Hello,

Based on what I see in your single image and your description, This appears to be a cottony maple scale (Pulvinaria innumerabilis)

The cottony maple scale (Pulvinaria innumerabilis) is an insect that primarily infests silver maple and honeylocust trees. However, it can also be found on other species like alder, box-elder, catalpa, elm, dogwood, hackberry, hawthorn, crabapple, oak, plum, pear, cherry, linden, lilac, willow, beech, poplar, and sycamore. These insects overwinter as immature females on twigs. More information at these links:

Cottony maple scale - Integrated Pest Management (msu.edu)

InsectsandMites_CottonyMapleScale.pdf (msu.edu)

They cause damage by sucking sap from the tree, which can lead to twig and branch dieback. Additionally, they secrete excessive honeydew, which can be unattractive and attract nuisance wasps and sooty mold. More information at these links:

Cottony Maple Scale (Pulvinaria innumerabilis) - Urban IPM | Montana State University

insect_fact_sheet_cottony_maple_scale.pdf (montana.edu)

Natural enemies like twice-stabbed lady beetles, wasps, and flies help control cottony maple scale, so insecticides are rarely needed in landscapes. More information is at this link:

Cottony maple scale - Integrated Pest Management (msu.edu)

If you’re dealing with an infestation, consider monitoring the situation and promoting natural predators to manage the scale population.

Cottony maple scale usually causes little harm to healthy trees. Natural predators will control the infestation within one or two years. Treatment of cottony maple scale with insecticides may do more harm than good as the insecticide will kill their insect predators. More information at this link:

There are small, white objects resembling kernels of popcorn on the branches of my silver maple tree. What are they? | Yard and Garden (iastate.edu)

I hope this helps!