I have been spraying dormant oil and insecticide for the past 9 years on a 10 year old magnolia tree. This year the scale is totally out of control, what can I do, short of burning or cutting the tree down?
If you use the "search" box to "search forums" at top of this page for "scale" or "scale insect" some threads should come up which may help.
Thought there was some mention of a systemic , maybe a nursery retail outlet would know. Not sure what to suggest, other than maybe a pair of gloves and manual removal and washing down with water. Guess you've already tried this if practical. An article on using yellow mouthwash is here http://janets-garden.blogspot.com/2006/05/oleander-and-full-scale-battle.html .
There are several posts and comments on scale in this forum! Controls differ depending on which scale you have. Some scale do not need to be chemically sprayed or applied horticultural oil used at all. Biological and cultural control are common means to use for several scale types that attach to ornamental trees. Fruiting trees can be a different story as some scale types may not go away but can overwinter and re-infect a tree year after year until they have effectively been stopped. Below are some links that you can look through. If you are not satisfied with the content in the links then contact your Virginia Cooperative Extension for more information. Magnolia Scale Fact Sheet -- Woody Ornamental Integrated Pest Management at Penn State Scale Insects Virginia Cooperative Extension Jim
