Ynghylch

The St Mark's fly, or 'hawthorn fly, is a very common, long, shiny, black fly that can be found in large numbers during the spring around woodland edges, fields and wetlands. It hangs in the air over the vegetation, drifting along with its legs dangling underneath it. St Mark's flies will often land on any objects in their way, including fence posts and people, and are rather sluggish at rest. The larvae live in the soil feeding on roots, grasses and rotting vegetation, and are often found around compost heaps. The adults feed on nectar and are considered to be important pollinators for fruit trees and other plants.