Ptochoryctis sundarbanica Sterling & N. Singh, 2025

Ptochoryctis sundarbanica Sterling & N. Singh , sp. nov.

urn:lsid:zoobank.org:act:

( Figs 1–6, 9 View FIGURES 1–10 )

Type material. Holotype. [ India] ♂, West Bengal, Sundarbans, Pakhiralay , 22.142N, 88.833E, 24.ix.2019, N. Singh, M.J. Sterling et al. leg. ( NZCZSI, 19844 / H10) GoogleMaps . Paratype: 1♂, same collection details as holotype ( NZCZSI, 19845 /H10). The type material is held in the collections of the Zoological Survey of India, Kolkata GoogleMaps .

Diagnosis. Externally, this species bears some resemblance to Ptochoryctis anguillaris Meyrick, 1914 but can be distinguished by its smaller size, the white rings on the black flagellomeres, the shape of the postmedial markings and its slightly reduced hindwings ( Figs 1, 5, 6 View FIGURES 1–10 ). In the male genitalia, the comparatively long apical process of the valva ( Fig. 2 View FIGURES 1–10 ) is close to that of Ptochoryctis acrosticta Meyrick, 1906 , but in P. sundarbanica the posterior apex of the uncus is tapered whereas in P. acrosticta it is not ( Clarke 1955: 493 Fig. 1b View FIGURES 1–10 ) and externally these two species could not be confused as P. acrosticta lacks the postmedial markings of P. sundarbanica ( Clarke 1955: 493 Fig. 1 View FIGURES 1–10 ).

Description. Male ( Figs 1–6, 9 View FIGURES 1–10 ). Forewing length 4–4.5 mm, wingspan 9–10 mm. Head: frons worn but traces of silver white scales remaining; vertex with some shortish silver white scales pointing anteriorly over base of antennae, the remains of tufts of silver white scales pointing posteriorly from occiput posterior margin; pilifers with small bristle tufts. Labial palps very small (less than 1.5 x diameter of eye), recurved; basal segment with brownish scaling, second segment much longer than third, moderately curved, brown scaling on outer surface, otherwise white; third segment short, straight, thinly covered in white scaling. Haustellum with silver white scaling on basal portion. Antenna ¾ length of forewing, scape white, flagellum dark with short black pectinations covered with short white sensillae for about ¾ of length, apical portion roughly ciliate, flagellomeres black and cream banded ( Fig. 5 View FIGURES 1–10 ). Thorax: worn with remains of silver scaling, tegulae short, silver; forelegs with femur, tibia and tarsus brown, thin tibial epiphysis, mid and hind legs white, thin tuft of long white scales on hind legs. Wing venation: forewing with R 1 from ½ discal cell, R 3 absent, R 4 and R 5 stalked, R 4 pre-apical, R 5 post-apical, M 1 and M 2 present, M 3 and CuA 1 separate, CuP present; hindwing with M 3 and CuA 1 stalked for a short distance. Forewing elongate, moderately broad but appears broader due to long forewing cilia, costa gently arched, apex obtusely rounded, termen angled substantially inwards, tornus slightly and obtusely rounded, silver white, iridescent, basal half unmarked, dark brown marking commencing postmedially on dorsum, rising above half and curving towards termen, joining with broad, sharply angulated, interrupted dark brown subterminal line, cilia white with internal brown line and a broader grey brown terminal line, long, very long towards tornus. Hindwings moderately broad but somewhat reduced, cilia very long, whitish reticulated with pale greyish brown. Ventrally: forewings with substantial dark brown scaling; hindwings silver.

Female. Unknown.

Pre-genital abdomen ( Fig. 4 View FIGURES 1–10 ). White, anal tuft small, white. Patches of tergal spines on posterior parts of T 2 –T 7, T 8 and sternites unsclerotised.

Male genitalia ( Figs 2–3, 9 View FIGURES 1–10 ). Uncus short, anteriorly broad, tapering moderately towards posterior apex, anterior margin of dorsal surface strongly emarginate. Gnathos uniformly wide, medial plate obtusely rounded posteriorly. Tegumen broadly banded dorsally, lateral extensions of tegumen longer than median width of band. Vinculum well sclerotised, U shaped, projecting beyond base of valvae. Saccus broad and short. Juxta with broad basal plate, anellus lobes broad, posteriorly level with or slightly above base of costa of valvae. Valva basally broad, tapering slightly towards apex with a slightly curved apical process, ventral surface with fine setae towards costal and saccular margins. Sacculus indistinct, longer than broad with a small, membranous extension of the posterior distal margin. Aedeagus thin and slightly curved.

Biology and early stages. Early stages unknown. Adults found at light in degraded mangrove habitat at edge of village in September.

Distribution. India (Sundarbans, West Bengal).

Etymology. Ptochoryctis sundarbanica sp. nov. is a latinised adjectival form of Sundarbans.

Remarks. Fig. 6 View FIGURES 1–10 is an image of the holotype at the sheet to which it was attracted, taken by Dr. Roger C. Kendrick (the same image is reproduced on iNaturalist ( Kendrick 2020)).