Acalyptris extremus Stonis & Diškus, 2020

Stonis, Jonas R., Diškus, Arūnas, Remeikis, Andrius, Vargas, Sergio A. & Solis, M. Alma, 2020, Diagnostics and updated catalogue of Acalyptris Meyrick, the second largest genus of Nepticulidae (Lepidoptera) in the Americas, Zootaxa 4748 (2), pp. 201-247 : 234-239

44. Acalyptris extremus Stonis & Diškus , sp. nov. ( Figs 151–163 )

Diagnosis. External characters of A. extremus are not sufficient for species identification. In the male genitalia, the unique shape of valva with a strongly bulged inner lobe ( Fig. 156 ), and particularly two pairs of extremely developed horn-like processes ( Fig. 159 ) easily distinguish the new species from all known Acalyptris species.

Description. Male ( Figs 151–154 ). Forewing length 2.1 mm; wingspan 4.7 mm (n = 1).

Head. Scape golden cream; frontal tuft orangish ochreous to ochre-brown; collar comprised of pale ochreous piliform scales; antenna slightly shorter than one-half length of forewing; flagellum ochreous cream with golden gloss on upper side and underside, with about 39 segments.

Thorax. Tegula yellowish cream with some irregularly scattered brown scales; thorax yellowish cream with golden gloss; forewing yellowish cream with golden gloss and some sparsely scattered brown and dark brown scales prevailing in apical 1/3; fringe golden cream, without fringe line; forewing underside densely covered with pale grey-brown scales, with some purple iridescence; no androconia. Hindwing and fringe grey to yellowish cream (depending on angle of view), without androconia. Legs glossy, yellowish cream, with dark grey-brown scales on upper side.

Abdomen. Fuscous on upper side, grey cream on underside; anal tufts inconspicuous; genital plates large, cream. Genitalia ( Figs 155–163 ) with capsule about 360 µm long, 240 µm wide. Valva with two pairs of extremely large processes ( Figs 156 , 159 ). Phallus about 290–330 µm long, with a large cathrema and unique carinae ( Figs 161–163 ).

Female. Unknown.

Bionomics. Host plant is unknown. Adults fly in June (one specimen was attracted to light). Otherwise, biology is unknown.

Distribution ( Fig. 1 ). Currently known from a single locality in Bolivia (Yungas: Coroico) at elevation about 1660 m ( Figs 6–8 ).

DNA barcode. We barcoded the male holotype of the new species; the sequence is available at GenBank under voucher/sample ID MN982365 .

Etymology. The species name is derived from the Latin extremus (extreme), in reference to the unique, extremely developed horn-like processes of valva in the male genitalia.

Type material. Holotype: ♂, BOLIVIA, Nor Yungas Province , Coroico, 16°12ꞌ25ꞌꞌS, 67°43ꞌ53ꞌꞌW, elevation 1660 m, at light, 15.vi.2018, A. Diškus & J. R. Stonis, genitalia slide no. AD945 ( ZMUC).

Figures

FIGURE 1. Distribution map of Acalyptris species currently known in the Americas.

FIGURES 151–157. Acalyptris extremus Stonis & Diškus, sp. nov., holotype (ZMUC). 151–154, male adult; 155–157, male genitalia, slide no. AD945.

FIGURES 158–163. Male genitalia of Acalyptris extremus Stonis & Diškus, sp. nov., holotype, genitalia, slide no. AD945 (ZMUC). 158, pseuduncus, uncus, and gnathos; 159, 160, capsule without phallus; 161–163, phallus.

FIGURES 2–11. Habitats of Acalyptris species. 2–5, habitat of A. marmor sp. nov., A. barbudo sp. nov., and A. hilli sp. nov., selva central (“selva alta”), Satipo, Peru, 750 m; 6–9, habitat of A. mortalis sp. nov., A. extremus sp. nov., and A. murex Diškus & Stonis, Yungas, Coroico, Bolivia, ca. 1300 m; 10, 11, habitat of A. hyacinthum sp. nov., A. bifidus Puplesis & Robinson, and A. yucatani Remeikis & Stonis, tropical montane forest at the edge with the Choco biogeographical province, Valle del Cauca, Colombia, 550 m.