Share

June 23, 2004

Christmas Tree Scouting Report -
Number 13

Welcome to the Christmas Tree Scouting Report for the week ending Wednesday June 23, 2004. The next report will be available after 5 PM on Wednesday June 30. Next week will be the last Scouting report for the 2004 season. To receive a FAX of this week's message, please call (814) 865-1636.

In Berks and Lancaster counties, eggs of the first generation of cryptomeria scale have hatched and the majority of crawlers have settled and covered themselves with their protective armor. The best control is achieved when the crawlers have just hatched and have not begun to produce their protective cover. This scale also has a second generation. Begin scouting for eggs of the second generation in late July and when the first crawlers are observed, apply your first spray. Two or three sprays 7-10 days apart will be needed to control this pest. It may be necessary to spray for both generations in order to get good control. Crawlers of cryptomeria scale may settle under the female's covering on last year's growth, making penetration of sprays very important.

All life stages of elongate hemlock scale were present on Fraser fir in Columbia and York counties. To scout for this scale look for chlorotic spots on top of the needles and white cottony material on the undersides of the needles. Examine needles back toward the trunk of the lower branches for best scouting results. It takes multiple sprays to control this scale because all life stages are present throughout the growing season. Because elongate hemlock scale crawlers also settle on older needles and under the female covering, penetration of spray into the trees is also vital for good control

Spruce spider mites are still causing damage to the new growth on Canaan fir in Lancaster County and Fraser fir in York County. If the base of the new growth is beginning to yellow or look chlorotic, there is a good chance spider mites are causing damage. Two sprays are necessary for effective mite control 7-10 days apart, unless prohibited on the label.

The white pine weevil was very damaging this year in white pine, spruce and Douglas fir. Make sure when cutting out tops you remove all infested wood. At this time the larvae are at the base of the damage. Usually the bark is soft and has a reddish color to it and is easy to peel away, revealing the red-brown frass and white larvae. The fresh cut should show a nice green ring under the bark.

No active spores of Rhabdocline were found when needles were inspected in Berks, Lancaster and York Counties. Time will tell how well those sprays worked. Those red-brown marks that are so notorious of Rhabdocline symptoms will begin to appear later in the fall and winter.

Cooley spruce galls are beginning to open on blue spruce in Columbia County. However, the eastern spruce galls have not begun to open. If you have a small plantation and were planning on scouting your field and removing these galls by hand, you must do it before the galls open at your location. Otherwise, the next time to control these gall- forming adelgids is this fall or early next spring.

Damage from Eucosma larvae was found in fir terminals in Lancaster County this week. The shoots were beginning to wilt and upon close examination, a small hole could be seen in the stem, just below the wilting. If the wilted stem is split open, a single caterpillar should be found. Because we have never been able to collect adult moths of this species, we do not know which of the borers in the genus Eucosma this may be.

The last report for this season will be issued Wednesday June 30th, after 5:00pm.