Nacaduba hermus?

[horace2264]

Is this Nacaduba hermus?

28461

[Psyche]

Yes. A male.
FW postdiscal band barely or not dislocated at vein 6.
Dark striae within bands weak or obsolete.
HW tornal black spots with sparse blue scaling.

C&P4's statement that HW submarginal & postdiscal banda are close & touching is not reliable.

TL Seow: Cheers.

[LJK1410]

Hi Dr Seow,

Regarding the females of Nacaduba hermus and Nacaduba russelli, is there any reliable way to distinguish between the two? Also how should one determine if the dark striae is weak or strongly developed, I get confused by this quite a bit.

Take this female for example, it seems to have many features that suggest N.russelli, to me it seems the dark striae within the bands are well developed and HW marginal spots seem 'lozenge' shaped:
https://www.inaturalist.org/observations/187340675

This female I shot also seems to have strong dark striae as well:
https://www.inaturalist.org/observations/187225319

A couple females I raised:
https://www.inaturalist.org/observations/189196905
https://www.inaturalist.org/observations/189196903

On another note, having raised many of the caterpillars from that area, all males turned out to be pretty clear-cut examples of N.hermus. I also raised a single caterpillar from Springleaf Nature Park where the only shot of that female N.russelli was sighted from, it turned out to be a male N.hermus too (https://www.inaturalist.org/observations/189323889).

[Psyche]

It is always easier to ID the male.
For example the males of N. beroe & kurava have weak dark striae especially the male N. beroe.

The female Nacaduba have stronger dark striae.
Dark striae at the cellend are always stronger.
Look at the FW & HW postdiscal bands.
The dark striae should be unbroken & continuous.
This is the case in N. pavana & russelli in the 4line Blues.
The rest have the bands in broken small or speckled pieces.

N. pavana 1 male & 2 females.
https://www.butterflycircle.com/checklist/mugshots/Nacaduba%20pavana%20singapura/NP_adult_male_02.jpg
https://4.bp.blogspot.com/-PHJWYq36n14/TrSQ3V-fwBI/AAAAAAAAL9o/ULwf_Ju7LSk/s1600/NP_adult_01.jpg
https://www.butterflycircle.com/checklist/mugshots/Nacaduba%20pavana%20singapura/NP_adult_female_01.jpg

N. russelli have the inner margins of the HW marginal spots convex, so the spots are elliptical with rounded ends.

N. pavana have the inner margins of the HW marginal spots
'flat' & level.

FW marginal spots are variable.

Past IDs of N. russelli (including one by me) appear to be in error. They should be female N hermus.

Note the dark striae & the shape of the HW marginal spots.
https://yutaka.it-n.jp/lyc4/81235001.html

There seem to be no reliable record.


TL Seow: Cheers.

PS. Error correction.
It is the shape of the HW marginal (not submarginal) spots that differentiate N.pavana from N. russelli.

[LJK1410]

Noted, will continue to keep an eye out for N.russelli, thank you Dr Seow.

[horace2264]

Yes. A male.
FW postdiscal band barely or not dislocated at vein 6.
Dark striae within bands weak or obsolete.
HW tornal black spots with sparse blue scaling.

C&P4's statement that HW submarginal & postdiscal banda are close & touching is not reliable.

TL Seow: Cheers.

Many thanks, Dr Seow for the id confirmation. :)

[Psyche]

The 4line blues with obsolete dark striae are very confusing.
It does not help that C&P4's key seem in error & muddled.
In particular, the line that the HW submarginal & postdiscal spots are close in hermus & subperusia ,while they are well apart in sanaya & pendleburyi just does not hold.
all the species mentioned have variable overlaps in this respect.

I have worked out the following.

Nacaduba sanaya elioti.
Dark striae obsolete.
FW postdiscal band often dislocated at vein 6.
Submarginal spots not well-formed ,with many straight margins.
Black tornal spot without metallic bluish scales.
Orange ring bright.

Taxon elioti is a synonym of taxon naevia ie they are the same ssp.
Note bright orange ring.
https://yutaka.it-n.jp/lyc4/81220010.html
Males & females.
https://www.inaturalist.org/observations/176583621
https://www.inaturalist.org/observations/162449146
https://www.inaturalist.org/observations/177945364
https://www.inaturalist.org/observations/147389511


Nacaduba hermus swatipa.
Dark striae more prominent in speckled bits.
FW postdiscal band usually not dislocated at vein 6.
Submarginal spots are mostly broadly lunulate (moon-shaped.)
Typically HW submarginal & postdiscal spots close.
Black tornal spot should have a few metallic bluish scales.
Male & female.
https://www.inaturalist.org/observations/189323889
https://www.inaturalist.org/observations/189196903


Nacaduba subperusia lysa.
Dark striae obsolete.
FW postdiscal band often not dislocated.
Submarginal spots mostly lunulate, more rounded on HW.
HW submarginal & postdiscal spots close.
Orange ring thin ,weaker & ?paler.
https://yutaka.it-n.jp/lyc4/81210010.html
See Otsuka L131.
Should be correct as N. subperusia. P. Malaysia Males.
https://2.bp.blogspot.com/-ToaJYf3xH1I/WJ0ItEWBAaI/AAAAAAAAce4/c2ysVd4KLzc71tR2z8rMtryoL7fG0gbYwCLcB/s1600/DSC_2628.JPG
https://3.bp.blogspot.com/-CCzm1ZlQsQE/UrRNXf_V1vI/AAAAAAAAM_c/083nczhETzE/s1600/HFH_0013+Nacaduba+subperusia+lysa.jpg
Thailand. Male & Female.
https://thaibutterflies.com/wp-content/uploads/2016/07/Nacaduba-subperusia-1-1080x675.jpg
https://thaibutterflies.com/wp-content/uploads/2016/07/Nacaduba-subperusia.jpg


Nacaduba pendleburyi pendleburyi.
Dark striae obsolete.
FW postdiscal band not dislocated.
Male upperside with border a thread but widen at the apex.(diagnostic.)
C&P4's key state the HW submarginal & postdiscal band are well apart but this female shows otherwise.
https://yutaka.it-n.jp/lyc4/81191001.html


N. angusta & pactolus are obvious species.


TL Seow: Cheers.