In commercial and everyday use, the term weight is usually used to mean mass, and the verb to weigh means to determine the mass of or to have a mass of. Used in this sense, the proper SI unit is the kilogram (kg).
For other uses, see Aphid (disambiguation). Aphids, also known as plant lice and in Britain and the Commonwealth as greenflies, blackflies, or whiteflies (not to be confused with jumping plant lice or true whiteflies), are small sap-sucking insects, and members of the superfamily Aphidoidea.
1 Aphids are the most common tiny red insects found on plants. 2  These insects pose a significant pest control problem for gardeners. 3  Aphids are tiny, but they can cause big damaâ¦. 4  Common Plant Pests That Cause Plant Damage Successful gardeners are experienced in the art of identifying and managing pest insects.