The Large Bee-fly (Bombylius major) is a common site in our garden in Summer. It is easily spotted as it hangs in the air hovering over a specific spot. Any flies or other flying insects that dare to fly into its territory are swiftly chased away. Although it is very similar in appearance to a bee, it is in actual fact a harmless member of the fly family.
HABITAT AND DISTRIBUTION
The large bee-fly lives in a range of habitats from gardens and grasslands to heathlands, woodlands and coastal areas. Widespread in the UK (more common in the south), the large bee-fly also lives across Europe, North America and parts of Asia.
Like a large bee, the large bee-fly has a brown and hairy bulbous body and grows to around 14 - 18mm in length (including the proboscis), with a 25mm wingspan. The back has a large dark area that breaks up and becomes narrow stripes near the rear end, and its legs are long and spindly. Its long narrow wings have dark edges to them, earning the large bee-fly its other name of Dark-edged Bee-fly. The head has large eyes, small antennae and an extremely long proboscis (a long sucking mouth-part). The large bee-fly is the only UK species to have dark edges to its wings. As with a lot of fly species, the male has large eyes that are close together, whereas the females eyes are a little smaller and further apart (a good way to remember sexing many fly species is Chap = close together, and a Female = far apart!)
DIET, BEHAVIOUR AND REPRODUCTION
The long proboscis is used to reach nectar from the many flowers it feeds on, including primroses and violets. Bee-flies mate end to end, as can be seen in the photograph. The female usually flicks her eggs towards the nesting holes of bees (especially Andrena sp.) and wasps, where its parasitic larvae can grow and consume the hosts larvae and food store. The adults can be seen on the wing from March - June.
OTHER NOTABLE FACTS
There are 4 species of Bombylius in the UK. The Dotted Bee-fly (Bombylius discolor) is similar to this species but has spotted wings and no dark edges. The other 2 species, the Western Bee-fly (Bombylius canescens) and the Heath Bee-fly (Bombylius minor), are both paler in colour and have clear, unmarked wings.