Blue green aphid
Bluegreen aphids (BGA) are relatively large (up to 3 mm), matt blue-green, with a pair of slender tubes like exhaust pipes (cornicles), projecting from the back to beyond the tip of the abdomen. Winged aphids fly into pastures or crops and start colonies of wingless aphids, which cause damage. Overcrowding or plant deterioration triggers the development of new winged aphids which migrate to establish new colonies. Winged aphids can spread viruses.