Arnold, when I used the terms primary pollinator and secondary pollinator, I was using them in a purely de facto sense: by primary pollinator, I meant whatever pollinator plays the most important role in the survival of a species; by secondary pollinator I meant whichever other ones play (or have played) a role. You seem to be aware of an existing breakdown of pollinators into primary (bees) and others (secondary). That is not what I was thinking of. Aren't bees also attracted by fragrances? I know that sight is important to them, that they see flowers differently than we do, that flowers have bee guides and other patterns visible in UV light, but I thought scent was important, too. Jim McKenney Montgomery County, Maryland, USA, USDA zone 7, where - and it's amazing to me - we have bees this week! The local bee population tanked years ago, and bees are no more common now here than bison.