Line Blue ID request

[Commander]

Dr Seow, your advice is sought for this Line Blue. Is it an Ionolyce or a Nacaduba?

28093

[Psyche]

It is male Ionolyce helicon. Correction; Male Nacaduba beroe.

These two can be quite confusing at times in fieldshots.

To be I. helicon two criteria together necessary.
FW postdiscal band is fully dislocated (sometimes not at vein 6)+ HW submarginal spots 3, 4, & 5 sharp-pointed (sometimes only 3 & 4.).
Added Observation (Courtesy of Jian Kai) HW postdiscal band always intact in space 4 & 5, but broken in N. beroe.
Males.
https://1.bp.blogspot.com/-HkzcUPgNd2o/T0jNKVE5Y0I/AAAAAAAAHBA/2dNSji2MbLA/s1600/PointedLineBlue-KSK3.jpg
https://inaturalist-open-data.s3.amazonaws.com/photos/208679885/large.jpg
https://inaturalist-open-data.s3.amazonaws.com/photos/227536580/large.jpeg
Females.
https://inaturalist-open-data.s3.amazonaws.com/photos/213295861/large.jpg
https://inaturalist-open-data.s3.amazonaws.com/photos/181289141/large.jpeg
https://inaturalist-open-data.s3.amazonaws.com/photos/19800782/large.jpg


Nacaduba beroe.
FW postdiscal band typically only a mid-dislocation at vein 5 ,but occasionally somewhat like Ionolyce.
HW submarginal spots 3, 4, & 5 lunulate in particular spot 3 is never pointed.
Males.
http://www.butterflycircle.com/checklist/mugshots/Nacaduba%20beroe%20neon/SixLineBlue.jpg
http://www.butterflycircle.com/checklist/mugshots/Nacaduba%20beroe%20neon/Nacaduba-beroe-(Opaque-Sixline-Blue)---Jonathan-Soong2b.jpg
https://inaturalist-open-data.s3.amazonaws.com/photos/219052903/large.jpg
Females.
https://inaturalist-open-data.s3.amazonaws.com/photos/24801365/large.jpg
https://inaturalist-open-data.s3.amazonaws.com/photos/112226181/large.jpeg
Female below.
https://inaturalist-open-data.s3.amazonaws.com/photos/11323784/large.jpg
Variant.
This female is N. beroe from the FW postdiscal band, but HW submarginal spots a bit sharp.
https://static.inaturalist.org/photos/93920857/original.jpg

N, berenice often have the HW submarginal spots sharp-pointed.
Male & female.
https://inaturalist-open-data.s3.amazonaws.com/photos/233949538/large.jpg
https://inaturalist-open-data.s3.amazonaws.com/photos/223882291/large.jpg

This which looks like I. helicon should be N. beroe.
http://4.bp.blogspot.com/-H03HQ8Y2p8I/VQ-ZXm2GGUI/AAAAAAAAApA/YkC84oKoRVE/s1600/BBB%2B-%2B0609.jpg


TL Seow : Cheers.

[LJK1410]

Hi Dr Seow,

Regarding the ID features of Ionolyce helicon and Nacaduba beroe, I looked through all my shots and other examples on iNaturalist for both species and I noticed for about 90-95% of the pictures the HW post-discal band in space 4&5 for N. beroe typically has some extent of dislocation, while I. helicon is more continuous. Could this be used as an additional feature to differentiate the two? I have a difficult time judging the HW submarginal spot in space 3 sometimes, whether it is sharply pointed or more lunulate especially for some not so clear-cut examples, even the one above I thought it was N. beroe.

Here are some other (I'm fairly sure) examples of N. beroe with the FW post-discal band more dislocated than the typical individuals
28094
28095

[Psyche]

Hi Dr Seow,

Regarding the ID features of Ionolyce helicon and Nacaduba beroe, I looked through all my shots and other examples on iNaturalist for both species and I noticed for about 90-95% of the pictures the HW post-discal band in space 4&5 for N. beroe typically has some extent of dislocation, while I. helicon is more continuous. Could this be used as an additional feature to differentiate the two? I have a difficult time judging the HW submarginal spot in space 3 sometimes, whether it is sharply pointed or more lunulate especially for some not so clear-cut examples, even the one above I thought it was N. beroe.

Here are some other (I'm fairly sure) examples of N. beroe with the FW post-discal band more dislocated than the typical individuals




I think you found the right differences.
I check through scores of images of both species.
The differences are consistent enough to use it.

In I. helicon there is no dislocation in the HW postdiscal band in space 4 & 5.
Even if the band is a bit crooked, there is no break in the black & white striae forming the margins.

In Nacaduba beroe, the HW postdiscal band in space 4 & 5 is broken at vein 5 to some extent, with complete breaks in the white striae.

Based on your new observation, Khew's image is that of a male Nacaduba beroe.
The submarginal spot 3 was never quite pointed.

Great work. Fieldshot identification is a job that requires patient scrutiny.



TL Seow; Cheers.

[Commander]

Well done, Jian Kai! You're our Nacaduba consultant now! :grin2:

[Psyche]

Well done, Jian Kai! You're our Nacaduba consultant now! :grin2:


I fully concur.:)

[LJK1410]

Hahaha I don't think I'm experienced enough for that yet :bsmile::sweat: