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Tent Caterpillars Return

BT Spray Tent Cats 2016 MapTent caterpillars have emerged almost a month later than they did last year. The IHCA has begun a spray program to minimize their impact on the community and its landscapes. The unlucky target, the western tent caterpillar, is not especially troublesome, but they are a nuisance. So, the IHCA sprays.

Contractor Davey Tree is again performing the spraying. They use a naturally occurring bacteria, Bacillus thuringiensis, or “Bt”, to kill the caterpillars. It is highly effective and almost non-toxic to everything that is not a caterpillar. It’s the same bacteria used by WSDA and others for gypsy moth control and has been proven safe over decades of widespread use. It is a component of Issaquah Highlands’ Integrated Pest Management plan.

Weather determines when spraying is conducted. Marker flags will be left in sprayed areas. Target areas are shown on the attached map and are limited to Hawthorne, cherry and choke cherry trees, most of which are in streetscapes and all of which are outside private yards.

Questions? Contact: IHCA Executive Director, Sarah Hoey