The key and the lock – attracting certain flies to your garden

Flies or dipteria covers quite a gamut of flying insects. Here I’m not talking about blue bottles but insects like hoverflies, drone flies and bee flies. These eat nectar and/or pollen of certain flowers and help us with pollination.

But that’s not the only reason why they’re a welcome addition to the garden. Although adult hoverflies are mainly flower specialists, consuming nectar or pollen, hoverfly larvae are mostly carnivorous. The larvae of some hoverfly species eat aphids. Hurrah! While the larvae of some other species, such the drone fly, live in stagnant pools of water where they consume bacteria. Points for them too. Also some files are an essential part of the food chain that support insectivorous birds such as warblers and robins.

Typical diptera mouthparts are made up of a short fleshy tube they use to suck up liquid or semi-liquid food. Some also ingest pollen. Because the tube is quite short, diptera tend to visit small, flat flowers which present their nectar openly.

Many flowers of the carrot or umbellifer family (Apiaceae), are like this. A few great ones for the garden – that are also really easy to grow – are:

  • Orlaya grandiflora – finely cut foliage and produces umbels of tiny pure-white flowers surrounded by showier white petals. 
  • Ammi visnaga – forms flat, dense heads of green-white flowers set against ferny, green foliage.
  • Bupleurum griffithii 'Decor' – lime-green with tiny flowers surrounded by a ruff of zigzagged bracts. 
Hoverfly on  Euphorbia  by D. J. Martins

Hoverfly on Euphorbia by D. J. Martins

Other flowers that are attractive to the short ‘tongues’ of the dipteria include some members of the Euphorbiaceae family, and members of the Asteraceae that have very small florets in the central disc of each flower. A few good ones are:

  • Euphorbia conigera – a compact summer-flowering perennial with lime flower-heads that brighten shady corners. Wear gloves when handling though – the sap may irritate your skin.
  • Aster amellus – showy, rich purple-blue flowerheads that have golden yellow centres. Great for end of summer and autumn interest.

Finally, and worth a mention is the bee fly. They are common in gardens during the early months of the year so really need early flowering plants to feed from such as Aubrietia and Primula.

Come back to my blog to find out how to encourage other insects to your garden. This is in the run up to BBC Gardeners’ World Live in June where I’ll be exhibiting my border: “Useful and beautiful.”