Excelsior

Hey all, I am new to doing bees and have a question about how to tell which potions I need to put on them.
If it has a yellow minus on the left side does that mean I need to put the corresponding potion on it or how do I tell what to do?
Thanks
Arathor

Here is a post in the help & player guide sections http://www.uoex.net/forum/viewtopic.php?f=8&t=941


Hope that helps