Dear Sir/Madam,
I am uploading one image for indentification purpose. Species captured for Jayanti river, Alipurduar, West Bengal, India in the month of April 2018. Extreemly sorry for poor quality image upload.
This looks to be a fairly typical male Nacaduba berenice. In your area should be ssp. plumbeomicans.
Dark striae strong; FW band crooked; innermost costal spot present ;submarginal spots narrow, point acuminate .
There is a lot of confusion with the 6Line Blues in ID.
I'll start with the two easier ones.
A. Larger size. Males with the dark striae within the white striae poorer. Females generally with better dark striae.
Males termen(outer margin) straight.
A1. Nacaduba beroe gythion : a ,Male with the dark striae very poor or obsolete.b. FW with the innermost costal spot above the midcell band absent.
c. FW postdiscal band often dislocated in the middle; submarginal spots variable. d. wing base often dark in the male.
Criterium b is about 98% certainty. Criteria a + b is absolute certainty.
B: Dark striae well-developed in both sexes. Smaller.
B1. Nacaduba berenice ssp ormistoni & plumbeomicans.Male FW with gently rounded termen (outer margin).Upperside pale blue with frosting (icing).
FW postdiscal band crooked or dislocated; submarginal spots often narrow in male, irregular.