Rearing notes for our third instar eri caterpillars (Samia ricini). These are offspring of Europe sourced sibling-paired adults from a previously reared brood and have been reared indoors on citrus (Citrus).
Rearing Notes 12/15/16-12/??/16:
Third Instar Eri Silkmoth (Samia ricini) Caterpillars Feeding on Citrus (1)
Third Instar Eri Silkmoth (Samia ricini) Caterpillars Feeding on Citrus (2)*
*Shown in 4x speed
Eri Silkmoth (Samia ricini) Caterpillar Molting to Third Instar*
*Shown in 16x speed
Rearing notes for umber skipper (Poanes melane) chrysalises that were originally obtained as eggs laid by two wild caught females in captivity or found on various wild grasses in the Albany Eastside Permaculture Garden.
Rearing notes 12/17/16-12/26/16:
Rearing notes for our Indian walking sticks (Carausius morosus). These are offspring of an adult we have been rearing since March 2016 and a wild caught brown form adult no longer with us.
Rearing Notes 12/4/16-12/25/16:
Today we had two anise swallowtails (Papilio zelicaon) eclose from presumably diapausing chrysalises.
This year in particular, we have been noticing a lot of bizarre occurrences in nature that have been hinting at a prolonged fall and a very early spring. Not only are annual flowers blooming and deciduous trees losing their leaves and inflorescing simultaneously, but a number of our lepidopteran pets have been going through some off-sync life cycles such as our anise swallowtails (Papilio zelicaon) eclosing haphazardly throughout the winter like it is spring time. While it is likely that indoor conditions probably had something to do with these disturbing occurrences, in previous years we have not had the same problem keeping diapausing anise chrysalises indoors. Just today we had two individuals, one male and one female, eclose from what appeared to be diapausing chrysalises right in the dead of winter. What a terrible mistake this seems! Where we live, this time of year has some of the lowest average temperatures and obviously, the shortest photoperiod.
The male is shown below.
Yes, we have made several other posts already discussing this so this is not really any new news. But while some of the other anise swallowtails that we have seen eclosing from diapausing chrysalises in October and November were sort of ambigous, both in their reason for eclosing and in their appearance, these seem like they really thought it was spring time. For one, the previous individuals came from diapausing chrysalises that went into diapausing in the summer for absolutely no reason other than their genetics (presumably); the two that eclosed today came from diapausing chrysalises of an actual last and fall brood that pupated in October (even at low temperatures, they should not take two months to eclose normally so we assume that they were diapausing at some point). Even more interesting is that the two that emerged today is that they actually look distinctly spring-like. By that, we mean that they have typical spring time anise swallowtail characterstics, certain features that ocurr almost exclusively in the first spring brood eclosing from diapausing chrysalises of the previous year(s). Below we compare the male (left) to a mid-June male from this year.
A few things are evident that cue us in here. The spring indivuals are typically smaller and much paler in color. While we don't have exact wingspan data, we did notice (in person of course) that the shade of the left on to be particularly pale which is consistent with the photos. Lighting can have an effect on the shade of the yellow but this is the best that we can do. Next is the amount of blue and black on the borders of the wings. Summer males typically have very little blue such as the one in the picture on the right while spring males usually have a lot like the one on the left. Summer individuals (both males and females) tend to have a lot more black on the borders as well compared to spring individuals which is also apparent in the photos. While it is unclear what exactly causes these differences, these little things were quite interesting for us to take note of.
The last two fifth instar anise swallowtail (Papilio zelicaon) caterpillars from an October brood still have yet to pupate after two and a half months!
On 10/8 we caught a wild female anise swallowtail (Papilio zelicaon) adult who laid three dozen or so eggs that we collected and raised. On 11/24 we harvested the chrysalises formed from this brood of caterpillars. At the time of this chrysalis harvest, there were still two young fifth instar caterpillars that had been lagging behind. Today, they are still somehow with us. They have made gradual progress over the weeks, having clearly eaten and grown over time, and they appear to be completely healthy. Needless to say, we are quite baffled.
As herb feeders, anise swallowtails normally have an extremely fast growth rate. At room temperature, say 60=70 degreed Farenheit, these caterpillars have absolutely no problem completing development from the time they hatch to pupation in three, possibly four weeks (assuming other rearing conditions are not decent enough). When our October brood of caterpillars were fourth instar, they were only about at day or two apart in development but by the time they reached fifth instar, only about have of them seemed to develop at a normal rate and completed larval development in the expected three weeks. The other half pupated over the course of November in what seemed to be a complete random order. By the time we collected the chrysalises on 11/24, a few had only just finished pupating. The ones that lagged behind were cleary growing at a raye that is completely out of the scope of what should have been normal even given that the temperatures have gradually dipped a few degrees over the course of the month. But nothing can compare to the two individuals that are still eating and growing as this post is being written, almost two months since the first few individuals of this group pupated. These are caterpillars that hatched from eggs laid on the exact same day!
Why did this happen? These are not sickly individuals. They are not like some sick caterpillars that fight a prolonged battle with a virus or a parasite that they inevitably succumb to. We have seen plenty of those in our time rearing lepidopterans. No, these two fifth instars appear and act completely healthy and are not undersized (see the left and middle images). And as seen in the picture at the right, they have produced quite a bit of frass in one day, no less than what we would expect of them. The temperatures are currently 50-60 degrees Farenheit, no where near intolerable (bear in mind that the temperature wasn't always so low back in October and November, when the lived most of the lives thus far). So how are we supposed to explain this one?
The only logical assumption that we can make is that this is caused by having experienced too many stressors, including the temperature (as of late). And, of course, the lagging behind only results in a downward spiral where caterpillars that are already slightly behind are more susceptible to getting even more behind; the two individuals right now have experienced a nightmare of rain and cool temperatures that the faster grower never experienced and this is making them lag behind even more than they would have. Its plausible that when stress reaches a tipping point, things start not working right as they do in so many other animals including ourselves, including stunted growth.
We have begun overwintering our Saturniid (giant silkmoth) and Sphingid (sphinx) pupae.
It's a little late to begin doing so, but we finally got around to overwintering our diapausing pupae in the refrigerator at 40 F (4-5 C). The species we were sure would need this overwintering treatment were cecropia (Hyalophora cecropia), polyphemus (Antheraea polyphemus), imperial (Eacles imperialis), modest sphinx (Pachysphinx modesta), achemon sphinx (Eumorpha achemon), and white-lined sphinx (Hyles lineata) since the stocks orginated from regions with very cold winters. The only diapausing Saturniid/Sphingid pupa we didn't put in the fridge was Smerinthus ophthalmica since it was obtained locally and it does not even get close to 40 F here.
To overwinter the pupae of the six mentioned species, we simply dumped them all in various airtight contaners lined with paper towels with a drop of water. Dissapointingly, when we weighed the cecropia cocoons just to see if any had died since the time that they spun in July and August, we discovered two had lost a significant amount of mass and were therefore likely dead. All the other pupae/cocoons of the other species seemed alive. We will probably take them out of the fridge once the trees start growing leaves again (March or April 2017) and will check on them every few weeks just to make sure no mold forms.
Two of our umber skipper (Poanes melane) caterpillars pupated today! Also, another caterpillar has begun building a cocoon.
It took five days of waiting since the first cocoon was spun for it to happen, but it finally happened -- the first two of our umber skippers (Poanes melane) have pupated. With the first individual, we could tell because the silk of its cocoon is very thin and the dark color of the chrysalis underneath can be easily detected. In fact, the cocoon is so loose that all we had to do was pull off a blade of grass out from it in order to expose the chrysalis for our observation.
The second individual to pupate was never really in a cocoon at all. What we believe happened was that the caterpillar had already started spitting silk in the container with the rest of the caterpillars that are still feeding so when we removed it, it was already very late into the prepupal stage that it could not build a cocoon anymore. For the last few days, it has basically sat in very thin silk mat formed on top of a few grass blades as an immobile prepupa. Because this one pupated later than the individual shown above, it was still teneral when we took pictures of it; it still looks (and felt) slightly wet and soft and the color is much darker.
Since this is first time we have ever seen umber skipper chrysalises, in real life or elsewhere, we spent quite some time marveling over these two. They are decently large (for a skipper, that is), almost the same in size and mass as a full grown caterpillar (they don't shrink much). At first glance, they look very much just like any generic moth pupa because of the dark earthen color and the lack of major ornamentation. However, they are, of course, actually shaped quite like other skippers. Like other skipper species we have raised, the chrysalises have the chracteristic bulging eyes that create a squarish head and have an overall very elongated, cylindrical shape with a pointy cremaster. Interestingly, they have freckles along the back and just the slightlest amounts of hair (fuzz!) just like common chekerspot skippers (Pyrgus communis).
What really caught our eye with these chrysalises though was the proboscis piece. This piece is actually detached from the rest of the pupa and is extremely elongated such that it reaches all the way across to the end of the abdomen like a very long needle! When we have observed umber skipper adults nectaring, we have never really took note if their proboscises were especially long, but this makes us think that they must be. And apparently, a long proboscis on the chrysalis is quite common among grass skippers (Hesperiinae). For what particular reason, we do not know as they seem to suck on a large variety of what seem to be fairly ordinary nectar flowers. The way that the chrysalises are shaped reminds us a lot of the pupae of some feeding sphingids (Macroglossinae) that also have very long proboscises that are detached (partially).
On another note, we had another fifth instar that finished building a cocoon today. We took this one very early on, as soon as we realized that it was ready so it hadn't wasted any silk before we took it out which could explain why its cocoon is so well formed. It is much larger and more structured than what the other two individuals produced. Seriously, it actually looks like a cocoon! There is a lot of the waxy substance incorporated into the silk, which came from storages on the undersides of the last to abdominal segments on the mature fifth instar. The stuff allegedly helps to keep the cocoon waterproof.
Our first Jacobs' silkmoth (Rothschildia jacobaeae) has eclosed.
On November 28, we received four freshly spun R. jacobaeae cocoons that we did not know were diapausing or not. Now, 17 days later, we have our answer since one of the two smaller cocoons (2.9g) eclosed into a stunning male. We have never seen an adult of these species or any other Rothschildias so we were quite amazed by the moth's morphology. The wing shape is particularly interesting, with the forewings extremely elongated, slightly falcate, and the upper margin almost perpendicular to the body when resting in a natural position; the hind wings are quite elongated as well and are slightly pointed but rounded at the tips. The wing pattern is quite interesting as well, with the most conspicuous features being the large translucent discal spots on each wing which all Rothschildia have. Jacobaeae's hindwing discal spots are very uniquely shaped, as they are extremely large and tapered down until they meet the postmedial line. The margins of the wings also have a nice design to them. Aside from wing shape and pattern, what really makes this moth stunning are, of course, its magnificient colors. Both the wings and body have a splended burgundy color unlike most other Attacini silkmoths which are typically varying shades of brown or grey. Along the subterminal areas is a nice band of shiny purple scales, and the wing margins are a blend of silver and gold. We did not properly measure wingspan (forewing base perpendicular to body) but it is probably arund 5 inches. Since this individual is male, the abdomen is not extremely plump and the antennae are relatively large, though for some reason part of the right antenna got broken off (perhaps when escaping the cocoon?). We hope the other three cocoons eclose soon and one of them is female so we can pair them.
Rearing notes for our second instar eri caterpillars (Samia ricini). These are offspring of Europe sourced sibling-paired adults that we reared from September to October 2016 and have been reared indoors on citrus (Citrus) and oak (Quercus).
Rearing Notes 12/5/16-12/14/16:
The first of a large batch of umber skipper (Poanes melane) caterpillars that were orginally collected as eggs or immature larvae on grasses has built a cocoon.
After 29 days since we had our first umber skipper molt to the fifth and final instar, we have our first one to complete building a cocoon. What a frighteningly long wait for these guys! 29 days is quite an unexpectantly long interval for this instar, considering that the caterpillars are so small (relatively, that is, to some other genera) and they typically have many broods throughout the year. And the grasses that they eat shouldn't be the worst host plant ever; they should be quite nutritious even at this time of year. The caterpillars appeared to grow to maximum size in only about a week or so but then seemed to stall indefinitely!
The fact that it has been cooler in recent weeks is definitely a contributing factor to this slow growth (assuming that it is slower than normal growth). But what may also be a factor is disease, which, in hindsight was more or less inveitable given our situation and season. The cold, the extremely high humidity in the closed container and the house in general (due to rain), the lack of air flow, and the poor quality of the leaf cuttings that were only changed 2-4 times a week certainly took a toll on the caterpillars as the weeks went by. We had our first caterpillar fall from what appeared to be disease a few weeks ago and since them we have had a couple more deaths already. We believe that it is highly likely that some of the caterpillars that appear to be healthy are already infected and this is what is affecting their growth in a negative way. Like people, the caterpillars do have immune systems that can handle disease to an extent so sometimes even infected individuals can sometimes survive to adulthood but will still display temporary symptoms like the stalled growth.
However, potential disease factors aside, the most likely culprit is probably what they are eating. Grasses are notorious for containing very little nutrients, much less when compared to flowering plants. It is not uncommon for grass eating species to take a few months to complete development, so the two months it took our umber skippers to grow is nowhere near out of the ordinary. On top of that, almost all skippers including the umber skipper are supposed to diapause in the larval stage until spring and it is possible that things got a bit complicated because of this. Clearly, the ones that have already pupated did not go into diapause, probably due to indoor conditions, but they may have been slightly confused nonetheless.
The cocoon that was finally spun today may not be complete, but it was holding together enough so that we could pull it off the petri dish (it was attached to it on one side) and reveal the silk work. The cocoon is essentially a clump of grass blades stuck together with a layer of soft white silk (removing the grass will break the cocoon). It is quite thin so in some places the caterpillar inside is still somewhat visible. It actually doesn't appear to be quite that much different than the silken nests that the caterpillars regularily make to rest in or to molt; the only difference is that it is definitivly thicker now. However, one interesting thing to note about it is that there are is a pile of messy silken balls on one side (shown in the bottom middle and left). We aren't even exactly sure that stuff is silk. It actually resembles the white powders clumps on the last two abdominal segments of the fifth instar caterpillars (see rearing notes 12/1/16-12/11/16) when it is rubbed off. Perhaps we will get some more insight on this when a few more build their cocoons.
This timeline is a series of daily posts recording our observations on and experiences with various insects in Albany California and surrounding areas, from 2012-2017. Since we did not publish this site until 2016, posts before that were constructed retroactively. Starting in August 2017, we moved to Ithaca, New York; posts from there on can be viewed at Timeline 2017-present: Ithaca, New York.
August 2017 (49)
July 2017 (121)
June 2017 (79)
May 2017 (77)
April 2017 (91)
March 2017 (35)
February 2017 (12)
January 2017 (10)
December 2016 (12)
November 2016 (26)
October 2016 (49)
September 2016 (84)
August 2016 (94)
July 2016 (99)
June 2016 (53)
May 2016 (21)
April 2016 (4)
January 2016 (1)
August 2015 (3)
July 2015 (3)
June 2015 (2)
June 2014 (3)
May 2014 (1)
April 2014 (3)
March 2014 (3)
December 2013 (2)
November 2013 (2)
October 2013 (5)
September 2013 (11)
August 2013 (15)
July 2013 (9)
June 2013 (5)
May 2013 (4)
April 2013 (3)
March 2013 (2)
February 2013 (3)
January 2013 (2)
December 2012 (2)
November 2012 (1)
October 2012 (2)
September 2012 (2)
August 2012 (5)
July 2012 (1)
June 2012 (1)
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
Coenonympha tullia california
Langia zenzeroides formosana
Orthosia hibisci quenquefasciata
Papilio machaon oregonius
Papilio polyxenes asterius
Samia cynthia advena
Papilio glaucus × Papilio rutulus
Papilio polyxenes asterius × Papilio zelicaon
Araneae (Class: Arachnida)