Potato leafhoppers (PLH) are being reported at damaging levels in many areas across the province, including areas where they are not typically a problem. PLH dramatically reduces alfalfa yield and forage quality. Reduced stem and root growth, and vigour results in stunting and slow regrowth. New seedings are very susceptible and can be permanently damaged, so be sure to check these fields. Adult PLH are 1/8th of an inch long, lime-green and wedge-shaped. They insert a stylet into a leaf midrib and inject a toxin that results in a wedge-shaped yellow “hopperburn”. Damage is often confused with moisture and heat stress. Scouts are reporting that many, many alfalfa fields are above threshold levels. Once hopperburn is observed, the damage is done and it is too late for control, so scout early and be prepared to spray. https://fieldcropnews.com/?p=3902
Blister beetles have been reported north of Lake Erie. Blister beetles are normally only very rarely reported in Ontario, but are more common in the US Midwest. Their bodies contain a toxin that can cause serious illness and even death, when infected hay is consumed by horses.