Designated and Declared Pests
Oystershell Scale
- Lepidosaphes ulmi
A declared pest in Fremont County, oystershell scale is a waxy-covered insect that sucks the sap out of a plant or tree. The species most impacted by this pest are aspen, cottonwood, ash, lilac and cotoneaster.
During the dormant overwinter period, you can gently scrub off scale from trunks and limbs and apply dormant oil spray for partial control. Starting in late April and May, look for scale hatch and apply horticultural oils, soaps and contact insecticides according to product labels. A number of products are available at local stores.
Fremont County Weed and Pest offers a Cost Share on chemical controls for oystershell scale.
