How to Gender Identify a

Have you ever asked yourself, "How do you know if a Monarch is a boy or a girl?" Well, it is actually quite easy to do if you want to gender identify the adult butterfly or even the pupa! All it takes it a good eye…

Look at these two pictures carefully…compare both butterflies and see if you can find the ONE thing that the butterfly on the LEFT has that the butterfly on the RIGHT does NOT have.

malemonarch femalemonarch

So, did you 'spot' the difference? If you said, "The Monarch on the left has a spot on its hindwings and the other one doesn't" then you are absolutely correct! Those single black spots identify that the one on the left is a male. These 'scent spots' are scales that the female does not have.

If you didn't see the spots, here they are marked for you!


The male butterfly's abdomen end in what is called 'claspers' which are different from a female butterfly's abdomen. a

In this picture here, you can see the 'forked look' of the claspers and if you look very carefully, you can even identify that black scent spot of this beautiful male Monarch!

You said you can gender identify the pupae, too?

That's right! You can even identify a male from a female when the Monarch butterfly is a pupa (in its chrysalis)! A magnifying lens or reading glasses can be handy if you have a difficult time seeing things that are really tiny!

Look carefully at the top of these two pupae…find the cremaster (the black 'stem'). Now, look at the black dots under the cremaster. This is where you want to look for gender identification purposes.

femalemonarchpupaid malemonarchpupa

Notice anything different? The one on the left has something that the one on the right does not…

Look VERY carefully! It is so tiny that it may be hard to spot. It is a vertical line…(I know, they BOTH have vertical lines but those are at the top by the cremaster…keep looking!)

If you didn't see it, then look at the next two pictures to see if they help you.


Do you see it now? The pupa on the left is a FEMALE and the pupa on the right is a male. The female has that vertical line after the black dots below the cremaster ends. Males do NOT have that line.

Isn't that easy?

You now have the tools to help you identify Monarch butterflies and pupae!

PS: As for the caterpillars…you would have to dissect them in order to be able to identify male from female and we wouldn't want to do that!

2010–2013 Sherry Skipper Spurgeon All Rights Reserved.