Papilio polyxenes asterius (Ithaca) Rearing Notes (June 30, 2019–July 6, 2019)

Rearing notes for our black swallowtails (Papilio polyxenes asterius). Stock originated from eggs laid by a wild collected female in Ithaca New York, May 2019.

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July 5

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• Now that it has been a few days, it is quite clear that the fertility is probably at least 90%, which is really impressive for captive females. Seems to be slightly higher fertility than the P. zelicaon eggs. 
  

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July 3

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• Most of the eggs are slowly starting to turn brown now.

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July 2

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• Some of the eggs that were laid on the first day have already started turning brown. Fertility looks decently high so far. ​
  

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July 1

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• The females laid about another 200 eggs. Assuming most eggs are fertile (which we won’t be able to tell until tomorrow), then we would definitely have enough already, so we took the females out of the cage. ​
  

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June 30

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• Three males and four females eclosed. Almost all of the pupae have eclosed now.
  
• The four females laid 200+ eggs, which is outstanding. We had noted that the wild-caught female that these females descended from was a very good layer (it laid almost three hundred eggs over the course of a week), but we had assumed that it may have been because it was a wild individual, which tend to be more fecund than hand-paired individuals. Now, it seems likely that the polyxenes are generally very good egg layers and lay eggs much more readily compared to zelicaon. As of now the eight zelicaon females that we have currently have laid only about three hundred eggs in total over four days, and the single female that they descended from laid only about one hundred in its lifetime. We have noted that the polyxenes do tend to by more active (energetic in behavior) than the zelicaon, a trait that makes them more difficult to handle and hand-pair, which could correlate with better egg laying. 
  
• Since we already have so many eggs with only four females that will continue to lay, we were reluctant to create more hand-pairings despite having an abundance of virgin butterflies, with the assumption that the eggs obtained so far are fertile. We did, however, create one new pairing with a fairly large and very blue female, since it would be a shame not to breed at least some of the individuals with notable and desirable phenotypes (in our eyes).
  

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Alan Liang​
​Alan Liang is a student at Cornell University in Ithaca, New York pursuing an undergraduate degree in entomology. He is co-owner and a main contributor of the Liang Insects blog and photographs.

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