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Effect of Exposure of Bees to Light

Honey bee colonies in hives live in both darkness inside their hives and in light when they are out foraging.

If two colonies are opened in sunlight and some frames are removed from each to spare boxes. And if then the exposed combs are spread apart so that they are roughly twice as far apart as they would be normally. Then after a period of about ten minutes the frames from the two colonies can be mixed without fighting.

The above is a simple observation the actual reasons are not understood, but this does not stop us making use of the phenomena.

The honey bees visible spectrum starts a little higher than human eyesight at about 422 nanometres and extends to 646 nanometres at the red end (Bertholf 1931) these are extremes that are themselves variable... 422 nm - 483 nm and 504 nm - 646 nm respectively. Normal human response is 400 nm to 770 nm (there are also 'spreads' to these figures). Von Frish however, states 313 nm as the lower limit and speculates that this is perceived in a chromatic fashion rather than as flourescence.

Spectrum of bees eysight

The green curve represents human spectral response, whilst the overlaid red curve is that of the honey bee. There has been some conjecture that the bee's response either stays at roughly 10% or increases again to a secondary peak as the wavelength decreases into the ultra violet. Such conjecture mainly stems from the ray patterns in flowers that become enhanced (to human vision) when illuminated by UV.

Much of this work will be revisited using direct measurements of nerve impulses using electrodes implanted in bee's brains. The work is under way, but is considered too incomplete for publication... When confidence can be placed in the results I will publish a page on this website.

The effectiveness of each part of the spectrum. In 1917 many experiments were performed by S.O. Mast, whereby bees reactions to coloured light were compared to their reactions to white light (white as judged by human eyes).

Individual colours can be distinguished by humans, Von Frish and Mast consider the visualisation of colour to be the same in bees as in humans, but Bertholf attempts to consider 'brightness', 'colour' (frequency or wavelength) and 'saturation'. There are many pitfalls in this work which up to now has relied on human observation to establish relative 'brightness' between a 'coloured' light source and a 'white' light source.

I personally believe that all this work needs re-appraisal due to a revision in the theory of colour vision that occurred around 1980.

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Written... 08 March 2002