About Zeltus amasa
Zeltus amasa is a small butterfly species belonging to the small genus Zeltus, with a total wingspan of 28–32 millimeters. It can be easily recognized by its long, fluffy hindwing tail: 13 millimeters long for the first variant, and 7 millimeters long for the second variant. This species has false eyes, legs, and antennae on its hindwing that mimic its real head and divert attention away from it; when attacked, it will fly off in an unexpected direction. Male Zeltus amasa: Upperside: The forewing has a small greyish-blue basal area covering the basal half of the cell and the lower basal portion of the wing, while the rest of the forewing is black. Overall, the male forewing is blackish, with a pale blue basal area. The hindwing is mostly greyish-blue, with a large black patch at the apex; the color pales towards the hind margin, becoming more or less pure white at the anal angle and on the abdominal fold. Tails are white, with a pale blue line running down their centers. There is a pale blackish spot at the anal angle, and a second pale blackish spot in the first interspace. Cilia are white. Underside: The forewing is pale rufous-brown, with four-fifths of the hinder marginal area, extending from the base below vein 2, colored bluish-white. Markings are slightly darker than the ground color: a bar at the end of the cell, edged with white on both sides; a slightly outwardly curved, even narrow discal band of the same width as the cell bar, edged with white on both sides, extending from near the costa to below vein 2; and an indistinct similar submarginal band that lacks white edging. The hindwing has an upper portion of paler rufous-brown, which pales hindwards and becomes pale bluish-grey on the lower two-thirds of the wing. Markings include: a black sub-basal spot below the costa; a pale bar at the end of the cell, edged with white on both sides; a broken discal band of the same narrow width as the discal band on the forewing, edged with white on both sides, running straight from the costa to vein 4, with a linear mark in the next lower interspace well inwards, and below this a line that is twice acutely angled, then bending inwards straight onto the abdominal margin above the anal angle; a submarginal double series of somewhat lunular marks, where the outer series ends in a large black spot in the first interspace just above the upper tail, and a second large black spot at the anal angle; and a fine terminal black line with an inner white line. Antennae are black, ringed with white. The head and body are blackish above, with blue pubescence, and whitish below. Female Zeltus amasa: Upperside: The forewing is dark brown overall, with the outer portion shading slightly darker. The hindwing has a narrowly pale costa, and is brown across the rest of the wing; the color pales hindwards and becomes white towards the anal angle. There is a large black subterminal spot above the upper tail, a small black spot at the anal angle, a suffused brownish spot or mark between these two spots, and a short double series of brownish lunular marks on the white ground above the spots. Underside: The ground color is paler than in the male, and the markings are the same as the male's.
