Overwintering Summer 2018 Pupae

Upon returning to Ithaca after Winter Break, we placed the pupae from last summer in the refrigerator to overwinter.

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After a chaotic week of flight delays due to snow storms on the East Coast, we have finally made our way from California back to Ithaca. Since a sustained period of cold is necessary for most diapausing pupae to break diapause in the spring, we placed two airtight plastic boxes full of pupae from our last summer's rearings into the refrigerator, set to 5° C. Ideally we would have done this much earlier (probably in October when it starts getting chilly outside), but since the dorms require us to unplug refrigerators over Winter Break, we decided to wait until after we came back. Hopefully, the 3-4 months in the refrigerator will be sufficient enough for the pupae to undergo a normal diapause (assuming we take them out in May). 

The species overwintering are as follows (locality/date stock originated): Papilio glaucus (New York 2018), Papilio rutulus (California 2017), Papilio zelicaon (California 2017), Hyalophora cecropia (New York 2016), Callosamia promethea (New York 2018), Antheraea polyphemus (New York 2018), Darapsa myron (New York 2018), Hemaris diffinis (New York 2018), and Paonias myops (New York 2018).  

Also included were our batch of northern walkingstick (Diapheromera femorata) eggs from last fall. We are unsure of the conditions required for these eggs to undergo normal diapause and break it, but assume it follows the same principle as lepidopteran pupae.

Alas, the list of pupae is much shorter than we had hoped, since many of the species we reared last summer never entered diapaused and the stock was lost (Papilio troilus, Papilio cresphontes, Actias luna, Pachysphinx modesta, Eumorpha pandora, to name a few...). Nonetheless, we are grateful for the species that did make it and look forward to rearing them again this summer.

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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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