Since the weather has started to show signs of warming starting last Monday (not linearly but, on average, slowly but surely increasing) we had most of our pupae that were being kept refrigerated at our home in Albany, California sent to us which we received today. The pupae are, for the most part, in good condition. One Papilio eurymedon and one or two Smerinthus opthalmica dried out, several Manduca sexta seem to be rotting (may be disease as many of the last instar larvae of this brood died from disease), and a few lunas (Actias luna) are evidently dead (brood generally undersized and unhealthy). Surprisingly, all of the regals (Citheronia regalis) are alive. We can't quite tell with the cecropia (Hyalophora cecropia) at the moment since their cocoons are thick, but they seem more or less okay. ​All of the eastern festoons (Allancastria cerisyi) are alive. We did not have sent the rutulus (P. rutulus) for fear that they might eclose too early or in shipment, anise (P. zelicaon) because the umbels (Apiaceae) here have not grown out yet, or pipevines (Battus philenor hirsuta) because there is no pipevine (Aristolochia) here. 

The trees are just starting to leaf out, so the hope is that by the time that we eventually might obtain eggs from the pupae that we did receive, all of the food plants will be ready to use. For the native species, such as the cecropia and luna, we are also hoping that by taking them out of cold storage around the same time that the local weather is warming should help ensure that they eclose in sync with the local populations for the purpose of outbreeding with wild males. ​

Brian Liang
Brian 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, insects articles, and site design. ​

Ideally, we probably should have done it immediately when we returned to Albany California in mid-December or perhaps even ask our mother to do it for us even earlier, but as of today we have begun refrigerating (40°F/4-5°​C) our pupae that require it. 

These include: all of the Saturniidae--cecropia (Hyalophora cecropia), luna (Actias luna), and regal (Citheronia regalis); Manduca sexta; and, we are assuming, the pale swallowtails (Papilio eurymedon), which come from Utah/Oregon, and eastern festoon (Allancastria cerisyi). Although our Smerinthus opthalmica pupae are native stock that do not require cold treatment, we also decided to toss twenty of so of these in as well as a risk splitting measure because it is difficult to predict what the situation will be when the ones outside the refrigerator emerge. Ideally, we would have put all of the opthalmica pupae in the refrigerator as well as the diapausing pupae of the other species we have such as the western tigers (Papilio rutulus​) and anise (Papilio zelicaon) swallowtails but because all of these are native, it could potentially be harmful in the long run. 

After four months in Ithaca, we have finally returned to our permanent residence in Albany, California where we still have a heap of overwintering pupae. This is the first of several posts that we will be making to update status of each species. 

In early September, we made a brief post indicating that the last of our regal moth (Citheronia regalis) larvae that we reared during the summer had finished pupating that also included a few photographs of prepupal larvae and pupal mass data that we received via email, both courtesy of our mother. But because the pupae were formed during our absence, this is actually the first time that we ourselves are seeing and photographing them; below are new photographs taken today of the thirteen pupae that are now three months old. 

​The sex ratio is oddly skewed with only three of them being female, but at least our hope of breeding a second generation with this stock was quite limited anyway as it is for numerous reasons. The pupae are very hard and fairly stiff; they do not squirm. Although they are glossy, most of the cuticle is actually rough with very distinct separation of segments, especially of the last one, and several odd bumps such as the pair of tough, elevated plates on the thorax. The head and mass of appendages, for some reason, have very little separation between them though. Overall, although they look quite similar to the pupae of the relatively closely related imperial moth (Eacles imperialis), the regal pupae have significantly shorter cremesters and are pitch black rather than dark brown.

While we were away, these pupae were kept in a small plastic tub which, in all honesty, was probably not a very good housing solution for an extended periods of time given climate of the house. Fortunately, all thirteen pupae that were present upon our return appear to be alive (although sixteen data points were previously recorded?). However, before taking the pictures that are shown, they were covered in a few tiny white mites that we can only assume must have been eating away at what dead external material and were not necessarily harming the pupae themselves. Like most pupae, they have a distinctive, somewhat unpleasant, odor to them.

The last of our regal moth (Citheronia regalis) larva that have not pupated has died, ending the rearing project for this year.

On the day that we left, there were still three regals (Citheronia regalis) that were still feeding. All three were small and far behind the rest in development with two of suspect for disease. At the time, we didn't want to over-complicate matters by having to find a way to keep them alive during the family leave and to make our mother take care of them when she got back, so we decided to simply toss the two suspect ones and hoped the last one would finish feeding quickly enough. 

By the time our mother came back on August 20 and checked on this last one, it was still alive but unfortunately was not a prepupa yet and had nothing to eat because all of the leaves had dried out. We thought that it would surely finish and pupate soon though, but it never did. Today our mother reported that it is now dead after spending a few days as a prepupa.

Now that the older, healthier ones are already done pupating and all, this really isn't a big deal to us, but it is something sort of interesting to note. We really don't know exactly went wrong, but from the pictures it's probably just disease. We have seen similar things happen in other saturniids and in sphingids during the prepupal stage. 

As for the final data on our regal pupae, we have 5.77, 5.97, 6.1, 6.24, 6.33, 6.45, 6.54, 8.12, and 8.82 (weighed August 20) and 6.6, 6.62, 6.8, 6.97, 7.00, 7.13, and 7.94 (weighed August 22). None of them were guaranteed to have been weighed within 24 hours of pupation like we usually do, so it may be slightly inaccurate in terms of control. The mean is 6.8413 (Sx = 0.8258, n = 16); the median is 6.61. We definitely hoped for bigger pupae (and bigger larva to begin with), but for this first time we are still impressed by their size. We will be sure to get some shots of these when we return home during break.

Well, it's been a few days since we have arrived in Ithaca and there are numerous rearing projects still in progress back home in Albany that we no longer have direct control of anymore. Fortunately, our mother has agreed to help take care of anything that are require immediate attention, at least for now. With that said, from now on we will periodically post updates on any significant events that take place in Albany as they occur and are reported to us. 

The first update is for Papilio rutulus. On the day that we left (August 16), there were still three stragglers left, including two that were unusually small and probably unhealthy. We had left the three together in a tub in darkness with heaps of willow (Salix) cuttings to ensure that they would not starve for the five days that nobody would be at home. At the time, we actually suspected that they would stop feeding before the five days, and we were correct; two of the three have already pupated into 1.08 and 1.45 g pupae and the last one is a prepupa. The 1.45 g one is quite surprising, placing fifth of 26 in weight, and was most definitely the one of the three that was not sickly. . . On the other hand, the 1.08 is third to last. The one thing to note, however, is that these weights were not necessarily taken right after pupation (well, within 24 hours), which was the procedure we used to collect all of the other data points.

The second update is for the regals (Citheronia regalis). Before we left, we were hoping desperately for the things to pupate so that we could just see it once before the rare opportunity would be lost. Unfortunately, that never happened, even after five days of being in the prepupal stage inside the incubator. In the end, it is not unreasonable for earthen pupates, especially such massive ones as these, to take an absurdly long time to pupate, but of course it was still a major disappointment. At some point during our leave, five of them did finally pupate though at 6.6, 6.62, 7.0, 7.13, and 7.94 g (again, these weights are probably slightly less than they would have been if they were taken immediately after pupation). While not unimpressive relative to other species that we have reared, these weights are still somewhat disappointing for how large the caterpillars were. Based on old records, they roughly shrank to just above a third of their peak larval weight, which is a pretty steep drop compared to most other things. Although we have not received any pictures of them yet, our mother assures us that they do not suffer from any deformities, which is a great relief given how difficult it often is with earthen pupators. 

Lastly, we come to the various machaon swallowtails, which all decided to come at the worst possible time. . . In the days before we left, we had very hastily created some hybrid pairs of P. polyxenes asterius and P. zelicaon and left what we hoped were fertilized females outside in the cage to lay eggs. After five days, all but one of these females is still alive and, according to our mother, there are no fresh eggs. Right now, it looks like we have failed this time. But hopefully we will be able to try again, now that we have easy access to P. polyxenes asterius here in Ithaca!

Update: The last rutulus pupated at 0.95 g. The collective average for the rearing is 1.258571429 (n = 27).