Fabulous Foxgloves
The flowers show many easily observable adaptations to being pollinated by bees. First of all, you can look at their shape. Their main pollinators are bumble bees, especially long-tongued species such as the common carder bee, so the long, bell shaped flowers are ideally suited to being pollinated by them. The lower lip of the flower allows the bee to land before climbing up the bell.
The dark pink ‘splodges’ on foxgloves are not there just for decoration but are believed to be ‘nectar guides’ which direct insects towards the nectar at the base of the flower. They act a bit like lights along a runway guiding the pollinators in! The entrance to the flower also has guard hairs which are believed to deter other smaller insects from crawling into the flower. The hairs may also offer some support to the bumble bee as it tries to make its way up the flower.
Foxgloves also highlight the really interesting bee behaviour of nectar robbing. Normally the relationship between bees and flowers is one of the best examples of mutualism (when two organisms of different species work together, each benefitting from the relationship), with the flowers getting pollinated and the bees getting food. However, nectar robbing occurs when bees either bite through the base of a flower to ‘steal’ nectar (primary robbing) or use robbing holes that others have made (secondary robbing). It usually happens when a short-tongued bee, for example a buff-tailed bumblebee (Bombus terrestris) wants to get the nectar from a flower with a long corolla or ‘bell’. As she can’t reach the nectar, she bites a hole in the flower so that even her short tongue can reach it! There is even evidence that bees pass on this crafty behaviour to previously well-behaved pollinators!
So keep a look out for bees acting suspiciously around your foxgloves or for any robbing holes that show you that a burglary has taken place! PS Don’t forget that foxgloves also contain a substance, digitalis, which is used to stimulate the heart. For this reason they should not be eaten and are considered poisonous. More about this in my next blog.
Photo credit: Tamsin Bent
The dark pink ‘splodges’ on foxgloves are not there just for decoration but are believed to be ‘nectar guides’ which direct insects towards the nectar at the base of the flower. They act a bit like lights along a runway guiding the pollinators in! The entrance to the flower also has guard hairs which are believed to deter other smaller insects from crawling into the flower. The hairs may also offer some support to the bumble bee as it tries to make its way up the flower.
Foxgloves also highlight the really interesting bee behaviour of nectar robbing. Normally the relationship between bees and flowers is one of the best examples of mutualism (when two organisms of different species work together, each benefitting from the relationship), with the flowers getting pollinated and the bees getting food. However, nectar robbing occurs when bees either bite through the base of a flower to ‘steal’ nectar (primary robbing) or use robbing holes that others have made (secondary robbing). It usually happens when a short-tongued bee, for example a buff-tailed bumblebee (Bombus terrestris) wants to get the nectar from a flower with a long corolla or ‘bell’. As she can’t reach the nectar, she bites a hole in the flower so that even her short tongue can reach it! There is even evidence that bees pass on this crafty behaviour to previously well-behaved pollinators!
So keep a look out for bees acting suspiciously around your foxgloves or for any robbing holes that show you that a burglary has taken place! PS Don’t forget that foxgloves also contain a substance, digitalis, which is used to stimulate the heart. For this reason they should not be eaten and are considered poisonous. More about this in my next blog.
Photo credit: Tamsin Bent
