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Post by Adam Cotton on Jan 31, 2017 13:00:54 GMT
I have seen specimens of Troides species with similar colour change on the hindwings. I suspect it is either due to the effect of light on the specimen or possibly humidity. I seem to remember seeing specimens here in Thailand in display frames that turned this colour.
Adam.
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Post by nomad on Jan 31, 2017 13:20:41 GMT
Certainly seems to have fooled Charles Oberthur and others, so I am in good company. His description of bright red is interesting, which this specimen is certainly not.
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Post by deliasfanatic on Feb 1, 2017 14:51:26 GMT
I think it was mentioned in Haugum & Low (I don't have it in front of me right now), but of course those specimens could also have changed over time.
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Post by nomad on Feb 1, 2017 17:28:13 GMT
I guess so, can you check please what Haugum & Low low say about this aberration, I have their Ornithoptera monograph parts but unfortunately not their Troides. What be interesting to know what they mentioned.
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Post by deliasfanatic on Feb 2, 2017 4:30:14 GMT
Looking in H&L, there are comments in the general section about the whole genus: the possibility of "changelings" isn't mentioned, instead discussing these specimens as forms that occur in shades from cinnabar orange to bright red on hindwings and abdomen, and that they most commonly occur on Java. It confirms that rutilans is the oldest available name for such forms.
More detailed notes are given in the section for T. helena helena. H&L say that the yellow may be wholly or partially replaced by red, and that red + yellow scales may be intermingled. The form occurs in both sexes, was first recorded from Java and Sumatra, and also occurs in T. oblongomaculatus. Here, they comment that Jordan made a study (1932) that concluded that this red replacement is natural and not caused by chemical or other origins.
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Post by trehopr1 on Feb 2, 2017 6:40:03 GMT
I personally own a Troides minos male from India which has entirely (mahogany brown) hind wings. I've owned it since 1979 when I purchased it from the daughter of a insect dealer who died. He only had about 14 drawers of pinned leps laying about in his room. I presumed the items had been held by him personally (as his own stash) of things he had come across over the years which he liked. Even then, their were lots of expensive things present I could'nt afford but, this oddball looking Troides I could at $30.00 It along with a few other things came home and I've long admired its unique appearance. It has never changed in any way over all these years. It's wings are still nice and flat (the way it left the spreading board). It does not bear any apparent exposure to humidity. I would think any specimen such exposed would have droopy wings or some evidence of mold -- even slight. Non present on my specimen. Also, no greasing whatsoever of the wings or body ( which might alter it). I will post some pic's of it this weekend when things slow down. I do believe these red or brownish aberrants pop up within populations every now and again. Perhaps, every several thousand butterflies. I'll leave others more knowledgable than me about these things to ponder why. But, they are out there and I presume rare in collections. If you look at the (Nagypal website) on Birdwings butterflies you will find a photo of a red aberrant female Troides minos when you tap on the name and scroll down the photo's of that species.
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Post by nomad on Feb 2, 2017 17:05:08 GMT
Jordan made a study (1932) that concluded that this red replacement is natural and not caused by chemical or other origins. Thank you for your clarification that is a naturally occurring aberration, which no doubt fades with time. I look forward to seeing the Troides minos aberration, I have some old Oxford specimens of that species to put up later.
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Post by trehopr1 on Mar 29, 2017 4:10:14 GMT
Well, I finally had a little time on my hands this past weekend to photograph my mahogany brown Troides minos male which I mentioned on an above post. I have included 2 additional photos of it below. As mentioned in my previous post; I discovered this unusual find in a small collection of drawers owned by a dealer who had passed on. At the time I didn't necessarily find it pretty -- just something unlike any Troides that I had ever seen in any book. It is now as I found it in its drawer so many years ago. I thought it important that others should know and see for themselves that peculiar things like this do occur in nature from time to time. The data present says South India 1950. No specific collector, location, or time of year.
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Post by trehopr1 on Mar 29, 2017 4:10:52 GMT
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Post by trehopr1 on Mar 29, 2017 4:11:24 GMT
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jhyatt
Aurelian
Posts: 224
Country: U.S.A.
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Post by jhyatt on Mar 29, 2017 12:56:04 GMT
Interesting specimen, Trehopr. I recently surveyed the older birdwings in the McGuire center collection, looking for instances of brown staining on green males. In looking through all the uncurated drawers I saw perhaps 350 Troides specimens. I recall seeing one male (don't recall which species it was) with coloring very similar to this T. minos; there was another specimen not quite so dark but clearly darker than usual. So this is indeed an uncommon aberration... Cheers, jh
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Post by Paul K on Mar 29, 2017 13:59:41 GMT
It is very rare aberration. I saw hundreds of Troides in Thailand but they all were pure yellow. Believe it or not they are more common here than Pieris rapae in Canada, T.helena and aeacus of course .
Paul
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Post by Adam Cotton on Mar 29, 2017 14:38:02 GMT
I have never seen a live Troides of this colour, but I have seen them turn a similar colour over a long period of time exposed to heat, humidity and sunlight.
It is possible that your T. minos is natural, I am not saying that it cannot be, but if it is it must be extremely rare.
Adam.
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Post by wollastoni on Mar 29, 2017 17:50:10 GMT
I agree with Adam. I unfortunately highly doubt it is a natural colour.
Delias yellow can also turn into this red/brown if stored in strange conditions (humidity/heat). I doubt it is a sunlight issue though (as my Delias which turned red were in a lot of papered specimens).
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Post by trehopr1 on Mar 29, 2017 18:45:26 GMT
I do recall some collectors on the other forum once lamenting that their specimens of Phoebis avelleneda were seemingly changing colors somewhat over time. It was said that the orange coloration present was turning more reddish or reddish/orange as time progressed. Perhaps, the color yellow is susceptible also to change when the right conditions (heat/humidity) present themselves. I do wish I knew more about the background of this unusual specimen but, alas I do not. I found it as you have seen it stashed in a small collection of Cornell drawers tucked in the corner of a small room. The former owner whom had passed on must have found it odd enough or unique to keep it for himself; as everything present in those drawers was either rare, seldom seen, pricey, or an aberration of some sort. There were 2 pairs of O. alexandrea present as well; alongside a couple bi-lateral gynanders, some scorching Agrias, and an assortment of various Papilionidae and Nymphalidae the likes of which I knew nothing about at the time. All are nowadays very pricey or seldom offered. I think what attracted my attention most about it was the uniformity of its brown coloration. Had it been partially colored or even looking stained by greasiness or water than I most certainly would have passed on it.
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