Megacraspedus violacellum ( Chretien , 1915)

Huemer, Peter & Karsholt, Ole, 2018, Revision of the genus Megacraspedus Zeller, 1839, a challenging taxonomic tightrope of species delimitation (Lepidoptera, Gelechiidae), ZooKeys 800, pp. 1-278 : 149-152

Megacraspedus violacellum ( Chretien, 1915)

Toxoceras violacellum Chrétien, 1915: 330.

Cauloecista chretienella Dumont, 1928: 34, figs 5A, B, syn. n.

Cauloecista halfella Dumont, 1928: 36, figs 5C, D, syn. n.

Mesophleps arnaldi Turati & Krüger, 1936: 76, pl. 11, fig. 27, syn. n.

Examined material.

Lectotype ♂, Toxoceras violacellum , here designated, "Toxoceras violacellum" "Gafsa 29.II.08" “TYPE” "Genitalia ♂ P. Viette Prèp. No. 2673" (MNHN) [photographs examined]. Lectotype ♂, Cauloecista chretienella , designated by Viette (1951: 57), “Holo-TYPE” "Cauloecista chretienella" "MUSEUM PARIS TUNISIE METLAOUI C. DUMONT 1921" "Imago 1.X.21" “type” "Cauloecista halfella Dum. Lepidoptera, vol. 3 1920, p. 34" genitalia slide PGCGN 8015 (MNHN) [photographs examined]. Lectotype ♀, Cauloecista halfella , designated by Viette (1951: 57), “TYPE” "Cauloecista halfella Type" "MUSEUM PARIS TUNISIE METLAOUI C. DUMONT 1921" "18.9.21 ex halfa" "Cauloecista halfella Dum. Lepidoptera, vol. 3 1920, p. 36" (MNHN) [photographs examined].

Lectotype ♂, Mesophleps arnaldi (without abdomen), designated by Li and Sattler (2012: 56), [Libya], “Zuetina” “20.ix.1934” “Krüger” (BMNH). Non-type material. Tunisia. 7 ♂, prov. Beja, 7 km W Nefza, W lake Sidi el Barrak, 30 m, 4.x.2007, leg. B. Schacht (TLMF, ZMUC, ZSM); 1 ♂, prov. Kebili, 10-20 km W Zaafrae, 10 m, 30.ix.-1.x.2007, leg. B. Schacht, genitalia slide GEL 1269 Huemer (TLMF).

Redescription.

Adult. Male (Figure 126). Wingspan 21-23 mm. Segment 2 of labial palpus with scale brush about half the length of segment 3, blackish brown on outer surface, white with black-tipped scales on inner surface, whitish on upper and lower surface; segment 3 same length as segment 2, creamcoloured. Antennal scape without pecten; flagellum dark brown, indistinctly ringed lighter. Head light grey-brown; thorax and tegula as forewing. Forewing light grey-brown; brown streaks through fold and in middle of wing until before apex; a narrow white line in middle of costa; a black dot in fold at 2/5 and one at end of cell; veins in costal and apical parts of wing finely dusted with whitish scales; fringes grey. Hindwing grey with concolorous fringes.

Female [based on original description and figure of lectotype] (Figure 127). Wingspan 18-20 mm. Forewing well developed, broadest at one-third, apical third tapered, more mottled with dark brown and black than in the male. Hindwing reduced to a short stump, transparent, grey, without scales. Otherwise similar to male.

Variation. The forewings vary from lighter to darker greyish brown, and there can be one or two additional small dots in the middle of the forewings. The specimen from Sbeidla is slightly more broad-winged and has the dorsal part of the forewing yellowish brown.

Male genitalia (Figure 246). Uncus sub-rectangular, slightly longer than broad, apical margin evenly rounded; gnathos hook moderately slender, apically pointed, slightly longer than uncus, weakly curved at about two-fifths; tegumen with broad and moderately deep anterior emargination, additional weak emargination medially, with short sclerotised sublateral ridges merged near middle of tegumen; pedunculi small, sub-triangular; valva massive, extending nearly to apex of uncus, basally widened, distal part broad, with longitudinal sclerotised ridge, apex converged, rounded; saccular area densely covered with setae, without separated sacculus; posterior margin of vinculum with deep emargination, weakly curved lateral hump, vincular sclerites broadly sub- triangular with posteriomedial ridge; saccus massive, stout, broadly suboval, tapered distal part, apically rounded, ratio maximum width to length about 1, posterior margin distinctly emarginated, with sinusoid mediolateral humps, medial part smooth, without sclerotised ridge, lateral sclerites approximately 0.6 times maximum width of saccus; phallus massive, with weakly inflated coecum, distal three-quarters stout, medially with area of numerous spinules, dorsomedially convex with broad tooth-like projection, apically rounded.

Female genitalia. Undescribed. Unfortunately we did not obtain permission to examine the genitalia of the only available female.

Diagnosis.

Megacraspedus violacellum is characterised by its large size and its light grey-brown forewings with two brown streaks and two black dots. It resembles M. squalida (Figs 128-129) and M. peyerimhoffi (Figs 145-146), but these species are without brown streaks in the forewings, having only obsolete black dots. The male genitalia are similar overall to M. armatophallus sp. n. (Figure 266) but unmistakable in Megacraspedus in the unique shape and sclerotisations of the phallus.

Molecular data.

BIN BOLD:ADI7610 (n = 1). The distance to the nearest neighbour M. ibericus sp. n. is 7.45% (p-dist).

Distribution.

Libya, Tunisia.

Biology.

The larva and pupa are described in details by Dumont (1928: 35-36). The larva feeds within a stem of Macrochloa tenacissima (Loefl. ex L.) ( Poaceae ) until March. Then it builds a semi-rigid chamber, composed of extremely fine, pure white silk, in which it lives a and grows slowly until the end of August/beginning of September when it pupates. Larvae collected in Tunisia were reared in Paris during the second half of September. The adults have been collected from the middle of September to early October. The label data “II”, referring to February, on a type specimen is probably the date the larva was collected.

Remarks.

Toxoceras violacellum was described from an unstated number of specimens collected at Gafsa, Tunisia in November ( Chrétien 1915: 330). We have been able to examine photographs of a syntype, labelled as type, from MNHN including the genitalia slide. This specimen is here designated as the lectotype in order to fix the identity of the species and conserve stability of nomenclature.

Cauloecista chretienella was described from an unstated number of specimens ("♂♂, ♀♀") bred from larvae collected by Al-Mitlawi [ “Metlaoui”], central Tunisia ( Dumont 1928). A lectotype was designated by Viette (1951: 57). We have been able to examine photographs of this male specimen, incorrectly labelled as holotype, from MNHN. It fully corresponds with M. violacellum both externally and in genitalia and we therefore consider M. chretienella to be a junior synonym of M. violacellum (syn. n.). However, the female labelled allotype belongs to M. squalida .

Cauloecista halfella was described from two females bred from larvae collected by Al-Mitlawi [ “Metlaoui”], in central Tunisia ( Dumont 1928). A lectotype was designated by Viette (1951: 57). We have been able to examine photographs of it which correspond with males of M. violacellum in wing markings and colour. Furthermore type-material of Cauloecista chretienella (= M. violacellum ) and C. halfella was described from the same locality and bred from the same host plants without any remarks as to differences in the biology. We therefore consider M. halfella to be a further junior synonym of M. violacellum (syn. n.).

Mesophleps arnaldi was described from two specimens collected by G. Krüger at Az Zuwaytīnah (' Zuetina '), Libya ( Turati and Krüger 1936: 76). A lectotype was published by Li and Sattler (2012: 56), who also transferred arnaldi from Mesophleps to Megacraspedus . These authors also suggested the synonymy of M. arnaldi with M. violacellum without, however, formally synonymising them. We examined the lectotype of M. arnaldi and consider it to be a junior synonym of M. violacellum (syn. n.).

A single male specimen from Sbeidla, Tunisia, coll. C. S. Larsen (ZMUC) was dissected by D Povolný. However, whereas the adult matches a faded M. violacellum the (remounted) genitalia correspond with M. glaberipalpus sp. n. which belongs to a different species group. We believe that a mix up of slides has probably happened during preparation or labelling.