Elongate Hemlock Scale

Elongate Hemlock Scale is a relatively new pest of Fraser fir in Mitchell County, but it seems to be spreading pretty rapidly. This time of year the crawler stage of the insect crawls around to new needles and begins sucking plant sap and producing new covers. The crawlers are very tiny and yellow. The insects feeding turns the needles yellow and continues to enlarge the scale coverings. The female coverings are elongated, parallel sided and light to dark brown. The male coverings are white. When they mature, the male insects emerge from beneath the coverings and fly to the wingless covered females. They mate and the fertilized female produces eggs under her scale cover. The scale covers are waxy and may be so numerous that the needles have a whitewashed appearance.

Treatment for this pest runs through the month of August. The combination of Asana XL+ Dimethoate has seemed to give the best control. Most of the scales are on the interior of the tree, so excellent coverage is very important. Growers with only a few trees infested with Elongate Hemlock Scale may be able to get control by doing spot treatments. Consult your local Cooperative Extension Agent to help make this treatment decision.