ID help for this moth from Sumatra please ?

[Nad Rimba]

Any idea on the species ID of this moth ? I found 3 species really similar, but i can't succeed to confirm which one is it between these 3 species : Brunia antica ? Eilema marguerita ? Eilema prabana ?
Thanks for your help
Nad

260412604226043

[Psyche]

Moths are extremely difficult, not to mention Sumatra have many endemic species.

In your specimens, the yellowish margin which is broad at the costa goes fairly broadly round the apex to the distal margin.


In both the Brunia species it narrows at the apex & goes narrowly round the distal margin.


B. antica Taiwan & Japan where B. sarawaca is absent.
http://twmoth.tesri.gov.tw/peo/MothInfo/V07-20151127-016
https://www.google.com/imgres?imgurl=http%3A%2F%2Fwww.jpmoth.org%2F~dmoth %2F77_Arctiidae%2F75.1%2520Lithosiinae%2F3260Bruni a_antica%2FBrunia_antica_941126467.jpg&imgrefurl=http%3A%2F%2Fwww.jpmoth.org%2F~dmoth%2F7 7_Arctiidae%2F75.1%2520Lithosiinae%2F3260Brunia_an tica%2FBrunia_antica.htm&docid=KnJWV3dHVB5efM&tbnid=DrV26qYW6MQ3jM%3A&vet=10ahUKEwij2v-SmfPkAhWjH7cAHWyOCOQQMwh3KCkwKQ..i&w=720&h=522&itg=1&bih=937&biw=1920&q=brunia%20antica&ved=0ahUKEwij2v-SmfPkAhWjH7cAHWyOCOQQMwh3KCkwKQ&iact=mrc&uact=8

B. sarawaca thi from BOLD is probably correct.
http://v3.boldsystems.org/index.php/Taxbrowser_Taxonpage?taxid=596084
http://v3.boldsystems.org/pics/LEFIJ/MJP00029%2B1522152732.jpg

You can also see both species in this article.
https://www.zobodat.at/pdf/ENT_0038_0141-0176.pdf

From this it should be Eilema ,E prabana is a good candidate.
http://www.jpmoth.org/~dmoth/Digital_Moths_of_Asia/90_NOCTUOIDEA/02_EREBIDAE/02_ARCTIINAE/04_Lithosiinae/16_Eilema/Eilema%20prabana/Eilema%20prabana.htm

I have no idea of the other Eilema species you mentioned.

TL Seow: Cheers.

[Nad Rimba]

Thanks a lot for your help Dr Seow !

E. marguerita is endemic of Sumatra (Zool. Meded. 10 (8): 129, (9: pl. 4, f. 1a-b)) : https://www.repository.naturalis.nl/document/149267

Here is the approximate translation in English of the description :

After related to I. oblitterans Feld. (male) Vein system similarly depicted on the adjacent text figure; the median makes a turn in the cell, so that it was initially very narrow, and suddenly broadened at the end. There is a fold in the cell with string scales and a brown spot beneath it
from ditto scales to vein 3. Between veins 1 and 2 is another fold with modified scales, as with I. oblitterans Feld.

The front wing veins 7, 8 and 9 are stalked in such a way that 8 and 9 come together at the same point, so that a trident is formed, or 8 and 9 very shortly after one another. The location of these three veins relative to SS a varies! For the female, 8 and 9 are always short on 7 (see text figure).

Head, tegulae, patagia, thorax and abdomen end yellow; the first part of the abdomen gray; legs yellow to brown-yellow; the coxae and the bases of the femora turn yellow. Front wings very light brownish yellowish-white with a purple hue; the costa yellow or yellow-white. Rear wings white with a yellow tint, particularly marginal and apical. No trace of a wing drawing.

[Psyche]

If the forewing of E. marguerita is very light brownish yellowish-white & it is related to E. oblitterans then it probably looks the same.
https://www.africanmoths.com/pages/EREBIDAE/ARCTIINAE/Lithosiini/Eilema%20oblitterans.html

If so this can only be E. prabana.


TL Seow: Cheers.

[Nad Rimba]

Thanks Dr. Seow for your explanations. It helped me a lot.
Cheers
Nad

[Psyche]

This gets very complicated.

In checking correct examples of Eilema prabana one thing did not match well.
There should be a dark patch on the prothorax.

E. prabana.

http://v3.boldsystems.org/index.php/Taxbrowser_Taxonpage?taxid=588636
http://v3.boldsystems.org/pics/LEPMY/BIOUG09047-H04%2B1399648792.JPG

https://www.researchgate.net/figure/2-Adult-males-1-Dubatolova-prabana-Moore-comb-nov-2-Indiania-eccentropis_fig1_267642363

http://virtualcollections.naturalsciences.be/virtual-collections/entomology/lepidoptera/arctiidae/lithosiinae/eilema-prabana-celebesa-tams-1935-1


Singapore do have Brunia antica & E. prabana.

E. prabana is described as very dark ie blackish grey.
http://www.mothsofborneo.com/part-7/lithosiini/lithosiini_10_1.php


Brunia antica in Singapore.
https://www.inaturalist.org/observations/777156
https://www.inaturalist.org/observations/14695527

Likely Eilema prabana. Prothorax with a dark patch.
https://www.inaturalist.org/observations/8488541
https://www.inaturalist.org/observations/8427538

The width of the yellow margin is likely a variable feature.


Thus it is much more likely your pix are Brunia antica , that is if B. sarawaca does not occur in Sumatra.


TL Seow : Cheers.

[Nad Rimba]

Thank you Dr. Seow, the dark patch is indeed very visible on E. prabana.