Quote Originally Posted by Oldtimer View Post
Bees can mostly detect this, although I have seen bees gathering pollen from wind pollinated pine trees, this at a time when there were few options.
Both my wife and I have witnessed bees covering our scrub pines at a certain time in the summer. Usually late in the evening and usually when there has been plenty to forage on during the day. We guessed that they were after the sap for propolise but we really don't know.