Acalyptris peteni Diškus & Stonis, sp. nov.

(Figs 8–20)

Type material. Holotype: ♂, GUATEMALA, Petén Dept., El Remate, 16°59’N, 89°42’W, elevation ca. 190 m, lowland tropical forest, mining larvae 07.ii.2012, ex pupa iii.2012, field card No. 5077, LT-GT Scientific Expedition, genitalia slide no. AD510 (ZMUC). Paratype: 1 ♂, same label data as holotype, genitalia slide no. AD511 (ZMUC).

Diagnosis. In male genitalia the new species differs from all known Neotropical Acalyptris, except A. tenuijuxtus (Davis) and A. unicornis Puplesis & Robinson, by the combination of an inverted V-shaped juxta and the large, sinuous cornutus in the aedeagus. From the possibly related A. tenuijuxtus and A. unicornis it differs in the shape of apically pointed and strongly sclerotized juxta, the very narrow valva, apically broadened aedeagus, and much longer, more elaborately sinuous cornutus; also the new species differs in the distinctly broadened hindwing with brown androconia forming an oval patch with a cream centre.

Male (Figs 10–11). Forewing length 1.7–1.8 mm, wingspan 3.7–4.0 mm. Head: palpi greyish cream; frontal tuft pale orange or cream in front, pale orange-brown on vertex; collar cream, weakly developed, comprised of piliform scales; eye-caps cream; antenna with ca. 28 segments, slightly shorter than half of forewing; flagellum grey on upper side, grey-cream on underside. Thorax, tegulae and forewings cream, speckled with fuscous scales; cream spots of forewing (large median and two smaller apical) weakly defined, rather irregular, with weak orange tinge; orange tinge can be also prominent on forewing apex; cilia cream apically, greyish cream on tornus; underside of forewing fuscous in two basal thirds, with cream broad elongated median spot; remaining (apical) third entirely cream, occasionally with a few dark brown scales. Hindwings cream-white, distinctly broadened at basal half and with brown androconia forming oval patch with centre remaining cream; cilia greyish cream. Legs brownish cream, with fuscous darkening on upper side. Abdomen: upper side mostly cream, glossy, with few cream brownish (or pale brown) scattered scales (mostly in proximal part of abdomen); underside cream, glossy; anal plates cream; anal tufts short, cream.

Female. Unknown.

Male genitalia (Figs 15–20). Capsule longer (270 m) than wide (150 µm). Vinculum with two large lateral lobes (Fig. 15). Pseuduncus with two long and two short processes (Figs 15, 18). Uncus with small sclerotised central projection and sclerotised lateral arms (Fig. 18). Gnathos with narrow caudal process, tiny central element and slender lateral arms (Fig. 18). Valva (Figs 15, 19) 135 µm long, slender, with tiny sublateral process; transverse bar of transtilla absent. Juxta 60 µm long, with pointed caudal extention (Figs 15, 20). Aedeagus (Figs 16, 17) 255 µm long, 55–80 µm wide, with three carinae (two short, heavily sclerotized, spine-like and one long, weakly sclerotized, lobe-like); vesica with two very large cornuti (one sinuous and broad, other more straight and slender) and some minute ones.

Bionomics. Mines in leaves (Figs 13, 14). Host-plant unidentified. Egg on upper side of the leaf. Larvae mine in early February (and probably January because numerous empty leaf-mines found by us in early February). Mine gallery sinuous or contorted with dark brown to blackish frass deposited as central line (Fig. 14). Larval exit slit on upper side of the leaf. Cocoon deep beige, length 2.5–2.75 mm, maximal width 1.8 mm (Fig. 12). Adults emerged in March.

Distribution. Known from a single locality in NE Guatemala (Petén Dept.) (Fig. 8). The type material was collected in lowland secondary evergreen broadleaf tropical forest (Fig. 9).

Etymology. This species is named after Petén, a vast lowland region of Guatemala.