the aspen trees are turning and getting ready for winter --- however they
are alive with bees gathering what looks like dot size grains of yellow -
on the underside of the leaf only  and are packing the brood nest with
it... It is not honeydew or nectar --- thought at first it was sort of
insect excreta? has anyone else seen this --- south central B.C. area..
   any ideas?   where can I send leaf for examination??