Large Willow Aphids

There was excitement as volunteers worked clearing the lakeside bank just over a week ago as unusual looking creatures were discovered clumped together on a willow stem. These have since been identified as Large Willow Aphids (Tuberolachnus salignus), a new species for the reserve. This species is the largest of the aphids found in Britain with adults measuring between 5mm and 6mm in length.  Adults have been recorded in two forms; winged and wingless. It is thought that temperature determines whether wings develop or not.

They are commonly seen in dense colonies on willow trees, and are frequently seen to be very active during cold, frosty weather, when they can be found walking along the ground, over rocks and along the handrails of foot-bridges. No males have been found in this species, possibly because none exist. Females are able to give birth to live young that are genetically identical to themselves.