Euploea is extremely difficult to ID from the underside.
Each species also have a lot of regional variations so that it is not possible to use the same species from another region (different ssp.)for comparison.
E. core have prominent subapical FW spots & can be eliminated.
http://yutaka.it-n.jp/dan/30270030.html
E. midamus chloe have HW submarginal spots short at most 2- 2.5 X that of the marginal spots & the FW long & sharper.
http://yutaka.it-n.jp/dan/30350010.html
https://wingscales.com/Nymphalidae/E...-midamus-chloe
E. algea menetriesii have the HW submarginal spots elongate to about 4x the marginal spots.Dark.FW apex more rounded.
http://yutaka.it-n.jp/dan/30280010.html
https://wingscales.com/Nymphalidae/E...gea-mentriesii
E. sylvester harrisii. HW submarginal spots about 2 X that of the marginal spots . UpF brilliant blue in both sexes.
http://yutaka.it-n.jp/dan/30310010.html
https://wingscales.com/Nymphalidae/E...ester-harrisii
E. modesta modesta; HW submarginal spots 2-3X that pf the marginal spots. The two series of spots tend to have a widening gap in the middle.
http://yutaka.it-n.jp/dan/30240001.html
https://wingscales.com/Nymphalidae/E...odesta-modesta
Female.
https://lh3.googleusercontent.com/pr...YZLdEjybAXlIJM
http://malaysiabutterflies.myspecies...pecies-modesta
This looks to be the female Euploea modesta modesta.
TL Seow: Cheers.
Thank you, Dr Seow!