Apha floralis Butler, 1881 species group

Zolotuhin, Vadim V., Pugaev, Sergey N. & Du, Tran Thieu, 2020, A review of Apha floralis species group (Lepidoptera: Eupterotidae), Acta Biologica Sibirica 6, pp. 611-635 : 611

Apha floralis Butler, 1881 species group

Description.

Moderate sized moths (fore wing length 24-29 mm in males, 30-35 mm in females), characterized by bright, contrasting pattern. The basal fascia of the fore wing is dark brown, dentate and sometimes indistinct. The discal spot is round, dark brown and is always present. The antemedial fascia is angled or curved, towards the costa approximately at a right angle. The apical patch of the fore wing is elongated, semicircular, and extends along the costa. It is pale in colour, usually with a dark centre. The postmedial fascia is yellow, usually of the same colour as the apical forewing patch, straight, and running towards the apex of the wing; it is fused with the apical patch in A. floralis , A. zephyrus , A. witti , A. kantonensis , and A. chloralis . The postmedial fascia is bordered basally by a well expressed, thin, dark shadow giving the impression that it is a double line; in some species the postmedial fascia is not clearly visible and weakly separable in colour from the distal part of the wing, but its basal shadow is always well defined. The submarginal fascia is zigzag-shaped, brown, sometimes indistinct. The hind wings are darker basally while the external field is bright yellow, usually without prominent pattern. The postmedial fasciae of the hind wings are of the same colour as those of the fore wings.

Male genitalia.

Uncus well developed, bilobed; the lobes usually strongly widened at the apex; gnathos very weakly sclerotized, distinct and consisting of two separate branches, not fused, but held together by a membrane; valvae are without saccular lobes, however these lobes are present in A. witti , but they are weakly developed with only a moderate sized prominence; the saccus is weakly developed, the aedeagus width is equal to the coecum length. The vesica is without an appendix and bears cornuti which are not extended longitudinally as in other species groups but form a compact basal circle.

Female genitalia.

The papillae anales are ovoid with numerous setae. The posterior and anterior apophyses are almost equal in size, with similar length and width. The postvaginal plate is well developed, with a medial incision; the plate is often transverse (i.e. extended longitudinally across the segment). The antevaginal plate is also well developed, it is high and has a medial incision of different depth. The antrum is short, wide and weakly sclerotized. The ductus bursae is not long; it is membranous or very weakly sclerotized. The corpus bursae is globe-shaped with a single, claw-shaped signum at its equator.

Diagnosis of the group.

Valvae are without saccular lobes, except for A. witti . The aedeagus is truncated. The antemedial fascia with angle of curvature about 90°.

Distribution.

The group occupies the southern area of the generic range and is known from northern India, Nepal, southern China, north-eastern Myanmar, Cambodia, and Vietnam (Figs 39 , 40 ).

Bionomics.

Species of this group develop at least two generations per year which can be seasonally dimorphic with regard to size and pigment saturation. They are confined basically to mountainous relief, known from altitudes of from 500 to 3000 m, but were also found at the lower altitudes of coastal biotopes. The caterpillars are covered with long hairs which are situated in tufts on verrucae but do not form specific brushes. They resemble large Arctiini caterpillars and feed on various deciduous trees and shrubs including members of Anacardiaceae, Annonaceae, Caprifoliaceae, Fabaceae, Malvaceae, Rosaceae, Rubiaceae, Salicaceae and Sapindaceae. The caterpillar stage lasts for 1 to 4-5 months. The pupa is enclosed in a thin, weak cocoon in the shelter of leaves, bark or on soil.

The group includes 5 species.

Figures

Figures 35 - 49. Preimaginal stages of A. chloralis: 35 - eggs; 36 - head of the caterpillars L 6; 37, 38 - L 1; 39, 40 - L 2; 41, 42 - L 3; 43 - L 4; 44, 45 - L 5; 46, 47 - L 6; 48 - L 7; 49 - pupa.