I was looking for my queen the other day. I thought I had found her with her yellow mark on her back, but she was really to small to be a queen. I thought it might be pollen, so I tried to gently scratch it off, but it wouldn't come off, although it surely was pollen. I later found the queen. Her mark has got smaller this summer. Not as large as it was in the spring.
Here is a comaparisment of the two:
(http://img176.imageshack.us/img176/3796/queenworkerva6.th.jpg) (http://img176.imageshack.us/my.php?image=queenworkerva6.jpg)
(click to enlarge)
I laughed of the thought of having a lot of bees with the same spot on the back in the hive. It would be fun to find the queen then :-)
I found a bee with almost the exact same spot in my other hive aswell :-)
They are playing a joke on you. Yes it would be hilarious if all the workers decided to put on a yellow mark.
Annette
Wow, I know that these ladies are smart and all, but that is a little spooky. Next thing they are going to dress up in a bee suit and veil to make us think that we have already checked the bees and we will turn around and go home.
F
Worker #30673, just because you can dress like the queen doesn't mean you get to lay around the hive and do nothing all day. Now get back to work! :-D
Your mark is probably from the orchid family , they leave the polen on top of the insect.
I've noticed too that Liatris leaves a mark similar to that on the back, maybe not quite so yellow. None of my queens have been foraging on liatris, so I don't have to worry about matching marks. ;)
I have many bees comming into one of the hives with yellow-white stuff on thier backs that looks like pollen.