My friend and coworker Julie has been teaching me all about rearing bumble bees lately. She is starting a few colonies in the lab, and every once in a while there are casualties. And to my absolute joy, I get to dissect them so that they don’t go to waste 🙂 Typically when they die we look for parasites and signs of disease, but at this time of year, we are also interested in whether they are mated or virgin queens. So in this dissection, I was looking for the spermatheca, the organ where sperm is stored until it is released when eggs are laid. In a virgin queen, the spermatheca is completely clear, like a little piece of perfectly round glass. The mated queens have a milky spermatheca. As you can tell, this one had mated.
There’s a lot of other stuff going on here, too. You can see the intestines, the white ovaries extending up from either side of the spermatheca, the stringy white malphigian tubes (part of the excretory system), and lots of other good stuff that I will save for another time.