So I'm just not getting many tomatoes this year.
The bees come and hang out with the squash blossoms and the sunflowers, and pretty much ignore the tomatoes. The bumblebees like them, though the two poor bumblebees I see in there are working hard trying to cover all those blossoms.
So I went to look up tomato pollination, and I find there is a whole mythos about tomatoes being self-pollinating. Apparently, according to this site, "The wild progenitor of our domestic tomato, in its native Peru, was pollinated by a solitary bee that was specifically adapted to it. As tomatoes were carried to other areas, its pollinator did not go with it, and pollination was often lacking."
Looking around, I came across a wonderful Instructables which explained things further:
"Tomatoes, as well as other members of the Solanaceae require a special kind of pollination to achieve proper fruit set. This form of pollination is known as "buzz pollination". Buzz pollination is accomplished by Bumblebees (Bombus), by gripping the flower with their legs and vibrating their flight muscles; honeybees (Apis) are incapable of doing this. In small gardens, bumblebee populations can be insufficient to properly pollinate tomatoes and related plants. Here's how to buzz pollinate your plants to produce larger fruits."
The 10-second video and the one-step Instructable then goes on to demonstrate a perfect (and hilarious) way to pollinate your tomatoes, which I will allow you the pleasure of discovering. It made me laugh.
Back at the first site, they tell us "Greenhouse growers for many years employed humans with electric vibrators (one brand name: Electric Bee!) to accomplish pollination. Today these have been mostly replaced with cultured bumblebees who do it more efficiently and cheaply."
All of which explains why I saw the single bumblebee in my garden, going from flower to flower and making a strange "bzazz" noise as it climbed onto each one. Yay, bumblebees! Still, I think I'll follow the Instructables and see if it helps.