We have returned to Albany, California from Ithaca, New York as per Cornell University's winter closing, giving us a chance to check on our overwintering pupae.
It seems that it is almost impossible to get these to diapause as pupae. The pile of cocoons that had before we left to Ithaca, New York eclosed in September, despite receiving darkness treatment, with most of the moths being pinned by our mother as shown below.
But what is much worse than that is that a few days after we returned to Albany, California over winter break, the cocoons that resulted from the eggs laid by pairings that our mother made with the moths she did not pin started to eclose. While it was at least still possible to rear the larvae before on poor quality leaves, there is not much we (and eventually our mother, once we leave to Ithaca again very soon) can do this time unless we resort to searching for tender citrus (Citrus) leaves like we did last winter. At this time, we are simply not feeling motivated to go through this trouble for a species that we have reared so many times already, will continue to be a problem if we do not find a way to make them diapause, and is frankly an eyesore most of the time. Therefore, we have chosen to no longer continue rearing them, at least for no; if we ever want to rear them again, we will have to obtain a new stock.
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.
Ithaca, New York
This timeline is a series of daily posts recording our observations and experiences with various insects 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 for our entomology 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.
June 2018 (2)
May 2018 (17)
April 2018 (2)
January 2018 (2)
December 2017 (8)
November 2017 (1)
October 2017 (5)
September 2017 (25)
August 2017 (18)
Full Species List
(Alphabetical by scientific name)
Papilio polyxenes asterius × Papilio zelicaon
Full Species List
(Alphabetical by scientific name)
Butterflies & Moths
Common checkerspot skipper
Great spangled fritillary
Milkweed tussock moth
Salt marsh moth
Virginia creeper sphinx
Western tiger swallowtail
White-marked tussock moth
Butterfly & Moth Hybrids
Black swallowtail × anise swallowtail
Grasshoppers, Katydids, & Crickets
Carolina band-winged grasshopper
Lesser meadow katydid
Sword-bearing conehead katydid
Two-spotted tree cricket
Cornell Botanic Gardens
Mundy Wildflower Garden
Albany, California Updates