Category: Samia_cynthia_advena

Samia cynthia advena L5 Rearing Notes (8/5/17-8/??/17)

8/8/2017

Rearing notes for cynthia silkmoth (Samia cynthia advena) fifth instar larvae. Stock originated as pupae from Pennsylvania.

Rearing notes 8/5/17-8/??/17:

8/8:

The larvae are starting to get a bit whiter

8/7:

There are still only two in fifth instar that look like they are doing okay for now, but growing very slowly; we will be quite lucky to even have a few make it at this rate

8/6:

The larvae are making very slow progress; only two are fifth instar and the rest are falling more and more behind and dying, most likely as a result of poor treatment in the earlier instars where we were forced to overcrowd to fit them in the incubator; we will be lucky to get these fifth instars through

8/5:

Although less than last instar, the larvae still have black spots; they are less white than S. ricini and even have a bit of blue in some places like our first strain of S. ricini; their tubercles seem to still be larger than those of S. ricini

Authors
Brian Liang

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Samia cynthia advena L4 Rearing Notes (7/30/17-8/3/17)

8/3/2017

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Rearing notes for cynthia silkmoth (Samia cynthia advena) fourth instar larvae. Stock originated as pupae from Pennsylvania.

Rearing notes 7/30/17-8/3/17:

8/3:

One of them has entered apolysis and is only 0.7 g compared to 0.9-1.3 for S. ricini fourth instars; it measures 27 mm

8/2:

The larvae are making some progress, but several of them died, especially among the smaller individuals that have gotten behind; its getting worrisome at this rate, but hopefully at least a few will make it
Side by side with fourth instar S. ricini, the larvae are clearly less powdered and white (in fact, they seem to have a slightly greenish undertone); they have longer and hairier tubercles that are slightly orange; as of now, they definitely seem to be smaller (may have to due with incubation and poor rearing conditions)

8/1:

Some of the larger larvae have developed an appreciable amount of the white powder, especially on the tubercles, but the black spots failed to disappear; they seem to have a slightly skinnier body shape compared to S. ricini and are a darker shade on the yellow portions
The larvae are diverging greatly in size and developmental age, perhaps because they are confined into a petri dish where it is difficult for them to aggregate

7/31:

Even after a day of feeding, the larvae are still mostly yellow; at this rate, they won't be very white in the last instar either

7/30:

The larvae have molted to fourth instar and, just like before, are still covered in rows of black spots and have very long tubercles; the head capsules are yellow when teneral and still yellow after drying

Authors
Brian Liang

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Samia cynthia advena L3 Rearing Notes (7/26/17-7/29/17)

7/29/2017

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Rearing notes for cynthia silkmoth (Samia cynthia advena) third instar larvae. Stock originated as pupae from Pennsylvania.

Rearing notes 7/26/17-7/29/17:

7/29:

The oldest larvae have entered apolysis and are only 17 mm versus 20 mm in S. ricini; we are starting to suspect that the rapid growth caused by incubation could be negatively effecting the size of our larvae

7/28:

The larvae are getting much larger and whiter now but not nearly to the extent of S. ricini; S. ricini would only have a few black dots going down the center
The tubercles are still very prominent and are, perhaps, longer than those of S. ricini

7/27:

The larvae are starting to gain some powder, especially around the tubercles, making them whiter

7/26:

The third instar larvae are surprisingly still completely yellow (including the head capsule) with lots of black spots and powderless, much like last instar, except the tubercles are larger; Samia ricini would already be completely white without any markings and black head capsules

Authors
Brian Liang

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Samia cynthia advena L2 Rearing Notes (7/22/17-7/25/17)

7/25/2017

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Rearing notes for cynthia silkmoth (Samia cynthia advena) second instar larvae. Stock originated as pupae from Pennsylvania.

Rearing notes 7/22/17-7/25/17:

7/25:

The larvae have entered apolysis and are still very yellow with hairy black tubercles all over them; Samia ricini would be pale by this time (almost white) with little markings at all
As predicted the duration of this instar was faster than first instar

7/24:

Larvae are still very thick skinned and hairy, much more like typical Atticini early instar larvae and not at all like Samia ricini now

7/23:

The larvae are still extremely yellow and the tubercles have tanned to black again; they are still very hairy unlike Samia ricini which are not hairy at this stage

7/22:

A lot of the larvae have molted to second instar and are still a dark shade of yellow, unlike Samia ricini larvae which are clearish; their head capsules and tubercles are yellow or mixed yellow and black (S. ricini usually black); and the hairs are still white

Authors
Brian Liang

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Samia cynthia advena L1 Rearing Notes (7/17/17-7/21/17)

7/21/2017

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Rearing notes for cynthia silkmoth (Samia cynthia advena) first instar larvae. Stock originated as pupae from Pennsylvania.

Rearing notes 7/17/17-7/21/17:

7/21:

Now into the fifth day already but some are finally in apolysis. . . the larvae are taking a surprisingly long time to grow despite being in the incubator; they are eating and pooping copiously, so most likely they have poor utilization of the host (which is to be expected with this species); we have seen a similar trend in Samia ricini which take a very long time in first instar before speeding up in the coming instars, after seemingly better acclimating to the host plant
The larvae measure 7 mm, on par with ricini

7/20:

The larvae are still a dark yellow even after they are very plump now
They are hard to remove from the leaf because they regurgitate; when we cut out the part of the old leaf that most of them were on and put it onto the new leaf, they for some reason regrouped together on this old piece and ate is all before moving on

7/19:

The larvae are getting plumper and proportionally less hairy; they are starting to look more similar to the ricini but still much more heavily marked in black

7/18:

About a dozen more larvae hatched, but that seems to be about it based on how many eggs there are in total
The older larvae have taken quite well on the sweetgum (Liquidambar styraciflua), eating messily from the sides in several gregarious groups; they have gained a slightly greenish undertone since the skin seems clear like ricini, but are mostly just yellow
They have a much stronger grip than the ricini which are incredibly weak; you can feel the resistance as they are being pulled off the leaf

7/17:

About 40 larvae have hatched
The newborn larvae have slightly heavier darker markings than Samia ricini and have white instead of black hairs; they measure 3 mm
See Cynthia Silkmoth Eggs Hatch

Authors
Brian Liang

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Cynthia Silkmoth Eggs Hatch

7/17/2017

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Our cynthia silkmoth (Samia cynthia advena) eggs have started to hatch. Stock originated as pupae from Pennsylvania, November 2016.

After about ten days, the cynthia silkmoth (Samia cynthia advena) eggs have started to hatch. About 40 so far.

The newborn larvae look similar to the ricini (Samia ricini), obviously, but they aren't exactly the same. The cynthia look to have bigger black markings and their hair is white, not black. The cynthia are shown on the top row; the ricini are on the bottom.

Like the ricini, they group together immediately as they hatch, regrouping quite quickly when broken apart. We put the larvae all on sweetgum (Liquidambar). The only other option was Prunus, namely plum, which we don't have a whole lot of good quality leaves of. The sweetgum should work for these, as it did with the ricini, but in our experience these larvae are so polyphagous that they will pretty much eat anything initially. You can't tell for sure if a host is suitable until the fourth or fifth instar. . . So far there have been a few nibbles.

Authors
Brian Liang

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Samia cynthia Eggs

7/10/2017

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We have collected some eggs laid by our first female cynthia silkmoth (Samia cynthia advena).

The first of our two female cynthia silkmoths (Samia cynthia advena) that paired twice (leaving the other female without a mate. . .) a few days ago managed to squeeze out a few eggs. She laid quite a few on the first two nights, but after that seemed to completely loose interest. We have always had troubled with getting these saturniids to lay eggs, especially the Atticini. In total we only managed to get 62 out of her before she died, still with a rock hard abdomen probably containing some 200 eggs.

We have put these 62 into the incubator since its getting quite late considering we only have about five weeks before we leave for New York. We're not sure what host plant we will use for these once they hatch. Obviously, tree of heaven (Ailanthus altissima) would probably be preferred, but we don't have that anywhere here. The top two alternative that we are considering are sweetgum (Liquidambar), which our second instar Samia ricini seem to be doing exceptionally well on, or plum (Prunus) which was the best host for our previous Samia ricini rearing.

Authors
Brian Liang

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Samia cynthia advena Rearing Notes (7/1/17-7/7/27)

7/7/2017

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Rearing notes for our cynthia silkmoths (Samia cynthia advena). Stock originated as overwintering cocoons from Pennsylvania, 2016.

Rearing notes 7/1/17-7/7/17:

7/7:

The first female has begun to lay some eggs, but not a whole lot
Unfortunately, the second female can't get paired because the two good males have apparently been spent. . .

7/6:

Because it didn't start laying any eggs, the female got itself paired again. . .
The other female eclosed but is crippled (probably because we took it out of the cocoon)

7/5:

The female got paired last night, but it still has not started laying eggs; the pair broke when we opened the box in the morning, before be got a chance to take any pictures

7/4:

Fortunately, a female eclosed as well as another, very large male
We were curious to see if the last remaining pupae was actually developing since it still weighed 2.6 grams (the highest initial weight recorded last year was 2.8) and actually found it to be quite close to eclosing; it's a wonder how these manage to eclose so in sync with each other
We put all of the moths into a tub to allow them pair by themselves

7/2:

Two more males eclosed today, but one of them must not have been able to find a good spot to expand because the wings were folded; its surprising that they managed to emerge so close together
We have weighed the remaining two cocoons, presumably females, and while they are clearly still alive it is hard to tell whether they have dropped significant weight since we can't exactly match them up to the six original numbers that were recorded
We have noticed that the males usually start flying like mad sometime near midnight, which is probably when they pair naturally in the wild

7/1:

The first moth has eclosed; it is a male
See Cynthia Silkmoths Have Begun to Eclose

Authors
Brian Liang

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Cynthia Silkmoth Female Ecloses

7/4/2017

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Finally, a female cynthia silkmoth (Samia cynthia advena) has eclosed. Stock originated as cocoons from Pennsylvania.

Today we had two more cynthia silkmoths (Samia cynthia advena) eclose, one of which (thankfully) is a female. We are still somewhat in disbelief that these cynthia silkmoths emerged so close to each other and at about the right time that they would in the wild while exposed to the most unnatural conditions. We still don't know when exactly they decided to break diapause and why.

The female is not much larger than the males in terms of wing area, but of course it is much fatter. This particular female has slightly wrinkled wings, but that is probably a result of us disturbing it just slightly while it was expanding. It looks much darker in color than any of the males, a bit closer to the chocolate brown of Samia ricini.

We are going to put all of the moths into a tub and try to let them pair by themselves. This shouldn't be a problem, based on what we have seen with ricini. However, these are distinctly wild and are extremely active. If it doesn't work, we can place them in an actual flight cage, but it's doubtful it will come down to that.

Authors
Brian Liang

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Cynthia Silkmoths Have Begun to Eclose

7/1/2017

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Our cynthia silkmoths (Samia cynthia advena) have begun to eclose. Stock originated as cocoons from Pennsylvania.

After a long, ambiguous wait, one of our cynthia silkmoths (Samia cynthia advena) has finally eclosed. We originally put these in the fridge in January after confirming that they were in diapause and then took them out again right at the start of May and put them in the incubator at 80 °F. When they didn't eclose by mid-June, we knew something was obviously up. Just like the imperials (Eacles imperialis) that don't normally eclose until late summer, they must take some pretty specific cues or simply have some kind of internal timer to make sure that they come out the second the weather warms up. So, putting them in the incubator probably wasn't enough.

At that point, we fished out five cocoons (we started with six) from piles of other cocoons and pupae, including Samia ricini, from the incubator and turned it off to help with the utility bill. After weighing, we confirmed that one was dead and tossed it. The remaining four were left in a cardboard box.

Even though we knew we had missed one of the cocoons, it still was still surprising when we found this incredibly colored and crisp male in the incubator today. It was unmistakable as cynthia and not the, what now seems quite hideous, ricini. This true cynthia, perhaps also somewhat inbred at this point, is still a very robust and wild-like moth. The thing's perfectly clean and well shapen wings are a beacon in the legion of crippled and deformed ricini's that also recently eclosed. Not to mention, they are a lot bigger and much more functional.

The coloration of this male cynthia is also completely different than the drab ricini. The dark, chocolate brown of the latter is replaced by a fine goldenish tan. The vertical stripes are also lined in the most glorious pink that provide a much needed contrast. In general, the patterns on the wings and the body are also just so much more defined. Those ricini's are truly some sad creatures. . .

Authors
Brian Liang

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