Papilio zelicaon and Papilio polyxenes asterius Side by Side Pictures

We compare side by side adult male and adult female anise swallowtails (Papilio zelicaon) and black swallowtails (Papilio polyxenes asterius) from Albany, California and Cleveland, Ohio respectively. 

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Now that we have both males and females of the two species, we decided to compare them side by side. The shapes of the bodies is surprisingly different. While the zelicaon female is extremely fat and stout with a fur smothered ball-like abdomen, the polyxenes female is more petite with a hairless, tube-like abdomen. Both females in the picture are no more than one day old and have not fed, so it should be a fair-enough comparison. It is also consistent between our other females not shown. Another clear difference is the shape of the wings. Polyxenes has slightly longer forewings compared to the hindwings, making it look just slightly more T-shaped which, coincidentally or not, is a characteristic of the model mimic, Battus philenor. Similarily, the tales of the polyxenes seem fatter and shorter like Battus philenor whereas the zelicaon's are long and skinny like tiger swallowtails. However, there does seem to be some variation in both of these traits, so it may be coincidental for these two individuals. 

In the males, there seems to be a similar trend. The zelicaon male's abdomen is much hairer than the polyxenes'. Although the zelicaon male actually looks more T-shaped, it is very noticeable that the polyxenes male does have longer and skinnier forewings. In both sexes, the zelicaon has a larger (wider) and hairier thorax.

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Authors
Brian Liang

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