September

Look for egg masses

If you live in a quarantined county, survey your property for gypsy moth egg masses. Look for egg masses in crevices and protected hiding spots on rough bark, the undersides of branches, under signs attached to trees, and even on buildings, play equipment, benches, and picnic tables.

New egg masses are firm to the touch. Old ones are pale in color, will crush easily, often look tattered and are not of concern. If you find many fresh masses and are interested in participating in the suppression spray program, contact your county suppression coordinator on how to proceed.  Don’t remove egg masses! To qualify for the state sponsored suppression program egg mass densities must meet certain damaging threshold levels on your property. You can conduct predictive surveys on your own.

Hold off treating or removing egg masses until after the first hard frost to let a natural enemy of gypsy moth, Ooencyrtus kuvanae, attack eggs of the gypsy moth.

Examples of a new, fresh egg mass (left) that caterpillars will hatch from next spring and an old egg mass from last year that is already empty (right)

Photo Credit: Bob Queen, WI DNR.