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June 29 2005

Christmas Tree Scouting Report - Number 14

Welcome to the Christmas Tree Scouting Report for the week ending May 11, 2005. This is the last weekly report for 2005. We will continue to monitor for the second generations of pine needle scale and cryptomeria scale. When these events occur, we will make a special short report. Otherwise, the regular reports will return in 2006 with the first report available on Wednesday March 29 th. To receive a FAX of this week’s message, please call (814) 865-1636. If you have pest activity to report, or would like to receive these reports by e-mail, please leave a message at (717) 772-0521 or e-mail sgardosik@state.pa.us and your name will be added to the distribution list.

There were still eggs of Cryptomeria scale (Aspidiotus cryptomeria) that had not hatched in Cumberland, Dauphin and York counties. So if you have applied your second spray for this scale about 7-10 days ago, you may want to consider a third. Eggs of the second generation will begin to be laid underneath the females protective cover in late July early August and followed about two weeks later by crawlers. There will be a short message alerting growers to this activity.

Begin looking for the second generation of pine needle scale in mid July. These crawlers are red in color and will be found out on the needles. Two sprays of a registered insecticide will be needed 7 to 10 days apart for best control.

A grower in Schuylkill County reported white pine weevil damage in small trees of white pine and spruce. Some trees were planted this spring and terminals were not much more then pencil width. In Berks County white pine weevil damage was found in two to three foot Norway spruce. Normally growers do not spray such small trees because the weevils tend to prefer the thicker terminals. You may want to consider scouting your younger trees for weevil damage.

We received a report from New Jersey that the redheaded pine sawfly was emerging. There is one generation of this sawfly in Pennsylvania and their preferred hosts are Red, Scotch and white pine. Look for yellowish green larvae with a red head and several rows of black spots running the length of the body. Full-grown larvae are about 1 inch long and found in clusters on the foliage. The larvae of the redheaded sawfly tend to eat in colonies and can strip the needles of entire branches and completely defoliate smaller trees. Since larvae feed in groups, colonies can be pruned out or spot sprayed unless larvae are too abundant and control by hand is not practical.

I had a report this week of spruce spider mites on concolor fir in Schuylkill County. Earlier this season a grower from Dauphin County reported the same. Normally there are not too many pests that bother concolor but spruce spider mites can cause damage on all Christmas tree species.

Thank you for your support of the Christmas Tree Scouting Report during the 2005 spring season. I had quite a few new requests to be added to the e-mail distribution list this year. For past reports or more information and color pictures of Christmas tree pests and diseases, check out the Penn State’s Christmas Tree home page  Please send any comments or suggestions for improvement to sgardosik@state.pa.us or call (717)-772-0521. Thank you and have a good year.