Insight into St Mark’s Fly (Bibio marci): named as they often appear around St Mark’s Day on 25 April. They are abundant for a short time, maybe only a couple of weeks, flying with their long dangling legs hanging down.
The male (above left) is smaller, 12mm, than the female (above right), 14mm, with a big head and large eyes. The male also has clear wings whilst the female’s are smoky.
They’re thought to pollinate fruit trees.