Winter Moth

This is an invasive pest from Europe that feeds on a wide range of trees and shrubs. Caterpillars enter into buds in large numbers and eat the developing flowers and leaves in early spring, defoliating the plant. This impacts a wide variety of commercial fruits and also kills a wide variety of trees in forest and landscape.

A serious outbreak starting at the tip of Cape Cod about 15 years ago has spread through eastern MA, RI, and eastern CT, as well as southeastern NH, coastal ME, and Long Island. The effect has been devastating.

There was a major outbreak in Nova Scotia and Prince Edward Island in the 1950's, and a separate outbreak in the Pacific Northwest in the 1970's (Vancouver BC, and in Oregon and Washington). Both were controlled largely through an i... read moremported biological agent, the tachnid fly Cyzenis albicans. In fact, the control of the outbreak in eastern Canada serves as a textbook model for the deliberate control of an exotic pest through the release of a biological agent.

C. albicans has been released in several locations in eastern Massachusetts beginning in 2005, but it has not yet had a noticeable impact on moth populations.

Spinosad and Bacillus thuringiensis 'Kurstaki' are two biorational products that have been proven effective and do minimal harm to other insects when properly applied.

These very hungry caterpillars, also called inch worms, have dropped to my garden on long threads from the rampant Norway maples in this area, their favorite breeding ground. During late May, they consumed fruit tree leaves, and they have eaten generous portions of my peony leaves and buds, as well as the other perennials all in one or two days.I suspect they are responsible last year for eating my spruce trees without my knowing. I am told by several of my local nursery folk that a new product is not harmful to animals and can be used on vegetables and fruit trees in organic gardening. It contains a mixture of spinosyn A and D in .5% solution. Spinosad is the trademark of Dow.