​Rearing notes for Smerinthus ophthalmica second instar larvae. This stock originated from wild eggs or larvae collected in the San Francisco Bay Area (California) in June 2016 and April 2017 that were then either inbred or outbred with local males in summer 2017.

May 30

May 29

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.

Two female Smerinthus opthalmica eclosed last night from the twenty or so pupae that we received from Albany, California on April 20, although we were unaware of this until this morning.  Both moths are dark gray (although in the images, they appear fairly brown), which is interesting because the very first ophthalmica we found, which eventually became the maternal line for our entire stock, was exceptionally tan. At one point last year, we had made it a goal to create a tan a strain as possible through selective breeding. Several of the maternal parents of the current pupae were tan, but because we have limited control of eclosions times and the wild males we called in tended to be very dark, most of paternal parents were gray (even when acknowledging that it is normal for males to be less tan than females). Of course, it would be impossible to try to trace individual lineages of these pupae right, but hopefully a few tan genes did make it into this sample of pupae even if they are not fully expressed in these two individuals that have already eclosed. Both moths are quite small for females, one being a fair notch smaller than other. This was expected considering that none of the twenty or so pupae are particularly large due to sub-optimal rearing conditions last year and, perhaps, genetics. 

​It is somewhat surprising that these were able to develop and eclose so quickly. The pupae were taken out of the refrigerator on April 28, so it has at most been 13 days since the pupae broke diapause. The species is generally has fast development, and these are small pupae, but this is still down quite a bit from the times we observed last year using incubation at 80 °F/27 °C (~20 days). Also odd is that these first two are females when it should be the smaller males that eclose first. Hopefully, some males do come out in the coming days so that we can obtain some pairings.

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. ​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 cersyi). 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. 

Although we have generally been unimpressed by the insect diversity in the Bay Area, it is hard to deny that we are concerned about the loss of stock of a few major species that we did have access to in Albany, California and not in Ithaca, New York. As of this winter break, we still maintain a decent number of wetern tiger swallowtail (Papilio rutulus) pupae, reared from the summer, as described in this recent post; these are probably the most important considering how difficult it already would be to maintain a stock of them even if did not have to leave to Ithaca. As for the other native species, we still have a handful of anise swallowtail (Papilio zelicaon) pupae reared or collected by our mother while we were in Ithaca, a fair number of pipevine swallowtail (Battus philenor hirsuta) pupae from larvae reared in summer, and a large number of Smerinthus opthalmica pupae also from larvae reared in the summer. 

It is especially important that we maintain this stock of anise because they are something that we could conceivably rear in Ithaca and would be very difficult to obtain otherwise (from other breeders). Further, if we encounter P. polyxenes asterius at some point in Ithaca, it would be a grand opportunity to conduct further experiments between the two, including hybridization. The main problem right now is that, at least historically and when reared in captivity, this local stock has proven to be quite poor in the execution of the winter diapause. Already we have thrown away a significant number of dead pupae while inspecting them today and can expect their numbers to continue to steadily decline before a chaotic emergence sometime in the spring. In fact, we have never had a huge success with breeding these from overwintering pupae and have always much more on collecting eggs as they appear in the wild in order to reinvigorate the colony. Nevertheless, the pupae that we have now are certainly better than nothing and if worst comes to worst, we can ask or mother to collect eggs for us as we still have fennel (Foeniculum vulgare) growing in our yard in Albany. 

The pipevine pupae arguably suffer an even higher diapause mortality rate (and losses from stray emergences) than the anise since most of them already enter diapause very early in the year. Less than half of what we initially had in June have made it to this winter break. The good thing is that, although they are one of the few species truly unique to our time in Albany (most other species at least have a regional counterpart in Ithaca), our hopes of breeding these was never high, so we will not concern ourselves too much with them. In the past, we have never been able to get the females to lay eggs in captivity, and even if we somehow managed to do it, we do not have easy access to live pipevine (Aristolochia spp.) plants  in Albany or Ithaca. Even if we were to stay in Albany, the most logical thing to do if we really did want to continue rearing them would be to just collect a fresh stock of them come Spring where the eggs and larvae are extremely easy to find in big numbers; the same cannot be said of the eggs and larvae of the other native species mentioned in this post. 

The opthalmica, like the rutulus and anise, are very important. Not only are they the easiest of the three to breed, both in Albany and in Ithaca, we also have the largest number of them (200+), even after finding a few dead ones and one that had been fed on by some sort of flesh-eating fly larvae (presumably not parasites). We can afford to make mistakes with these so we are considering risk-splitting them with several treatments: some we will overwinter in the refrigerator, some we will keep outside, and some we might bring over to Ithaca.