Just wanted to do a quick survey of what kind of pollination tactics ya'll use in your greenhouses. If course if its an open hoop house, there's bees and other things, but I'm thinking more along the lines of a closed (except for venting) situation (year round maybe).
Last year was my first greenhouse year, and I grew tomatoes, cucumbers, and peppers, all in large tubs. I left the door open 24-7 once it was warm enough; the tomatoes didn't have as big a yields as the outdoor plants (though they did mostly ripen, unlike most of the outdoors ones--too rainy!). I found that if I didn't pollinate the cucumbers myself, they would just shrivel up and fall off; I picked male blossoms off and brushed them firmly against the female blossoms. The indoor peppers produced about as much as the outdoor peppers (I believe they don't need insects for pollination?).
I think this year I will try to grow some big enticing flowers near the door to my greenhouse to tempt insects in. And maybe some pungent flowers inside, too.