Aphids are soft, pear-shaped, and very tiny (1/16 to 3/8 inch long). Two short tubes project backward from the tip of their abdomen. Aphids have long antennae. Some types of aphids have wings, which a READ MORE http://www.organicgardening.com/learn-and-grow/aphids
Aphids are one of the commonest and most troublesome of all garden insects, attacking a large number of garden plants such as the rose, many trees and vegetables. Greenfly and blackfly are aphids and READ MORE http://www.gardenaction.co.uk/techniques/pests/aphids.htm