Athrypsiastias symmetra Meyrick 1915
Creators: name: Sterling, Mark J.
name: Price, Ben W.
name: Lees, David C.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Lepidoptera
Xyloryctidae
Athrypsiastias
Athrypsiastias symmetra

description: Athrypsiastias symmetra Meyrick, 1915
Figs 28, 53 A, B
Athrypsiastis symmetra Meyrick, 1915: 377.
DNA barcode.
N / A.
Type material.
Papua New Guinea: Holotype • ♀, New Guinea, Rossel Island. ASM.. 05, fwl 8 mm, specimen no. NHMUK 010219753 (external examination only).
Diagnosis.
Externally indistinguishable from other white species of Athrypsiastis. In the male genitalia, similarly to A. chionodes, the saccular process is almost straight after the curved base whereas in the other species of Athrypsiastis it is strongly curved, but the valva is postmedially broad and rounded in A. symmetra whereas it is elongate and tapering in A. chionodes. The anellus lobes are also shorter in A. symmetra than in the other members of this genus.
Description.
Male (Fig. 28). Forewing length 8–9 mm, wingspan 18–20 mm. Head: ocelli absent; frons with intense white appressed scales; vertex with iridescent white appressed scales, tufts of thin white scales of moderate length laterally on vertex, a ruff of long white scales on posterior part of occiput pointing posteriorly, overlaying collar of long broad flat white scales on anterior margin of prothorax, also pointing posteriorly; pilifers cylindrical, with a few bristles; maxillary palps white. Labial palps strongly recurved, long (3 × diameter of eye), thin, closely appressed to head; basal segment with small tuft of cream scales; second segment long, strongly curved, longer than third segment, thinly scaled white; third segment long, thin, with white appressed scales. Haustellum with basal portion scaled silver white. Antenna ¾ length of forewing, bipectinate, scape silver white, without pecten, pedicel short, dorsal surface of flagellum scaled silver white throughout, pectinations long, brown, covered in white sensillae, reducing at ¾, apical portion filiform. Thorax: greyish white, tegulae short, greyish white; foreleg with femur white, tibia white with broad epiphysis, tarsus white mixed ochreous, mid legs and hind legs white with small amount of long white scaling. Forewing broad, costa gently arched at base, thereafter straight, apex obtusely rounded, termen slightly angled inwards, tornus obtusely rounded, white, iridescent, unmarked except for a thin line of pale brown scales from base of costa to 1 / 6 and an indistinct pale brown patch on the dorsum of some specimens, cilia white. Hindwing as broad as forewing, rounded. Ventrally, forewing and veins scaled yellowish ochreous, otherwise forewing and hindwing white.
Female. Similar, antenna filiform throughout, forewing length 10 mm, wingspan 21 mm.
Pre-genital abdomen. Cream coloured, anal tuft cream coloured. Patches of tergal spines on posterior parts of T 2 – T 7; T 8 and sternites weakly sclerotised. Apodemes curved; venulae slightly sinuate.
Male genitalia (Fig. 53 A, B). Uncus anteriorly broad, anterior margin of dorsal surface very weakly emarginate, lateral edges tapering towards posterior apex. Gnathos fused medially, lateral arms broad, medial plate strongly sclerotised, strongly projecting posteriorly from lateral arms, projection rounded at apex. Tegumen band narrow, deeply curved, lateral extensions of tegumen longer than width of tegumen band. Vinculum robust, U shaped, base substantially projecting anteriorly beyond base of valvae. Saccus large. Juxta with broad U-shaped basal plate; anellus lobes short and broad. Valva long and broad, costal margin sinuate, ventral membrane from costa extending to apex of valva, thickly covered in long dark setae, curved ridge at anterior margin, saccular margin of valva almost straight, small, elongate ventral sclerite postmedially, close to ventral margin, apex of valva broadly rounded. Sacculus longer than broad. Saccular process commencing from distal part of sacculus, initially curving towards saccular margin, joining sub-basally to sclerotised flagellum of process, thin membrane from costal margin of valva also attached to flagellum of process sub-basally, flagellum of process curving distally through 45 °, thick appressed robust setae on flagellum from base to pre-apical region, thick brush of long, robust, bristles pre-apically to apex of process, extending beyond apex. Aedeagus almost straight with a ridge-like cornutus in the vesica. Bulbus ejaculatorius long, slightly coiled, long broad head.
Female genitalia. Not examined.
Biology and early stages.
A reported pest of Cinnamonum zeylanicum L. (Lauraceae) (Robinson et al. 2001: 70), Nephelium lappaceum (Sapindaceae) (Yunus and Ho 1980) and Theobroma cacao including damaging its bark (Papua New Guinea. Department of Agriculture, Stock and Fisheries 1961: 112; Robinson et al. 2001: 70). Adults recorded between December and January.
Distribution.
Rossel Island and Upper Setekwa River, Papua New Guinea.
Additional material examined.
(3 ♂) 2 ♂, Mt. Rossel, 2100 ft., Rossel Island, Dec. 1915 – Jan. 1916 (W. F. Eichhorn), specimen no. NHMUK 010219659, slide no. NHMUK 010316426; specimen no. NHMUK 010923081, slide no. NHMUK 010316442; • 1 ♂, Upper Setekwa [Setakwa] R., Snow Mountains, Dutch N. G., 2–3000 ft., Aug. 1910, specimen no. NHMUK 010922380, slide no. NHMUK 010316443.
Remarks.
This species was described by Meyrick from a single female specimen collected by Albert Meek from Rossel Island, New Guinea. There are no males collected by Meek from Rossel Island. However, there are two males from Rossel Island collected by Albert Frederic Eichhorn in 1916. It is hypothesised here that these are the males of the species described by Meyrick from the Rossel Island female as A. symmetra Meyrick. The specimen labelled Upper Setekwa River [sic] (specimen no. NHMUK 010922380), which was determined by Meyrick as A. symmetra, has the same genitalia as the Rossel Island males.
description: Published as part of Sterling, Mark J., Price, Ben W. & Lees, David C., 2025, A revision of the hitherto neglected genus Topiris Walker, 1863 (Lepidoptera, Xyloryctidae) with taxonomic notes on the genus Athrypsiastis Meyrick, 1910, pp. 297-368 in ZooKeys 1229 on pages 297-368, DOI: 10.3897/zookeys.1229.119155