Pennsylvania's Christmas Tree Scouting Report
Cryptomeria scale crawlers, or newly-hatched nymphs, were found moving on the needles of true firs in northern Dauphin, Lebanon, Schuylkill and York Counties this week.
In York County yesterday, the first Cryptomeria scale crawlers were found under a few adult scales. The hatch was very light, though. A very small percentage of the eggs underneath the scales had hatched and there was no movement of crawlers on the needles.
This week, when monitoring Cryptomeria scale populations on true firs in Lancaster and York Counties, only eggs were found underneath the off-white, waxy coverings of adult female scales, and no crawlers were seen moving on the needles.
This will be the last regular scouting report of the 2013 growing season. At this point in the year, much of the pest activity has slowed. There will be one or two special updates later in the summer to alert growers to the emergence of the 2nd generation of the Cryptomeria scale.
In Lancaster and York Counties this week, tiny, yellow Cryptomeria scale crawlers were just beginning to move along the needles of Canaan, Concolor and Fraser firs.
Newly emerged bagworm larvae were found on foliage of several tree varieties in Dauphin, York and Schuylkill Counties this week. The larvae had already begun to construct their protective coverings out of needle tissue.
Eggs of Cryptomeria scale were beginning to be found underneath 25%-75% of adult female scales this week in Lancaster, York and Schuylkill Counties. These bright yellow, jelly bean shaped eggs can be expected to hatch into bright yellow, oval-shaped crawlers in approximately two weeks.
The emergence of pine needle scale crawlers continues slowly this week on Eastern white pine in Cumberland, Lancaster and York Counties. Just a few burgundy-colored crawlers were found moving on the needles away from the white, oblong mother scales.
This week, pine needle scale crawlers were beginning to hatch under the female scale covers on Eastern white pine in Lancaster and York Counties. Approximately 25-50% of the eggs underneath the covers had hatched into crawlers, or 1st stage nymphs.
In northern Dauphin County, lesions of Rhabdocline needle rust are sporulating, and bud break of Douglas-fir in that location is at about 90%. Sporulation also has begun in Susquehanna County.
In Cumberland, Lebanon and York Counties this week, Douglas-fir needle midge adults were found in emergence traps and hovering around Douglas-fir buds. In York County, they have already begun to lay eggs inside the buds.
In Lancaster and York Counties, the first Douglas-fir buds are just beginning to break. The tips of the new, bright green needles are just visible. Percentage estimates may be 1%-5%. Some trees with bright, southern sun exposure may be farther along.
This week in Lancaster and York Counties, stem mothers (or 1st generation nymphs) of Balsam twig aphids were found hatched on the needles of true firs (the only host genus of this pest). When scouting for this pest, hold a dark flat surface under a branch and tap the upper surface of the branch.
Earlier this week, white pine weevils were first found in emergence traps in several locations around the mid-state. Weevils were found in Lancaster, Luzerne, Schuylkill and York Counties. Growers who have not set traps on their farms, can scout their blocks of Eastern white pine, Serbian spruce and other susceptible host trees.
Again this week, there were no weevils of any species found in the traps monitored by the IPM Program and its cooperators. These traps are located in Dauphin, Lancaster, Schuylkill, and York Counties.
Temperatures across the mid-state remained cool this week. As a result of this, insect activity was light and pest activity was essentially non-existent.
This is the first scouting report of the 2013 Christmas tree growing season. Weekly scouting reports will be published through the end of June. These reports will contain information on current pest activity in Central PA.
Presentation created & presented by Sarah Pickel, PA IPM Program; PA. Dept of Ag