They suck sap from stems and leaves and cause distortion of the shoots, stunted plants, reduced yield, and spoiled crops.

This aphid also acts as a vector for viruses that cause plant disease, and the honeydew it secretes may encourage the growth of sooty mould.

It breeds profusely by live birth, but its numbers are kept in check, especially in the later part of the summer, by various predatory and parasitic insects.

This aphid is usually seen in large numbers and is a tiny, plump insect about two millimetres long with a small head and bulbous abdomen.

Winged forms, known as alates, are longer and more slender than aptates and have shiny black heads and thoraxes.

The primary host plants are woody shrubs, and eggs are laid on these by winged females in the autumn.

All the offspring are female at this time of year and large populations of aphids develop rapidly with both winged and wingless forms produced throughout the summer.

[2][7][8] More than 40% of the eggs probably survive the winter, but some are eaten by birds or flower bugs, and others fail to hatch in the spring.

Among the latter, it shows a preference for poppies (Papaver species), burdock (Arctium tomentonum), fat-hen (Chenopodium album), saltbush (Atriplex rosea), chamomile (Matricaria chamomilla), thistles (Cirsium arvense),[8] and docks (Rumex spp.).

Early-sown crops may avoid significant damage if they have already flowered before the number of aphids builds up in the spring.

The plants are stunted by the removal of sap, the stems are distorted, harmful viruses are transmitted, and aphid residues may contaminate the crop.

[12] As a result of infestation by this aphid, leaves of sugar beet become swollen, roll, and cease developing.

In some other plants, the leaves do not become distorted, but growth is affected and flowers abort due to the action of the toxic saliva injected by the aphid to improve the flow of sap.

Black garden ants (Lasius niger), for example, remove predators such as ladybirds from the vicinity of aphids, thus keeping their "milk cows" safe.

[15] In the warmer parts of its range, apterous individuals can survive the winter and they may continue to reproduce asexually all year round.