Stigmella mentholica Diskus & Stonis 2021, sp. nov.
Creators: name: Stonis, Jonas R.
name: Diškus, Arūnas
name: Fernández-Alonso, José L.
name: Remeikis, Andrius
name: Solis, M. Alma
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Lepidoptera
Nepticulidae
Stigmella
Stigmella mentholica

description: Stigmella mentholica Diškus & Stonis, sp. nov.
(Figs 3, 25, 26, 31, 32–40, 63, 64, 68)
lsid:zoobank.org:act: 13111F27-B26F-472E-B3EC-A23954B7A6E1
Type material. Holotype: ♁, ECUADOR: SW of Quito, western slopes of the equatorial Andes, Via Aloag to Sto. Domingo, 0°26’46”S, 78°37’39”W, elevation ca. 3100 m, mining larva on Minthostachys mollis (Kunth) Griseb. (Lamiaceae), 24.ii.2000, ex pupa iii.2000, leg. R. Puplesis, genitalia slide no. AD697 (USNM). Paratypes: 2 ♁, 2 ♀, same label data as holotype, genitalia slides nos AD688♁, AD1033♁, AD1026 ♀ (USNM).
Diagnosis. The new species belongs to the Stigmella singularia species group, designated and characterized by Stonis et al. (2017a). Externally, males of S. mentholica sp. nov. differ from the most similar S. aromatica sp. nov. in the slender, subapical fascia of the forewing and indistinctive patch of silvery or golden shiny scales on the apex. In the male genitalia, S. mentholica differs from all other known Neotropical Stigmella, including other species of the S. singularia group, by the combination of a distinctly truncate uncus and very long caudal processes of the gnathos (Fig. 34). Only two other species, S. aromatica and S. odora sp. nov, feed on the same host plant Minthostachys mollis, but there are significant differences in the morphology of the leaf mine: in S. mentholica, the leaf mine is a wide, relatively short gallery (Fig. 3), while the leaf mine of S. aromatica is a slender and long gallery, almost fully filled with frass (Fig. 10), and the leaf mine of S. odora is a combination of a very slender gallery and an irregular blotch (Fig. 6).
Male (Figs 25, 26, 31). Forewing length 2.6–3.0 mm; wingspan 5.8–6.7 mm (n = 3). Head: palpi cream; frontal tuft dark orange; scape golden cream; collar golden cream but at certain angle may look pale grey, metallic glossy; antenna distinctly longer than half the length of forewing; flagellum with 36 segments, dark grey to brown-grey or pale grey, with golden gloss and some purple iridescence. Thorax and tegula golden brown. Forewing pale golden brown, strongly shining, at base with intense purple iridescence; fascia subapical, slender, comprised of silvery or golden shiny scales; apex of forewing brown-purple, with indistinctive patch of silvery or golden shiny scales; fringe grey; underside of forewing black-brown, without spots or androconia, except for slender scaleless spot at base. Hindwing pale grey to dark brown depending from angle of view, without androconia; fringe grey. Legs glossy grey cream; on upper side, covered with grey to brown-black scales with purple iridescence.Abdomen blackish grey to grey-brown on upper side and underside; genital segments pale brown; anal tufts short but distinctive, dark grey to fuscous.
Female. Smaller than male; forewing length 2.3–2.4 mm; wingspan 5.2–5.4 mm (n = 2). Palpi and scape snow white. Frontal tuft pale yellow. Fascia of forewing post median-subapical, glossy white, distinctive. Abdomen fuscous to grey-brown on upper side, ochreous grey to grey-brown on underside; genital segments cream-ochre on underside, ovipositor pointed. Otherwise as in male.
Male genitalia (Figs 32–40). Capsule longer (215–220 μm) than wide (195–200 μm). Vinculum with short, pointed lateral lobes. Uncus truncate caudally (Figs 33, 34). Gnathos with two very long, close-set caudal processes and a slender plate (Fig. 34). Valva (Fig. 38) 210–215 μm long, 75–80 μm wide, with slender apical process; transtilla with sublateral processes (Figs 35, 36). Juxta membranous, indistinctive. Phallus (Figs 37, 39, 40) 270–335 μm long, 85–90 μm wide; vesica with about 15–16 large spine-like cornuti and some minuscular cornuti (Fig. 37).
Female genitalia (Figs 63, 64). Total length 1070–1080 μm. Anterior apophyses gradually narrowing distally; posterior apophyses very slender, longer than anterior ones, distally bent (Fig. 63). Vestibulum without sclerites. Corpus bursae with a strongly folded distal part and oval-shaped basal part with many indistinctive pectinations. Accessory sac very small, indistinctive; ductus spermathecae without coils, but with a small, tube-like vesicle.
Bionomics (Figs 1–3). Host plant is Minthostachys mollis (Benth.) Griseb., Lamiaceae: Mentheae (Figs 1, 2). Larva pale green with brown-green intestine and pale brown head; feeds in February and probably in late January (note that in late February some leaf mines are already vacant). Prefer open, sunny areas. Leaf mine (Fig. 3) is a wide, sinuous, gradually widening gallery (easy to spot because the generally whitish appearance); at the beginning, with an interrupted line of brown-black frass, further on, with a wide margin, unfilled with the frass. Cocoon brown. Adults probably fly in March (indoors, emerged in March).
Distribution (Fig. 68). This species is known from a single locality in Ecuador, on the western slopes of the equatorial Andes, at elevation of ca. 3100 m, but the host plant has a much wider distribution in the northern and central Andes (see Discussion).
Etymology. The species name is derived from menthol, one of the principal components of essential oil of its host plant, Minthostachys mollis, in reference to the strong mint smell of its leaf mines.
description: Published as part of Stonis, Jonas R., Diškus, Arūnas, Fernández-Alonso, José L., Remeikis, Andrius & Solis, M. Alma, 2021, New leaf-miningNepticulidae (Lepidoptera): potential pests of aromatic Lamiaceae plants from equatorial Andes, pp. 363-383 in Zootaxa 4926 (3) on pages 365-366, DOI: 10.11646/zootaxa.4926.3.3, http://zenodo.org/record/4529319