Integrated Pest Management Strategies 1. Maintain plant health . Young healthy trees can withstand one to three defoliations with minimal damage. Older trees may not be able to withstand more than one defoliation. Wrap tree trunks with burlap bands or sticky bands in early June to trap the older Gypsy moth caterpillar as it treks from the canopy to hiding places on the ground.
Sticky bands have to be replaced periodically.
Spray Bt on the leaves of the tree at the time the Spiraea x vanhouttei is flowering. This control is best used on low populations and on small caterpillars. Spray the leaves with an insecticide. Sevin insecticide kills caterpillars on contact and when they ingest it. Treat the leaves in early June.