hawthorn-carrot aphid

On the primary host, these aphids are about 2 mm (0.08 in) long, with short antennae and short siphunculi, greenish-grey and dusted with wax particles. On the secondary host, wingless viviparous females are greenish-grey or yellowish-grey, again dusted with fine wax particles. Winged viviparous females are greyish-red with black markings. Egg-laying females are reddish-brown and winged males are reddish with black markings.

The hawthorn-carrot aphid migrates to its primary host in late summer and forms red, curling galls on its leaves. The following spring, females move to its secondary host, an umbellifer in the family Apiaceae, and produce live offspring, When these nymphs are sufficiently mature, they produce further live young. Most offspring are wingless, but some winged females are produced which are able to colonize new secondary hosts. In late summer winged females and males are produced and migrate to hawthorn trees. These aphids are attended by ants on both their primary and secondary hosts.