Its the Neonics again, not pyrethroids
If the paper you are referring to is:
http://pure.rhul.ac.uk/portal/files/10621848/Gill_etal_2012_Nature.pdf
Then what they appear to be saying is that synthetic pyrethroids make the damage from the neonicotinoids worse. Nothing new there, it has been know for years that even some fungicide tank mixes potentiated the effects of the neonicotinoids.
Synthetic pyrethroids have been used on flowering crops for some 30 years, so if there were major problems for bees we should have spotted them by now. Apart from anything else we treat honeybees in their hives with slow release pyrethroid strips to kill parasitic varroa mites.
As one of your other respondents pointed out. The synthetic pyrethroids are based on natural insecticides and the bees seem able to avoid them (also they lock into plant waxes as they dry and most farmers treat early to make sure the spray is dry before bees start foraging).
Oilseed rape is the only UK crop where bees and pesticides really come into contact. Bee pollination does increase yield by a useful amount, but the bulk of pollination is by wind borne pollen. Fruit trees are more dependant, but again solitary bees are better than honeybees or bumble bees.
Oh, one last thing. That is one weird bee in the photo! IMHO it is either a bumblebee drone or a fly passing itself as a bee mimic. Anyone else know better?