Typical examples of Orthomiella rantaizana and O. pontis seem to be straight-forward to separate. However, I frequently find my observations and photos seem to look intermediate between the two, and I can find no good way of telling them apart.
Pointers to identification are given in Pisuth's book mentioning the straighter termen in rantaizana, though specimen photos on Yutaka and in Kimura do not always show this well, so does not seem to be a reliable way to tell them apart. Probably the most useful differentiation is background colour? Paler on pontis. However, some paler individuals appear to have rather dark markings and look rather dark at the base of the base of the hindwing. It's quite confusing.
I would be interested in any useful feature to separate them, and comments on the identities of these photos (all taken at high altitude on Doi Pha Hom Pok, n Thailand).
Only image 2 would I call a definite O. pontis. The others all have features pointing to both as far as I can see.
Many thanks.
Image 1.
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Image 2.
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Image 3.
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Image 4.
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Image 5.
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Image 6.
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