How does eclosing Sphingid moth reach the surface?

[lamprima2]

Most Sphingidae species (and some other moths) pupate in the soil. I always excavate the pupae a couple of weeks after the larvae disappear to be on the safe side. I wonder what happens in nature. How do they reach the surface when eclosing? Does the moth eclose underground and dig its way out? If so, how do they avoid damaging the wings? Or does the pupa somehow propel itself to the surface, and then the moth hatches? 

[kevinkk]

Good question. I have wondered the same thing. They must wriggle to the surface, while there is probably a loosely filled tunnel that remains from the larva burrowing ,I can't really see a wet moth pushing very far through soil. I don't recall reading anything about the process either. The only way
I can see an adult moth going through soil would be by using the pupal shell as a shield while the moth pushes up, maybe that's plausible.

Just earlier this season, I thought I'd be clever with a female Smerinthus cerisyi pupa and keep it in a cage buried in some loose potting soil, so
she'd emerge with any local males, well, as summer kept going, I got tired of waiting and dug her up and brought the pupa indoors, where,
of course, she hatched a couple days later, but I'd already dug her up, so no new knowledge there.

Ok, I checked and there is in one of my Sphingid books is a mention of Manduca sexta, and Citheronia regalis pupa working their way to the surface as
pupa, there is no evidence mentioned for moths emerging underground.

[adamcotton]

I got tired of waiting and dug her up and brought the pupa indoors, where,
of course, she hatched a couple days later, but I'd already dug her up, so no new knowledge there.

The pupa probably sensed it was at the surface, and so emerged soon after.

Adam.

[lamprima2]

Kevin, thank you for your reply,
Adam, thank you for correcting my misspelling.
It looks like I need to find the answer experimentally.
There is no shortage of Manduca sexta in my area.
I've just purchased some Jalapeno peppers and am waiting
for the eggs. I am not going to excavate the pupae
this time. Let's see if the pupal shells are in the soil or
on the surface.

[adamcotton]

Good plan.

At a guess I suspect that just the top of the pupal case head will be at the surface, the rest will be below (still attached, of course).

Adam.

[lamprima2]

Good plan.

At a guess I suspect that just the top of the pupal case head will be at the surface, the rest will be below (still attached, of course).

Adam.

Adam, this is very possible.
I will share the results.

[Chuck]

It is my observation that in most cases the pupae are horizontal, not tilted toward the surface. When the moth ecloses it digs its way out; perhaps (?) it emits a chemical to soften the soil. But they do dig their way out. The forelegs are, obviously, quite beefy. Wings may be sufficiently pliable that they are not damaged (because, clearly, they are not) in the act.

[Paul K]

This applies to almost all moth species as most are pupate underground. As Chuck said they are definitely dig them self out. The pupa waits until rain or morning mist is loosening the dirt to make the journey to the surface easier.

[Chuck]

The more I think on this, the more interesting the question. It also applies to some beetle species, which are soft when eclosing.

Baby ducks and baby turtles have an "egg tooth" a sharp protrusion that allows them to break through the egg. It falls off within a week or so. I wonder if some ground-pupating insects have additional tools/ features to assist digging out and then serve no purpose, so perhaps are lost upon or immediately after eclosion. Surely the beetle guys would know this, and there must be a paper on it, right?

[lamprima2]

It is my observation that in most cases the pupae are horizontal, not tilted toward the surface. When the moth ecloses it digs its way out; perhaps (?) it emits a chemical to soften the soil. But they do dig their way out. The forelegs are, obviously, quite beefy. Wings may be sufficiently pliable that they are not damaged (because, clearly, they are not) in the act.

Yes, according to my observations, the pupae of M. sexta lie in the horizontal position. This does not mean that the pupa can not crawl to the surface. 

[kevinkk]

There is also the interesting differences between buried pupa, for instance, some pupa, Citheronia regalis for example, are smooth, while
Eacles imperialis is rough, which would seem to lend itself to being an aid to the pupa unburying itself, but apparently not necessary, given the
amount of underground pupa that are completely smooth.
Every time I have dug up pupa, the are horizontal, that goes for ones in potting soil, or in the dry moss I use in clear containers, they are always
horizontal, no matter what the species.

Perhaps it is easier for a horizontally buried entity to extricate itself as opposed to be buried vertically.

[jwa121]

I enjoy rearing the caterpillars of Saturniid moths, especially African species, many of which burrow into the soil to pupate. I typically let the mature caterpillars pupate individually, in separate containers in which I have put some cut-up damp paper towel.

But once the resulting pupae have appeared and suitably hardened, I will often bury multiple pupae together in damp coconut coir, in preparation for the emergence of the moths.

I can attest to the fact that the resulting moths always emerge unscathed, leaving their empty pupal shells behind, buried, in situ, in the coconut coir.

Occasionally, pupae buried in coconut coir will migrate upwards through the coir until they break the surface of the coconut coir and become just visible. It has been my experience, though, that most of the time the moths emerge underground and make their way to the surface, leaving their empty pupal shells buried, in situ.

John

[lamprima2]

jwa121,
Thank you for sharing your observations.
They suggest that the pupa, at least in some cases,
can move to the surface from its underground pupating
chamber. I suspect the coconut coir is much less dense
than average soil, which is far from natural.
Moreover, the way of emergence may depend on the
type of soil and the species of the moth.
As I previously said, I am raising a bunch of M. sexta,
hoping to find out how this species can emerge intact
from their underground burrows.
Best regards

[lamprima2]

This applies to almost all moth species as most are pupate underground. As Chuck said they are definitely dig them self out. The pupa waits until rain or morning mist is loosening the dirt to make the journey to the surface easier.

Paul K,
Thank you for your reply.
Nothing is definite until you prove it.
Is your opinion based on a personal observation or a peer-reviewed publication?
Please share the source.

[vabrou]

Lamprima2..... You use the phrase 'peer-reviewed publication' as if this means something. I can show you thousands of 'peer-reviewed publications' that are complete crap. 'Peer-review' can be helpful to capture basic things such as spelling and grammar, but even these corrections are few. I always try to pass on my unpublished manuscripts to knowledgeable fellow entomologist, and I am always glad I did because others reading what you write can point out foibles that you gloss over. What do I base this upon? I have spent the last 55 years daily reviewing past entomological publications for use as references and literature cited in my own hundreds of past and future publications, and 90% of the published entomological literature out there has BS presented as a premise for publishing them. These most always involve PhD's and are most always funded by a University. Also, you will find blatant plagiarisms in just about anything you look over. Most 'peer-reviewed publications' are not actually reviewed by actual peers of the subject or materials presented, for the details stated, nor the outcomes of such publications. At this moment, I could provide you with examples of hundreds of manuscripts I have done actual in-depth studies of publications in our N.A. entomological scientific literature.

Tell me a bit about you, who, what, where, when, how..... in an E-mail to: vabrou@bellsouth.net -- and I can send you a few examples via E-mail. Some of the foolishness I come across published by PhD's and university professors is mind-boggling. Major works here in the USA published in the last couple of decades have 1-2 errors on every page among hundreds of pages, some pages have 4-5 boo-boos and even hundreds of misquotes and plagiarisms, and plain stupidity throughout; other very detailed highly polished studies can have boo-boos in every paragraph, page after page after page. I have reviewed some (thousands) entomological publications going back to the late 1700s, the 1800s, the 1900s into present days. I don't claim to be all-knowing and wise, but I do claim to have done the work begun in my late teens; I am 75 presently.

One example of many I point out in a long term study I plan on soon submitting within upcoming months involves a N.A. moth originally described in 1973 (51 years ago), the two authors of this species description had 5 different species in their original describing corrupted TYPE series, just this fact would be a major boo-boo. But over the past half century these same authors placed thousands more labels misdeterming thousands of other specimens using this one species name, currently stored in major entomological collections across N.A. Sound amazing doesn't it? But these thousands of mis-determined adult moths actually involved 13 different species all labeled as being this one species they personally described in our scientific literature back in 1973. I don't know a single person (ever or anywhere) that peer-reviews any manuscripts or publications to this extent. I have found several other authors that changed (falsified) published photos to meet their published false data claims. In fact, some noted authors have been found to have falsified all of their scientific publications, sometime involving hundreds of their published research. They were caught when they submitted the names and handwritten signatures of 5 PhD peer-reviewers, none of which was aware, nor had ever seen any of this manuscript.

What peer- review does prevent are the newbies that make a 1-2 day field trips and want to publish a meaningful useful and accurate polished scientific study. When their submitted manuscript actually appears like something written by a schoolchild, and has more holes than a block of Swiss-cheese. These types of individuals need to perform and attack the premise of their planned studies for5, 10, 20, 30, 40, 50.... years, gain actual meaningful knowledge, and then publish their results. I have used the phrase 'floccinaucinihilipilification of seriously flawed research literature' to describe some of these examples of (complete BS) published literature. Why so much BS? Well nearly all university professors are required to publish often annually in order to keep their jobs. In effect, this forced publication usually has a publication deadline, and therein lies the cause of seriously flawed literature - a rush to a publishing deadline regardless of viability of information presented. Vernon Antoine Brou Jr., Abita Springs, Louisiana, USA

[Chuck]

My personal observations is that the adult moths dig their way out. I could understand a pupa wiggling itself to the surface ACCIDENTALLY in loose surroundings, but I know of none that work their way to the earth's surface.

Vernon, I won't say you're wrong about peer review, but my peers are killing me on our paper.

[lamprima2]

Dear vabrou,
I asked Paul K if his opinion was based on personal observation or a scientific publication. Note that personal observation or communication with someone else is perfectly OK with me as an amateur insect enthusiast.
By "peer-reviewed articles," I meant articles that have been reviewed by the scholar's peers to determine whether they are high-quality. I am a Ph.D. in genetics and embryology and have authored numerous publications, including papers in leading scientific journals. From my experience, peer review doesn't necessarily guarantee the high value of an article. Moreover, in some instances, high-quality manuscripts are rejected. However, most of the time, colleague criticism helps improve the quality of the article. I can't see an alternative to this system. Also, I am unsure what this discussion on the peer review process has to do with the topic of my post.

[lamprima2]

My personal observations is that the adult moths dig their way out. I could understand a pupa wiggling itself to the surface ACCIDENTALLY in loose surroundings, but I know of none that work their way to the earth's surface.

Vernon, I won't say you're wrong about peer review, but my peers are killing me on our paper.

Chuck,
Thank you for your input

[lamprima2]

Update on my "elementary school" project. No peer review is necessary for the preliminary data.Two out of six M. sexta pupae in this pot have eclosed. The moths emerged in a perfect shape. Both were released to the amusement of tomato-growing neighbors (I doubt we have any).  I'll probably have to wait until Spring when all six are hatched. Then, I'll cut the soil layer by layer to find out where the empty pupae shells are situated. To be continued.

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