A medium-sized black hoverfly related to Cheilosia with large grey dust-spots on tergites 2 and 3 of the males.

Often present at good stands of Ramsons in woods but sometimes absent for reasons that are unclear. It can also use Ramsons in more open locations such as parkland and open woodland in the north and west and abroad it will use other Allium species such as Three-cornered Garlic.

May and June.

The larvae develop in the stem bases and bulbs of Ramsons and the very sluggish adults can normally be observed sitting on the leaves (or on nearby foliage), particularly in May when the plant is flowering.

This is a widespread but localised fly.

Thought to be uncommon or under recorded in Leicestershire and Rutland.