The best way to keep insect pests at bay: foul the area with something so noxious they’ll never know what hit them. Enter the cayenne pepper.
In this case, you’re looking at ground Ristra Cayenne pepper from my 2015 crop. Unfortunately this particular batch happened to be so delicious to me that I chose to keep it for myself, but the concept is sound. Aphids, whiteflies, rose slugs, and a variety of other insect pests will absolutely hate it when you dust your plants with hot pepper. Just fill a spray bottle with water, mist the plants so the pepper flakes will stick, and sprinkle them onto the leaves.
At the risk of having the yard smell of pizza, I plan to experiment with adding garlic powder next spring.