| Author |
 Topic  |
|
loongfah
Member Purpuricenus
Singapore
374 Posts |
 Posted - 05/04/2013 : 17:08:39
|
350.76 KB
167.64 KB
315.32 KB |
|
|
Xavier
Scientific Collaborator
France
12136 Posts |
Posted - 05/04/2013 : 19:19:23
|
May be a Gyaritini, Gyaritus sp. ?
I find only 2 species known from Malay Peninsula : Gyaritus gahani Breuning, 1938 and Gyaritus malaccensis Breuning, 1938; could it be one of them ? |
 |
|
|
loongfah
Member Purpuricenus
Singapore
374 Posts |
Posted - 06/04/2013 : 09:12:29
|
Thanks, Xavier! I think you are right: it is a Gyaritus!
I took more pictures of the spines at the base of the elytra and attached below. BTW, it is 3mm in length:
111.68 KB
137.32 KB
137.25 KB
It seems a rather blunt spine, pointing slightly backwards and outwards.
If we also take into account both Sumatran and Bornean species, then the following are the candidates. I checked up Pascoe's description and some can be ruled out (those crossed).
Gyaritus affinis Breuning,1938 Sumatra Is.
Gyaritus aurescens Breuning,1940 Borneo
Gyaritus bangueyensis Breuning,1958 Borneo
Gyaritus cinnamomeus Pascoe,1864 Borneo (cinnamon)
Gyaritus fulvopictus Pascoe,1864 Borneo Sarawak (Pale brownish-luteous)
Gyaritus gahani Breuning,1938 Malayan Peninsula
Gyaritus giganteus Breuning,1938 Borneo
Gyaritus hamatus Pascoe,1858 Borneo (Purplish-black, elytra deeply punctate-striate, two very obscure almost-obsolete oblique bands, towards the apex a broader band nearly white)
Gyaritus malaccensis Breuning,1938 Malayan Peninsula
Gyaritus spinosus Breuning,1939 Borneo
Gyaritus varius = Axinyllium varium Pascoe,1864 Borneo (reddish chesnut)
Gyaritus viduus Pascoe,1886 = Gyaritus transversevittatus Breuning,1939; Borneo
and from the sound of it, G. aurescens, giganteus and spinosus also seem not likely? |
Edited by - loongfah on 06/04/2013 09:17:26 |
|
|
|
Francesco
Forum Admin
Luxembourg
9442 Posts |
Posted - 06/04/2013 : 09:19:42
|
No, this species belongs to the genus Oloessa (Cyrtinini).
Below the original drawings of Oloessa minuta Pascoe, 1864 (from the Moluccas!).
90.55 KB |
|
|
|
Xavier
Scientific Collaborator
France
12136 Posts |
Posted - 06/04/2013 : 10:08:53
|
| Well, I didn't know this genus; thanks Francesco, and sorry Loongfah! |
Edited by - Xavier on 06/04/2013 11:18:48 |
|
|
|
dryobius
Member Rosenbergia
USA
1885 Posts |
Posted - 06/04/2013 : 13:52:59
|
of course it is not Gyaritus, as Francesco stated.
Gyaritus will usually have a spine on the side of the pronotum which you can see. Otherwise, they look a little like Pteropliini. |
|
|
|
loongfah
Member Purpuricenus
Singapore
374 Posts |
Posted - 06/04/2013 : 14:43:55
|
Thanks everyone for your help! These are very fascinating genera.
It seems there are only 4 described Oloessa species, all in the Australasian region, with the nearest geographical location being the O.minuta mentioned by Francesco. From Pascoe's description of O. minuta, there are a few differences with my specimen, like (in minuta) pronotum punctures few and distant, the long and recurved spine, the seventh and eigth joints of antenna dark at the tips. |
|
|
|
Francesco
Forum Admin
Luxembourg
9442 Posts |
Posted - 06/04/2013 : 15:17:10
|
| Well. I move the topic in the secret section, waiting for your description. |
|
|
|
Xaurus
Member Rosenbergia
Germany
1912 Posts |
Posted - 06/04/2013 : 16:43:30
|
I can offer a 3rd idea: Loong Fah's sps don't belong to Oloessa minuta, I have this sps from Neuguinea (compared with the type in BMNH), with quite diff scapus and elytral spines.
Maybe this sps belongs to the genus Dyemus Pascoe, however the type material in London is in very bad condition.
|
|
|
|
Beckey
Member Rosalia
Japan
553 Posts |
|
|
loongfah
Member Purpuricenus
Singapore
374 Posts |
Posted - 07/04/2013 : 05:22:30
|
Dear Andrea and Shinichi, thanks for the further suggestions!
Indeed both Dyemus and Zeargyrodes have antennal structure closer to my specimen.
I think Dyemus is less likely because in my specimen, the scape is comparatively thicker more at the apical end rather than the basal end; there is also no mention of the elytral spine for Dyemus.
Shinichi, where are your specimens collected?
They look very similar indeed, except for the different shades of brown in the antennae and legs.
Not sure if this is the Zeargyrodes fasciatus (this is a monotypic genus) though.
Fisher described this species from a single female collected in Borneo, and although he has a very long description for the species, there is no mention of the elytral spines and the depression behind the spines. Under the description for the genus, he described it as "Elytra moderately elongate, unarmed at base, flattened on basal half, strongly convex posteriorly".
Seems interpretable in either way?
Other differences include "Antennae uniformly black", "Length 4.5mm", which might be due to gender difference? I also cannot ascertain if underneath, my specimen has the following character "last (abdomen) segment feebly depressed near apex and the surface with an obsolete longitudinal median line;" Otherwise, all the other details match very well indeed.
Are the spines a sexually dimorphic character? A side view of the Smithsonian type specimen will be very revealing. |
|
|
|
Xaurus
Member Rosenbergia
Germany
1912 Posts |
Posted - 08/04/2013 : 00:35:02
|
I have 1 spms of Z. fasciatus from Borneo (I don't know which sex, without genitals extraction), and this is diff from Loong Fah's spms.
Its interesting to know, are the elytral spines a sexdimorphal feature or not  .
What's about your spms Shinichi - are both sex without spines, or not ? |
|
|
|
Francesco
Forum Admin
Luxembourg
9442 Posts |
Posted - 08/04/2013 : 13:31:25
|
quote:
Originally posted by loongfah
It seems there are only 4 described Oloessa species, all in the Australasian region, with the nearest geographical location being the O.minuta mentioned by Francesco.
Actually, all other 3 species were described from Fiji!
Here their original pictures:
Oloessa poeta, O. bianor, O. cenea
The original paper could be download here.
There is no mention of sexual difference concerning the basal tubercle; however, the geographic distribution should suggest that Oloessa minuta is more related to Bornean than to Fijian taxa. |
|
|
|
Beckey
Member Rosalia
Japan
553 Posts |
Posted - 08/04/2013 : 16:03:21
|
I collected my specimens in Peninsula Malaysia.
I think Loong Fah's specimen might be rather teneral.
I confirm that all of my 8 specimens have elytral spines.
Consequently, it isn't sexdimorphal feature in my opinion. |
Edited by - Beckey on 08/04/2013 16:04:02 |
|
|
|
Xaurus
Member Rosenbergia
Germany
1912 Posts |
Posted - 10/04/2013 : 00:28:18
|
Compared with the type picture of Z. fasciatus Fisher, 1925 in the Smithonian your sps Shinichi is very similar or even the same like this, but I think diff to those from Loongfah. At all very nice small creatures  . |
|
|
|
Francesco
Forum Admin
Luxembourg
9442 Posts |
Posted - 30/11/2015 : 18:19:26
|
| It is Gyaritodes bispinosus Breuning, 1960, only known from Borneo. |
|
|
|
Topic |
|
Singapore: Pseudoloessa bispinosa
