ID help needed

[Psyche]

https://www.butterflycircle.com/atta...4&d=1751435660

Nacaduba hermus male.
The four line blues can be rather difficult to ID.

N. pactolus can be IDed by the combinations.
HW tornal black spot always with metallic scales.
white striae often broad or diffuse,dark striae absent.
HW submarginal spots 'flat' with level inner margins, topped by a large squarish spot 6.
https://www.butterflycircle.com/chec...-%20horace.jpg
https://www.butterflycircle.com/chec...0-%20Sunny.jpg

Species with the dark strae obsolete or nearly so.
N. sanaya, subperusia, & pendleburyi.

Species with strongly developed dark striae, tornal spot always with metallic scales.
N. pavana, russelli.

Species with heavy white striae and metallic scales on the tornal black spot.
B. pactolus, angusta.


Nacaduba hermus is uniquely halfway between those with strong and those with no dark striae.
Dark straie are patchy , partial or disintegrating.
The metallic scales on the tornal black spot may be weak or strong.
FW postdiscal band usually not dislocated at vein 6.
HW postdiscal band close to the submarginal spots which may be rounded.
https://yutaka.it-n.jp/lyc4/81200020.html
https://www.gbif.org/occurrence/2847201952
https://www.gbif.org/occurrence/4500772618
https://www.gbif.org/occurrence/2847201921
https://www.gbif.org/occurrence/4436196086


TL Seow: Cheers.

[Sailfish]

Thanks alot, Dr Seow.

[Sailfish]

Hi Dr Seow,

Is this Pelopidas mathias?
Screenshot 2025-07-04 211624(1).jpg

Thanks.

[Psyche]

Post 83.
https://www.butterflycircle.com/atta...8&d=1751685464
From its unevenly shaded ground colour this should be a male Pelopidas mathias.

Fieldshots of the two can be quite similar.
Females have similar spots.

Pelopidas mathias.
Male FW spots 2 & 3 quadrate, broad.
A line thru the two cellspots always cut the male brand.
In female, a line thru the cellspots moves toward or touch the spot in space 1b (variable).
Underside grey-tined, generally with a dirty look.
Males India .
https://www.ifoundbutterflies.org/si...d8457890-1.jpg
https://www.ifoundbutterflies.org/si...d8457890-2.jpg

https://www.ifoundbutterflies.org/si...a6d3a539-1.jpg
https://www.ifoundbutterflies.org/si...a6d3a539-2.jpg

Singapore.
https://blogger.googleusercontent.co...perside_01.jpg
https://blogger.googleusercontent.co...enedict_01.jpg
https://blogger.googleusercontent.co...perside_02.jpg
https://blogger.googleusercontent.co...S_adult_01.jpg



Pelopidas agna.
Male with FW spots 2 and 3 narrow.
A line thru the cellspots usually miss the brand.
In the female ,the line moves away from the spot in space 1b (variable).
Underside not grey-tinged, with a clean clear look.

Males India.
https://www.ifoundbutterflies.org/si...36ba6310-3.jpg
https://www.ifoundbutterflies.org/si...36ba6310-1.jpg

https://www.ifoundbutterflies.org/si...837_273650.jpg
https://www.ifoundbutterflies.org/si...837_273649.jpg

Singapore.
https://blogger.googleusercontent.co...A_male_05c.jpg
https://blogger.googleusercontent.co...A_male_05a.jpg
https://blogger.googleusercontent.co...A_male_06b.jpg
https://blogger.googleusercontent.co...SwiftF-KSK.jpg



Although these two are fairly common in Singapore , few observations have the desired upperside and unerside views together.
Such views are important to establish the variations in the appearances of the two species.

After a long search only two were found.
These observations show the two sides nicely.
https://www.inaturalist.org/observations/290635880
https://www.inaturalist.org/observations/295330377

TL Seow: Cheers.

[Sailfish]

Thank you Dr Seow.