Lethe sura and Lethe dura

[DaveChiangMai]

Been reviewing the Lethe sura/dura in my photo collection, and still confused by images available to find consistent differences. I think, the following are correctly identified, but would appreciate some comments.
I think images 1, 2, 3 are Lethe dura (from Inthanon).
and images 4, 5, 6 are Lether sura (from Doi Lang).
Would that be correct? All six images are of different individual butterflies.

Image 1. Assumed L. dura
24654

Image 2. Assumed L. dura
24655

Image 3. Assumed L. dura
24656

Image 4. Assumed L. sura
24657

Image 5. Assumed L. sura
24658

Image 6. Assumed L. sura
24659

[Angiud]

https://farm8.staticflickr.com/7551/15814205068_e1b631b7b9_b.jpg (https://flic.kr/p/q6rWd5)

Comparision between the two species of Lilacfork of Thailand (https://flic.kr/p/q6rWd5)

[Psyche]

These two species are terribly confusing & seem to have been thoroughly mixed up on the net.

Evans states.

1. Lethe dura ;Upperside FW outer area paler. Underside HW INNER MARGIN of dark band angled between veins 4 & 6.

2. Lethe sura :Upperside FW uniformly brown ;HW INNER MARGIN of dark band straight between veins 4 & 6.

Antonio have provide examples of both species .Note the tail is at vein 4.
The part of the band between veins 4 & 6 would be the band in space 4 & 5; the inner margin is edged in white.

In Lethe dura the spot in space 4 is bulbous or domed , the white margin is convex , the inner margin is angled at vein 5.

In Lethe sura the spot in space 4 is quadrate, the white inner margin straight, continuing to space 5.

Examples of Lethe dura.
1st pix upperside IDed it as L. dura.
http://www.wzsfz.com/upload/20140106072020.jpg
http://insecta.pro/images/1024/32807.jpg
https://wingscales.com/content/record/738-1-ece07.jpg

Lethe sura.
http://s4.sinaimg.cn/mw690/001P2xqBzy6WI9XWwn1d3
http://www.ifoundbutterflies.org/media_images/2015/95_6106-792-55445165d4c17-1.jpg
https://wingscales.com/content/record/771-1-5db92.jpg

Some images appear ambiguous.

1, 4, & 5 Lethe dura.

2, Looks to be L. dura the spot in space 4 is broadly whitish on the inner side. as in this link.
http://www.wzsfz.com/upload/20140106072020.jpg

3, Probably L. dura . the inner margin is angled; spot 4 (semi pyramidal)bigger than spot 5.

& 6 is L. sura.



TL Seow: Cheers.

[DaveChiangMai]

Many thanks for this. Yes, all very confusing, which probably accounts for why a web search is a mess for these two species, and provides no clarity. Thanks for the detailed reply. It's hard to see any differences between images 5 and 6 other than the shape of the white cell spot in cell 4. Apparently the wider/longer pale band on the centre of the underside of the upperwing is not a good feature (shows well on Antonio's photos).

[Psyche]

The diagnostic feature is the dark band on the hindwing, its inner margin is edged in white.
Between vein 4 & 6 is exactly opposite the 2nd & 3rd eyespot (from the top).

In image 5. the inner margin is strongly angled thus it is L. dura.

In image 6 the inner margin is slightly curved, almost straight & so should be L. sura. (Compare with Antonio's images).

TL Seow: Cheers.