The Ethmia terminella group from the Canary Islands (Spain) and Morocco (Lepidoptera: Depressariidae, Ethmiinae)

The Ethmia terminella group is reviewed. Three species and one subspecies are recognized: E. terminella terminella Fletcher, 1938, E. terminella micropunctella Amsel, 1955, E. bennyi Falck & Karsholt, sp. n. (Spain: Gran Canaria) and E. pseudoterminella Falck & Karsholt, sp. n. (Spain: Fuerteventura, Morocco). Adults and genitalia of these four taxa are illustrated. The taxonomic results are supported by the DNA barcodes from sequencing of the 658 bp fragment of the mitochondrial COI gene.


Introduction
Ethmiinae are a moderately small subfamily of Lepidoptera with about 250 described species in five genera (HODGES, 1998: 138). Like several other family-groups of Gelechioidea Ethmiinae have led a rather tumultuous existence in the Lepidoptera system. Until the middle of the last century they were either placed in the Yponomeutidae or in the Oecophoridae, but since then there has been consensus that Ethmiinae are nested within the Gelechioidea. Here they have been considered as a separate family (e.g. SATTLER, 1967), a subfamily or a tribe of Elachistidae or (as followed here) a subfamily of Depressariidae (HEIKKILÄ et al., 2013).
The Palaearctic Ethmiinae were revised by SATTLER (1967). All European and North African species are referred to the genus Ethmia Hübner, [1819]. SATTLER (1967) listed 25 species from Europe, and it was not until 2003 that further European species were described (DOMINGO et al., 2003;KARSHOLT & KUN, 2003). There are currently 28 species of Ethmia in Europe (KUN, 2011), 14 of which are found in the Iberian Peninsula (VIVES MORENO, 2014: 132-133). This author listed two species from the Canary Islands: E. quadrinotella (Mann, 1861) and E. bipunctella (Fabricius, 1775). SATTLER (1967) divided the Palaearctic Ethmia species into 23 species-groups, based on adult and genitalia morphology. Below we deal with the Ethmia terminella group which until now included only one species and one subspecies.

Material and methods
All specimens were attracted to artificial light. Label data are listed in a standardized way under each species, with the islands in alphabetic sequence, and the records in chronological order. Data on holotypes are cited literally from their labels.
A part of the material was subjected to DNA barcoding (sequencing of the 658 bp fragment of the mitochondrial COI gene) for detection of genetically distinct taxa and for obtaining molecular data for new species. The K2P divergences between the examined taxa were calculated using analytic tools in BOLD systems.
The photographs of specimens were taken with Canon EOS700D camera and Soptop SZN 6745 Trinocular zoom microscope and Toup Tek P10500A-E3 / E3ISPM05000KPA-E3 / 5.0MP USB3 camera. Those of the genitalia by using a Soptop CX40T Trinocular microscope and the same camera.

Results
According to SATTLER (1967: 80) characteristics for the Ethmia terminella group are: Male genitalia are characterized by the divided uncus; posterior part of gnathos with rows of fine rounded spines; short rounded labis and cucullus strongly tapered towards apex. Female genitalia are characterized by triangular anterior apophysis, with broad base evenly tapered towards apex; antrum fusiform; bursa copulatrix without appendix and signum dome-shaped covered with spines. Adults are whitish to greyish with four black dots on thorax.
Ethmia terminella terminella Fletcher, 1938 (Figs 1-2) Tinea sexpunctella Hübner, [1810] nec Fabricius, 1794 Ethmia terminella Fletcher, 1938. Entomologist's Rec. J. Var., 50(5): 53 Diagnosis: Characterized by the pure white forewing, with costal quarter uniform grey from base to near apex, and light grey on the dorsal quarter from near base to near termen, and an indistinct greyish marking just below laterally to the discal spot; 6 distinct black dots around the cell: 1 at base, 3 on vein R (at 1/3, 1/2 and 1 at cell apex (discal spot)); 2 dots on vein Cu; marginal dots distinctly black. Specimens from Spain are generally darker grey along costa and dorsum. In the male genitalia (Figs 6, 6a), the triangular posterior part of gnathos, and the short rounded labis are characteristic. In the female genitalia (Figs 10, 10a) tergite VIII with anterior margin sclerotized and sloping from near ostium bursae to ventral part of anterior apophysis; the relatively short, asymmetrical antrum with microspines in the exit area for ductus seminalis is characteristic.
Distribution: Most of Europe, apart from northernmost parts, North Africa and Turkey (SATTLER, 1967: 81). We were able to examine specimens in ZMUC from Tunisia and northern Morocco: Ouezzane, and a sympatric occurrence of E. terminella and E. pseudoterminella sp. n. is therefore possible. Not listed from Russia (SINEV, 2008: 53). Diagnosis: Characterized by the white forewing, with few grey scales along costa and 4 small black dots. The genitalia (Fig. 7) do not differ from the nominotypical subspecies.

Ethmia terminella micropunctella
Biology: Early stages unknown. The type specimens were collected at an altitude of about 100 m below sea level.
Distribution: Only known from the type locality in Jordan, and probably also from Israel: Sea of Galilee (SATTLER, 1967: 81).
Remarks: In the genitalia preparations of the type specimens the phallus has not been removed, and it is not possible to see details of the cornuti. Description: Wingspan 17-21 mm. Labial palpus white, segment 3 dorsally mixed grey at tip; segment 2 laterally and dorsally mixed with grey. Antenna dark grey, dorsally whitish. Frons, collar, tegula, neck and thorax white, mixed dark grey. Forewing narrow, costa almost straight, apex pointed; white, with heavy suffusion of grey to dark grey, basal streak and costa more whitish; 4 small, diffuse black dots around the cell, 2 on vein R, at its middle and at cell apex (discal spot); 2 dots on vein Cu; just below the discal spot, medially a diffuse white marking and laterally a diffuse darker grey marking; marginal dots black, very small and indistinct; fringe white, with grey suffusion. Hindwing light grey. Abdomen grey, segment 1-3 dorsally light ochreous.
Genitalia 0 (Figs 11, 11a): Posterior apophysis slightly longer than papilla analis; anterior apophysis short triangular, base wide. Sternite VIII almost divided by a heavily sclerotized posterior rectangular incision to ostium bursae, medial margins heavily sclerotized. Antrum slightly longer than segment VIII (length from tip of anterior apophysis to posterior margin), tapering towards ductus bursae, margins slightly curved, exit for ductus seminalis in the upper right side. Ductus bursae membranous, long, helical. Corpus bursae ovoid, with one elongate, dome-shaped signum, covered with spines.
Molecular diagnosis: Three specimens of E. bennyi were sequenced, resulting in DNA barcode fragments of 632 bp for one specimen and 631 bp for two specimens. The nearest neighbor to E. bennyi is E. pseudoterminella with 3.69 % divergence; to E. terminella the divergence is 5.45%. The barcodes THE ETHMIA TERMINELLA GROUP FROM THE CANARY ISLANDS (SPAIN) AND MOROCCO of E. bennyi exhibit 0 % intraspecific variation. The results support the status of E. bennyi as a distinct species.
Differential diagnosis: Characterized by the narrow forewing, with almost straight costa, the grey to dark grey color, and very indistinct markings. In the male genitalia the slender, long labis, and the relatively short cucullus are characteristic. In the female genitalia the long, symmetrical antrum, the shape of tergite VIII which is almost divided, and the heavy sclerotization of the margins of the colliculum are characteristic.
Biology: Unknown. The specimens were collected in spring at light. Distribution: Known only from a few scattered localities in the southern half of Gran Canaria at altitudes between 120 m and 1400 m.
Etymology: The species is named after our good friend, the Danish lepidopterologist Benny Lynggård, who helped the first author on part of a collection trip to Gran Canaria.
Remark: Despite the lack of the 4 dots on thorax, E. bennyi is placed in the terminella group, because of similar genitalia morphology both in male and female, and because the nearest neighbors in DNA barcodes are species belonging to this group. Description: Wingspan 15-21.5 mm. Labial palpus white, segment 2 dark grey dorsally and laterally, posteriorly pure white to near segment 3. Antenna grey. Frons, collar, tegula and neck white. Thorax white with 4 indistinct dots. Scapula white with few dark grey scales. Forewing with costa slightly arched, apex pointed; color at costal third dark grey to near apex; dorsal third grey to dark grey from near base to near termen; dorsal part of base, mid-third of wing and apical area white, with suffusion of dark grey, especially between the two distal dots; 5 distinct dots around the cell: 1 at base, 2 on vein R (at 1/3 and at cell apex (discal spot)); 2 dots on vein Cu; terminal dots black, distinct. Fringe white with suffusion of grey scales. Hindwing grey, lighter towards base. Abdomen grey.
Genitalia 0 (Figs 12, 12a): Posterior apophysis slightly longer than papilla analis; anterior apophysis short triangular, base wide. Sternite VIII with a posterior rectangular incision to ostium bursae, anterior margin sclerotized, sloping from middle down to apophysis anterior on right side. Antrum slightly shorter than segment VIII (length from tip of anterior apophysis to posterior margin), tapering towards ductus bursae, left margin with a bulb like thickening opposite to ductus seminalis, right margin almost straight, exit for ductus seminalis in the upper right side. Ductus bursae membranous, long, helical. Corpus bursae ovoid, with one elongate, dome-shaped signum, covered with spines. Molecular diagnosis: Two specimens of E. pseudoterminella were sequenced, resulting in 658 bp, full-length DNA barcode fragment for both specimens. The nearest neighbor to E. pseudoteminella is E. bennyi with a 3.69% divergence; to E. terminella the divergence is 4.89%. The barcodes of E. pseudoterminella exhibit 0.31% intraspecific variation. The results support the status of E. pseudoterminella as a distinct species.
Differential diagnosis: External appearance of E. pseudoterminella sp. n. resembles E. terminella Fletcher, 1938, but differs by the suffusion with darker grey scales in the white area of the forewing and by having only five (not six) black dots in the forewing (the lack of black dot on vein R at 1/2 is characteristic for E. pseudoterminella sp. n.). In the male genitalia, a barrel-shaped uncus, and the medium-sized (compared to other species in the terminella group) labis are characteristic. In the female genitalia, the asymmetric antrum without micro spins, and the shape of sternite VIII are characteristic.
Biology: Unknown. The specimens were collected in early spring at light. Distribution: Known from Spain (Fuerteventura) and Morocco. Etymology: The new species most resembles E. terminella. Pseudo means false in Latin.

Discussion
Due to their relatively large size and distinct and/or colorful wing markings Ethmiinae are well studied compared to several other groups of the so-called Microlepidoptera, and the discovery of two undescribed species from the Canary Islands is therefore surprising. Our study is primarily based on morphology, and the use of DNA barcoding supported these results. We find it likely that the use of the latter method in other species groups of Ethmia may detect cryptic diversity, but that is beyond the aims of the present paper.
Although the early stages of the new species are still unknown it is probably that their larvae may live on Echium, which is also the host plant of E. terminella and several other Ethmia species (SATTLER, 1967: 18-19). There is a high diversity of endemic Echium species in the Canary Islands (ARECHAVALETA et al., 2010: 150-151), and at least E. bennyi sp. n. may be connected to one of these.