I get hit with these guys also. Right about now just before going out side for the season. I use a mixture of 'Neam' oil and 'Murphy's Oil Soap'. Use a one qt. spray bottle. One teaspoon of Neam oil, one teaspoon of oil soap into a mixture of 60% water and 40% alcohol. You must use up the mixture in one day. Don't know why but that is what I was told. Start fresh each time. Just spray the leaves top and bottom. Wait a week and repeat. Best out doors in summer. When I used the Bayer mix. I lost several plants. Unknown if due to over watering or the chemicals in the stuff.
The Neam oil I purchased at my local Lowe's hardware store. It was about $10 pint. One pint should last several years.
Stush
