More Christmas tree pests
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
Each year we will find new growth on terminal shoots dead and hanging on the leader. At first glance, it looks like some insects may have girdled the shoot. However, these broken treetops are caused by birds perching on newly developed shoots. (see photo) Breakage typically occurs this time of the year when the new tops are elongating, before they are stiff enough to support a bird perching. Taller trees seem to be more affected, as the birds look for higher vantage points.
Cooley spruce gall adelgid
On Douglas-fir, the cottony eggmasses of Cooley spruce gall adelgid are now visible on this year’s growth. Once you find these cottony masses, it is too late to apply an insecticide. If you are having problems with this pest, you now need to wait for the second adults to be active in July through August (1500-1600 GDD base 50).