Can bees see red flowers? This questions causes queries and confusion, particularly given that it is reported bees cannot see red, yet bees are indeed seen visiting red flowers. Here is such a query:
The Short Answer is:
Bees cannot distinguish red very well, however, they can detect ultra violet markings in red flowers, and hence are often seen foraging on flowers in shades of red.
Like humans, bees are trichromatic – that it, they possess 3 independent colour receptors behind each eye lens. However, whereas in humans, these receptors pick up green, red and blue, in bees these receptors are most sensitive to the green, blue and ultra-violet light.
Hence, unlike humans, bees cannot see red or shades of red very well.
Whereas humans see only the visible spectrum, and not ultraviolet light, bees pick up ultra violet rays and markings that are invisible to humans.
So, although bees do not distinguish shades of red, they can, however see ultraviolet markings in flowers. These ultraviolet markings or stripes act as landing guides, leading the bee into the nectar and pollen reward offered to the bee by the flower.
Of course, bees are also attracted to flowers because of their scent.
There may be other factors too, which are relevant to whether a bee will visit a flower or not. These could include:
What would be interesting to know is how all these factors interplay when bees engage in nectar robbing of red flowers.
This topic has been extensively studied by scientists. One of the most famous is a study from an Austrian scientist called Karl von Frisch in 1956. He set up a number of clever experiments in which he trained honey bees to associate coloured cards with food rewards (a dish of sugar water).
Depending on how a bee saw the coloured card, they may or may get confused – for example, visiting a card that was either the same colour or not, would determine whether or not the bees could distinguish between the colours.
Of course, science moves on and what is proven today may be disproven or added to in years to come.
There are certainly a number of flowering plants and shrubs with red flowers that are attractive to bees.
I can't possibly list them all on this site, but here are just a few of them - enough to show you there are options available if you want red flowers for the bees in your garden:
Bumble bee on Zinnia. As far as I'm aware, some of the best Zinnia flowers for bees tend to be part of a 'series' or 'mix' that will include shades of red (as well as pink, yellow and orange). You could try; Zinnia Profusion Series; Zinnia elegans Giant Double Mixed; Zinnia elegans Pulcino Mixed; Zinnia elegans Sprite Mixed or Zinnia elegans Cresto Mixed.
Cirsium rivulare - 'Atropurpureum' is popular with a range of bees and other pollinators. It's a member of the thistles, but is a welcome addition to the garden border.
Bees cannot resist the pollen laden anthers in these beautiful deep red dahlias. Red dahlias recommended for bees: 'Bishop of Auckland'; ‘Bishop of Llandaff’; 'Cascade Ken'; 'Pulp Fiction'; 'Hillcrest Regal'; 'Happy Days Red Flame'; 'Dark Desire'; 'Trelyn Crimson'; 'Pat Knight'; 'Dilys Ayling'; 'Bednall Beauty'; 'Tartarus'; 'Freya's Thalia' and 'Starry Eyes - Red'. More are available!
Various shades of nasturtium exist, including various shades of red. You could try the Alaska series for mixed nasturtiums that include shades of red as well as deep orange.
Inconspicuous the flowers of Cotoneaster horizontalis may be, but these small flowers are a magnet for many bees!
Although I don't have an appropriate image, I'm aware that Alliums range in colours from whites through to purples and reds. For red varieties, try Allium amethystinum 'Red mohican'; Allium sphaerocephalon.
Yes, here are a few of the research papers, publications and articles you can look up for yourself (I have not listed them in any particular order):