Non-diapausing pupae subjected to prolonged chill: fully formed and DEAD
by Bill Oehlke
This narrative traces the process of procuring, inspecting, assessing and reporting on incoming cocoons, and potential problems that can occur with non-diapausing stock.
To meet the demand for fall and winter cocoons, I often purchase livestock from other breeders. I either do the inpsecting of incoming stock myself when I visit New Jersey in October, or my US shipping partner in New Hampshire does an inspection of all incoming cocoons before repackaging them for shipping in individual orders.
When I had nearly exhausted the usual supply of overwintering Antheraea polyphemus cocoons in January, 2012, I became aware that another individual, from whom I had not previously purchased stock, was offering polyphemus cocoons in very early February.
I contacted the individual and made arrangements to purchase fifty cocoons on a trial basis so that my shipping partner could assess quality of stock.
Fifty-one cocoons were shipped to New Hampshire, loosely packed, and forty-six of those were deemed healthy by my shipping partner.
Here is the report which I received from shipping partner who received the bulk order of fifty-one polyphemus cocoons.
"Xxxxx sent 51 cocoons via priority mail. There are 46 good. A note for you (up to you to pass along) - 4 of the 5 that are not good are
very clearly dead/desiccated. They have absolutely no weight, light as an eclosed cocoon. Since he just packed these up a few days ago I would assume they
were like this then as well. If he is new to assessing livestock he may want to know this or want them back.
"I have added 46 more poly to inventory
"Quality/Size: average size, but I'd say the ratio leans to male (more smaller/lighter).
"Packing He did not use any packing material but had them loose. It was an appropriate size box, but there was certainly room for some paper towel or
newspaper for padding to protect them against jolts and much jostling during handling."
I forwarded the shipping partner's report to the source of the cocoons and offered to have the ones deemed unsatisfactory returned if necessary.
The forty-six good cocoons sold out quite quickly so I made a request to source on February 22 for another fifty cocoons and suggested, "Please pack a bit more snugly with filler in way of Styrofoam peanuts or crumpled newspaper. Packages sometimes undergo rough handling in post office. Please also let me know if you have more polyphemus as I may wish to place another order in mid to late March."
The source indicated he would ship, and wrote he had even more, and stated, "I will inspect and pack them more carefully."
My shipping partner received the shipment and wrote me there were problems with the second shipment. I passed the concerns on to the source in the following email:
"Hi Xxxxx,
"My shipping partner has given me rather detailed reports: two of them. I will post them to a private page along with the digital images that she sent if you like.
Shipper reports that these were packed much better. Shipper felt some of the cocoons were very light, and opened three of them and found unhatched moths that were
dead. The pupal shell was broken at the bottom of the pupae, which is unusual, and fully formed moths were inside.
Non-diapausing pupae subjected to prolonged chill: fully formed and DEAD
"This usually only happens if
"At any rate my shipping partner has indicated that 26 feel good; 4 are definitely dead (the four she opened); and the remaining twenty are quite questionable.
I am prepared to pay for your postage and for 26 good ones at agreed to price for good cocoons, and would pay my shipping partner to return the 24 that are
either dead or questionable. I would not want to ship the questionable ones to my customers.
Or we can return all fifty and I would just pay you for your shipping costs to my shipping partner.
"It is not my business to tell you what to do with the remaining polyphemus cocoons in your possession, but you took our suggestion with regard to packaging to
heart, so here goes. My recommendation to you is that you not ship any more of your remaining cocoons to anyone unless you get a very good sense of pupa weight
when hefting or giving the cocoon a gentle shake.
"Thus far my shipping partner has only opened five cocoons; three that she felt were very light (all three proved to be dead), one that she felt was good
(it proved to show no development and is in true diapause and is healthy)
And one that is questionable (it is also dead, but does not show the pupal shell rupture). She has digital images which I can send if you like.
"I am not faulting you for the assessment of the cocoons. I think it is a lack of experience. Often a late summer brood of luna and or polyphemus will have some
larvae that produce the overwintering enzyme and will go dormant and if kept cold will survive the winter. Some larvae from that same brood will not produce the
overwintering enzyme and within 2-4 weeks of spinup will emerge as adult moths unless they are kept cold. If kept cold for long periods without the diapausing
enzyme, then development will occur, but moths will dehydrate and die without emerging. I suspect that is what happened here. How can you as a breeder and seller
know the difference?? All you can do is keep such cocoons at room temp for at least five weeks after spinup. If they have not emerged by that time, then they are
almost surely in diapause and are safe to keep cold for a prolonged period. Sorry for the bad news. Happy to send digital images, return all or just return the
bad ones, or return none and just pay for the ones deemed good by my shipping partner. Let me know what you want us to do.
"Sorry for the bad news.
"I do recommend for your own learning experience that you start hefting your remaining cocoons. Any that feel exceptionally light should be cut open.
I am sure you have more in your mix at home that will contain the developed moth and split abdomens."
a) Non-diapausing pupae are subjected to a prolonged cool spell, ie, the pupae which were not geared to overwinter based on lack of enzyme in their
systems, were kept cool. The moths would continue development during cool period (not in diapause (dormant stage)) but it was not warm enough for them to have
enough energy to actually eclose or
b) Diapausing pupae are kept warm from time of spinning until diapause is broken with the onset of a lengthening photo period. The natural photo period begins
to lengthen around December 21. If it is sufficiently warm, but not too warm, the pupae will begin to develop with moths typically beginning to emerge in
February or even in January if it is quite warm. If developed moths are then subjected to a prolonged chill, the result will be the same as in Eample a.
The source replied, "Thank you for this detailed information. I'm sorry that we are having trouble with this lot of cocoons and you are having to spend time
taking me and the grandchildren thru a learning curve. These cocoons were part of a lot of several hundred that were all second brood of 2011 spinning in very
late summer early fall. Shortly after spinning, say a few weeks some began to hatch. This puzzled us as we didn't think they triple brooded and food was going to
be a problem. We put them in the refrigerator, kept them damp, and thought all would be well till spring sale.
"I stepped in and examined the 50 we sent you and felt they all were normally heavy and felt good.
"So we are left with a problem of having a hundred to 150 cocoons that feel ok but may be partially emerged inside or other enzyme related problems.
"Short of opening them carefully with a razor slit.......what do you suggest?
Are you interested in buying any more and those that are opened can they still be sold?
At any rate I replied to the source,
"Hi Xxxxx,
Based on what my shipping partner has reported, I suspect about half of what you have left are cocoons of pupae that are healthy and in diapause, but that is
just a guess.
"I suggest you find about five cocoons that feel quite light and cut them open carefully with scissors. I suspect you will find fully formed moths that are dead.
They will likely still be inside the pupal shell.
"The more often you handle cocoons, hefting and giving a gentle shake, the better able you will be to determine which ones are good and which ones are not.
It is a hands-on-experience technique that one can probably only learn by first hand experience.
"After you have gone through about fifty cocoons and pulled out what feel like the lightest ones, go through the same fifty cocoons and pull out about three
cocoons and carefully slit them open. Hopefully they will have nice healthy pupae in them.
"I am going to forward the two emails with images that were sent me so you can see the difference between the pupae that are not good and the one opened that was
good. Shipping partner is going on a "sense of feel" to report that partner feels 26 are good.
"Inspector has own experience with rearing, and I have sat with inspector at her kitchen table in New Hampshire on a couple of occasions working with
partner on assessments of stock. You will be surprised at how proficient you become with the gentle shake and heft technique as you get experience.
You are probably in an area where there is sometimes 1) a full third brood when there is an early warm spring; 2)
only two full broods where there is a late cooler spring and cooler summer; and 3) a partial third brood
When the weather is intermediate between scenarios 1 and 2.
"Partner did not notice this problem with the first group of cocoons you sent. Perhaps she simply missed it and I will be refunding money to customers,
but more likely moths might still have been alive in the first batch of cocoons as they would not have been so far along in development and would have
been able to withstand cold.
"The cocoons spun up earliest in 2011 are likely the ones that would not be in diapause and would be trying a third brood.
Ones that spun up a couple weeks later are ones that will likely be good.
If you sent the first batch from your latest spinners, most if not all (I think inspector reported a couple "no good" [actually five] from first batch) would
likely be in diapause.
"I would discourage opening all the cocoons, because then there can be desiccation problems (rarely happens), and, first few times you try this, you will
probably knick a few pupae with razor or scissors. I prefer you do some self training with just a handful of cocoons as explained above.
"If you do experiment as indicated above and find that you can pick out ones that are no good (i.e. all five of the lightest ones are dead) and can pick out the
ones that are good (all three of the heavier ones look you pupa in forwarded email of healthy pupae, then I would be interested in trying another shipment of
fifty that you feel are good ones.
"I am happy to pay for the 26 in the second shipment already received, but do need to know now if it is okay with you to keep these and pay you just for
26 and postage??
I actively sell cocoons by contacting people in my email address book to see if they wish to purchase anything, but I have not sent out any emails in last week or
so because I was waiting to see how you wanted to handle the last shipment. I have a couple of customers on hold right now, waiting to see if we have polyphemus
for them or not.
"I still have promethea and cecropia cocoons to market and probably could market another fifty polyphemus cocoons, but need to do that as much as possible before
end of March.
"If you were to send fifty of your heaviest (unopened) cocoons to inspector, I would also be prepared to pay for those that are deemed to be good.
I think this is first time we have done business and every once in a while you run into a shady character. I do not want you to think of me as one who is
trying to fool you and that is why I presented the earlier options of 1) sending all cocoons back and just paying your shipping, 2)
paying for and keeping good cocoons and your shipping and just sending back ones inspector feels are no good, and 3) paying for and keeping good cocoons and
your shipping and discarding bad ones, I prefer the last option because then I don’t have to pay inspector to ship back the bad ones.
I do not think you are playing games with me at all. I suspect you just did not have experience with a brood in which some cocoons are non-diapausing.
Here on PEI, almost 100 percent of the polyphemus that I harvest will overwinter, but I do not try to market any until at least four to five weeks after
they have spun up. That way the ones that are not in diapause will have emerged and I can put rest in cold storage. It is a mistake, however, to
keep diapausing polyphemus at room temperature for winter, because as soon as photo period begins to increase after December 22, they will also start to
develop and emerge in January-February.
"Almost every year I have 1-4 polyphemus cocoons that will yield adults in very late July or even September when there would be no possible way that another
brood would make it through. Each summer I rear between 500-1000 of them to cocoon stage. Back in late 1990’s when I was supplying a major research project
with Max Planck Institute in Germany with literally thousands of polyphemus cocoons each summer and fall, I sometimes would bring in eggs from one of the
states, usually New Jersey to jump start the season. The early cocoons reared here had to be shipped to Germany as soon as the pupae hardened inside the
cocoons, because that earlier stock from New Jersey was not in diapause. The reason it was not in diapause was not because it was from New Jersey, but because of
the photo period the larvae were experiencing in their fourth instar. I guess that exposure is what determines whether or not the larvae will produce the
diapausing enzyme that arrests their development until after a prolonged chill.
"Let me know if you receive the images okay in the forwarded emails. I am going to send them right now. Also let me know what you want done with order we have
already received and not paid for. Also let me know how you make out with your own experience with opening a few of your remaining cocoons.
"Thanks for letting me know what you observed in fall with some of the moths emerging. I feel you must be feeling some frustration with fact of doing all
that work and having cocoons that are not good, but you will be much better prepared next time.
"I grew up in New Jersey and we usually only reared a few dozen first brood lunas and pollies and put our major efforts into the final brood.
Also with experience we were able to pick dates for pairings with some accuracy as you can delay non diapausing pupae for a short time with cooler
temperatures (never freezing), but not for a longer period of time.
"I will also ask shipping partner/inspecto to reheft the 25 additional ones she feels are good to make sure they have not progressed since last email
from her. I suspect they are good as damage was probably done in November-December."
"I have hefted the remaining stock and have been able to sense a difference in hefting cocoons that are healthy from those that have weight but
demonstrate a "softer"thud and possibly indicate advanced development/emergence.
"After examining the remaining 150 or so that I have remaining, I found about 30 that were suspect and of those about 20 were not viable, the remaining were healthy.
Who knows the condition of the 120? I suspect a percentage are not good but are beyond my ability to verify good health.
"Once I cut a small slit to verify they are good are they marketable to you? I can cut open all of them, I'm good at that with a razor, but beyond my use for this
years breeding I have beyond my needs.
"You do not have to return any of the past shipment. Payment for 26 would be satisfactory.
"I appreciate your suggestion to put less effort into the first brood and put more effort into what I hope to be a final brood.
"Here we do have some that overwinter and hatch very late in the mid summer. The female seems inclined to start a single brood.
I have about a dozen " wild " cocoons that I keep and try to use the females as my source of eggs and tie them out to attract " wild males".
"Cecropia was a favorite moth I raised when I first became interested in NY many years ago. I'm getting my 6,9, and 12 year old grandchildren interested in the
study and also the business aspect of it so they can learn about earning money and dealing with people. They have taken with enthusiasm your
correspondence and the technical, customer satisfaction and quality control aspects.
"If you have an abundance of these cocoons perhaps we can trade. This variety may prove less troublesome in South Carolina
and we do have food plant available.
"Once again thank you for your time and advise me as to how we may be able to continue to work together."
"Hi Xxxxx,
I mailed a bank money order for $xxxx yesterday. My shipping partner put two of the good ones into one order she mailed yesterday and reports
of the 24 “good” ones remaining, 22 still feel good, and the other two probably are as well, but I am not sure if we will try to sell those two.
Yes, the cocoons are still marketable once slit. We usually wrap over the slit with a bit of tissue and tape. As long as the head end of the cocoon is not sealed,
the moths can still escape okay.
If you wish to send another fifty of the ones you feel are good to shipping partner, they will be assessed, and I will pay $x.xx for the good ones plus postage.
We still have cecropia and we sell those at $6.00 US/cocoon plus one shipping and handling fee of $8.00 (I have purchased these cocoons from an experienced
Michigan breeder and Bonnie re-inspects them when she receives them. He usually sends 102-105 when I order 100 or about 52 when I order fifty, and usually there
are a couple of that number that shipping partner finds are not good. Cecropia are almost always single brooded.
Sometimes, very rarely, a couple of moths will emerge from a very early brood in one of the southern states. They start flying in Alabama in March-April.
If you send 50 polyphemus to shipping partner and they are assesssed as all good, then you would be entitled to a credit of xxx.xx (includes $6.00 for postage)
which could be applied to purchase of cecropia cocoons are partial purchase of cecropia cocoons combined with payment to you of unused balance. So if you opted for
ten cecropia cocoons x 6.00 = $60.00 plus $8.00 = $68.00. I would mail you a payment for $xxx.xx (or whatever your credit works out to be after assessment) minus
68.50 = $50.50 to you in form of payment.
I will be paying shipping partner a bit of a bonus for all the assessment work done. If inspector had not caught the problem, many people would have received stuff
that was not good, and that would not be good for me or my business. I am hoping that all the ones sent from the first batch received turn out to be good.
If you think you are going to be at this for a few years, then I would strongly recommend you take out a membership in WLSS. There is a one time lifetime fee of
$45.00. There are many articles on the site by myself and members (over 800 worldwide). All US species are depicted. Over 1450 different worldwide Saturniidae
species are depicted online on the site. There are maps of many countries and country checklists for most countries with Saturniidae populations.
If the boys are keeners, they will enhance their reading skills, general knowledge of geography, and learn much about Saturniidae from using the site.
I live in Canada but grew up in New Jersey. What I rear in Canada stays in Canada or gets shipped overseas. The stock that I sell in US is reared in US.
I either inspect incoming bulk shipments from US breeders to my sister’s address in New Jersey while I am visiting there in October, and I do some shipping from
there. I then either mail or drop off unsold cocoons with shipping partner on my way home to PEI. Subsequent bulk orders get direct shipped to shipping partner,
and partner ships from New Hampshire the remaining orders that I post from November until supplies run out in March-April.
I buy as much as $10,000.00 worth of livestock from US breeders each year, but I try to buy almost exclusively overwintering stock. I do have a member in
southern Alabama who sometimes sells summer lunas, polyphemus, securifera, giant swallowtails and imperialis for me. This past season I have received stock
from over a dozen breeders. Some supply large amounts of many species, others send smaller amounts of just one or a few species.
I answer all the customers questions, make all the payments, and send shipper payments to cover inspection, storage, shipping (postage + $4.00 for each box inspector
ships), packing (10% of selling price).
I also supply shipper/partner with the Uline indestructo boxes we use for shipping. My business is registered with Canadian government, and I also pay taxes on
profits. I am in the process of doing the annoying chore of filling out
Tax forms for 2011 right now (written in March; in Canada we have until end of April to file income tax forms).
Please get back to me promptly with what you want to do regarding the additional fifty poly I have requested. I regularly receive requests for cocoons, and
have some people requesting poly cocoons right now, probably even more than the 22 we still have on hand, so I need to know what is likely to happen.
I also sell eggs and that usually starts near end of March. I have several US breeders who direct ship eggs for me under my US shipping label
(New Jersey boyhood address where my parents still live), and some species will be flying soon in Alabama. I have egg shippers in
Alabama, Virginia, New Jersey, New York, Pennsylvania, Wisconsin, Michigan, Oregon, Colorado, Arizona, Delaware, Maryland, so can offer eggs of many
different species at different times."
Here are copies of the two reports inspector sent me regarding your most recent shipment of polyphemus:
First reply:
Xxxxx sent a nice note with 52 poly. He had opened several (did a nice job cutting discretely). Including those there are 48 good.
Of the remaining 4 one if definitely not, but I am on the fence about the other 3 so want to reassess them tomorrow (Tuesday).
I will do it first thing. He obviously paid attention to suggestions and sorted thru carefully.
++++++++++++++++++++++++
Follow-up reply:
Hi Bill,
I checked Xxxxx's remaining 4 poly and feel I can safely add 2 more into inventory (needed fresh eyes and hands) bringing his number to 50 :)
And so, some of the Antheraea polyphemus pupae/cocoons reared in South Carolina were naturally geared to overwinter and survived the prolonged chill. Those pupae/cocoons not geared to overwinter, did not survive. They had been healthy pupae and continued to develop, but in the cold did not have sufficient energy to escape from cocoons. Had they not been chilled, they would have produced healthy moths before cold set in. Such moths would have been good to preserve and sell as specimens or to release back into natural environment.
The moths have no internal heat source. In the wild on cold nights the moths will vibrate wings prior to flight to generate heat necessary for flight.
For multivoltine species that you hope are going to overwinter, it is always best to wait at least five weeks, to see if moths are going to eclose, before placing cocoons in cold storage.
If you have cocoons in diapause, they should remain in cold to keep them in diapause. If photo period lengthens and diapausing pupae are not kept cold, the pupae will begin to develop. The light waves that trigger break of diapause are probably of infrared wave length and can penetrate cocoon shell even though humans do not see the light or the process, sort of like x-rays.
I am very thankful that my shipping partner detected the problem. Either my inspector and/or myself do individually assess each cocoon upon receipt and again prior to shipping. We probably do miss some problems occasionally, but usually the problems are detected in advance and customers receive only quality cocoons in good health.
I am also very thankful to this particular breeder. Sometimes if we report to a source breeder that there have been problems with the shipment, that assessment is received with mistrust, anger or resentment. I can understand frustration, but the other feelings should be short-lived at best. Nobody likes to put in the time to rear these moths only to find the results are not up to par and in the case of death, time and possibly money have been wasted.
Problems need solutions. If you don't know there is a problem, you don't look for a solution.
I remember the year when birds attacked my rearing sleeves and destroyed hundreds of dollars of sleeves and ate thousands of almost mature polyphemus caterpillars. I found a solution to protect the sleeves and larvae, and now the birds and I get along fine.
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