Honeybee colour vision can be tuned to relatively small spectral differences

Honeybees (Apis mellifera) Learn Color Discriminations via Differential Conditioning Independent of Long Wavelength (Green) Photoreceptor Modulation
We tested honeybee vision using light emitting diodes centered on 414 and 424 nm wavelengths, which limit activation to the short-wavelength-sensitive (‘UV’) and medium-wavelength-sensitive (‘blue’) photoreceptors. Honeybee colour vision can be tuned to relatively small spectral differences, independent of ‘green’ photoreceptor contrast and brightness cues.
http://www.plosone.org/article/info%...l.pone.0048577

It is obvious that all of the neonicotinoids have some sub lethal effects on bees (primarily nervous system) so why does the EPA constantly give conditional license to each of these pesticides and upon later review do nothing. Is it really as it appears to be a case of obvious corruption (i.e. the exchange of players between the U.S. government and Monsanto).