Worms on Mugo Pine
We have worms on our mugo pine. They are eating all of the needles off. We had them last year and thought we had them under control, but they are back and more abundant than before.
European pine sawflies are the culprit. These green worm-like insects have black heads and rear up when disturbed. These sawflies prefer mugo pines but will also feed on scotch and jack pines but are seldom found on other pines. Weather, rodents and parasites help keep these insect populations under control. These pests are a common problem, despite all the help from nature. Monitor susceptible plants and control populations early. The strong of stomach can smash them with a leather clad glove. Or spray the colonies with one of the more eco-friendly insecticides such as lightweight horticulture oil, Neem or insecticidal soap. Other insecticides labeled for sawflies and pines will also provide control. And as always be sure to read and follow label directions carefully.