This article was originally written by Joel Bagg in 2012. It was edited June 27, 2023 by Christine O’Reilly to reflect current insecticide options to control potato leafhopper and the cessation of third-party alfalfa variety trials in Ontario. Potato leafhopper (PLH) is the most damaging alfalfa insect pest in Ontario in most years. While the damage created is not as dramatic as an alfalfa weevil or armyworm outbreak, leafhopper damage is more chronic and widespread. Many farmers are unaware of the significance of PLH damage, which is often blamed on the hot, dry weather that frequently accompanies it. PLH damage is common across southern Ontario. The Niagara area and counties north of Lake Erie are particularly affected and extensive damage…
