Like everything else this season, the leafhopper invasion is later than usual. The invaders from the Gulf usually arrive late April / early May but here we are in the middle of July and they are ravenous, devouring alfalfa at all growth stages. The potato leafhopper feeds on over 100 different plants from alfalfa to zucchini. The adults will lay eggs on the stems of the host plant, laying 3-4 eggs per day per adult for up to a month. That’s a lot of eggs.
The nymphs emerge and begin their feeding frenzy, injecting a plant toxin as they feed that discolors the leaves to a pale yellow or even a burnt appearance. The infected leaves lose their ability to photosynthesize, disturbing the production of photosynthate, which is a crucial sugary energy source needed for plant growth.
With the delayed harvest of alfalfa in many areas, the leafhopper population has been thriving and multiple generations are feeding on this year’s crops. Scouting has found their presence in all of the areas that Carovail services in the northeast. Sweeping fields to determine populations can help with treatment decisions in cases of high infestation. The addition of some nutrients as a foliar feed will help with recovery and should be based on current and past nutrient supplementation. Crops that are close to harvest should be harvested as soon as possible and regrowth should be monitored as the weather pattern is still conducive to continued infestation.