Quick facts

Common name(s): dark-edged bee-fly, large bee-fly, greater bee-fly

Scientific name: Bombylius major

Family: Bombyliidae

Habitat: grassland, parks and gardens, hedgerows, woodland

Diet: nectar

Predators: birds

Origin: native

What do dark-edged bee-flies look like?

Dark-edged bee-flies have round, furry bodies and hairy legs. They are golden-brown in colour but get their common name from the dark markings visible on the leading edges of their wings.

The most striking feature of this insect is its long proboscis (tongue), which is often mistaken for a stinger. Adults can grow to 1.8cm in length.

Credit: Geoff Foale / WTML

What do dark-edged bee-flies eat?

Adults: sip on the nectar produced by a variety of flowers, including primroses, grape hyacinths and bugle. Deep flowers are preferred but they will visit smaller flowers too.

Larvae: feed parasitically on the grubs of solitary bees and wasps.

Did you know?

A dark-edged bee-fly’s proboscis can measure four times longer than its head and cannot be retracted.

How do dark-edged bee-flies breed?

After mating, the female dark-edged bee-fly searches across exposed areas of soil or sand to track down nest burrows made by solitary mining bees or wasps. Once she finds a suitable target, she hovers above the entrance and skilfully flicks an egg towards it with a rapid twist of her body.

This spells bad news for the grub within. After hatching, the bee-fly larva crawls into the burrow and waits for the unsuspecting occupant to grow to almost full size. Then the bee-fly larva latches onto its host, feeding on its body fluids until the grub eventually dies.

The growing bee-fly remains in the burrow and pupates over winter, before emerging as an adult fly in the spring.

Did you know?

Female dark-edged bee-flies coat their eggs in dust before flinging them at solitary bee and wasp nests. This may camouflage the eggs, make them easier to throw and prevent them from drying out.

Where do dark-edged bee-flies live?

Dark-edged bee-flies are widespread in the UK. They are less common in Northern Ireland and northern Scotland, but have been advancing northwards in recent years.

They live in a range of habitats, including gardens, hedgerows and woodland.

Signs and spotting tips

Adults are usually on the wing from March until June, although sightings can occur as early as mid-February during unseasonably warm weather. The best time to see them is on dry, sunny days when temperatures exceed 17C. You might even spot them sunbathing on bare ground or leaves as they enjoy the warmth. Dark-edged bee-flies will avoid flying when conditions are wet.

Threats and conservation

Dark-edged bee-flies are common in many parts of the UK and are not considered a threatened species.