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August 16, 2007

Update on 2nd Generation of Cryptomeria Scale - August 16, 2007

For those of you who are planning on spraying for the second generation of cryptomeria scale, now is the time to plan.

Eggs were beginning to hatch on Fraser fir in Lebanon and Schuylkill counties this week.  In Lebanon county crawlers were still under the covering of the adult female scale. In Schuylkill county a few crawlers were found out on the needles. In Dauphin county eggs have begun to hatch and there are already early settled crawlers out on the needles on Canadian hemlock. In Juniata county eggs were found beneath the female covering but no egg hatch was observed on Fraser fir.

To scout for Cryptomeria scale use a 10-20mm hand-lens and a white surface such as a paper plate, and tap branches infested with Cryptomeria scale over plate. Using hand-lens look for lemon yellow jellybean shaped eggs about 1/4mm long or crawlers the same color and size but a little flatter and moving. Begin spraying for scale when crawlers are found and before to many crawlers settle and begin producing a protective covering.

In Schuylkill County ladybeetles were found among the Cryptomeria scale and predation by these beetles were observed. If a small round hole in the scale covering is observed, this scale was parasitized by a small wasp and when the new generation emergences a small round emergence hole can be seen.

When the weather conditions are dry during mid summer like we have experienced this year it can also have an effect on the Cryptomeria scale where it causes desiccation to the scale population, which is another natural control. Growers in Schuylkill Co. have observed scales that have just dried up.