I have seen this on a few occasions. For example, today not long after it rained I went over to observe my bees (B-TV)(Watching Chickens is Chick-TV). They were bringing pollen in. I know everything was still wet from the downpour we got an hour earlier.
My thinking is probably wrong on this, but wouldn't the rain have wash the pollen off? I figured it would be tomorrow before they could get back at harvesting.
I noticed the same thing today - as soon as the rain stopped, the bees were all over the plantain collecting pollen.
do field bees that get caught in storms find shelter? i ask because i suppose they could return with pollen they gathered before the rain. i'm just thinking out loud. do some blooms close during rain?
i've never thought about any of this. time to google.
I also watched my bees after our rain. Some had pollen!
A review article, freely accessible about rain and pollen is:
Pollen resistance to water in 80 angiosperm species: flower
structures protect rain-susceptible pollen
http://tinyurl.com/PollenandRain (http://tinyurl.com/PollenandRain)
Couple of points-- much pollen is viable for only brief periods, bees don't care, but flower are adapted to this.
Structure of the flowers, orientation of the flower, oil/waxy coating or ornamentation of pollen grains (using surface tension to avoid wetting) all protect the pollen
pretty interesting. thanks.