Will My Shrubs Regrow if Gypsy Moths Ate Them?

Description

• The white, adult female moths have a wingspan of 2 inches, and the tan to dark brown male moths have a wingspan of 1-½ inches. Adults appear during late summer and are not foliage eaters. The females leave egg masses on trunks, branches, home walls, outdoor furniture and cars. The dark, hairy larvae have six pairs of red dots and five pairs blue dots on their backs and measure 2 inches at maturity. Pupae are ¾ to 1-½ inches long. The larval stage is most destructive.

Damage

• The larvae start feeding heavily on foliage when they emerge in the spring. The pests can consume up to 1 square foot of leaf space every day, cites the University of Illinois Extension. The large amount of excrement the worms produces falls on homes, pools and patios. Severe damage reduces plants' vigor, making them susceptible to other pest infestations and infections. Although infested shrubs later regrow, repeated defoliation eventually kills the plant from stress.

Cultural Control

• Looking for moth presence around the landscape is the first step towards control. If moths are sighted, install pheromone traps on trees and shrubs. The traps attract male moths with scent similar female moths. Removing the males reduces the pest population. Look for egg masses on plants between July and April after the traps capture 50 months. Scrape the egg masses off with a spoon and drop them into soapy water. Each quarter-sized egg mass reduces following year's population by 500 to 1,000 moths.

Chemical Control

• Use a high-pressure garden sprayer or a backpack mistblower for trees and shrubs that are less than 50-feet-tall for severe infestations. Recommended insecticides include products containing Bacillus thuringiensis var. kurstaki. Do not use var. israelensis, san diego or tenebrionis, as these are not effective on gypsy moths.