Nacaduba russelli

A recent observation is certain to be the long lost Nacaduba russelli.
https://www.inaturalist.org/observations/252702953


The Nacaduba 4line blues roughly belong to two main groups.

The 1st group include species in which the dark striae within the postdiscal bands on both wings are obsolete or disintegrating & incomplete.

Nacaduba sanaya is an example of one in which the dark striae are practically obsolete (absent).
The metallic scales on the tornal spot is also absent.
https://besgroup.org/wp-content/uplo...i-LenaChow.jpg
https://www.butterflycircle.com/chec...race%20tan.jpg

Nacaduba hermus have the dark striae within the band disintegrated & broken.
The metallic scales in the HW tornal black spot is very weak.
https://www.butterflycircle.com/chec...LB_male_04.jpg
https://www.butterflycircle.com/chec..._female_06.jpg


Two similar species have the dark striae well-developed & continuous & the metallic scaling more prominent.

Nacaduba pavana.
https://www.butterflycircle.com/chec..._male_800x.jpg
https://www.butterflycircle.com/chec...lt_male_02.jpg
https://www.inaturalist.org/observations/180241157

Nacaduba russelli.
https://yutaka.it-n.jp/lyc4/81235001.html


The two can be somewhat similar.
The ID difference was made clear by Tite in 1963.

In N. pavana the UnH marginal spots have the inner margins level ie 'flat'.
In N. russelli the unH margial spots have convex inner margins, ie are lozenge-shaped.

The difference is quite clear here.

All previous observations of N. russelli look to be in error, with dark striae disintegrated.
They should be N. hermus.


TL Seow: Cheers.