Dear Francinaldo,

Before reading all the great papers suggested by my colleagues, I think you need a more basic introduction into the mechanisms of colour vision in bees (and other insects). I suggest to read the following two papers:

Chittka, L. & Kevan, P.G. (2005). Flower colour as advertisement. In Dafni, A., Kevan, P.G., Husband, B.C. (eds.) Practical Pollination Biology. Enviroquest Ltd., Cambridge , ON , Canada , pp. 157-196.

Chittka, L., & Wells, H. (2004). Color vision in bees: mechanisms, ecology and evolution. In: Prete, F.: Complex Worlds from simpler nervous systems; MIT Press, Boston pp. 165-191.

The first paper provides a step-by-step instruction how to measure spectral reflectance of (artificial) flower surfaces and how to calculate the respective colour loci (and distances) in a bee colour space. The second paper gives you a more general introduction into colour psychophysics and evolution of colour vision in bees. Both papers can be downloaded from Lars Chttka’s webpage:

http://chittkalab.sbcs.qmul.ac.uk/

Best wishes,

Johannes

Bees can distinguish only four colors of electromagnetic spectrum, they are yellow, blue-green, blue and ultra-violet , they cannot distinguish green color due their blurred vision,because bee have compound eye made up of small eyelets. The wave of light where bees respond is 650nm to 300nm that is the vision is shifted towards more energetic region of electromagnetic spectrum, that is why they cannot recognize red color.

For details visit following web site

http://www.sewanee.edu/chem/Chem&Art/Detail_Pages/ColorProjects_2003/Crone/

Hi,

have a look here: http://www.cals.ncsu.edu/course/ent425/tutorial/colorvision.html

Cheers, Nadine

Dear Francinaldo,

I do not know Euglossini bees. When teaching general entomology I use these resources on honey bees. Some of them may be interesting.

The web site cited by Sita Raju cannot be found.

http://www.neurobiologie.fu-berlin.de/menzel/Pub_AGmenzel/Giurfa-et-al_JCompPhysiolA_1997.pdf

http://www.academia.edu/858430/Nocturnal_bees_learn_landmark_colours_in_starlight

http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/upload/Yang_et_al_-_J_Insect_Physiol_-_2004.pdf

http://expertiseandevidence.com/wp-content/uploads/2013/01/WuMorTanRei2012.pdf

https://www.bienenforschung.biozentrum.uni-wuerzburg.de/uploads/media/117_SpaetheTautzChittka_JEB_2006_01.pdf

http://westmtnapiary.com/Bees_and_color.html

http://epress.anu.edu.au/wp-content/uploads/2011/02/ch113.pdf

http://www.dailymail.co.uk/sciencetech/article-473897/A-bees-eye-view-How-insects-flowers-differently-us.html

Thank you all. It is a very interesting field of work. I am at the begining. I have to study hard to understand the bee color vision and apply this knowledge in my work. As only males visit flowers in search of aromatic substances, my main question was to know if the color of flowers is an alternative tool for finding a floral source by male euglossine bees, or only the odor plume governs such behavior, as well as the spatial memory. Thanks.

Dear Francinaldo,

I think the one of most important things that could help you to interpret your results is to recognize is that the names "red" and "green" for the colours you tested are not useful indicators of how these stimuli are perceived by your insects (see e.g. Döring & Chittka 2007. Arthrop. Plant Interact. 1: 3-16, or Chittka & Döring PLoS Biol.5: e187 or Döring et al. 2009. Proc Roy Soc. B 276: 121; Archetti et al. 2009 TREE 24: 237-238) .

Instead you would need to measure spectral reflectance of the stimuli you presented. You can then feed these spectra into models of how the stimuli are processed by insect eyes, provided you know the spectral sensitivity functions of their eyes. This could give you an indication of how similar the "green" and "red" stimuli you used are in your bees' eyes.

Depending on the specific stimuli you used you might well find that they are not that different from each other in bees' eyes compared to what we humans are seeing - or they might be very different. Without measuring the spectra with a spectrophotometer there is no way to know. When measuring the spectra you will also need to make sure you are covering the UV spectrum (down to 300 nm).

Finally, if you are more interested in the response of these bees to colours it would probably be useful to conduct another experiment where you present more colours and get more information on the spectral properties of these stimuli beforehand (e.g. in the field: Döring et al. 2012: Physiol Entomol. 37:360-368; for studies in the lab see many of Lars Chittka's papers).

This is hectic for me to answer before i completely get into your experimental set up silva. i ask how do you know red is invisible for bees? if you found articles regarding this then you certainlt found related to green also as because the rods and cone cells which responsible for color coding provide genes opsin for color differentiation there is different opsin for coding green , red and blue as well...instead of using artificial color flowers you can try real true flowers. then for concluding research..upto my knowledge you can do with both green and red flower in same time and look for the genes responsible for red as well as green color and study the expression and analysis how and when and which color is more responded by bees? will it be useful? think this.

Dear Francinaldo,

the colour preference of bees has various aspects: 1. Not all bees exhibit similar colour preferences; about colour prefrences in euglossine bees there is almost nothing known. 2. Colour is more than hue; you mentioned already the contrast to the background, but also colour purity has an effect on colour choice. 3. Bees are sensitive in the ultraviolet range of wavelengths; thus UV-reflection properties of target colours have to be considered. 4. Choice behavior of bees (at least honeybees and bumblebees) is colourblind, if the target colour is seen under a small visual angle.

I recommend for further reading:

Katzenberger, T.D., Lunau, K., Junker, R.R. (2013): Salience of multimodal flower cues controls bumblebee’s initial responses and learning behaviour. Behav. Ecol. Sociobiol. (in press)

Papiorek, S., Rohde, K., Lunau, K. (2013): Bees` subtle colour preferences: How bees respond to small changes in pigment concentration. Naturwissenschaften 100: 633-643.

Rohde, K., Papiorek, S., Lunau, K. (2013) Bumblebees (Bombus terrestris) and honeybees (Apis mellifera) prefer similar colours of higher spectral purity

over trained colours. J. Comp. Physiol. A 199: 197-210.

Lunau, K., Papiorek, S., Eltz, T., Sazima, M. (2011): Avoidance of achromatic colours by bees provides a private niche for hummingbirds. J. Exp. Biol. 214: 1607-1612.

Best wishes

Klaus

I appreciate all considerations mentioned by Dr. Thomas and Dr. Klaus (and the others). I am reading all material listed here. I also think that the fragrances on the EVA circles surfaces may alter the light reaching the bees eyes. I could not assess if my results reffer to the innate or acquired bee prefference (Euglossa genus preffered yellow, Eulaema genus not - for example). Euglossa is found commoly in yellow flowers. I think it may influence the choices when bees are at the artificial flowers. In cerrado region, where I conducted my experiments, the lowest abundance of bees (compared with other ecosystems - Amazonia and Atlantic Forest) helped to measure more acurately the bee choices. I know that to publish my results I have to study a lot and take into consideration all above-mentioned questions. Now I am sure that my posdoctoral will be with this subject. Thank you all once again.

Dear Francinaldo,

You may be interested in the recent papers we have published, including

Vereecken NJ, Dorchin A, Dafni A, Hötling S, Schulz S & Watts S, 2013. A pollinators’ eye view of a shelter mimicry system. Annals of Botany, doi:10.1093/aob/mct081.

and

Vereecken NJ, Wilson CA, Hötling S, Schulz S, Banketov S & Mardulyn P, 2012. Pre-adaptations and the evolution of pollination by sexual deception: Cope’s rule of specialisation revisited. Proceedings of the Royal Society of London B 279(1748): 4786-4794.

Both PDFs are available on my RG page.

Best wishes,

Nico

Thanks, Nico.

Dear Francinaldo,

Before reading all the great papers suggested by my colleagues, I think you need a more basic introduction into the mechanisms of colour vision in bees (and other insects). I suggest to read the following two papers:

Chittka, L. & Kevan, P.G. (2005). Flower colour as advertisement. In Dafni, A., Kevan, P.G., Husband, B.C. (eds.) Practical Pollination Biology. Enviroquest Ltd., Cambridge , ON , Canada , pp. 157-196.

Chittka, L., & Wells, H. (2004). Color vision in bees: mechanisms, ecology and evolution. In: Prete, F.: Complex Worlds from simpler nervous systems; MIT Press, Boston pp. 165-191.

The first paper provides a step-by-step instruction how to measure spectral reflectance of (artificial) flower surfaces and how to calculate the respective colour loci (and distances) in a bee colour space. The second paper gives you a more general introduction into colour psychophysics and evolution of colour vision in bees. Both papers can be downloaded from Lars Chttka’s webpage:

http://chittkalab.sbcs.qmul.ac.uk/

Best wishes,

Johannes

Thanks Johannes. I will read them.

I do think that the odor would be a confounding issue, among the others addressed here. If you want to add a scent for the bees to use in locating the artificial flowers from a greater distance, you could use the same aromatic compounds on all color options. In this way, you would have a better idea of whether the bees were preferring the color or the odor. Regardless, you have to control one or the other. I would love to see someone work out the color vision of your study group! Thanks.

I still need to measure spectral reflectance of the stimuli I presented to male euglossine bees. It is difficult to find a group that performs such measures here in Brazil.

The attached might be helpful.

Bees see “primary colors” as blue, green and ultraviolet .They can distinguish yellow, orange, blue-green, violet, purple, as combinations of their three primary colors.

Wish you good luck.