The Importance of Ivy to Insects

Often seen as a pest in many gardens Ivy (Hedera helix) can be found across Britain. It is well known that this important native plant provides cover to a wide variety of bird species but what about its importance to insects?

As you can tell from the title of this post, I believe that ivy should be encouraged where possible due to its vital importance to insects. Firstly it provides cover and a hibernation site for a variety of insect species that overwinter in ivy bushes. Secondly ivy itself is eaten by around 70 insect species so is an important foodplant.

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Thirdly as ivy flowers rather late in the year it provides a really, really important floral resource for a large number of insects. In one study nearly all of the pollen collected by Honey Bees (Apis melifera) in Autumn was from Ivy.

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The nectar is also used by a wide variety of species and may even be more important than the pollen to insects. When examined, honey bee crops were found to contain almost only nectar from ivy. 94.6% of bumblebees visiting ivy flowers have also been found to not have been collecting pollen, they are visiting for the sugar rich nectar instead.  It is thought that this nectar may even increase honey bee colony fitness allowing them to survive better in the winter.  Ivy is also important for wasps, hover flies, moths and butterflies. Over 72 species have been recorded on ivy and this list is thought to be incomplete.

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Finally, I’m going to mention Colletes hederae, a solitary bee species that specialises on feeding on ivy flowers. This species was only discovered in 1993 and has only been in Britain for a few years (please note that this doesn’t mean it isn’t native or is invasive). This species is now spreading northwards in Britain, if you see one of these bees then please report it here . Little is known about the ecology of this species so there is lots still to discover.

Colletes hederae female

Colletes hederae female

Colletes hederae female

Colletes hederae female

I hope that this short post makes you think twice before you chop down the ivy in your garden.

Further Reading

Ivy: an underappreciated key resource to flower-visiting insects in autumn

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7 responses to “The Importance of Ivy to Insects

  1. Ivy is taking over our garden & it is alive with bees, hovers & butterflies 🙂

  2. I’d be interested to have more info on the statement you make about ivy nectar helping honey bees to survive better through winter. I’m a beekeeper and would be interested in the scientific background. There’s a lot of old wives’ tales about ivy in the beekeeping community.

    • Dear David,

      Thank you for your comment. The study I linked to at the bottom found that ivy nectar was 49% sugar and that of the honey bees studied, 89% of the pollen they collected in the Autumn was from ivy flowers. 80% of the honey bees also only visited the ivy flowers for nectar so shows that both the nectar and pollen must be important for them! I’m not sure that the study proves that this actually helps the bees overwinter but it would make sense in my eyes if it did, providing they could store the pollen and nectar overwinter. It would be interesting if this was studied further.

      I hope that helps,

      Ryan

      • Thanks for that Ryan. I’ve skimmed the paper and will look in more depth when I’ve more time. The statement “It is thought that this nectar may even increase honey bee colony fitness allowing them to survive better in the winter” was, as you now admit, conjecture more than science. You also said “When examined, honey bee crops were found to contain almost only nectar from ivy” which is not proven by science in the paper as far as I can see so far. The paper says “strongly suggesting that the sole content of bee crops was ivy nectar” a supposition based on % sugar content but no analysis of other factors. But there again it is a good suppostion as honey bees tend to only feed on a single nectar source and do not normally mix nectars in the honey sac.

        I would say that averaged over many years (rather than just two) and over a wider area than the balmy Sussex coast, that nectar is the principal attractant to ivy for honey bees. Comparitively ittle pollen is collected unless the queen is actively laying and brood being reared but honey bees will always seek out nectar with high concentrations of sugar (it is easier to convert and reduce to storeable honey – 80+% concentration – in the damper weather of autumn). In the south of Britain the queen may continue to lay throughout winter but farther north there may be a broodless period.

        Many beekeepers believe Ivy honey is poisinous to humans and bees! It is an acquired taste but like the bees I love it!

        By the way the I first became aware of ivy bees at least 4 years ago down here in Dorset. They regularly feed on the ivy in one of our apiaries.

  3. Great piece; and marvellous pictures. I’ve been trying to tell people how essential Ivy flowers, and the shelter,of what must be our most important evergreen plant, is for years.

    A friend had a very old pear tree in her garden that was as much ivy as peartree, but it still cropped prolifically every few years. The flowers in the Autumn were always packed with hoverflies, bees, wasps and hornets. With the tits, chiff chaffs and chaffinches and dunnocks popping in and out of it as well, I could watch it all day.

    Highlight was when the Red Admirals showed up on mass, each Autumn,and covered the ivy like Christmas tree decorations. They had probably been stopping off there for a century. It was so important!

    Then, came the berries, and the tree would boil with wood pigeons and fieldfares performing amazing antics to get at berries along twigs too thin to support them.

    I think it may actually be our most important plant.

    I was quite dismayed to hear my friend say the ivy had died, after I left and stopped looking out for it. It must have been catastrophic for a whole ecosystem that had developed over a century or more. Very sad loss. No wonder we are losing all the bees, with tidy maniacs with chainsaws and strimmers, making less and less of this plant able to flower any more.

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