Trifurcula (Glaucolepis) lituanica Ivinskis

Ivinskis, Povilas, Van, Erik J. & Rimsaite, Jolanta, 2012, Trifurcula (Glaucolepis) lituanica sp. nov., an unexpected new stem-miner on Salvia pratensis occurring in eastern Europe (Lepidoptera: Nepticulidae), Zootaxa 3570, pp. 41-55 : 43-46

Trifurcula (Glaucolepis) lituanica Ivinskis & van Nieukerken sp. nov.

( Figs. 1, 2 , 5–10 , 14–18 , 23–32 )

Trifurcula lituanica Ivinskis sp. n. in litt.: Ivinskis 2004: 33. [Nomen nudum, no description]. Fedalmia dubiella ; partim: Klimesch 1961: 764; Klimesch 1990: 44 [misidentification]

Type material. Holotype 3: LITHUANIA, Ringovė, 55° 02’ 59.6”N 23° 31’ 18.1”E, stemmines on Salvia pratensis , 19.vii.1999, e.l. 21–27.iii.2000, P. Ivinskis, Genitalia slide EJvN4210, RMNH.INS.24210 (coll. Leiden).— Paratypes: 8 3, 4 Ƥ. AUSTRIA: 13, Umgebung von Linz, Steyregg, 12.v.1947, J. Klimesch, genitalia slide RJ1539; 13, Linz, Pfenningb[er]g, 25.iv–5.v.1948, J. Klimesch, genitalia slide EJvN4269; 2Ƥ, Umgebung von Linz, Pfbg [Pfenningberg], 3.v.1948, J. Klimesch, genitalia slide EJvN4267 (all coll. Munich).— GREECE: 13, Piería, Leptokaria, 15 km W, Olympos, 750 m, 21–23.v.2001, J. Junnilainen, genitalia slide EJvN3398 (coll. Junnilainen).— LITHUANIA: 43, 2Ƥ, data as holotype, emerged 21.iii–12.iv.2010, Genitalia slides 3 Tr.01, EJvN3721, Ƥ BJ1530, EJvN4266 (coll. Vilnius and Leiden).— SLOVENIA: 13, Prje [recte Brje, Ajdovščina], 28.iv.2007, J. Junnilainen, genitalia slide EJvN4277 (coll. Junnilainen).

Non type material: BULGARIA: Blagoevgrad Province, Ilindentsi, 41°40’18,6”N 23°16’55,96”, 880 m, 7.viii.2012, stem-mines with larvae on Salvia pratensis, P.Ivinskis, N. Savenkov (coll. Vilnius).— CZECH REPUBLIC: 1Ƥ, Moravia, Klentnice, 25.viii.1997, A. Laštůvka [watercolour and drawing of genitalia examined]; 9 larvae, 1Ƥ, Moravia, Čelechovice na Hané, 5–14.vii.2012, emerged 14.vii.2012, A. Laštůvka; 13, Czech Republic, Moravia mer., Bořetice, Zázmoníky Nature Reserve, 21.iv.2011, J. Liška (all coll. Laštůvka) [data received from A. and Z. Laštůvka].— LITHUANIA: Kaunas, western part of city, southern valley of river Neris, 54° 54’ 50.0”N 23° 52’ 46.1”E, 15.vii. 2008, 2 stem-mines with larvae on Salvia pratensis, P. Ivinskis (coll. Vilnius).— ROMANIA: 2 larvae in ethanol 96% ( RMNH.INS.18487, 18488), stem-mines, Sibiu prov., Brădeni, 3 km N, 563 m, 46.1073 N, 24.8408 E, limestone grassland on hill, 30.vii.2011, stem-mines on Salvia pratensis , E.J. van Nieukerken (coll. Leiden).

Diagnosis. Trifurcula lituanica resembles T. headleyella closely: males especially can hardly be separated externally, although T. lituanica has a more pronounced shining basal area of the forewing. The female does not differ externally from the male, in contrast to T. headleyella , where the female has a completely black head (ferruginous in lituanica ), and a very strongly metallic basal area contrasting with almost black distal part, whereas the basal area in T. lituanica is not strongly metallic. The male genitalia are best recognized by the aedeagus (phallus), which has just one short cornutus in T. headleyella , but several cornuti in T. lituanica , of which the basal one is also longer than in headleyella . The valva is narrower than in T. headleyella . The female genitalia are easily recognised by the ductus spermathecae with 7 convolutions against only 2–3 in T. headleyella .

Description. Male ( Fig. 1 ): Forewing length 2.2–2.4 mm, wingspan 4.7–5.0 mm. Head: frontal tuft pale fuscous, scape white, antenna with 37–43 segments. Thorax and forewing dark fuscous, basal third of forewing covered with grey shining scales, demarcated from darker outer part; just beyond middle two opposite silvery white metallic spots, separated by 2–3 dark scale rows; cilia line present, cilia grey, underside dark fuscous. Hindwing grey on both sides, underside in apical third with “velvet” patch of raised scales. Abdomen fuscous, with paired tufts on tergites 6–8.

Female ( Fig. 2 ). Forewing length 2.0– 2.4 mm, wingspan 4.6–5.0 mm, antenna with 31–34 segments. External characters as in male, velvet patch absent. Abdomen slightly pointed at tip.

Male genitalia ( Figs. 5–10 ). Capsule length 265–315 µm. Vinculum narrowed anteriorly, with clear concavity (bilobed). Tegumen pointed. Uncus pointed. Gnathos with large triangular, rounded central element. Valva length 135–170 µm, approximately triangular, distal process straight, pointed. Transverse bar of transtilla absent. Aedeagus (phallus) 295–335 µm long, near phallotrema two lateral rows of about 7–10 spines (not cornuti, Fig. 9 ), vesica with long, slightly curved, basal cornutus of ca. 110–145 µm long, and group of ca 60–70 µm long needle like cornuti apically ( Fig. 10 ), close to phallotrema spines.

Female genitalia ( Figs. 14–18 ). Total bursa length ca 790–870 µm. T8 with scales and ca. 6–7 setae at either side, anal papillae pointed, with 26–30 setae in total. Posterior apophyses about twice as long as anterior ones. Ductus spermathecae with relatively long straight part and ca. 6.5–7.5 convolutions. Corpus bursae covered with small pectinations, and indistinct paired reticulate signa of about 225–300 µm long.

Larva yellow, head capsule pale brown. Feeding with dorsum upwards, final instar about 5 mm long.

Cocoon ( Figs. 24, 26–28 ). Dark brown, 4 x 2 mm. Upper side covered with plant epidermal tissue.

Biology. Host plant: Salvia pratensis L. ( Lamiaceae ). Egg deposited on the stem. Stem-mine ( Figs 23–25 , 29 ) most frequently in the lower parts of the stem, confined to one internode on one side of the stem, or running along a corner of the square stem. Mine a gallery with a total length of up to 23 cm, better visible on the green plant, much obscured in dried material. The mine starts usually upwards and goes back down after a u-turn. The frass is concentrated in the midline. The epidermis over the mine is elevated compared to the rest of the stem. The mine widens gradually in the second part and can occupy up to two thirds of the stem width. The larva eats out a rather wide semi-circular emergence slit, and then prepares the cocoon on the inner side of the epidermis covering the final part of the mine, near the slit. The cocoon is clearly visible within the epidermis. We found one to four mines per stem.

Voltinism. Univoltine. Larvae and cocoons found between 15 July and 7 August. From these larvae, adults emerged the next spring, but a single female in Moravia emerged immediately in July. Adults have been found in the wild from late April to mid May, usually earlier than T. headleyella , but another female in the Czech Republic was found late August, although the Salvia stems at that time are mostly dried out. These Czech females may indicate a partial second generation.

Distribution ( Fig. 32). Up to now isolated records are known from Lithuania (Kaunas district, two localities 40 km apart), the Czech republic (two localities in Moravia), Austria, Slovenia, Romania, Bulgaria and Greece. To be expected in a larger part of Europe with the host. Salvia pratensis occurs widely in Europe, with a northern border through the lowlands of the Netherlands, northern Germany and Poland to Russia ( Hedge 1972). The Lithuanian locality is close to the northern border of the plant’s distribution area.

Habitat and conservation ( Figs. 30–31 ). In Lithuania T. lituanica has been found only in the valley of the river Nemunas and its tributary Neris, where it occurs in flood plain meadows. Salvia pratensis occurs here on the slightly higher slopes of the floodplain. This plant is protected in Lithuania by law and included in the Red data book ( Rašomavičius 2007). In Austria there is probably only one locality, the Pfenningberg in the municipality of Steyregg. The locality is on the western slopes of the Pfenningberg, close to the Danube ( Klimesch 1990). In Romania the mines were found in a sunny limestone grassland on top of a hill. On the same plants of Salvia in Romania, we observed different stem-mines nearer the tip of the stem, belonging to an agromyzid, probably Ophiomyia labiatarum Hering, 1937 ( Hering 1957) . The Greek locality (15 km W of Leptokaria) is an open mountain meadow with a rich vegetation including Salvia pratensis , and the Slovenian locality is a dry meadow with Sanguisorba officinalis in a river valley (Jari Junnilainen pers. comm.). Although the host is a widespread species, its occurrence in nutrient-poor grasslands in river valleys and on limestone make it vulnerable for habitat change: natural succession, afforestation, fertilizers and poor management are a risk for such vegetation types, and in general modernisation of agriculture in EU countries has often led to the loss of such habitats. Currently the species seems not to be threatened, but could become vulnerable when land management in eastern European countries changes too fast on a large scale.

DNA barcodes. For three specimens the DNA barcode has been analysed, two complete ones of one male paratype (RMNH.INS.23721, Genbank accession number JX261901 ) and a larva from Romania (RMNH.INS.18487, Genbank JX261899 ), differing only in one nucleotide, and an incomplete sequence of the holotype of 308 nucleotides (Genbank JX261900 ), identical to that part in the other two (see appendix)

Etymology. Trifurcula lituanica : an adjective, named after the country where the species’ life history and hostplant were discovered.

Figures

FIGURE 29. Trifurcula (Glaucolepis) lituanica, life history.

FIGURES 1 – 4. Trifurcula (Glaucolepis) species, adult habitus, dorsal. 1. T. lituanica, male holotype; 2. T. lituanica, female paratype, Austria; 3. T. headleyella, male, France, Génicourt-sur-Meuse, RMNH. INS. 24212; 4. T. headleyella, female, Germany, Marmagen EvN 95068. Scales 1 mm.

FIGURES 5 – 10. Trifurcula (Glaucolepis) lituanica, male genitalia in ventral view. 5 – 6. Holotype, RMNH. INS. 24210; 8. Paratype Lithuania, RMNH. INS. 23721. 7, 9 – 10. Paratype Slovenia, slide EJvN 4277, 9 showing phallotrema spines, 10 cornuti at slightly deeper level. Scales 100 μm (5 – 8), 50 μm (9 – 10).

FIGURES 14 – 18. Trifurcula (Glaucolepis) lituanica, female genitalia. Paratypes, Lithuania, slide EJvN 4266 (14, 16), Austria, slide EJvN 4267 (15, 17 – 18). Scales 200 μm (14 – 15), 50 μm (16 – 18).

FIGURES 23 – 28. Trifurcula (Glaucolepis) lituanica, life history: stemmines and cocoons on Salvia pratensis. 23 – 24. Lithuania, Ringovė, 17. viii. 2005; 25 – 28, Romania, Brädeni, 30. vii. 2011 (photos taken later), in 25 the larva has been taken out of the mine. Scales 2 mm.

FIGURES 30 – 31. Trifurcula (Glaucolepis) lituanica, habitat in Lithuania, Ringovė, 17. viii. 2005.