Pollen beetles are harmless so there's no need to get rid of them. Runner bean flowers and tiny podlets drop when the plant is short of moisture - they're very thirsty - and if pollination is poor. If bees etc are in short supply you can pollinate the flowers with a paint brush. And we've had weird weather this year with alternating hot and cold, droughts and rain.

And runner beans hate lots of heat - flowers refusing to set this year is a problem all over the place, so you're not alone. Beattie's right about water supply, that's important, and its one of the reasons runners should be planted in a deep trench full of well rotted compost at the time of planting - this helps with moisture and nutrient supply.