When you hear about pollination, it’s likely that you think about bees first. However, hoverflies are also very effective pollinators, and are as good as collecting pollen via the hair on their bodies as bees1.
However, hoverflies are not only important in pollination! They can have other roles in ecosystems, as some hoverflies can recycle biological materials and control pests, such as aphids, on plants1,2,3.
If you want to attract more hoverflies to your garden, there are a number of things you can do:
The first thing you can do is reduce the mowing of your lawn. Allowing it to grow in spring and summer will provide hoverflies with plenty of forage, as flowers like dandelions and lesser knapweed may bloom. Doing this will also help other pollinators, like bees and butterflies, as well as wildlife such as hedgehogs, frogs and birds seeking shelter.
You can also attract them to your garden and help them thrive by planting hoverfly-friendly flowers. There are a variety of different plants you can introduce into your garden if you don’t have them already. Plants like late flowering asters (Aster, Rudbeckia and Helenium), knapweed, ivy and fennel are great for foraging hoverflies, as well as dandelions and buttercups (which you’ll get for free if you mow your lawn less)4,5. Research at the Garden has been undertaken to determine where hoverflies are foraging by DNA barcoding pollen found on their bodies, so this also gives an indication of which plants are suited to hoverflies. It’s also a good idea to have a variety of plants that flower at different times of year, as this means that hoverflies like the marmalade hoverfly (Episyrphus balteatus) have access to nectar all year round. For example, you could plant fennel to flower in summer and ivy to flower in autumn.
Additionally, you can create a hoverfly lagoon, which is a fun and interesting activity for children and adults alike. Some hoverflies, such as the common drone fly (Eristalis tenax), lay their eggs in water, which then develop into larvae (also known as rat-tailed maggots) and dwell in the water. If you have a pond, you may have already seen them. However, if you don’t have a pond, you can easily make a hoverfly lagoon with things lying around your house and garden. You could make one out of an old washing up bowl, plastic storage box or large milk bottles, for example. This is a great way to recycle any containers you have. The container of your choice can be filled with water and then leaves, grass and twigs can be added. These will float and so will act as platforms for female hoverflies to sit on when they lay their eggs. The lagoon is best placed in shaded positions, where evaporation is lower. Once your hoverfly lagoon is completed and has been in place for a few weeks, see if you can spot any rat-tailed maggots swimming around.
These actions will encourage hoverflies into your garden all year round, and hopefully in larger numbers than before. These actions aren’t only beneficial for hoverflies: they will also encourage other insects into your garden, and therefore birds and small mammals also.
If you’d like more information on creating a hoverfly lagoon, visit this website: https://www.thebuzzclub.uk/hoverfly-lagoons
References
1.Stubbs AE and Falk SJ. British Hoverflies. 2nd ed. Reading: British Entomological Society; 2012.
2.Doyle T, Hawkes WLS, Massy R, Powney GD, Menz MHM and Wotton KR. Pollination by hoverflies in the Anthropocene. Proceedings of the Royal Society B: Biological Sciences [Internet]. 2020 August 21 [cited 2020 Oct 12]. Available from: https://royalsocietypublishing.org/doi/10.1098/rspb.2020.0508
3.Chambers RJ and Adams THL. Quantification of the impact of hoverflies (Diptera: Syrphidae) on cereal aphids in winter wheat: an analysis of field populations. Journal of Applied Ecology.1986;23:895-904.
4.Gardener’s World. The best flowers for hoverflies. [Internet]; 2019 June 28 [cited 2020 Oct 13]. Available from: https://www.gardenersworld.com/plants/the-best-flowers-for-hoverflies/
5.Sadeghi H. Abundance of adult hoverflies (Diptera: Syrphidae) on different flowering plants. Caspian Journal of Environmental Sciences. 2008;6(1):47-51.