A Moth species from North Sumatra

[horace2264]

Dr Gabriella Fredriksson wrote to ask me about the ID of a moth species which has infested the forest there, and one which has attracted groups of orangutan to feast on them.

The best I can do is to identify it as an Achaea species, but what is the species ID? :hmmm:

[Psyche]

I think it should be Achaea eusciasta.
The FW discal mark is a black dot followed by a large oval/oblong spot.
http://lepidoptera.butterflyhouse.com.au/cato/eusciasta.html

TL Seow:Cheers.

[Psyche]

There are four widespread species of Achaea here which are very similar & can be pest.
They are A. janata, serva eusciasta, & mercatoria.

By comparing the cats of A. janata & serva , these two are very unlikely & can be ruled out.
http://lepidoptera.butterflyhouse.com.au/cato/janata.html
http://lepidoptera.butterflyhouse.com.au/cato/serva.html

The adult of A. mercatoria can be recognised by the falcate forewing tip.
http://www.africanmoths.com/images/Erebidae/EREBINAE/achaea%20mercatoria1%20upp.jpg

This leaves Achaea eusciasta .

TL Seow:cheers:

[horace2264]

Many thanks, Dr Seow for the detailed explanation on the deduction process. :)
I have passed on the ID to Dr Gabriella Fredriksson.