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Post by midnightflight on Jul 15, 2011 18:23:28 GMT -8
Hello,
My partner and I have recently started raising moths. We have had luck with lunas, but lately we have lost all of our Cecropia larvae due to disease, which was devastating, and now we fear that our pupae of luna, promethea and polyphemus are all dead. They were moving around quite a bit last week, we put them outside in the shade for an afternoon (covered so nothing could get to them and not in direct sunlight), and since then not a single cocoon has moved or made any noise. This really concerns me. We feel that the remaining lunas should definitely have hatched by now, and the polyphemus as well.
Is it likely that a few hours outside would have killed all of the pupae, and if so, why? We had heard that letting the cocoons be exposed to some natural light and environment would be beneficial. The high was in the mid 80's, but again, they were in the shade.
Is there a way to tell if they are alive or dead?
That has been a really bad week for us... any advice from more experienced lepidopterists would be extremely appreciated.
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Post by simosg on Jul 15, 2011 22:40:54 GMT -8
Open the cocoons and squeeze the thorax of the pupae carefully between your fingers. If they are alive, the will move their abdomen a little. If they are dead for a longer time, they will be less heavy than living ones. Living ones feel cold on your hand, dead ones not (if they are dead for a while).
Hannes
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Post by bigwhitmer on Jul 16, 2011 22:34:00 GMT -8
I've raised prometheas only once so I'm not going to claim any expertise there.
As I'm guessing you already know, polys and lunas have active pupae, especially the lunas. If they are not moving, I have to believe they died from excessive heat.
Luna cocoons are easy to cut open. Just pick a side and carefully cut a slot with sharp scissors. Remove the pupa. If alive, it should already be moving. If not, give a little squeeze as suggested above. If still not moving, it is done.
Poly cocoons are a lot bigger pain to cut open. I usually take a sharp knife and work carefully to cut a slot in the end. Once the slot is big enough, I carefully cut through the side of the cocoon. Usually multiple cuts are necessary to get the pupa out. Repeat above steps.
Giant silk moths do not like the sun and/or lots of heat.
Maybe 4 years ago, my kids' school released a poly that had been raised at the school. It was abnormally hot for an early June day, being in the high 90s. Poly flew upwards, flew around for awhile and then suddenly plummeted to the ground. It was alive but could not flap its wings or stand. On the other side of town, I had just finished showing my polys and cecropias to a preschool class. I put the cage full of moths in my car. Something I don't remember anymore delayed my departure. All the moths were just like the poly. All these heatstroke moths ended up at my house. I hoped they would recover but they never did. I believe the females did pump out eggs but the eggs had never been fertilized. All the moths lived multiple days after the heat incident but I don't remember how many.
Back in the mid '90s, I was in the habit of taking my aquariums of cecropias outside to clean the aquariums. I would sit the caterpillars to the side during the cleaning. Sometimes, I'd find rampant sickness spreading through the caterpillars the next day, with lots of death eventually happening. I don't remember how many times this occurred but I eventually figured out that bright sun + lots of cecropia cats in close quarters = death for many of the cats. Now I leave the cats inside, clean the aquarium outside, and don't have any rampant diseases killing my cecropias.
Fortunately, I have no personal stories about having a bunch of poly or luna cocoons dying. But I have to believe that if your cocoons are dead, heat was the cause.
I'm not aware of "some natural light and environment" being beneficial to poly and luna cocoons. How much light they saw as cats affects when they are eclosing so maybe that was what you were being told and it got twisted in the translation.
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Post by beetlehorn on Jul 18, 2011 20:22:49 GMT -8
Rearing anything is a learning process, and sometimes lessons are hard learned, but so being they are also not easily forgotten. I would have to agree with the last reply, and say even though you had them in the shade, they overheated due to lack of free flowing air. I use a cage I specially constructed for Saturnidae. It is screened at all sides even the door. This allows the cocoons to be in the shade yet have proper ventilation, and I can leave them outside so as to be exposed to natural elements. This does several things in favor of your rearing stock. First it protects the cocoons from wasps, mice and birds. Secondly it ensures your stock to eclose at the time that is natural for them (females can call in wild males), thus coinciding with wild moths. Thirdly it is much more convenient than having them in the house. I have included a photo of one of my cages. I hope this can be of some use to you in the future. Tom
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Post by beetlehorn on Jul 18, 2011 20:25:42 GMT -8
Here is the photo I wanted to share. Attachments:
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Post by jackblack on Jul 19, 2011 1:03:17 GMT -8
Many years ago 25 approx I knew old Ray Straatman alias Krupten , he visited me regularly in Kuranda Nth Queensland where I lived, Ray was a bit of an eccentric well respected butterfly expert ,we discussed many things about life in general, he told me touch the pupa with your tongue if it is cold it is live , if room temperature it is dead .
I bred many types of Lepidotera over the years raised the larva indoors , nothing required sunlight or light directly , most things always hatched for me , most important I found keep up humidity and spray pupa with water regularly .
Jack
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Post by bichos on Jul 21, 2011 0:44:25 GMT -8
Many years ago 25 approx I knew old Ray Straatman alias Krupten , he visited me regularly in Kuranda Nth Queensland where I lived, Ray was a bit of an eccentric well respected butterfly expert ,we discussed many things about life in general, he told me touch the pupa with your tongue if it is cold it is live , if room temperature it is dead . I bred many types of Lepidotera over the years raised the larva indoors , nothing required sunlight or light directly , most things always hatched for me , most important I found keep up humidity and spray pupa with water regularly . Jack :Pwell did you lick your pupae   I guess it's got to do with microbial activity, busy little bacteria produce heat and so living pupae have no bacteria and thus, are cold. I wouldn't be spraying pupae directly oh no. |
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Post by jackblack on Jul 21, 2011 23:45:07 GMT -8
I didn`t have to as there was no question they were alive .
I spray pupa directly with water all the time over 30 years of breeding Leps of all sorts in Australia , no problems .Hatch rate is generally 95 to 99%
Why wouldn`t you spray your pupa ? What sort of hatch rate do you have then ?
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