Papilio eurymedon Pupae Arrive

We received 12 pale swallowtail (Papilio eurymedon) pupae today. 

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Even though pale swallowtails (Papilio eurymedon) are supposed to be a common California thing, our particular region doesn't have them. . . or, we kind of do but they are rare and would only ever found in natural places like canyons. Therefore, it is somewhat ironic that we would need to obtain our stock from someone else. 

Today we received 12 overwintering pupae. Their parents were from two different lineages, one from Utah and the other from Oregon, so they are genuinely high quality outbred stock. Actually, it's a bit strange (in an interesting good way) because the populations from the two states are probably quite different in in terms of their host plants preferences, diapause and diapause breaking responses, appearance, etc. 

There were 6 green and 6 brown morph pupae. They are distinctly different forms and not at all intermediate, mottled messes like a lot of P. rutulus. The brown coloration is very dark, rich, and smooth looking, especially on the lateral stripes; it is not at all like the typical golden or grayish brown of P. rutulus. As for the green, it's nothing like we've ever seen before! It is brighter in shade than the green on our P. rutulus and like the brown, it is very smooth and even. There is a single lighter form brown pupae that has bits of green on it, but it doesn't look anything like the P. rutulus​ pupae we currently have. In terms of shape, the P. eurymedon seem to be slighter fatter and shorter. The last set (highest segment) of little bumps on the back is also greatly reduced. 

Another big surprise for use was how large the pupae were. From greatest the least, the weights are 1.53, 1.43, 1.41, 1.37, 1.29, 1.22, 1.17, 1.03, 1.02, 1.01, 0.90, 0.76. Of course, they most likely have dropped up to 0.1-0.2 g since they first pupated even if they are diapausing. Numerous field guides and internet sources/pictures point towards the adults being much smaller than P. rutulus (sometimes even smaller than P. zelicaon!). While this may be somewhat true, the pupae size easily rivals that of any tiger (well, except P. multicaudatus which is off the charts). If they are smaller than the P. rutulus, it is only by a small margin based on our samples of the two species. 

With these under our belt, by next year in Ithaca, we shall be packed with all kinds of tiger genera. It will be a tough road trying to keep every single one of these eurymedons alive and to get them to emerge together (especially in Ithaca climate), but if all fails we could try a little hybridization. . . which we would probably attempt anyway if we get a stable amount of these and other species. The major concern after that is getting the host plants. They like ceanothus (Ceanothus) for sure, and it they would most likely respond best to it when trying to get them to lay eggs, but that it doesn't seem like Ithaca would have the stuff except as a garden ornamental. Hopefully, Prunus will also work. The same goes with P. rutulus​. 

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Authors
Brian Liang

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