Magnolia scale active 6/8/2020 - Ask Extension
From what I've read this date appears to be very early for magnolia scale. I'm treating it with four seasons oil (2 tablespoons per gallon) I'm not se...
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Magnolia scale active 6/8/2020 #649015
Asked June 10, 2020, 4:22 PM EDT
From what I've read this date appears to be very early for magnolia scale. I'm treating it with four seasons oil (2 tablespoons per gallon) I'm not seeing results while spraying directly on crawlers. How long will it be before I see results? Or should I treat with another spray?
Lapeer County Michigan
Expert Response
It would be unusual to encounter active magnolia scale this soon in the season.
An early spring application of dormant horticultural oil can help reduce an infestation if applied after the danger of freezing nights has passed, but before the buds have opened. Good coverage, especially the undersides of branches, is important. I'm not familiar with 4 seasons oil.
June to early July is the time to apply systemic insecticide that is drenched into the root zone, so that it has time to move from roots up to twigs. You can do this yourself but you must read the label, calculate the correct amount to use for your size tree, purchase that amount and apply it 4-8 weeks ahead of when the crawlers are active.
August through September is usually active crawler time in Michigan and is the time to apply a contact insecticide spray to manage the crawler stage. If you choose the systemic you should not need the spray. Follow all label directions to avoid damage to the plant or to people.
Would this be magnolia scale then?
Would this be magnolia scale then?
Yes it is. Thank you for the clear photos.
It seems like the problem is under control. I used all seasons oil spray on trunks and under leaves of trees. My tallest magnolia is over 25 ft tall and I was wondering if I can expect crawlers up that high? Will there be another hatch of crawlers this season? Thank you for your help
Magnolia scale do not have a preferred height on trees, though they are more common on branches than the trunk. You may see crawlers again August or September. If you do, a foliar insecticide would control them.
