Cosmopterix feminella Sinev, 1988

Koster, Sjaak J. C., Baldizzone, Giorgio, Deutsch, Helmut, Huemer, Peter & van Nieukerken, Erik J., 2019, The Eastern Palaearctic Cosmopterix feminella Sinev, 1988, introduced in Italy: taxonomy, biology and a new synonymy (Lepidoptera, Cosmopterigidae), Nota Lepidopterologica 42 (1), pp. 49-61 : 49

Cosmopterix feminella Sinev, 1988 Figs 1 , 2 , 3, 4 , 5

Cosmopterix feminella Sinev, 1988: 709. Holotype ♀, Russia: Primorskiy Kray, Khasanskiy district, 3 km southeast Andreyevka, 5.viii.1985, Sinev (Coll. Zoological Institute, Russian Academy of Sciences, St. Petersburg) [examined].

Cosmopterix feminae Kuroko, 2015: 48. Holotype ♀, Japan: Mt. Hikosan, Fukuoka Pref., 26.vii.1955, reared from Digitaria violascens , Kuroko. (Coll. Entomological Laboratory, Osaka Prefecture University). Syn. n. [not examined].

Material examined.

Italy: 58♀. See Table 1 and Suppl. material 1 .

Diagnosis.

In Europe C. feminella resembles C. crassicervicella and C. attenuatella . The latter species occurs in Europe only in the Macaronesian Archipelago. It differs from both by the narrower forewings, which are ten times as long as wide compared to eight times in C. feminella and C. crassicervicella . In the forewing C. feminella can be distinguished from both other species by the absence of a white costal line in the basal area and by the absence of the apical protrusion of the orange-yellow fascia, and in the abdomen by the uniform ochreous-brown dorsal coloration. In C. attenuatella the abdomen is dorsally more or less spotted orange-brown and in C. crassicervicella the abdominal segments two to six are dorsally orange-yellow. The female genitalia of C. feminella can be recognised by the large central hump on the posterior edge of sternite VII, by the distally hood-shaped sterigma and by the small but prominent crescent-shaped signa.

Redescription.

Female (Fig. 1 ). Forewing length 3.9-4.1 mm. Head: frons shining grey with greenish and reddish reflections; vertex and neck tufts shining dark brown with reddish gloss, medially and laterally narrowly lined white; collar shining dark brown with reddish gloss; labial palpus, first segment very short, grey, second segment four-fifths length of third, both segments dark brown, dorsally and ventrally lined white. Antenna: scape dorsally shining brown with reddish gloss and white anterior line, ventrally shining white; flagellum shining dark brown with short white line from base, changing in annulated white line to one-half, followed towards apex by four to five dark brown, one white, one dark brown, one white, four dark brown and three to four white segments at apex, sometimes apical segment grey to dark brown. Thorax and tegulae shining dark brown with reddish gloss, thorax with white medial line, often widening posteriorly, tegulae narrowly lined white inwardly. Legs: shining dark brown with reddish gloss; foreleg with white line on tibia and tarsal segments one to three and five; tibia of midleg with white oblique basal and medial lines and white apical ring, tarsal segments one and two with greyish white apical rings, tarsal segment five white; tibia of hindleg as midleg, tarsal segments one to four with narrow white apical rings, segment five dorsally white; spurs shining white, ventrally more grey. Forewing shining dark brown with reddish gloss; four white lines in basal area, subcostal from base to one-fourth and bending inwardly in distal half, short medial from one-fifth to just beyond subcostal, subdorsal underneath medial, about as long as medial or reaching slightly beyond it, very narrow dorsal from base to one-fifth, sometimes hardly visible; bright orange-yellow transverse fascia beyond mid length, narrowing in dorsal half; bordered at inner edge by broad tubercular golden metallic fascia, narrowing towards costa and with small subcostal patch of black scales on outside; bordered on outer edge by two tubercular golden metallic spots at costa and dorsum, dorsal about twice as large and nearer to base, costal and dorsal spots inwardly edged by few blackish scales; rather broad greyish white costal streak, inwardly edged dark grey; longitudinal silvery white spot in middle of apical area and shining white line in apical cilia; cilia dark brown around apex, paler towards dorsum. Hindwing shining brownish grey with reddish and greenish gloss; cilia dark greyish brown. Underside: forewing shining greyish brown, white costal and apical line distinctly visible; hindwing shining grey. Abdomen dorsally shining ochreous-brown with reddish golden gloss, laterally shining grey, ventrally shining grey, segments broadly banded white posteriorly; anal tuft dorsally ochreous-brown, ventrally blackish brown.

Male genitalia. Male unknown.

Female genitalia (Fig. 2a-c ). Posterior edge of sternite VII deeply concave with very large convex hump in centre. Sterigma elongated, distally hood-shaped, ostium bursae rounded, basally V-shaped with rounded labiate extension. Ductus bursae narrow, slightly shorter to about as long as corpus bursae. Ductus seminalis from upper part of corpus bursae. Corpus bursae elongate, two small, crescent-shaped signa.

Biology.

The biology has been described by Kuroko (2015) (as C. feminae ), from which we cite the following. Host plants: Digitaria ciliaris (Retz.) Koeler and D. violascens Link ( Poaceae). Larva (last instar): head blackish brown, body cylindrical, pale yellow, prothoracic shield and anal plate black, prothoracic legs blackish brown. The larva mines the leaves and makes an irregular blotch mine from near the base towards the apex of the leaf. The frass is ejected from a hole at the beginning of the mine. The larva changes leaves to make more than one mine. Pupation takes place outside the mine in a spindle-shaped whitish brown cocoon in a folded space on a leaf. In Japan (Kyushu: Mt. Hikosan) up to four generations per year occur. The larva of the last generation hibernates full grown and pupates in the middle of May the following year. The adults are on the wing in late May, in late July, from mid-August to mid-September and in late October. The European specimens of C. feminella were collected in the months June, August, September and October.

Distribution.

Russia: Primorskiy Territory, Japan: Honshu and Kyushu, Italy: Piemonte and Friuli Venezia Giulia regions (Fig. 5 ).

DNA barcodes.

We obtained completely identical DNA barcodes from six specimens of C. feminella from Italy, all belonging to the new Barcode Index Number BOLD:ADG7284, and with a distance of 5.8% to the nearest neighbour, an unidentified Cosmopterix species from Madagascar with BIN BOLD:ACT2622 (specimen BIOUG18998-F03). This specimen was collected with a Malaise trap and therefore its external morphology is poorly preserved ( Lopez-Vaamonde et al. 2018). Unfortunately no barcodes are yet known from the Asian populations. The distance to barcodes of European species is larger, the smallest being 6.1% to C. scribaiella (Zeller, 1850) (Fig. 6 ).

Remarks.

Cosmopterix feminella has been described on the basis of four females, caught between 25 July and 15 August in Primorskiy Kray, in the south-east of the Russian Far East.

In his study on the genus Cosmopterix of Japan, Kuroko (2015) described a new species, C. feminae , based on reared females only, and compared it with C. feminella from Russia, of which also only females were known. His conclusion was that the Japanese species shows sufficient differences to describe it as a new species, based on the following features: the apical segment of the antenna is black in C. feminae ; but white in C. feminella ; in the forewing the subcostal line starts from the base of the wing in C. feminae , which is not the case in C. feminella ; in the female genitalia the sterigma (lamella antevaginalis) lacks the tongue-shaped extension at the top as seen in C. feminella ; the ductus bursae is about half the length of the corpus bursae in C. feminae instead of nearly the same length in C. feminella .

Cosmopterix feminae is here synonymized with C. feminella for the following reasons: In the European series from Italy the apical segment of the antenna is white in 12 specimens, but it is dark grey in two specimens and black in one specimen, thus this character is apparently not constant. According to the original description of C. feminella the subcostal line also starts from the base of the forewing. Sinev (1988) provided a drawing of the forewing in which the subcostal line does not reach the base of the wing. Actually it does start from the wing base, but the curve of the wing margin hides this when seen from above, as in the figure. Probably this has convinced Kuroko that this line starts beyond the base of the wing. As Sinev (1988) mentioned, the tongue-shaped extension at the top of the sterigma (lamella antevaginalis), belongs to the hood-shape form of the sterigma. When the sterigma is embedded on the genitalia slide in ventral position, the so-called tongue-shaped extension can be caused by pressure on the cover slip. Kuroko (2018) described the length of the ductus bursae as about half the length of the corpus bursae, however, in his drawing (Plate 21, fig. H) the length of the ductus bursae is only slightly shorter than the length of the corpus bursae and equal in length to the length of the ductus bursae compared to the corpus bursae in the drawing by Sinev (1988: fig. 2, below in centre). The above differences are thus considered insufficient to regard C. feminae as a separate species.

Figures

Figure 1. Cosmopterix feminella, female habitus, Asti, Cascine Bet, 12. vi. 2016, RMNH. INS. 15509. Scale bar: 2 mm. Photo J. C. Koster.

Figure 2. Cosmopterix feminella, female genitalia. 2 a. ventral aspect, genitalia slide JCK 8673; 2 b. sterigma enlarged, in ventral view, genitalia slide JCK 8673; 2 c. sterigma enlarged in lateral view, genitalia slide JCK 8674. Scale bars: 0.1 mm. Drawings J. C. Koster.

Figure 5. Map of collecting localities of Cosmopterix feminella in Italy.

Figure 6. Neighbor Joining tree of DNA barcodes of European Cosmopterix species.

Figures 3, 4. Collecting sites of Cosmopterix feminella in Italy. 3. Asti, Cascine Bet. Photo G. Baldizzone; 4. Udine, Medeuzza, Confl. Torrente Torre-Natisone. Photo H. Deutsch.