http://www.southernexposure.com/isol...es-ezp-35.html
I've posted the above here many times but whenever insect pollination of tomato blossoms comes up I do it again.
It's written by Dr. Jeff McCormack who used to own SESE and is The best info I've found re insect pollination/
Sweat bees. aka Halictids, are THE most important pollinators of tomatoes but they are so tiny you don't even know they are doing their thing.
I think Jeff's distances for tomato plants are way too conservative but then he was commercial and had to do what he had to do.
After growing over 3,000 varieties I don 't think I've ever seen bumble bees pollinating but that maydepend on their frequency in different areas. Fact is that most blossoms are already pollinated as the stigma moves upwards, before the blossoms are even open. Honey bees yes, see them a lot and yes, they work the blossoms, but for the protein pollen as an energy source since tomato blossoms have no nectar.
There are a few varieties that have crossed more frequently than others for me, but I don't think that's relevant here, since often in hot weather the stigma exherts, that is, gets above the pollen bearing anthers and thus easier for insect pollinators to X pollinate,
Carolyn