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Photo#574751
Male Eastern Tiger Swallowtail - Papilio glaucus - male

Male Eastern Tiger Swallowtail - Papilio glaucus - Male
Kokomo, Howard County, Indiana, USA
August 7, 2011
Is there any way to tell from this photo whether this is a male or a female? I know it's an Eastern Tiger Swallowtail, but I didn't get a chance to see it with the wings open before it flew away.

Moved

Moved
Moved from ID Request.

He is a male
If you look at the end of the abdomen, there is a relatively flat, roughly diamond-shaped part right at the tip. That is the right "valva" or "clasper", which is a part that only males have. The tip of a females abdomen is blunter and has no such appendage. There is a pair on the male, that lie side to side (from the lower side there is a groove visible where the two meet). These valvae are large and easily visible in many butterflies, but may vary somewhat in shape. In some though, they are small and often hidden by long hair-like scales (but still the tip of the usually more slender abdomen will be of a different shape from that of the females). On this species, there are other clues in the wing shape and pattern (even on the under side) but they are subtle and hard to describe briefly. Most obvious is that the black markings are often crisper and narrower in the males. Also, male wings are usually a little less broad in shape.

This fellow looks to be in good shape (all the parts seem to be there and intact), but he also looks old and somewhat faded (or perhaps the exposure makes him look that way?). This aging tends to make the males look more similar to females in coloring, but doesn't change the pattern itself.

 
Thanks, David!
Frass or Not?
I was prepared to frass this photo as soon as my question was answered, but I'd hate for the valuable information you gave me to be lost - you are an excellent teacher!

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