arumi
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Posts: 83
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Post by arumi on Dec 19, 2018 10:41:25 GMT -8
What is your opinion about this one?
any other specimens observed?
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arumi
Full Member
Posts: 83
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Post by arumi on Dec 21, 2018 5:33:54 GMT -8
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Post by bandrow on Dec 21, 2018 6:37:04 GMT -8
Greetings,
I downloaded the paper but really haven't examined it closely. My first impression is that the holotype is a minor male, and that the external morphological differences could fall within the normal range of variation due to size. There is slight difference in the genitalia, but even that is subject to variation. My expertise in scarabs is in the Nearctic fauna, especially the Melolonthinae. In the genera Phyllophaga and Serica, I have seen much more drastic variation in the male genitalia within a species than is exhibited in this Megasoma. I can't say with any authority that this is not a valid species, but I would remain suspicious until more specimens are available to confirm its status.
Cheers!
Bandrow
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Post by africaone on Dec 21, 2018 9:48:19 GMT -8
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Post by Adam Cotton on Dec 21, 2018 13:33:09 GMT -8
That doesn't mean much in terms of the real status of the taxon, websites and databases like CoL are just data aggregators, they are like a compendium of names and there is very little editorial decision-making on the names included in the site. Adam. |
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Post by africaone on Dec 22, 2018 1:03:52 GMT -8
It is an updated list following papers and specialists, not just an automatic and robotic compil of names. That doesn't mean of course it is right. Just for info, certainly not the worst and that may help searching an answer. Many unpublished info are not included, that signs a kind of reliability.
Exemple. Megasoma rex is synonym of Megasoma actaeon johannae, two recently described taxa, not yet included in this database as not yet formely published despite the author (Schoolmeesters) knows that ...
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arumi
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Posts: 83
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Post by arumi on Dec 22, 2018 4:29:02 GMT -8
what is your opinion about M.rex and M.a.johannae, and M. vazdemelloi btw?
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arumi
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Posts: 83
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Post by arumi on Dec 22, 2018 4:29:22 GMT -8
Greetings, I downloaded the paper but really haven't examined it closely. My first impression is that the holotype is a minor male, and that the external morphological differences could fall within the normal range of variation due to size. There is slight difference in the genitalia, but even that is subject to variation. My expertise in scarabs is in the Nearctic fauna, especially the Melolonthinae. In the genera Phyllophaga and Serica, I have seen much more drastic variation in the male genitalia within a species than is exhibited in this Megasoma. I can't say with any authority that this is not a valid species, but I would remain suspicious until more specimens are available to confirm its status. Cheers! Bandrow thanks for answer |
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Post by africaone on Dec 22, 2018 8:10:14 GMT -8
what is your opinion about M.rex and M.a.johannae, and M. vazdemelloi btw? rex is obviously a synonym of johannae, ssp level of johannae seems logical. |
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Post by bandrow on Dec 22, 2018 8:26:09 GMT -8
Greetings,
Good comments all around...
I often use the Biological Library website (BioLib.cz) and it also lists Megasoma svobodaorum as valid, which is to be expected, as it is a formally published name. But as we all know, many formally published names end up being synonyms, once more information or specimens become known concerning a given described taxon.
I have a default reaction of suspicion when it comes to new species of taxa that fall into the "trophy" category of insects - Megasoma, Dynastes, Macrodontia, Xixuthrus, etc., in the beetles, and Ornithoptera (and many others I suspect) in the Lepidoptera. These taxa garner high attention from collectors and this helps drive over-description, in my opinion. Certainly, there is no reason a new valid species cannot be discovered in any one of these groups. I just think there is a tendency to look for minor differences to justify erection of new taxa.
Time - and more specimens - will eventually either support these names, or prove them to be invalid. In the case of M. svobodaorum, it seems that more specimens should be available with time - Bolivia is a fairly well-collected country and certainly many Megasoma come out of there annually. I would also fully expect a new species of Megasoma to be described from Peru soon, since so much material is flowing out from there now!
Cheers!
Bandrow
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arumi
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Posts: 83
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Post by arumi on Dec 22, 2018 13:48:20 GMT -8
Greetings, Good comments all around... I often use the Biological Library website (BioLib.cz) and it also lists Megasoma svobodaorum as valid, which is to be expected, as it is a formally published name. But as we all know, many formally published names end up being synonyms, once more information or specimens become known concerning a given described taxon. I have a default reaction of suspicion when it comes to new species of taxa that fall into the "trophy" category of insects - Megasoma, Dynastes, Macrodontia, Xixuthrus, etc., in the beetles, and Ornithoptera (and many others I suspect) in the Lepidoptera. These taxa garner high attention from collectors and this helps drive over-description, in my opinion. Certainly, there is no reason a new valid species cannot be discovered in any one of these groups. I just think there is a tendency to look for minor differences to justify erection of new taxa. Time - and more specimens - will eventually either support these names, or prove them to be invalid. In the case of M. svobodaorum, it seems that more specimens should be available with time - Bolivia is a fairly well-collected country and certainly many Megasoma come out of there annually. I would also fully expect a new species of Megasoma to be described from Peru soon, since so much material is flowing out from there now! Cheers! Bandrow Agree about over-description. but one deal if someone really focused on group and have a lot of material from different places, so for him it's very easy to see even minor difference and describe ssp for example. and other if someone just describing it by a single specimen which looks weird for him. By the way i had conversation with one japanese guy who said that he got few minor elephas from S. Peru from locals, which may be M. svobodaorum Also other guy got pair from Peru and Bolivia border (attached), which resembles M. svobodaorum, but hard to judge until genitalia not examined. Someone told me that it differs even in proportion, in comparison with minor male of elephas, which can't have such developed cephalic horn in this size. Anyway S. Peru and Bolivia quite far from M. e. elephas areal isn't it? so if those speimens really from there it may be real sp.  |
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Post by bandrow on Dec 23, 2018 18:45:57 GMT -8
Greetings,
This is very true on both points!
As more specimens become available, it will be easier to confirm the validity of M. svobodaorum. I do not know enough about the distribution of the various Megasoma species and subspecies but it sounds like there is some evidence - in morphology and distribution - to give validity to this form. As more information becomes available - please let us know about it... this is interesting.
Cheers!
Bandrow
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Post by africaone on Dec 28, 2018 10:26:22 GMT -8
lambillionea just published www.lambillionea.be/Revision of the Megasoma actaeon (Linnaeus, 1758), janus Felsche, 1906, and ramirezorum Silvestre & Arnaud, 2002 complex: description and review by Jaak Van Meenen & Tom Schouteet Price : 59 € + post. Published by "Lambillionea éditions" in XII-2018. ISBN: 978-29-602285-0-2 |
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arumi
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Posts: 83
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Post by arumi on Dec 28, 2018 15:35:21 GMT -8
if someone will get pdf let me know on pm pls
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Post by bandrow on Dec 28, 2018 20:59:04 GMT -8
Greetings,
Thanks, Africaone, for the heads-up on this!
Arumi - I believe we still subscribe to Lambillionea at the museum where I work - I will watch for this to arrive in the New Year when I return...
Cheers!
Bandrow
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