Could be from from household bug spray, if that happened after spraying.
A blast of water spray, every couple days, till there gone, will take care of aphids.
A spraying of one Tablespoon reg dawn dishsoap to a gallon of water, every couple, three days, will do the trick, for many bugs.
There are new dormant sprays to use these days, even mid-season ! Check/ask about, best one to use at your nursery. They control overwintering bugs, and fungus.
If you suspect fungus, find a dormant spray that you can use now. You'll be needing to use it regularly, in future, for trees health.
Ttfn friend 👍