Albany, California Updates (9/27/17-9/30/17): Manduca sexta Prepupae and Mysterious Black Form Larva
Back in Albany, our Carolina sphinx moth (Manduca sexta) larva are becoming prepupa and a mysterious black form larva has appeared.
On September 27, our mother sent us these two pictures our the Manduca larvae. The first of the largest last instar larvae asking how close we would say they are to pupating (they seem to be quite close) and the other of a newly molted fifth instar that, for some reason, has a black body. The first thing that we would normally think when larva turn black, especially in sphingids, is that they are diseased, typically with a bacterial infection that kills them within a day or two after the color change. However, she told us that the larva only turned black after the molt and was behaving normally, crawling around and eating. . .
With some research, we have found a study that describes a sex-linked mutation in Manduca sexta (affects females more) that causes the cuticle to turn black but not the schlerotized portions, just like this larva. Because we bought the original eggs from a farm that probably heavily inbreeds them, it definitely could be possible that this is what we have. And now that we think about it, in last time's rearing, we did notice that that one of our larva was very melanized (perhaps abnormally so). This was the oldest larva that turned out to be a very small female, which again aligns with the study that indicates that mutants are fast growing and small.
However, on September 30, our mother sent us a follow up informing us that some of the larvae had become prepupa but also that the black larva now appears to be dead. The scherotized portions are now completely black, making it look like disease, so perhaps we were wrong about it being a mutant after all.
Albany, California Updates (9/18/17): Samia ricini Egg Hatchlings; Actias luna Update; Manduca sexta Larva; Papilio zelicaon Pupae
Back in Albany, our eri silkmoth (Samia ricini) eggs have begun to hatch, luna moth (Actias luna) eggs have proven infertile, Carolina sphinx moth (Manduca sexta) rearing continues, and anise swallowtail (Papilio zelicaon) rearing finishes.
It's been a while since we have received updates from our mother about the ongoing rearing projects, but today she sent us pictures of several of the species.
The ricini's have finally begun to hatch, just short of two weeks since they were laid which is quite fast compared to previous rearings. This is probably because of the intense heat Albany is experiencing these days, with the temperatures hitting record high 80's and 90's °F at some point around the time during and after these were laid. Bear in mind that even 80 °F is a rare occurrence any time of year there.
As for the Manduca's, our tells us that there aren't as many left as she had hoped there would be. She only ever obtained one pairing and got about 70 eggs out of that and there are apparently much less than that now. Based on last time's rearing when we did it ourselves, this species can be troublesome in the first two instars because they are so small (proportional to how big the full grown larvae and the moths are) and thin-skinned such that accidental deaths and desiccation is common. It is hard to see in the picture, but I would say that they are mostly third and fourth instars in there already. Again, this is surprisingly fast considering that the eggs were laid on September 2, even for this species, and probably has to do with the extreme heat.
The luna (Actias luna) eggs were also laid on the 2nd and still have not hatched. When she told us this, we suspected that they may be infertile and these new photos confirm that. None of us know what exactly went wrong given that we know for a fact that at least one pairing occurred. These moths were second generation inbred (perhaps more if they were inbred before we received the original eggs), so that might have something to do with it? It seems somewhat doubtful though, but we really don't have any other explanations right now.
Finally, we have the zelicaon. It has been a long and messy ride with these with us making massive hand-pairings right and leaving a small plant in our front yard clobbered in hundreds of eggs right before we left. A good chunk of these eggs and resulting larva were clearly lost or killed somehow in the process (which is somewhat to be expected when rearing in bulk in an outdoor cage that doesn't provide complete protection from enemies) as she informed us a while ago that she only counted 80 or so larva of different sizes. Along the way, she also found a few wild larva and eggs scattered around our fennel (Foeniculum vulgare) plants, which makes the rearing even messier. At some point, we told her to take all the larva inside to try to minimize losses (especially when they are ready to pupate) and to try to get them to diapause with darkness. After all of this, it was a big relief when she told us that most of them had pupated and sent us this picture showing that a good enough amount of them had made it and that almost all of them were light tan (diapausing). When we asked her what she did to get them to diapause, she told us that she reared the larva in opaque tubs but put that she did it completely outside, opening the lids in the morning (around 8-9 AM) but making sure to put them in a shaded location as not to let them burn out from the sun. From this, we can only assume that the natural conditions of this time of year are probably enough to cue most larva into diapausing which is why this worked.
Back in Albany, we now have tons of eri silkmoth (Samia ricini) eggs. Stock obtained as eggs, March 2017.
Well, its been a few days since we got the reports that our ricini's have started to eclose and now our mother sends us a picture (above) of eggs asking us what to do with them. To be quite honest, like last time, we don't nearly need all of the eggs so we told her to just save a hundred them or so and dump the rest. We have also asked that she send two dozen to us.
As for the host plant, back in Albany there really isn't anything very good left to use at this time of year. Both the sweetgum (Liquidambar styraciflua) trees and our plum (Prunus sp.) tree are probably still doable though, even if the leaves are already half a year old and deteriorating. In the end, we settled on the plum simply because it is more convenient for our mother but in terms of which one is superior, I would lean towards the sweetgum based on the past two rearing of this year with this strain of ricini's. Here in Ithaca, we will definitely be using castor (Ricinis communis), which herbaceous and still looks great right now.
Back in Albany, our eri silkmoths (Samia ricini) have begun to eclose. Stock obtained as eggs, March 2017.
We will never be able to figure out how to get these pesky ricini's to diapause. . . On this last brood, we tried to use darkness, but we had a feeling that it simply wouldn't do the trick based on past rearings and we were correct. Our mother reported that five of these moths eclosed on September 3.
Because we don't want to lose the line, we told her to keep a few to breed. The next day, she sent us this picture showing that they had paired.
Actually, because we have already reared this species so many times, we could have just called it a good run and just let them go, especially at this time of year and the current circumstances. But, as we noted in an earlier post, there is actual castor (Ricinis communis) here in Ithaca, which seems to be by far the best host plant for these. If we can get some eggs over here, we may even be able to try it right now.
Back in Albany, the last of our cecropia moth (Hyalophora cecropia) larvae are finishing their cocoons. Stock originated as eggs from New York, June 2016.
It is mind-boggling to us that the first species to hatch this year is the last to finish. Our cecropia moth (Hyalophora cecropia) cocoons reared from last year first started eclosing near the end of April and we already had a thousand eggs by May. . . and yet five months later the last of them are still finishing up. Our mother sent us these two pictures today, first of two cocoons she recently collected from the apple (Malus sp.) tree sleeves and the second of a runaway larva that she found back that is only now spinning.
We blame this slow growth on the horrible conditions that the larva had to endure in our California Bay Area weather as well as overcrowding. It was simply not a good idea to start the larva off immediately in sleeves where they get easily lost and killed by the cold, windy, and dry climate. The ones that did survive were simply not healthy either, growing at this sluggish rate and not attaining a very large size at all (a very steep drop from last year's average). At the same time, every last one that we attempted to rear inside were wiped out by disease, which is typical for this species. With that said, one of the things that we greatly look forward to here in Ithaca is rearing the eastern species in their proper climate.
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.
After a few more of our Carolina sphinx moths (Manduca sexta) eclosed back in Albany, California, our mother successfully created a pairing. Stock originated as eggs, June 2017.
Our Manduca's back at home started emerging a few days ago on August 29; our mother has been keeping us updated ever since. She reported that three more emerged the following morning on the 30th. Although she pinned the first one, she set the other three outside in the cage picture above outside at our request. We figured that if these are like other sphinx, a natural pairing in a large outdoor flight cage would probably be the best way to go. The next day, she put in more newly emerged moths into the cage, but there were no pairings. It not until the second night on August 31 that a pairing was finally obtained which is shown in the picture above. Based on our conversation, I don't think that she even fed the moths at any point so far, but that should be fine for the first few days and it certainly didn't stop them from pairing!
When our mother checked on the pairing on the morning (probably somewhere between 8-9 AM) after it occurred, the participants had already broken up. She couldn't tell which female was the one that had paired, so she took them all inside into a container with a branch of tomato. According to her, about 20-30 eggs were laid that night (September 1), scattered haphazardly and not all on the plant, although we are not sure to what extent the plant is even necessary for these crazy things. Sometime later on the next day (September 2), she changed her estimate to 50 eggs, but we don't know whether she miscounted at first or the moth laid more eggs during the day. On a side note, the weather in Albany are hitting record highs this week in the 90's and 100's ° F; we don't know if this could have had any influence on the breeding process.
After a few more of our luna moths (Actias luna) eclosed back in Albany, California, our mother successfully created a pairing. Stock originated as eggs from Alabama, April 2017.
Back on August 26, two of our luna moths (Actias luna), a male and a female, emerged back at home which our mother pinned. Another emerged on August 27, and presumably a few more after that too because on the 31st, we got a photograph (above) from our mother of a mating pair that she had obtained the previous night in an outdoor flight cage. She reported that the pair had separated when she checked around 9:20 PM and on the morning of the next day, the female had laid 10 eggs (a bit strange, since we would have expected a little more than that). By the next day on September 2, she reported 60-70 eggs.
She also sent these pictures of the luna cocoons that are left. It appears that the only ones that have not yet emerged are the five dark diapausing forms.
Back in Albany, our Carolina sphinx moths (Manduca sexta) have begun to eclose. Stock originated as eggs, June 2017.
We had all but forgotten about our Manduca pupae after coming to Ithaca, so we were caught off guard when we received reports today that one of them has already eclosed. We were actually aware, though, that they would eclose sometime now; in the last few days before we left when we checked on them one last time and realized that some of them were already showing signs of development (such as darkening of the eye and solidification of the wing pads). These pupated between July 27 and August 7, so the timing is reasonable too. In hindsight, we should have tried to get these all to diapause given the inconvenience of having them eclose 10,000 miles away so close to the end of the season, especially because our tomato plants are on their last leg. With this species, it probably would have also been very easy to accomplish this with a simple photoperiod trick.
Ultimately, the biggest loss with having them emerge now though is that we don't get to see them. We have little experience with this group of sphinx, so it would have been a very valuable opportunity to learn how to feed and breed them and become familiar with their behavior. Because they are such a common laboratory reared species, we assume that they are easy to pair and lay eggs, so for now we have asked our mother to hold off on pinning them all and to leave a few to try to breed. Hopefully we will still be able to gain some insight on the subject when she reports back over the next few days.
Albany, California Updates (8/26/17-8/27/17): Actias luna Eclosions; Papilio zelicaon Updates; Pyrgus communis Prepupa
Back in Albany, our luna moths (Actias luna) have begun to eclose, anise swallowtail (Papilio zelicaon) rearing continues, and checkerspot skipper (Pyrgus communis) larva has become a prepupa.
Today, we got some exciting yet unsettling news that two lunas (Actias luna), a male and a female, have emerged back at home. When we reared these, we had put a great deal of effort into controlling the amount of daylight they received, making sure to keep them in a dark tub for at least 12 hours a day in order to increase the chances that would diapause. (Of course, the set up wasn't perfect as we were not always consistent about it and there are still many factors that might make it different that what they naturally experience that would cue diapause. For example, a diminishing photoperiod may have helped.) Even at the time, though, we had a bad feeling that not many of them cooperated, seeing as only a handful of the cocoons were the course and dark brown as they should be if they are diapausing. Because this is such an inconvenient time for them to be breeding and we would feel pretty terrible about making our mother deal with them, we decided the best thing to do for now is to get one pairing just to keep the line going and then pin the rest.
As for our Papilio zelicaon, the last few are still eclosing and our mother is trying her best to hand-pair them. She reportedly already paired a male polyxenes with a female zelicaon, but it has not begun to lay yet. The several hundred pure zelicaon eggs that we already had in the cage from the mass pairings we did before we left are making progress, but according to our mother, there are only about 80 or so caterpillars. Mysterious losses always seem to be high when rearing outdoors, even with a screen cage to protect them. . . She also found eight random caterpillars on a different fennel in our yard that we must have overlooked when we were there.
Ithaca, New York
This timeline is a series of daily posts recording our observations and experiences with various insects (primarily Lepidoptera) around the Cornell University campus in Ithaca, New York, starting from the time we moved here in 2017. As this is a personal blog, we try to keep collections/rearings for university research and course work to a minimum, and mainly focus on just the species we catch and raise for our own fun and interest. Posts prior to this time can be viewed at Timeline 2012-2017: Albany, California, though there is occasionally some crossover when we have returned home during breaks or reared stock derived from home (see Albany, California Updates).
July 2020 (1)
August 2019 (2)
July 2019 (35)
June 2019 (46)
May 2019 (20)
March 2019 (1)
January 2019 (1)
September 2018 (1)*
August 2018 (9)*
July 2018 (11)*
June 2018 (22*)
May 2018 (18)*
April 2018 (2)*
January 2018 (6)
December 2017 (5)
November 2017 (1)
October 2017 (5)
September 2017 (26)
August 2017 (19)
*Currently, a significant portion of 2018 posts are missing. The notes/photos for this time period are saved on our personal files but the posts were never built due to a busy schedule that year. We are still actively building these posts when we have the time.
Full Species List
(Alphabetical by scientific name)
- Not every species we encounter is necessarily presented on this site, rather a selection of those that were of particular interest to us and that we felt were worth documenting.
- We can't guarantee that all species have been identified accurately, particularly taxa we are not as familiar with.
Battus philenor hirsuta
Liminitis arthemis arthemis
Limenitis arthemis astyanax
Papilio polyxenes asterius
Papilio polyxenes asterius × Papilio zelicaon
Albany, California Updates