Gnathitischeria arcana Diskus & Stonis 2023, sp. nov.

Gnathitischeria arcana Diškus & Stonis, sp. nov. urn:lsid:zoobank.org:act: DD981BA1-B22E-4C7D-BF34-8A9D4 ABDB 51C (Figs 482–485, 535–561) Type material. Holotype: Ô, GUATEMALA: Petén Department, Tikal, 17°13’22”N, 89°37’24”W, elevation 315 m, mining larva on Acmella repens (Walter) Pers. (Asteraceae), 6.ii.2012, field card no. 5074, leg. A. Diškus, genitalia slide no. AD 1099 (MfN). Paratypes: 1 Ô, 1 ♀, same label data as holotype (MfN); 5 Ô, 3 ♀, Petén Department, El Remate, Biotopo Cerro Cahuí, 16°59’51”N, 89°42’13”W, elevation 120 m, mining larva on Acmella repens (Walter) Pers. (Asteraceae), 7.ii.2012, field card no. 5075, leg. A. Diškus, genitalia slide nos AD 847 Ô, AD 1072 Ô, AD 936♀ (MfN). Diagnosis. Externally, this new species can be confused with G. atitlani sp. nov. (described above), but the latter is larger and with much more distinctive pale patches on the forewing. In the male genitalia, the unique shape of a modified uncus (Fig. 536), a pseudognathos (Fig. 537) and large, greatly elaborated dorsal lobes of the valva (Fig. 542) instantly distinguish G. arcana from the congeneric G. atitlani. In the female genitalia, G. aracana differs from G. atitlani by larger ovipositor lobes, slightly shorter apophyses and a longer corpus bursae. This new species is also distinctive because it feeds on Acmella repens, Asteraceae. DNA barcode. We barcoded two specimens of the type series, but not the holotype; the sequences are available in the GenBank database under the accession numbers OQ413552 and OQ413553. Description. Male (Figs 483–485). Forewing length 2.5–2.8. mm; wingspan 5.6–6.3 mm (n = 5). Head: palpi and frons cream; colour of frontal and collar unknown (rubbed); antenna slightly longer than one half the length of forewing; flagellum grey to grey cream. Tegula grey; thorax ochre-yellow; forewing brown-grey, with irregular ochre-yellow spots; fringe grey, grey cream apically, without fringe line; forewing underside dark grey-brown, without androconia or spots, except for a small scaleless basal spot. Hindwing dark grey-brown on upper side and underside, without androconia; fringe grey. Legs glossy cream, covered with dark grey scales on upper side. Abdomen grey-brown on upper side, grey-brown with ochre-yellow scales on underside; genital plates pale ochre; anal tufts moderately long, dark grey or brown-grey. Female (Fig. 482). Forewing length 2.5–2.9 mm; wingspan 5.6–6.4 mm (n = 2). Similar to male but pale marking of the forewing is brighter and larger. Male genitalia (Figs 535–549) with capsule 385–400 µm long, 245–285 µm wide. Uncus comprised of two medium long, wide, modified, strongly medially and distally thickened lobes (Fig. 536). Tegumen relatively short, with a large pseudognathos possessing two large, pointed lateral lobes. Socii medium large, weakly paired, membranous. Valva ca. 360–370 µm long; dorsal lobe slender and long; ventral lobe of valva greatly elaboarated, large, thickened, with sinous inner margin. Anellus present, thickened caudally (Fig. 539). Vinculum almost triangular but widely rounded distally. Phallus ca. 210 µm long, bifid apically, with wide but very weakly chitinized lateral lobes (Fig. 541). Female genitalia (Figs 550–554) ca. 1350 µm long. Ovipositor lobes relatively large, rounded, sparsely covered with peg-like setae; second pair of ovipositor lobes almost three times smaller; lateral lobes short, indistinctive, possibly spinose. Posterior apophyses only slightly longer than anterior apophyses; prela comprised of three pairs of rod-like projections; median and inner processes almost equal in length; transverse prela weakly chitinized. Corpus bursae moderately long, very slender proximall third, round distally. Ductus spermathecae sinuous, with about four medium large and large coils and irregularly-shaped, indistinctive vesicle. Bionomics (Figs 555–561). Host plant is Acmella repens (Walter) Pers. (Asteraceae) (Fig. 555). Larvae mine leaves in February. The blotch-like mine is irregular, without frass. Adults occur in March. Distribution. This species is known from two lowland tropical forest localities in the Petén Department of Guatemala: Tikal at an elevation of 315 m and El Remate at an elevation of 120 m. Etymology. The species name is derived from Latin arcanus (mysterious), in reference to the unusual shape of dorsal lobe of the valva in the male genitalia.Published as part of Stonis, Jonas R., Diškus, Arūnas, Remeikis, Andrius, Orlovskytė, Svetlana, Solis, Alma, Paulavičiūtė, Brigita, Xu, Jiasheng & Dai, Xiaohua, 2023, Genera of Tischeriidae (Lepidoptera): a review of the global fauna, with descriptions of new taxa, pp. 1-131 in Zootaxa 5333 (1) on page 109, DOI: 10.11646/zootaxa.5333.1.1, http://zenodo.org/record/826113