ACOSMERYX SERICEUS (Walker, 1856) -- Silky forest hawkmoth

TAXONOMY

Philampelus sericeus Walker, 1856, List Specimens lepid. Insects Colln. Br. Mus. 8: 181. Type locality: [Bangladesh,] Sylhet.

Synonym. Philampelus sericeus Walker, 1856.

Synonym. Acosmeryx anceoides Boisduval, 1875.

Synonym. Acosmeryx sericeus rufescens Mell, 1922.

ADULT DESCRIPTION AND VARIATION

Wingspan: 96--106mm. Forewing with outer margin dentate. Forewing upperside general background colour violaceous-grey, with the brown lines more prominent than in other species of the genus; first discal line well-marked, running straight from vein M3 to the hind margin, merging anteriorly with an oblique line that reaches the outer margin just anterior to the hind angle; a grey submarginal band ends at or just beyond vein M3. Hindwing upperside with an indistinct brown discal line, distal to which is an equally indistinct, slightly tawny, paler band. Hindwing underside with conspicuous white scaling at costal margins, between the lines. Metanotum chocolate-tawny at sides. Abdomen upperside with chestnut brown markings of tergites prominent. Underside of abdomen, most of hindwing. and the disc of forewing along the marginal band bright tawny. Antenna shorter in male than in Acosmeryx naga naga.

In the male genitalia, gnathos widest in middle. Harpe with process more rounded distally than in Acosmeryx naga naga, with the ventral ridge higher and not dentate. Aedeagus with left process broad.

ADULT BIOLOGY

FLIGHT-TIME

China: vi (Yunnan); 2-17.vii (Xizang/Tibet); 24.vii (Hong Kong).

Kendrick (2002) states that it is multivoltine in Hong Kong, occurring from March until December, with a peak from June to September.

EARLY STAGES

OVUM:

LARVA: Full-fed 75--90mm.

PUPA:

Larval hostplants. Actinidia and Vitis (Inoue, Kennett & Kitching, [1996] 1997).

PARASITOIDS

LOCAL DISTRIBUTION

China: Yunnan (Laojun Shan, 2579m; Hekou; Gaoligong Shan); Xizang/Tibet (Xiachayu, Zayu County); Guangxi; Guangdong (Guangzhou; Dongguan); Hong Kong (Shek Kong); Hainan.

GLOBAL DISTRIBUTION

Nepal, Bhutan (Irungbam & Irungbam, 2019), northeastern India, Bangladesh, Thailand, southern China, Vietnam (Le & Vu, 2024) and Malaysia (Peninsular).

BIOGEOGRAPHICAL AFFILIATION