Mercantouria Huemer, Lopez-Vaamonde & Triberti

Huemer, Peter, Lopez-Vaamonde, Carlos & Triberti, Paolo, 2016, A new genus and species of leaf-mining moth from the French Alps, Mercantourianeli gen. n., sp. n. (Lepidoptera, Gracillariidae), ZooKeys 586, pp. 145-162 : 147-148

Taxon classification Animalia Lepidoptera Gracillariidae

Mercantouria Huemer, Lopez-Vaamonde & Triberti gen. n. Figs 1, 2, 3, 4-5, 6-7

Type species.

Mercantouria neli Huemer, Lopez-Vaamonde & Triberti, sp. n.

Description.

Adult (Fig. 1). Forewing length 5.1-5.8 mm. Head. Vertex and face loosely scaled; ocelli absent; proboscis naked, well developed. Antenna about as long as forewing, smooth, each flagellomere with an annulus of slender scales basally and another of shorter scales at apex, about 0.2 × length of basal ones, completely covered by the first ( Triberti 1998); scape moderate, about 3.0 × length of pedicel, pecten missing. Labial palpus long, upturned, pointed apically, segment 2 as long as apical one, slightly thickened with scales towards apex. Maxillary palpus smooth, shorter than apical segment of labial palpus.

Thorax. Smoothly scaled. Forewing narrow, lanceolate; discoidal cell with distal margin nearly vertical, 13-veined; all radial veins separated but vein R4, R5 and M1 very close at their bases; veins M2 and M3 connate and arising from lower angle of cell; Cu1b arising from cell more apical than R2. Hindwing narrowly lanceolate, 8-veined; cell opened between M2 and M3, R4+R5 not parallel to the costal margin and meeting directly with M1+M2 (Fig. 2). Legs with tibial spur pattern 0-2-4; epiphysis present but partly hidden by long scales.

Abdomen. In the male segment 7 and 8 weakly membraneous, with a pair of coremata on each segment; anterior pair of coremata consisting of hairlike scales, longer and thicker than the posterior pair (Fig. 3). Sternum and tergum 7 reduced into a thin sclerites; sternum 8 also reduced but tergum is formed by a small, fan-shaped sclerite, with a narrow median ridge. Female postabdominal segments unmodified.

Male genitalia (Figs 4-5). Tuba analis produced beyond tegumen, membraneous, with a narrowly sclerotized subscaphium, widened basally. Tegumen weakly sclerotized, simple. Valva stout, with sacculus distinctly protruded and rounded apically, setose; cucullus straight, upturned, covered with strong setae on dorso-distal area; costal margin irregular with similar setae medio-distally. Diaphragma with some fine setae at base of anellus. Phallus slightly shorter than valva, apically with long rod-like sclerite branching off at right angle, no cornuti are visible.

Female genitalia (Figs 6-7). Lamella postvaginalis not connected with apophyses anteriores. Ostium bursae located under a lobate sternite 7. Ductus bursae completely membraneous, slender; corpus bursae ellipsoidal with two curved sickle-shaped signa, one of which is slightly longer than the other.

Etymology.

The generic name refers to the region of Mercantour National Park (France).

Diagnosis.

Mercantouria belongs to the Gracillaria group for the presence of a very short vein R2+3 in the hindwing, running in parallel with apical part of vein Sc+R1. Moreover this new genus shares with most genera of the Gracillaria group the following characters: legs more or less smooth-scaled except for mid femur and tibia thickened with raised scales; forewing 13-veined with M2 and M3 connate, R1 arising from cell near base of wing, upper vein of cell weakened on basal part just beyond the point where R1 branches off; hindwing 8-veined, with radial veins always 2-branched, veins M1 and Cu1a stalked with veins M2 and Cu1b respectively, vein M3 branched from vein Cu1a, cell opened between M2 and M3; in male genitalia abdominal segment 7 and 8 weakly membraneous, each of them having a pair of coremata which are in a bundle of long and hairy scales, the latter covered with more or less deformed scales; in female, corpus bursae with two large sickle-shaped signa.

Within Gracillaria group the genera are difficult to identify on the basis of apomorphies and comparisons are rather complicated due to the “cross” distribution of characters. Mercantouria shows some similarity to the genus Caloptilia and allied genera ( Gracillaria , Povolnya , Euspilapteryx , Aspilapteryx and Eucalybites ): (1) forewing 13-veined and hindwing 8-veined, albeit with slight differences in the relative positions of some veins; also in Gracillaria and Povolnya there is a similar venation but in the former there are strong differences in the pregenital segments, the segment 7 being like the preceding and without coremata and the latter with peculiar male genitalia, with the tegumen having a pair of peniculi projected from caudal margin of tegumen; (2) male abdomen with two pairs of coremata more or less similar in length and thickness; a similar condition is found in Povolnya and Euspilapteryx but the latter differs from the new species in the forewing venation (12-veined) and female genitalia (only one signum); (3) in the female genitalia, the bursa copulatrix has two corniform signa; this character is shared with Aspilapteryx and Eucalybites however both differ from forewing venation (12-veined) and coremata of different size or only one pair.

Mercantouria differs from these genera in the following morphological characters: 1) the forewings show veins R4, R5 and M1 very close, weakened or obsolescent at their bases; this character is unknown within Gracillaria group and it seems closer to Acrocercops group. 2) The hindwings show veins R4+R5 directly connected with radial vein and divergent from costa, this condition is only similar to Eucalybites and Aspilapteryx ; however both clearly differ by having the forewing 12-veined. 3) Lack of pecten which also occurs in a few taxa closely related to Caloptilia : subgenera Timodora Meyrick, 1886, Phylloptilia Kumata, 1982 and the genus Povolnya , sometimes considered as another subgenus of Caloptilia ( Kumata 1982). 4) The male genitalia has a highly modified valva (Fig. 4) unlike any other known in the genus Caloptilia ; only a somewhat similar shape of the valva is seen in Aspilapteryx spectabilis (Fig. 8) ( Huemer 1994) and Eucalybites aureola ( Kumata 1982) but easily distinguishable from the cucullus, which is straight and covered with strong setae along its margin in the new genus.