Nice! Along other lines: We have issues with aphids in the early spring when plums are leafing out and blooming. They do disappear with first serious summer heat. Any ideas on a chemical of two that works.
Aphids appear shortly after blossoms drop and leaves begin to open. You'll sometimes see ants going up and down trunk feeding on their sticky sap secretions. The ants actually host and protect the aphids.
You may want to try some concentrated Neem Oil. Mix 1 to 1.5 ozs into gallon of water with a 1/2 oz of dish detergent. Put that into a small garden sprayer and spray both sides of leaves and trunk in early morning or late afternoon. Treat every 10-14 days until aphids gone. Usually takes 2-3 treatments and they are gone. The Neem Oil is organic and won't harm people/pets. Best to spray with temps under 85.
Clean your sprayer out with hot water when finished as that Neem is sticky stuff and will gum up the sprayer.
I don't like to use pesticides until there are more serious problems like borers and beetles. The neem should work and if very wet season, you may want to try some fungicide every other treatment in place of the neem oil. If dry, only use the neem and it should eradicate the aphids.
The aphids will make leaves curl up and appear brown/black
SD