Hello Barb,

Please compare what you have to descriptions and pictures in these bulletins.

https://www.canr.msu.edu/news/why-is-sap-dripping-from-my-magnolia-tree

https://bygl.osu.edu/node/1803

https://extension.psu.edu/magnolia-scale
If what you have does not exactly match the pictures in the above bulletins, please let me know.

In magnolia scale, the large bumps on the branches are adults which protect the developing crawlers underneath the scale.

Wait for the tiny crawlers to emerge (sometime in August when GDD base 50 is at 1900-2000) and spray them. For small infestations, and a pollinator friendly approach, you can us a plastic kitchen scrubber to gently scrub off the adult scales before the crawlers hatch.

You can monitor the correct time to treat crawlers by observing the branches for crawlers, or by the Growing Degree Days (GDD) for base 50 in your area. GDD Tracker is an online site used by professionals, and you may use it, too. See https://www.canr.msu.edu/news/use_gddtracker_to_schedule_applications_to_turfgrass

The time to treat the crawlers ( 1900-2000 GDD base 50) will be coming up sometime in August.

Hi Barb
We can’t say without knowing the active ingredient that will be used. The service must provide you with that information.
There is a systemic soil drench or injection method for magnolia scale control. The insecticide is absorbed throughout the tree, including the flowers, so it may affect bees and other pollinators. From the OSU bulletin above, 
“Systemic neonicotinoids offer another effective option that minimizes impacts on beneficial insects. Products based on the active ingredients imidacloprid, dinotefuran, or thiamethoxam are highly effective against magnolia scale if applied (sprayed) late in the season to target 1st instar crawlers”

From Georgia State Extension—
“Systemic insecticides (such as neonicotinoids, dinotefuran, imidacloprid, etc.) applied as bark sprays or soil or stem injections can reduce magnolia scale problems. Because neonicotinoid insecticides are implicated in harming pollinators, such as bees, these insecticides must be used according to label instructions.”


There are effective injections for apple scab control available to licensed professionals.

Hello
Yes you can use your 4 gallon sprayer, just don’t dilute your 2 gallons of ready to use neem oil. This assumes your sprayer has never been used for anything like glyphosate or other herbicide or chemical that would harm the tree.
I checked the tracker tool for magnolia scale. The crawlers are predicted to begin hatching in the East Lansing area about August 6th. You can check the tree visually about this time and look for the tiny crawlers moving around. A magnifying hand lens can be helpful to see them. Compare what you see with the picture of the crawlers in this bulletin

https://www.canr.msu.edu/news/why-is-sap-dripping-from-my-magnolia-tree

Regards, Laura

Glad to help- also, it may take another treatment next spring and/or next August again, to get control. Dead adult scales remain on branches but rub off easily. So, please continue to monitor for crawlers in August for the next couple seasons.