The Bee-fly – Bombylius major

posted in: Gardening | 6
this is an image of a bee-fly in flight

There's a ferocious looking little insect in my garden called the bee-fly - Bombylius major. Seriously they really do strike a touch of fear in you the very first time you encounter them.

 

They look so intimidating with their large proboscis that looks just like a sharp sewing needle. Furthermore they also have a thick hairy body like a small bumble bee. Along with a high pitch buzz. They look and sound so threatening but honestly they're no threat to anyone. That is unless you're a ground nesting solitary wasp or bee.

Bee-fly - Bombylius major

Every year the bee-flies seem to hover around the same spot in my garden.  I also notice quite a few different solitary bees visiting the garden; and many a time I watch them burrowing into the soil to make their nests at this time of year.  The bee-fly is a bee mimic. Because it looks and sounds so much like a bee it tricks the solitary bees into thinking that it's not really a threat. But it's a deadly threat!

 

The bee-flies seem to know where those nests are. They wait for the adult female solitary bee to leave its nest.  Then the female bee-fly lands on the soil in the general vicinity of the nest.  Collects a grain of soil with her long thin dangly legs. Rolls her egg in that soil and then flicks her egg in mid air on to a dark spot on the soil (thinking that it's the entrance to the nest).

this is an image of a bee-fly that looks deadly but won't sting or bite and uses its long proboscis to drink nectar from certain plants
Bombylius major bee fly (Diptera: Bombyliidae) looks deadly but won't sting or bite and uses its long proboscis to drink nectar from certain plants

Their Life cycle

Their larvae are parasitic and once hatched the bee-fly worm-like larva makes it's way inside the solitary bees nest. It feeds on the pollen and nectar reserves that the female solitary bee has collected for 'her own brood'; then the bee-fly larva attaches itself to one of the solitary bee larva and feeds from it. It literally sucks it dry! Then the bee-fly stays in the nest where it pupates. Next spring it emerges from the nest and the cycle starts all over again.

The female bee-fly is a bit of an opportunist. She will also take a chance and lay eggs near the nests of other flies and beetles too. They hover about 4 feet from the ground ... though they never hover very long in the same position. Then they'll dart vertically in the air another couple of feet and then back down again. They do this at warp speed so it's not easy to photograph them while also manually focusing a camera lens.

Believe me they are fast! Their wings flap about 100 times per second. Bumblebees are so slow, clumsy and awkward in flight compared to these stealth flyers.

The males seem to become very territorial and if a female arrives on the scene there's an aeronautical display as they seem to spin together like two kites in mid air.  It happens so quickly that I've never yet been able to capture it on camera.  Blink your eye and you'll have missed it but you won't have missed hearing all that buzzing!

this is an image of a bee-fly in flight
Bee-flies are good pollinators and are about 18mm in length
A bee-fly with it's long thin legs extended
A bee-fly with it's long thin legs extended
You can see the coloured wing pattern quite well in this shot that distinguishes it as Bombylius major
You can see the coloured wing pattern quite well in this shot that distinguishes it as Bombylius major

Create an Ecosystem in Your Garden for Bee-flies

 

If you want to encourage bee-flies into your Scottish garden then you need to grow pulmonaria's, forget-me-nots, muscari, primroses and aubretia. These plants are rich in nectar and are in flower around the same time that the bee-flies are in flight.  While in the wild you might see them feeding on dandelion flowers. Not the type of flower you really want to encourage in your own garden. 

 

I grow lots of pulmonaria varieties in the garden but Pulmonaria 'Blue Ensign' is very popular with the bee-flies as it grows in the same place where they like to hover which is also in a warm and sunny part of the patio.   There the soil gets baked in the sun and it seems to be a favourable spot for solitary bees to burrow and make their nests in.   (click here to see some of the solitary bees in Scotland).  

 

If you've got a patch of ground that's south facing you can make a few holes with a pencil and see if it encourages some solitary bees into your garden.  The solitary bees will feed on the same plants above and collect the pollen for their nests.

 

There you have it - all that's necessary to create your own small ecosystem in your garden!

 

a bee-fly about to suck nectar from a blue pulmonaria flower

They use their long proboscis to sip nectar from the Pulmonaria flowers and their wings never stop even when they are feeding.

The video is in slow motion and shows a bee-fly feeding from some aubretia.

 

When To See Bee-Flies

The best time to see them in flight in Perthshire is from April to early June. Late April being the peak ... but that all depends on the weather. They don't fly unless the temperature has reached 17°C / 62.6°F. So you'll only spot them on a warm and sunny spring day. When it's colder they perch upside down on the branches of shrubs and trees. They can stay perched like that for over a week. It's very rare though to find them in this position. Every year I search around the branches of shrubs. So far I've only ever found one 'sleeping' in the garden and that was back in 2011, I found it perched on a Cercis canadensis 'Forest Pansy'.

a bee-fly sleeping upside down hanging from a leaf.
Bee-fly perching from a leaf in colder spring weather May 2011

I find them fascinating to watch and very cute. Back in 2012 I wrote an article about their aerodynamics.

 

If you live in the UK you'll also be able to watch this amazing video.  Miranda Krestovnikoff has described them as having the body of a bumble bee and the face of a mosquito and aptly named them Beesquitoes!

Rosie Nixon
Follow Rosie Nixon:

Rosie is based in Perth, Perthshire as a garden photographer, writer and nature lover. She enjoys soaking up nature in her own garden and is easily distracted from doing the weeding by anything that flutters, flies, buzzes, creeps or crawls! She enjoys sharing the beauty of creation through her photography. Rosie has been featured on TV on BBC2's The Beechgrove Garden and she uses the Scottish outdoors as her natural light studio. Her work can be seen at the only photographic gallery in Scotland - Close Gallery, 4b Howe Street, Edinburgh.

6 Responses

  1. Millymollymandy

    Great post, Rosie! Thanks for educating me about bee flies, as I didn't know they laid their eggs near solitary bees' nests like that. The video is brilliant. 🙂

    • Rosie Nixon

      It's a great video isn't it …showing them so gracefully in flight like that. Thanks for the visit Mandy 🙂

  2. amanda peters

    Just found you of Mandy's blog, wonderful information and photos of the Bee-fly. Just seen my first one this week after four years of looking ! had not realised how small they were and very cute 🙂
    Amanda xx

  3. myaberdeengarden

    I can't believe I had never heard of these bee-flies. I will now look out for them, but maybe it isn't warm enough up here. I haven't even seen solitary bees up here, though I have at least heard of them and even have a nesting box just in case. A really interesting post – thanks.

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