Hi,

Please send me the full product name for what you purchased. I'll need to read the label for this specific product to assist you.

Hi,

Unfortunately that product is not labelled for use on magnolia scale or for ornamental landscape areas. It should not be used to treat magnolia scale. You can read the full product label here: https://labelsds.com/images/user_uploads/Alpine%20WSG%20Label%204-1-19.pdf

It may be that chemical was recommended previously, but further research has shown it to not be as effective for controlling this pest. I did find one publication that still recommends it's use during August, but they reference a product labelled for use with trees "Orthro Tree & Shrub is one possible trade name": https://entomology.ca.uky.edu/ef431. However, I checked that product line and it no longer contains the active ingredient Dinotefuran.

Generally, systemic insecticides containing the active ingredient Imidacloprid, can be applied as a soil drench at the root zone of the infested tree usually in early May a few weeks before crawlers hatch to allow the insecticide time to move through the tree.

Unfortunately, you may have been looking at an outdated bulletin that did not have currently recommended practices for this pest.

On the bright side, we are approaching the time of year where you would apply Horticultural oils, often called summer oils, in late August. These have been shown to be very effective in reducing scale populations. Oils can also be applied in fall before freezing weather and again in early spring before the flower buds swell to kill the overwintering nymphs located on the stems. 

We do have an updated article on this topic that you can find here: https://www.canr.msu.edu/news/why-is-sap-dripping-from-my-magnolia-tree

You could apply neem oil, but it's generally not used for scale. 

What you'd be looking for is a horticultural oil product like this one:

https://www.amazon.com/Bonide-BND212-Horticultural-Spray-212-Concentrate/dp/B000FOONE0/ref=asc_df_B000FOONE0/?tag=hyprod-20&linkCode=df0&hvadid=<personal data hidden>1&hvpos=&hvnetw=g&hvrand=<personal data hidden>113779089&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9051606&hvtargid=pla<personal data hidden>898&mcid=d798f4888fb23651816a5d30cbe60059&hvocijid=<personal data hidden>113779089-B000FOONE0-&hvexpln=73&gad_source=1&th=1

I'm not endorsing this product in particular, this is just to give you an example of what to look for. The active ingredient will be mineral oil and there are concentrate and ready to use formations that should be available.

Be sure to read the label since there may be a different concentration to use in the summer as opposed to fall. Also, take care to avoid spraying during the heat of the day, since oil can cause burning if applied when it's sunny out.

Yes, the crawlers from magnolia scale should be large enough for you to see. You'll likely want to do a few applications, even if you don't see them though. I'd recommend spraying soon, then following up with 1-2 more sprays at 2-3 week intervals. Be sure to follow the directions on the label of the product you purchased, though. There will be recommendations there on how best to treat for magnolia scale using that product.