Butterflies love the butterfly bush

I planted a butterfly bush (also known as buddleja) just a couple days ago remembering the huge butterfly bush we had at the other house and it always attracted butterflies and hummingbirds as well.  I went outside to let the dogs do their business and there was a beautiful Monarch butterfly on the newly planted bush ... but ... I couldn't get a good picture of him since he wouldn't sit still so he flew to a nearby coneflower (echinacea) where he finally posed for me to take a picture!  And a few minutes later one of the hummers that visit my feeder constantly was feeding on the butterfly bush as well, so yeahhh I'm happy the butterfly bush is already doing it's thing.

I've always been a curious one.  Teachers used to get frustrated with my million and one questions about anything and everything.  Thank God we have Google now to answer a lot of my questions!  

So I asked myself how do I know if it's a male or female Monarch butterfly?  

Well, according to the experts males have a small black spot on the hindwing.  Which you can see in the picture below.  Females do not.  Males also have slightly narrower black wing veins.