Category: Hyalophora_cecropia

Collecting Hyalophora cecropia Cocoons

8/16/2017

Because we will be moving to Ithaca, New York tonight, we had no choice but to collect all the cecropia moth (Hyalophora cecropia) cocoons despite that not all larvae have spun.

We never thought a cecropia brood started all the way back in April would still not be finished now in mid August. We normally would have collected all the cocoons once all larvae had finished spinning, but since we will be moving tonight, we had to collect all the finished ones and resleeve up the remaining few larvae with as many leaves as possible.

The cocoons this year are far smaller than the ones last year, despite having received nearly identical treatment (indoors on apple first three instars, and sleeved outside in the last two). The only difference was that some of the larvae this year were sleeved since birth. The larvae this year also grew much, much slower than last year's which all finished spinning at the beginning of August and began in June. We can't really understand why this year's rearing was so poor. We started off with hundreds this year and nearly all died off overtime, mostly the ones that were sleeved since birth. Last year we started with three dozen and got about the same amount through and they were respectable in size, with females at 8 g and males at 6 g. This year, the cocoons are a measly 3-6 g. We didn't imagine cecropias could even get down to 3 g without opting for a supernumerary sixth. Maybe inbreeding reduced their size?

Authors
Alan Liang

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Hyalophora cecropia Rearing Notes (7/31/17-8/??/17)

8/8/2017

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Rearing notes for our cecropia moth (Hyalophora cecropia) larvae. These originated as eggs from New York, June 2016.

Rearing Notes 7/31/17-8/??/17:

8/8:

The cocoon is finished but still pale in color and soft; another larva began spinning

8/7:

Another larva began spinning

8/6:

The prepupa that began spinning yesterday is finished; the otehr one still has not started and will mostly pupate naked without a cocoon

8/5:

Two larva became a prepupa and one has already spun most of its cocoon; the other one has already become very compact and nearly immobile but still has not spun, so perhaps will not
The prepupa from yesterday is finished with its cocoon

8/4:

The larva that began spinning two days ago is now finished; the silk has become brown but is still a little soft
The larva that began spinning yesterday is almost done as well

8/3:

The prepupa from yesterday had already spun most of its cocoon already but is still visible inside
Another larva became a prepupa and has begun spinning

8/2:

Surprisingly, the larva that was 14 g yesterday (not bad for male, but small for female) had runny frass today and is now a prepupa searching for a place to spin; we resleeved it onto a new branch
Of the remaining larvae, the largest few are feeding quite a lot and have suddenly begun making decent progress after probably weeks in this instar already; they are in the 10-11 g range

8/1:

The largest is at 14 g; a few of the other larger ones are at 9-10 g; only these few seem to actually be making some progress

7/31:

It's been awhile since the first larva spun a cocoon and the remaining larvae are still growing very slowly; the largest is still only at 12.7 g and most of the rest are far behind that

Authors
Alan Liang

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Hyalophora cecropia Rearing Notes (7/20/17-7/26/17)

7/26/2017

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Rearing notes for our cecropia moth (Hyalophora cecropia) larvae. These originated as eggs from New York, June 2016.

Rearing Notes 7/20/17-7/26/17:

7/26:

Unfortunately, the prepupa that failed to spin a cocoon looks to be dying now and won't pupate, so we disposed of it; perhaps it was diseased

7/24:

Collected the finished cocoon; will detach and weigh once the prepupa has pupated

7/23:

The cocoon is mostly hardened and is more vibrant in color
The the other prepupa did not spin a cocoon and as already become immobile, we took out of the sleeve and will just let it pupate inside

7/22:

The spinning prepupae looks to be finished and the silk has begun turning brown, though still light and not hardened yet
The other prepupa seems to have "forgotten" to spin a cocoon which sometimes happens with silk cocoon spinners, but usually only when disturbed while doing so, which this one was not; it simply lies at the bottom of the sleeve and has become stubby and compact

7/21:

It turns out there were actually two larvae from the same sleeve that became prepupae yesterday and one of them has already begun spinning; the other that was transferred to a separate sleeve strangely has done nothing and rests at the bottom of the sleeve

7/20:

After a very long 24 days, the largest larva has finally excreted runny frass and became a prepupa; we sleeved it up on a separate branch with enough leaves to spin a cocoon in it's weight has dropped to a very low 9.1 g; we don't now how much it weighed at it's peak (the last recording was two days ago at 12.7 g) but it is obviously a small individual, even if male

Authors
Alan Liang

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Hyalophora cecropia L5 Rearing Notes (6/26/17-7/??/17)

7/6/2017

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Rearing notes for our cecropia moth (Hyalophora cecropia) fifth instar larvae. These originated as eggs from New York, June 2016.

Rearing Notes 6/26/17-7/??/17:

7/6:

This slow progress is starting to become disturbing now; the largest is less than it weighed before, at only 7.6 g and the second largest is at 6.7 g which is surprising considering they have been feeding everyday, albeit not as much as would be expected at this stage; last year we also seemed to have a problem with larvae occasionally becoming stunted in the fifth instar

7/5:

7/4:

Strangely, larvae are not growing nearly fast as expected, perhaps from the cooler temperatures this week; the largest is still only a 7.7 g

7/3:

7/2:

The largest larva has grown to 6.8 g, which is not a bad start, but ideally we hope to get them at least 10 more grams bigger than that, as last year we had one that was near 20 g

7/1:

The larvae become very compact when disturbed and hold their thoracic legs together with their head sunken in

6/30:

Several younger larvae are making their way into fifth instar now and some color variation can be seen on the enlarged thoracic tubercles, being different shades of orange and yellow, with some having nearly red ones

6/29:

The scoli are beginning to spread out a little as the larvae's body grow

6/28:

The larvae have become slightly paler and bluer all around presumably due to their cuticles beginning to stretch from their growth

6/27:

Ah yes, what fine beasts these things are now, finally starting to pick up the pace in terms of eating and growing; they gobble down whole leaves in one sitting no problem and already look plumper than before

6/26:

The first two larvae molted to fifth instar today after spending 14 days in fourth instar
The fifth instar appearance is similar to that of fourth instar, except the tubercles are more developed, especially the enlarged thoracic and middorsal one at the rear which have acquired a black ring at the base and have become orange; also, any traces of black spots on the body (especially prominent on melanic individuals) are clean gone now, giving the larva a much smoother look; the lateral sides have also become distinctly yellow-green while the dorsal side is pale blue
The cuticle on the fifth instars looks extremely loose and baggy, and proportionally, the head capsule, legs, and tubercles are all enormous compared to the body, so clearly they will grow tremendously this instar

Authors
Alan Liang

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Hyalophora cecropia L4 Rearing Notes (6/12/17-6/25/17)

6/25/2017

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Rearing notes for our fourth instar cecropia moth (Hyalophora cecropia) larva. These originated as eggs from New York, June 2016.

Rearing Notes 6/12/17-6/25/17:

6/25:

6/24:

6/23:

6/22:

6/21:

6/20:

6/19:

6/18:

6/17:

6/16:

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6/12:

Authors
Alan Liang

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Hyalophora cecropia L3 Rearing Notes (5/30/17-6/11/17)

6/11/2017

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Rearing notes for our third instar cecropia moth (Hyalophora cecropia) larvae. These originated as eggs from New York, June 2016.

Rearing Notes 5/30/17-6/11/17:

6/11:

A few more larvae entered apolysis; the one that did yesterday still hasn't molted but has slightly wrinkly integument now, so probably getting close

6/10:

One of the third instar on apple entered apolysis for fourth instar; it measures about 25 mm in length, though it is definitely not the largest individual (some younger larvae already measure 28 mm); the tubercles are swollen, especially at the base, and the integument is very tight and shiny
The other larvae on apple are all doing very well, still forming small aggregations and stripping the top leaves of all the branches
The larvae on plum are quite interesting in that the ones sleeved since birth n the shade are extremely melanic now that they are third instars - one is practically like a blackish second instar but with the third instar tubercles
Unfortunately, the larvae on willow and sweet gum all got diseased and died - seems we should've just stuck with the apple all along and sleeved them!

6/9:

It seems the larvae that were sleeved outside since birth have now fully caught up to the ones raised until third instar indoors despite being about a week behind back in second instar; their thermoregulation is probably well suited to the outdoor temperatures now after being outside for weeks, so they don't mind the cold nights and hot days, while the indoor ones that are now sleeved as third instars seem to be in shock due to the extreme temperatures and have thus slowed down at bit

6/8:

The third instar larvae display are large variation in scoli size, even among those of similar body sizes; some are large and vibrant, while others are small and dull
A few larvae on plum molted to third instar and are catching up fast, likely to surpass those on willow which seem possibly diseased

6/7:

Larvae are slightly larger as always; the blue on the dorsal side is really starting to come in now

6/6:

It seems only the larvae on apple, both indoors and sleeved outdoors, will be decently successful at this rate along with the few larvae sleeved on plum
The rest of the hosts are just no good - the larvae on alder already died (learned the hard way that this host plant is real nasty), the ones on sweet gum couldn't utilize the host very well based on their incredibly slow growth rate and have just recently started dying off as well, and the ones on willow have reached third instar, but several already died from disease

6/5:

Many of the apple larvae that were sleeved from birth molted quite synchronously into third instar and are very healthy from the good ventilation
The largest third instars have become much more vibrantly colored, especially the tubercles which have noticeably enlarged and become brighter when compared to newly molted third instars (center photo)

6/4:

The apple larvae are growing rapidly now, consuming large portions of the leaves and becoming yellow green laterally and turquoise dorsally; those on willow don't like quite so good - at least a few died of disease and possibly more will, though the largest few still look healthy
The plum larvae are making quite a comeback and are nearly full grown in second instar now; those on sweet gum and alder, however, look diseased so it won't be surprising if we loose them all before even the third instar

6/3:

The apple third instars still look very strong and healthy, becoming firmer and greener; those on willow are mostly healthy as well, though likely because of indoor rearing, a few look possibly diseased
The larvae on plum are doing well and have surpassed those on sweet gum and alder which have had several diseased looking individuals die

6/2:

All the larvae have grown a lot since yesterday due to the warmer temperatures today (mid-high 70s day); it was definitely on the cold side before so they really needed the warmth
The apple larvae are all growing very well now, so we decided to sleeve the third instars and largest seconds outside as there should be no risk of desiccation or stunted growth now
The larvae on willow seem especially melanic, as some third instars look almost like second instars, with a yellowish body and black head capsule, and black tubercles in place of blue ones

6/1:

The third instars on willow fed minimally today which is somewhat unsettling, as Hyalophora larvae typically start having disease problems at this instar
The third instars on apple look quite healthy and have become plumper and smoother; they still seem loosely gregarious
The larvae on plum, sweet gum, and alder remain mid second instar, though the ones on plum have made surprising progress compared to how slow they were going in first instar

5/31:

Two more larvae on willow molted into third instar and another one did on apple (indoor) as well; the the older third instar from yesterday has become slightly greener
The larvae on sweet gum have picked up speed a little now that they are all third instar though it's still very apparent their growth on it is much slower than on willow and apple

5/30:

One of the larva on willow molted into third instar after spending eight days in second instar; the third instar is dramatically different than the second instar, being yellowish green with much larger, rounder, and brightly colored tubercles - red dorsal thoracic, yellow dorsal abdominal, and blue lateral; the black intertubercular spots have remained but are bluis, and the head capsule still has some black on it but is now greenish, though less melanic individuals will likely have less or no black on the head capsules and reduced black spots (this individual is definitely a melanic one, as it was nearly entirely black in the second instar rather than yellow)
The larvae outdoors on apple are surprisingly large now - not much smaller than the ones indoors despite being very small when first molted; the ones indoors are still ahead though, with a few that will likely molt into large third instars tomorrow
The larvae on plum and sweet gum are still small, but growing steadily; the larvae on alder are still feeding normally and only a few small individuals were dead today, so perhaps they might not actually be diseased

Authors
Alan Liang

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Hyalophora cecropia L2 Rearing Notes (5/20/17-5/29/17)

5/29/2017

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Rearing notes for our second instar cecropia moth (Hyalophora cecropia) larva. These originated as eggs from New York, June 2016.

Rearing Notes 5/20/17-5/29/17:

5/29:

Several of the larvae on willow are now in apolysis and a few of the ones on apple indoors are as well
The larvae on plum and sweet gum have hardly grown as always, but at least they don't look diseased
When changing the food for the alder larvae, several were dead and some of the others did not look so healthy either; there had been feeding, though not sure if enough to consider normal; afraid that the larvae had developed disease, we removed all the unhealthy ones and transferred the remaining to an airy container away from all other larvae

5/28:

Surprisingly, the willow larvae have come to surpass apple and all the other hosts despite not even being very old; they are all very large, and one of the second instars entered apolysis; full grown second instar length is about 16 mm and mass is 0.1 g
The apple larvae outside actually look very healthy and close to apolysis, though they are simply just a bit small
The larvae on alder are starting to put on some volume now, but it is still quite shocking how far behind they are compared to those on willow which are the exact same age based on hatch date

5/27:

Indoor apple and willow larvae are currently in the lead, probably not just in growth rate but genuinely in size as well; in fact, those on apple outdoors may still be ahead based on the tightness of their cuticles except they are much smaller so it appears they are behind the indoor ones
A few more larvae on plum molted to second instar but are extremely small, almost all the larvae on alder have molted to second instar, and there are still only a few second instars on sweet gum

5/26:

The largest larvae on apple have become very yellow and plump; the dorsal thoracic tubercles are also turning reddish meaning they are likely approaching the end of the instar
Most larvae on willow are now second instar are on par with the indoor apple larvae in terms of size; several larvae on alder also molted, though some look quite small; there remains just one second instar on sweet gum

5/25:

The larvae on all hosts are now in second instar except those on plum; the ones on apple indoors are much larger and ahead, with those outside and on willow close behind

5/24:

The larvae on apple outside are becoming much yellower as their cuticle stretches
The larvae on plum outside are still far behind those on other hosts except sweet gum, despite being some of the oldest of all the larvae
A few more larvae on willow molted into second instar; the older ones are already as large as the ones outside on apple despite being days younger
The larvae on alder and sweet gum are still mostly in apolysis, with several on sweet gum still just growing

5/23:

Over 60 larvae outside on apple are second instar now, and the vast majority are indeed yellow despite the first few melanics; we resleeved these 60 using three sleeves and recollected all the first instars into a container for them to molt indoors
It is very apparent now that we recollected outdoor larvae that the indoor larvae are much larger despite being younger - the apple photo on the right is of the indoor larvae and the left and middle one are outdoor, and as shown, some of the outdoor larvae are only half the size (photos are scaled the same)
Of the three indoor non-apple hosts, willow larvae remain ahead with several in second instar; alder is close behind with most larvae in apolysis; sweet gum is still last, with most larvae still growing

5/22:

The second instar larvae have become slightly yellower now that their cuticle has stretched a little, though many are still quite melanic
The larvae indoors are clearly growing at a much faster rate and are larger, as a some on apple and now willow as well are now second instar

5/21:

A few more larvae outside molted to second instar and some are quite melanic; the ones from yesterday already look a bit larger than before
A few larvae on the apple indoors have molted as well, but probably spent only half the time as the ones outdoors, probably due to the more constant warm temperature and higher humidity; unusually, these are almost entirely black
Larvae on willow are far ahead of the other indoors hosts besides apple, as most are preparing to molt to second instar

5/20:

A few of the larvae sleeved outside on apple have molted into second instar after spending a long 11 days in first instar
The second instar are yellow with much larger tubercles than before; there are intertubercular black spots and varying degrees of black melanization, with some having more black on the tuebrcles and head capsule than others
The larvae on plum have begun to become yellowish but are still quite behind for how old they are
The larvae on willow, alder, and sweetgum indoors continue to feed well, with willow still in the lead - one of the larva is already preparing to molt to second instar

Authors
Alan Liang

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Hyalophora cecropia L1 Rearing Notes (5/10/17-5/19/17)

5/19/2017

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Rearing notes for our first instar cecropia moth (Hyalophora cecropia) larva. These originated as eggs from New York, June 2016.

Rearing Notes 5/10/17-5/19/17:

5/19:

The largest larvae on apple are preparing to molt to second instar and are quite yellowish; they measure about 10 mm
Larvae have mostly stopped hatching, meaning we had quite a low hatch rate - probably about 60%; perhaps one of the females was infertile or the inbreeding caused some of the eggs to be nonviable

5/18:

The newly sleeved larvae on apple have adjusted well to the change in environment, with none crawling or falling off the plant and feeding well on the leaves; the older sleeved apple larvae are quite large and will probably molt soon
The larvae on plum simply can't compare to those on apple anymore - all of them are much smaller despite being almost as old as the oldest apple larvae; perhaps this variety of Prunus simply is a great host
Of the larvae indoors on willow, alder, and sweet gum, those on willow are noticeably larger than the ones of the other hosts, and some have already become yellowish; the ones on alder are not too far behind, and a few of the ones on sweet gum are quite large, but the majority are much smaller
16 more larvae hatched which is very little considering there should be a few hundred still unhatched; not sure if they just weren't fertile from the start or if hatch rates were just low for some reason

5/17:

Sleeved 100-150 of the oldest indoor larvae on apple onto the apple tree in the yard; being a few days old definitely got them off to a strong start so we did not experience any problems with larvae falling or wandering off the plant this time
The larvae sleeved on plum are a bit larger now and have fed quite a lot, though their numbers are somewhat low in one of the two sleeves due to many dying or falling off when we first sleeved
The indoor larvae are all doing well on willow, sweet gum, and alder - especially willow, though the ones on birch don't seem quite as good

5/16:

About 80-90 more larvae hatched; 50 were placed on sweetgum and the remaining on birch
The larvae on willow and alder have formed large but loose aggregations and have settled down, feeding readily on the hosts
More of the larvae sleeved on apple are now yellowish

5/15:

Another 60 or so larvae hatched; most were put on red alder (Alnus rubra) and the remaining 20 some larvae on willow
The larvae sleeved on apple are probably approaching the end of the instar now as some have become yellowish, especially around the tubercles
The indoor larvae on apple are doing extremely well, eating a lot and producing plenty of frass; we plan to sleeve them out soon as they are already quite strong and we don't want to risk disease from the overcrowded conditions

5/14:

Another 40-50 or so larvae hatched and were mostly placed on apple except for eight that we put on alder to see if they would take the host
The larvae that we tried willow and sweet gum on have eaten a bit so it looks like both will probably work; we're going to wait another day just to confirm that they have fully settled down on them
The larvae sleeved on apple outside are the largest of our larvae by far already, with the ones that have formed aggregations being especially large
The larvae on plum are doing alright, though they haven't grown as much as the ones on apple; it might have to do with the fact that the plum tree is in a more shaded area than the apple tree

5/13:

Another 100 or so hatched today; we put the majority in plastic containers with apple cuttings, but left 16 to try on willow (Salix) and sweet gum (Liquidambar), eight to each host
The larvae sleeved on apple look quite good still, though there have been several larvae that have desiccated since sleeving already; the ones that haven't have fed quite a bit and look slightly larger than wen they first hatched
The larvae sleeved on plum are feeding well now, though many larvae in one of the sleeves have desiccated due to falling onto the sleeve

5/12:

Over a 100 more hatched today; instead of directly sleeving them on the tree, we decided to put them is plastic containers inside with cuttings, just to give them a little start before putting them outside; several of the larvae that we sleeved directly outside the past two days were knocked off by the wind while placing them on the branch and larvae that crawled onto the sleeves desiccated before they could crawl back onto the leaf
The larvae on apple are doing quite well now and seem to have moved around a lot as the aggregations have changed, with as many as five larvae in a group now
The larvae on plum have settled down and eaten a bit

5/11:

About 100 more larvae hatched and were sleeved on plum (Prunus cerasifera); unfortunately, wind probably knocked off several while transferring them on the leaves - next time we'll try to wait until the air is more still to go outside and put them on
The larvae on apple have made several small holes on the leaf edges and there are many pieces of frass on the bottom of the sleeve, though the larvae themselves don't look too much larger yet; some have formed small aggregations of two or three while others are feeding alone

5/10:

Fifty larvae hatched and were sleeved on apple (Malus); see Hyalophora cecropia Eggs Have Begun to Hatch

Authors
Alan Liang

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Hyalophora cecropia Eggs Have Begun to Hatch

5/10/2017

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Our cecropia moth (Hyalophora cecropia) eggs have finally begun to hatch. . These originated as eggs from New York, June 2016.

It's been a long 19 days since our first cecropia eggs were laid (4/21), but today some finally hatched - 50 to be exact. That's about the same amount of eggs that were deposited on the first day which makes sense. The little neonate larvae began crawling out of their shells starting early in the morning, and by noon most that hatched today had done so.

The newborn larvae are a familiar site but nonetheless interesting, hatching grey with flaccid yellow tubercles at first and later becoming completely black with small but erect, haired tubercles. They measure about 5 mm in length, though there is some variation in size at birth. They already resemble the all too familiar mature larvae, just black with different anatomical proportions, notably the tubercle size.

Anyway, on to the rearing. Since this year we have so many larvae and many more to hatch, we will definitely be sleeving a good majority of them on our two apple trees (Malus sp.) and plum tree (Prunus cerasifera). For the 50 we have so far, we decided to put them on one of the apple trees, all to one sleeve for now. The sleeves are 5-gal paint strainers that can be bought in bulk at a reasonable price online; the material is quite fine and soft and provides good ventilation. So far the larvae have aggregated into small loose groups of mostly 2-4 and have fed a little. It's going to be a cool week so we don't expect them to grow at a very fast rate for now, but hopefully they will at least settle down and start feeding by tomorrow.

Authors
Alan Liang

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Dissecting a Developing Hyalophora cecropia Egg - Horn As an Ancestral Saturniidae Trait?

5/9/2017

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To confirm that our Hyalophora cecropia eggs (deposited starting 4/21) are alive and developing, we decided to dissect a few eggs, and made some very intriguing discoveries.

It's been over two weeks since our first cecropia eggs were laid, and we were starting to become a little impatient and worried that something was wrong as these usually take about two weeks to hatch at room temperature. We decided to open a few eggs just to see if anything was developing, and we were quite amazed by what we found. Two of the eggs contained nearly fully developed larvae, except that they were bright yellow rather than black. This didn't really come as a surprise as melanization is usually always the last step in egg and other types of insect development, such as pupa and molting.

It was the last egg we opened that really revealed something very intriguing. The larva was only partially developed, being bright yellow like the other two with a mostly formed head capsule and body. However, the appendages (pro and thoracic legs) and tubercles were not yet developed, making the larva look like a naked worm. And here comes the big surprise: the larva had a horn - yes, HORN - at the rear end of the abdomen, probably on segment 8 were the large, middorsal tubercles would normally be. The presence of a horn and absence of other tubercles on the body makes the larva highly resemble a larva in the Sphingidae larva!

This is an incredibly interesting discovery in the cecropia embryo, as it has many ancestral implications in relation to other members in the Bombycoidea superfamily, in which many larva bear some sort of structure on the rear abdomen. In the Saturniinae subfamily, it is usually a large middorsal tubercle accompanied by other smaller tubercles along the body, but in most other groups such as the Ceratocampinae subfamily and Sphingidae and Bombycidae families, it is usually a horn that may or may not be accompanied by other tubercles on the body (never in Sphingidae). The cecropia embryo we observed thus resembles more of a horned larva of another Bombycid group at this stage of development, which is really quite fascinating. It is possible to see evidence of evolution and common ancestry here because ancestral traits among species are often preserved in the embryonic stages of development. Thus, the horned and tubercle lacking cecropia embyro currently resembles the ancestral larva of it and other similar groups but as it continues development, the horn will eventually be reduced and modified into the middorsal tubercle and the other tubercles on the body will develop, forming a cecropia larva.

Authors
Alan Liang

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