It is also called greenfly and blight.
Aphids feed by inserting their beaks into stems, leaves, or roots, and sucking the plant juices.
Usually they gather in large colonies. The life cycle of aphids is complex and varies in different species. Different host plants and different parts of the plant may be used at different stages of the life cycle. Cows Many kinds of aphid secrete a sweet substance called honeydew, prized as food by ants, flies, and bees. This substance consists of partially digested, highly concentrated plant sap and other wastes, and is excreted from the anus, often in copious amounts.