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Post by nomad on Apr 19, 2019 15:23:21 GMT
Having futher researched this, I can only add that I believe this to be the only genuine P. machaon britannicus ab.niger remaining in private ownership, all the previously known extant examples being now in museums. I recently saw a pair of ink-stained fakes, but having seen the real thing, they were so obviously not authentic, but they made an impact nevertheless. Most if not all the British examples are in the British Museum. I have not heard of any in other British Museums. The type is also in the BMNH. I have been privileged to hold the BMNH drawer of ab. niger and ab. obscura. |
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Post by radusho on Aug 27, 2019 11:36:44 GMT
one alive from Japan   |
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Post by Adam Cotton on Aug 27, 2019 11:48:57 GMT
I understand these are chemically induced by injecting the soft pupa with something. I would be interested to hear more about such experiments, although I wouldn't want to own one myself.
Adam.
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Post by exoticimports on Aug 27, 2019 12:47:49 GMT
not a chemical induced specimen. With injcection you alwayss get some yellow, never full black (incl. entire body, antenae). This is a genetic form from a regular breeding. Do you mean it was wholly accidental and not selectively bred to achieve this? Many years ago I selectively bred generations of one of the eyed Sphinx to enhance purple found on the UFW of a wild population. It worked to some extent, but then I lost my colony. As we know selective breeding can have dramatic results. Chuck |
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Post by xavm (Xavier) on Aug 27, 2019 15:53:32 GMT
I understand these are chemically induced by injecting the soft pupa with something. I would be interested to hear more about such experiments, although I wouldn't want to own one myself. Adam. Adam, Heavy oxyanions (e.g. vanadium) are known to move inhibit the Tyrosine kinase and induce the melanin path instead. Best wishes, Xavier |
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Post by xavm (Xavier) on Aug 27, 2019 15:54:08 GMT
Nice ab. Radovan
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Post by Adam Cotton on Aug 27, 2019 17:13:42 GMT
not a chemical induced specimen. With injcection you alwayss get some yellow, never full black (incl. entire body, antenae). This is a genetic form from a regular breeding. Thanks for pointing that out. I was curious why the underside was also all black. In other chemically produced melanics I have seen (photos) the upperside is black but the underside is yellow. Are you sure this is absolutely genetic, rather than temperature induced? Many years ago I selectively bred generations of one of the eyed Sphinx to enhance purple found on the UFW of a wild population. It worked to some extent, but then I lost my colony. As we know selective breeding can have dramatic results. Chuck I have achieved amazing results selectively breeding P. memnon myself. Adam. |
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Post by nomad on Sept 6, 2019 19:57:15 GMT
Very nice indeed, impressive to achieve this by selective breeding. I have never seen an injected pupae specimen that black, they always have got much yellow, and do not resemble the old British/Germany melanic specimens, but this one from Japan is very special specimen, well I hope it now is, unless as this appears to be a female, the breeder will attempt to obtain a series by further breeding. I wonder?
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Post by Adam Cotton on Sept 7, 2019 9:09:18 GMT
nomad, It's a male. The body is fat because it has just emerged and spread its wings but not yet ejected meconium. Adam.
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Post by nomad on Sept 8, 2019 15:40:06 GMT
Ah thanks Adam.  Would it be worth using this male in breeding with a normal female? What would be the result, would any black specimens appear? ... but I very much doubt will happen considering this specimens monetary value. |
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Post by Adam Cotton on Sept 8, 2019 16:19:26 GMT
Ah thanks Adam. Would it be worth using this male in breeding with a normal female? What would be the result, would any black specimens appear? ... but I very much doubt will happen considering this specimens monetary value. That would depend on whether the melanism is genetic or induced by cold temperature treatment, assuming that chemical inducement never produces truly melanic specimens like this one. If the latter is the case then there is absolutely no point in trying to breed from it. The only way to obtain further melanic specimens would be to repeat the cold treatment. If it really is a genetic character, then even if it is a recessive trait it should recur in 2 generations. Offspring of the mating between this and a normal female would have to be mated with each other. It should be noted though that if this melanism isn't caused by a single gene mutation, but a particular combination of several gene states, then truly melanic offspring could still be quite rare in the next generation, but intermediates may occur more often. Theoretically if melanism is controlled by a single recessive gene then 25% of the 'grandchildren' should be melanic. If the melanic gene is actually dominant then all of the offspring of this specimen would be melanic (or mostly so) but some of the 'grandchildren' would be melanic and some normal, probably with intermediates. It is worth noting that the black gene in P. polyxenes and other black N. American species in the machaon group is actually dominant, so all the offspring of a cross between that and European machaon are black with a narrow yellow band, but machaon-like specimens recur in the next offspring generation if the hybrids are not sterile. Adam. |
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Post by nomad on Sept 9, 2019 10:28:09 GMT
Thank you Adam.
I have supposed this to be a genetic aberration, as I have never seen one this black, however I do not know what current advancement there has been in chemically injected pupae, as it has been many years since that began. It is a pity there is not more information how this melanic was obtained, but I believe in a previous post it was stated to have been obtained by selective breeding, which I assume was on the twitter news feed, where this was seen.
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Post by Adam Cotton on Sept 9, 2019 11:16:01 GMT
If it was really "obtained by selective breeding" then it would be genetic. I would assume that in that case there are other specimens in the breeding stock carrying the melanic gene/genes. It is unlikely that chemically induced melanism has advanced to the level of melanism as seen in this specimen.
However it is also worth noting that the pupa was subsequently tied to the stem for emergence, so it is very possible that the pupa was treated with cold shock techniques in the immediate aftermath of the prepupa shedding its skin to form a soft pupa. Such treatment does cause melanism in many specimens, but also many others either die or emerge crippled. I heard that this cold treatment only works very soon after initial pupation, within a day or no more than the second day. Of course once the pupa is older it would naturally encounter very cold temperatures during winter (even as low as -40C in Ust' Nera, E. Siberia) but spring adults are not melanic. It is a very fast and large drop in temperature just at the critical time after the pupa is first formed that CAN cause melanism.
I would expect that more very similar truly melanic specimens will come from the same source in the next few months or years if it really is genetic.
Adam.
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Post by Adam Cotton on Sept 9, 2019 11:18:53 GMT
Was there any indication in the original "tweet" saying where the parent stock originated from? The wing shape doesn't really look like Japanese hippocrates, more like European machaon.
Adam.
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Post by radusho on Sept 9, 2019 18:47:15 GMT
these are original tweets in Japanese with comments:
/photo/1
/photo/1
From what I understood is that it is a completely accidental hatch from a larva found in the garden, no selective breeding, no temperature or chemical experiments, maybe no deep interest in entomology in general. It is impossible to obtain a pure black form with either temperature shocks or chemicals. Both work for certain wing areas, but none of them affect the entire specimen like this (incl. body also!). Most likely an extremely lucky combination of gene play and environmental conditions. Maybe further generations would produce no black specimens at all. I am not sure if I would risk ruining such a perfect specimens for further breeding with zero quarantees.
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Would it be worth using this male in breeding with a normal female? What would be the result, would any black specimens appear? ... but I very much doubt will happen considering this specimens monetary value.