Aphids are small, soft-bodied insects that feed by sucking the nutrient-rich liquids out of plants. In large numbers, they can weaken plants significantly, harming flowers and fruit. The tiny bugs can appear white, black, brown, gray, yellow, light green, or even pink!
Aphids tend to hide on the underside of leaves, and specifically look for misshapen, curling, stunted, or yellowing leaves. They produce a yellow “honeydew” sap that they leave on leaves or stems.
Read more on the Farmer’s Almanac: https://www.almanac.com/pest/aphids