Fact Sheets no. Oystershell scale is a common insect pest of many woody plants in Colorado. Oystershell scales feed on the plant by sucking plant sap.
Heavy infestations can kill branches and even cause the decline and death of the tree.
In most areas of Colorado, there is only one generation per year. Oystershell scales overwinter in the egg stage. The eggs hatch in the spring and the newly emerged Insects quickly attach themselves to the plant. Oystershell scale can be controlled in the winter by using a dormant oil. Oystershell scale adults and crawlers.