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Pierre
Member Rosenbergia
Switzerland
1755 Posts |
 Posted - 10/06/2012 : 21:55:22
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I found interesting to show here two extremely similar Trachyderini coming both from the same place in Bolivia.
This first one should be Chydarteres dimidiatus; what do you think about this? |
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Pierre
Member Rosenbergia
Switzerland
1755 Posts |
Posted - 10/06/2012 : 21:56:57
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Second specimen.
Seizes: 19 mm the first, and 14 mm this one. |
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Golofa
Member Purpuricenus
France
178 Posts |
Posted - 11/06/2012 : 07:23:44
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Chydarteres dimidiatus boliviana
Alain |
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Pierre
Member Rosenbergia
Switzerland
1755 Posts |
Posted - 11/06/2012 : 11:55:30
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| A new form? A subspecies for each country? |
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Francesco
Forum Admin
Luxembourg
9431 Posts |
Posted - 11/06/2012 : 12:48:50
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I do not know this boliviana.
They are both Chydarteres dimidiatus dimidiatus (Fabricius, 1787); the second specimen might be the var. scapularis Aurivillius, 1912.
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Golofa
Member Purpuricenus
France
178 Posts |
Posted - 11/06/2012 : 12:52:02
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Sorry, boliviana is not accepted !
It is C.dimidiatus dimidiatus
Alain |
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Pierre
Member Rosenbergia
Switzerland
1755 Posts |
Posted - 11/06/2012 : 21:08:07
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The eternal question about valid subspecies versus useless forms... this species is a good example. Highly various in its colour, where is the limit which designs a "good" subspecies?
Are altissimus, notatus, taeniatus real subspecies or could they also be simple examples of the chromatic variability of this species?
Do you have descriptions for these forms, Francesco? |
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Francesco
Forum Admin
Luxembourg
9431 Posts |
Posted - 11/06/2012 : 22:50:23
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The problem may occur in presence of a scarce number of specimens, but large series can help to clarify this topic
If a bounded area is colonised by specimens having the same somatic characteristics, these specimens may be supposed to constitute a subspecies.
The problem might also be the difference among subspecies or natio (usually limited to an enclave very small localities, e.g. a forest)... or between subspecies or vicarious species.
Theoretically, vicarious species are not fecund between them, while subspecies are. This fact is verifiable in laboratory or (indirectly) by the presence of intermediate specimens in the neighbouring areas, which imply their inter-fecundity.
Concerning this genus, I have Hüdepohl's revision with descriptions, pictures and keys. |
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Bolivia, Chydarteres dimidiatus dimidiatus
