Roses can support several species of aphid in the spring and summer, the most common is usually Macrosiphum rosae. This rose aphid can reach 3.5 mm in length and varies in colour from pink to green, it can form dense colonies and produces large amounts of honeydew. Roses are also host to a root aphid, the root aphid does not appear to affect the health of roses. 

Aphids are sap-sucking true bugs and are an important part of many food chains, supporting many predators. They range in size from 1 to 7 mm (¼ in or less) long. Some aphids are known as greenfly or blackfly, but there are species that are yellow, pink, white or mottled. There are more than 500 aphid species in Britain. Some feed on only one or two plant species, but others can be found on a wide range of plant hosts. Almost any plant can be a host, including ornamentals, vegetables, fruits, greenhouse plants and houseplants.

• Green or pink insects, cluster on the flower buds, shoot tips and young foliage
• White cast aphid skins are often seen on flower buds and leaves
• Flower buds and foliage can be covered in a sticky honeydew that aphids excrete
• Black sooty moulds may grow on the honeydew

Aphids form the basis of many food chains and it is not unusual to have some of these animals in a healthy balanced garden ecosystem. On established bushes aphids can usually be considered part of the biodiversity they support, natural enemies will normally reduce numbers during summer.

• Where possible tolerate populations of aphids
• Encourage aphid predators in the garden, such as ladybirds, ground beetles, hoverflies, parasitoid wasps and earwigs. Be aware that in spring aphid populations often build up before natural enemies are active in sufficient numbers and then give good control
• Check roses frequently from spring onwards so action can be taken before a damaging population has developed
• Use finger and thumb to squash aphid colonies where practical

Aphids usually overwinter on roses as eggs laid on the stems in the previous autumn. However, in sheltered places there may be active nymphs and adults all year round.

Aphid numbers start to increase in spring when roses are producing new growth and reach a peak in early summer. Some rose aphids are green but a common species, Macrosiphum rosae, is pink. During spring and summer, the aphids are mostly wingless forms, 2-3.5 mm long, that give birth to live young.

Winged forms develop when plants are heavily affected and aphids need to migrate to new hosts.