/sites/aginsects/files/imce/ENT_33_14%20PLH.pdf
https://ipcm.wisc.edu/blog/2020/07/potato-leafhopper-in-alfalfa/
https://cropwatch.unl.edu/2019/potato-leafhoppers-alfalfa