A neighbor has been trying for the past several summers to either
control or kill the Magnolia scale on his Magnolia tree.
His one and only method has been to apply some sort of oil spray via a
hand-pumped sprayer. The tree is about 15 to 20 feet tall and
naturally it's awkward and time consuming to apply the oil this way.
The oil really doesn't seem to be having any effect. By late summer,
many leafs have ugly black stains on them.
I read that the following chemical products are applicable in the
control of Magnolia Scale:
ACEPHATE (Orthene), ABAMECTIN (Avid), CARBARYL (Sevin/Sevimol),
DIMETHOATE (Cygon), MALATHION (Malathion), CHLORPYRIFOS (Dursban)
I believe that Cygon and Dursban are no longer available to the
average consumer through stores like Home Depot, etc. I've only seen
Dursban available as a granular for turf grass application anyways.
So my question is, which type of chemical control is available for
Magnolia Scale that (1) can be purchased by an average home-owner and
(2) can be applied via hose-end sprayer.
Can liquid malathion be applied via a hose-end sprayer in this
situation? And if so, when is the best time of year to apply?