The eggs hatch in the spring. During the growing season, females give birth to live young. Since it takes about 10 days to reach maturity, several generations are produced each growing season. At the end of the growing season, females produce eggs that overwinter. Aphids feed by inserting their mouthparts into tender new leaves from which they suck plant sap.
Plant sap has a high sugar content.
When they feed, the aphids excrete large amounts of a sugary liquid called honeydew. With a large aphid population, the honeydew can completely coat leaves. The honeydew serves as food for the sooty mold fungi, as well as various insects, including ants, wasps and flies. As the aphid feeds, it injects saliva into the leaf. The saliva causes yellow spots to develop on the leaf.