Don't cut down your ivy flowers.....yet!
Why the gardeners' foe in the bees' best friend
Ivy, often maligned as a garden pest, is vital to honey bees and other pollinators seeking food in autumn, research carried out in 2013 at the University of Sussex revealed.
The researchers surveyed ivy flowers from rural and urban locations in September and October to count the honey bees and other insects foraging for nectar and pollen. They also identified the pollen brought back to hives by honey bee workers to determine the proportion from ivy and then surveyed ivy to determine how widespread it is. In addition, the researchers measured the sugar concentration in nectar collected from ivy flowers by honey bee workers, and determined what proportion of honey bee foragers on ivy were collecting nectar versus pollen.
The main findings were:
- · On average 89 per cent of pollen pellets brought by worker bees to hives were from ivy. There was no difference between hives located in an urban (Brighton) versus a rural area (University of Sussex).
- · 80 per cent of honey bees foraging on ivy were collecting nectar not pollen.
- · Ivy nectar was high quality, with a lot of sugar (49 per cent).
- · Ivy flowers are visited by a wide range of insects, such as late-season butterflies, hover flies, other types of flies, wasps, bumble bees, and the ivy bee (a bee that specialises on ivy). Insects were attracted to ivy flowers in large numbers in both urban and rural areas
- · Ivy is common and available to insects in both town and countryside.
The researchers said “In September and October ivy is the main game in town if you want nectar or pollen. On a sunny day you will be amazed at how many insects there are on it. Our research shows that ivy is hugely important to honey bees and other flower-visiting insects, such as late-season butterflies and hover flies, in the autumn. In fact, if ivy did not exist we would probably try to invent it. Ivy should perhaps be considered a “keystone species” for flower-visiting insects in the autumn and therefore has a very important role in the ecosystem.”
Here are some further ivy facts:
- · Many people are unaware that ivy even has flowers, as the flowers are not colourful, and regard it as a parasite of trees and try to kill it. However, it is not a parasite.
- · Ivy also helps other species as well as bees. The berries are food for birds and thick masses of mature ivy that grows on walls and trees can provide nest sites for birds.
- · The caterpillar of one of our British butterflies, the Holly Blue, feeds on ivy, as do the caterpillars of several moths.
- · Ivy flowers are only made on mature ivy, which has oval leaves and not the well-known hand-shaped leaves made by immature ivy.
- · Ivy only flowers after it has climbed onto a tree, cliff, wall or other structure.
· Ivy flower nectar is accessible for insects with both long tongues (bees, butterflies) and short tongues (flies, wasps, some bees).