Stigmella hahniella ( Wörz, 1937 ), Gerasimov, 1952

Stigmella hahniella ( Wörz, 1937) View in CoL

Figs 6–8 View Figures 3–10 , 32–39 View Figures 32–39 , 40 View Figure 40 , 41 View Figure 41

Nepticula hahniella Wörz, 1937: 290. Lectotype ♂ (designated by Schoorl et al. 1985: 80). Germany, Württemberg, Lemberg bei Zuffenhausen, 17 u 25.7. [19] 36, Sorbus torm., Wörz. Genitalia slide ♂ VU no. 0434, SMNS – Lepid. Präparat-Nr. 215 Eup. ( SMNS). Pinned with female paralectotype and 2 cocoons on same piece of polyporus (Fig. 6). View in CoL

Stigmella hahniella ( Wörz, 1937) Gerasimov 1952: 241. New combination. View in CoL

Stigmella hahniella View in CoL ; important citations: Schoorl et al. 1985; Johansson and Nielsen 1990; Puplesis and Schoorl 1994; Laštůvka and Laštůvka 1997; Navickaitė et al. 2014; Robrecht et al. 2024.

Recognition.

Adult (Figs 6–8 View Figures 3–10 ) (based on earlier descriptions ( Schoorl et al. 1985; Johansson and Nielsen 1990). Wingspan ♂ 3.5–4.1 mm, ♀ 3.5–4.0 mm. Antennae ♂ with 19–23 articles, ♀ with 17. Moth characterised by black frontal tuft, white collar; forewings proximal two-thirds or three-quarters bronze brown, sometimes with faint purple tinge; apical third or quarter dark brown with faint purple tinge; demarcation between basal and apical colours sharply or weakly defined; hindwing in male with dark androconial scales at costa and dorsum. Could be confused with other dark winged Stigmella species, but sharp demarcation on forewing usually diagnostic; only black headed S. anomalella (Goeze, 1783) look rather similar.

Male and female genitalia resemble closely those of Stigmella crataegella ( Klimesch, 1936) , see diagnosis and illustrations in Johansson and Nielsen (1990), Schoorl et al. (1985) and photos in Navickaitė et al. (2014).

Leafmines (Figs 32–39 View Figures 32–39 ). Egg always on leaf underside close to midrib or another main vein. Mine starts often very contorted, but also regularly as a rather straight gallery; frass completely brown or green, coiled throughout, filling mine completely or leaving narrow margins in latter part of mine.

Larva: green, head capsule and thorax pale, larva with dorsum upwards.

Cocoon: pale brown.

Distribution (Fig. 41).

Austria * ( Zimmermann 1944; Huemer 2013), Bosnia * (new record) (Fig. 37 View Figures 32–39 ), Croatia ( Laštůvka and Laštůvka 1997), Czechia ( Laštůvka 1994; Laštůvka and Marek 2002; Šumpich 2011), France * (new record) (Figs 36 View Figures 32–39 , 38 View Figures 32–39 ), Georgia (new record) (Fig. 39 View Figures 32–39 ), Germany ( Wörz 1937; Buhr 1940; Huber 1969; Robrecht et al. 2024), Hungary ( Szőcs 1965, 1977 b; Pastoralis and Szeőke 2011), Italy ( Huemer 2002), Russia * ( Wörz 1937), Slovakia ( Povolný and Gregor 1952; Patočka and Kulfan 2009), Slovenia * ( Lesar and Govedic 2010), Ukraine: Crimea ( Navickaitė et al. 2014). Records based on mines only are annotated with an asterisk.

Several records were doubted in the past, such as those from Germany: Schwaben (Bavaria) ( Huber 1969) and Austria ( Zimmermann 1944), leading to removal of the species resp. from the Bavarian and Austrian lists ( Huemer and Tarmann 1993; Haslberger and Segerer 2016). The Austrian record was later confirmed ( Huemer 2013), and we think that Huber’s record is rather likely, considering the current knowledge of its distribution.

The old records from Pfalz and Thüringen by Wörz (1937) also could well be correct as also the new records show. An old record from Neubrandenburg in Mecklenburg-Vorpommern ( Buhr 1940) has been completely overlooked until now, and on first sight might seem unlikely, so far north. However, Torminalis does occur in this region, but probably as rather isolated trees ( Welk et al. 2016). Confirmation of this record is therefore needed as it is not impossible that Stigmella oxyacanthella (Stainton, 1854) could occasionally occur on this host and make rather similar mines. The renewed search for Stigmella torminalis also led to the rediscovery of leafmines of S. hahniella in Germany in 2023, now in Rheinland-Pfalz, and independently by Maurizio König in Baden-Württemberg and Bavaria. In 2024 it was found in Hessen (Figs 33 View Figures 32–39 , 34 View Figures 32–39 , 40 View Figure 40 ) and Thüringen (Fig. 32 View Figures 32–39 ) and the species was discovered in North East France (Figs 36 View Figures 32–39 , 38 View Figures 32–39 ).

The record from Russia, Sochi by Wörz (1937) was overlooked in the Russian checklist ( van Nieukerken and Sinev 2019), but the new record from Georgia, confirmed by DNA barcodes, supports its occurrence in the Caucasus region.

Records from Denmark ( Jøker 1944) on Crataegus and various Sorbus species are certainly incorrect and were also not repeated in the catalogue of Danish leafmines ( Sønderup 1949).

Host plant.

Only known from Torminalis glaberrima. Szőcs (1973, 1981 a) reported leafmines from Sorbus aria and S. degenii Jáv. (now respectively Aria edulis and Karpatiosorbus degenii (Jáv.) Sennikov & Kurtto ). As these have not been confirmed by reared adults or DNA barcoding we consider them as unlikely, or at least unproven.

Life history.

Bivoltine. Larvae are found from May to June and from August to October. Adults emerged respectively from June to July, and in March (probably forced indoors). There are no records of wild caught adults, very few adults are known. Most recent records are based on vacated leafmines, with a few dead larvae (used for DNA barcoding), and only a single photo represents a living larva https://observation.org/observation/321525068/.

DNA barcoding (Fig. 53).

We have four DNA barcodes, two from adults from Czechia and two from dead larvae in Germany, all belong to BIN BOLD: ADF 7891, with a maximum distance of 0.8 %, and average distance of 0.47 %. One barcoded larva from Georgia falls in another BIN, BOLD: AEF 9699, at a distance of 2.4 % from the European ones.

Material examined.

Adults (Host always Torminalis glaberrima). – GERMANY • 1 ♀ Paralectotype, pinned together with Holotype; Baden-Württemberg, Zuffenhausen, Lemberg ; [48.82°N, 9.14°E]; 27 Jun. 1936; A. Wörz leg.; emerged 17–25 Jul. 1936; Genitalia slide: VU 0438 | SMNS 215 ; GART 00125 b ; SMNK GoogleMaps . – HUNGARY • 2 ♂; Badacsony ; [46.799°N, 17.495°E]; J. Szőcs leg.; emerged 27–28 Jun. 1968; Genitalia slide: VU 1757 ; HNHM GoogleMaps . • 1 ♂ 1 ♀; Budaörs ; [47.47°N, 18.94°E]; 12 Jun. 1974; A. Borkowski leg.; emerged 04 Jul. 1974; Genitalia slide: RJ 1475; personal collection R. Johansson GoogleMaps . • 2 ♂ 1 ♀; Budapest, Rupphegy ; [47.474°N, 18.978°E]; J. Szőcs leg.; emerged 06 Jul. 1974, 26–28 Jun. 1975; Genitalia slides: VU 1472 , VU 1477 , VU 1754 ; HNHM GoogleMaps .

Leafmines and larvae (Host always T. glaberrima, coll RMNH unless otherwise mentioned). – AUSTRIA • 4 mines; Niederösterreich, Gumpoldskirchen: Glaslauterriegel ; 48.0303°N, 16.2507°E; alt. 300–340 m; 01 Oct. 1983; van Nieukerken & Boomsma leg.; EventId: VU no. 83323 - H; ZMA.INS.MIG.12041 GoogleMaps . • 1 mine; Wien, Leopoldsberg, W. of Kahlenberg ; 48.2773°N, 16.34782°E; alt. 200–425 m; 25 Oct. 1983; E. J. van Nieukerken leg.; EventId: VU no. 83540 - H; RMNH.INS.39794 GoogleMaps . – BOSNIA-HERZEGOVINA • 2 mines (Fig. 37 View Figures 32–39 ); Republika Srpska, Brezičani, 5 km NW Prijedor ; 45.014°N, 16.669°E; 17 Oct. 1983; van Nieukerken & Boomsma leg.; EventId: VU no. 83494 - H; ZMA.INS.MIG.12042 GoogleMaps . – FRANCE • 1 mine; Meuse, Chauvoncourt, Pelouses et vallons forestiers de Chauvoncourt – N 2000; 48.88963°N, 5.50107°E; alt. 296 m; 26 Jul. 2024; E. J. van Nieukerken leg.; EventId: EvN no 2024065–2 H; RMNH.INS.38649 GoogleMaps . • 5 mines (Fig. 36 View Figures 32–39 ); Meuse, Pagny-sur-Meuse , Chapelle de Massey ; 48.66367°N, 5.7259°E; alt. 288 m; 25 Jul. 2024; E. J. van Nieukerken leg.; EventId: EvN no 2024060–1 H; RMNH.INS.38641 , RMNH.INS.38642 GoogleMaps . – GEORGIA • 1 larva, 3 mines (Fig. 39 View Figures 32–39 ); Adjara AR, Chikuneti ; 41.57028°N, 41.86278°E; alt. 880 m; 26 Sep. 2018; M. V. Kozlov & V. Zverev leg.; slide: RMNH.INS.31426 . P; RMNH.INS.31426 (larva); RMNH.INS.48098 , RMNH.INS.48099 (leafmines) GoogleMaps . – GERMANY • 1 larva, 4 mines; Baden-Württemberg, Königheim, Haigergrund ; 49.63765°N, 9.57404°E; alt. 329 m; 14 Aug. 2023; Maurizio König leg.; RMNH.INS.31739 (larva), RMNH.INS.49915 , RMNH.INS.49816 (leafmines) GoogleMaps . • 2 mines; Baden-Württemberg, Tauberbischofsheim, Hunsenberg ; 49.64794°N, 9.63004°E; alt. 285 m; 25 Aug. 2023; Maurizio König leg.; RMNH.INS.49917 GoogleMaps . • 1 larva, 1 mine (Fig. 35 View Figures 32–39 ); Baden-Württemberg, Schweigern ; 49.49514°N, 9.66925°E; alt. 265 m; 10 Aug. 2023; Maurizio König leg.; RMNH.INS.31738 (larva), RMNH.INS.49786 (leafmine) GoogleMaps . • 3 mines (Figs 33 View Figures 32–39 , 34 View Figures 32–39 ); Hessen, Diemelstadt-Rhoden, Feldflur am Schartenberg ; 51.4558°N, 8.9922°E; 15 Sep. 2024; Dieter Robrecht & Hubertus Trilling leg.; Collection D. Robrecht GoogleMaps .

Photographs examined (Host always T. glaberrima). – CZECHIA • 1 ♂ 1 ♀ (specimens barcoded); Moravia, Valtice ; 48.7368°N, 16.7349°E; 18 Aug. 2006; A. Laštůvka leg.; emerged Mar. 2007; RMNH. 5012142, RMNH. 5012141; Collection A. Laštůvka GoogleMaps . • 1 ♀ (barcoding failed); Moravia, Němčičky ; 48.9478°N, 16.8272°E; 13 Aug. 2000; A. Laštůvka leg.; emerged Mar. 2001; RMNH. 5012143 ; Collection A. Laštůvka GoogleMaps . • 1 ♂ (Fig. 7 View Figures 3–10 ); Moravia, Prostejov ; 49.47°N, 17.1°E; A. Laštůvka leg.; emerged Mar. 2001; Collection A. Laštůvka GoogleMaps . • 1 ♀ (Fig. 8 View Figures 3–10 ); Moravia, Milovice ; 48.849°N, 16.7°E; A. Laštůvka leg.; emerged Mar. 2001; Collection A. Laštůvka GoogleMaps . – GERMANY • 1 mine; Hessen, Diemelstadt-Rhoden, Feldflur am Schartenberg ; 51.4558°N, 8.9922°E; 13 Sep. 2024; Hubertus Trilling leg.; https://observation.org/observation/327910701/ GoogleMaps . • 1 mine; Rheinland-Pfalz, BIT Hüttingen an der Kyll ; 49.9608°N, 6.5947°E; 26 Aug. 2023; Alexander Franzen leg.; https://observation.org/observation/285968698/ GoogleMaps . • 1 mine; same locality data as previous; 07 Sep. 2024; Alexander Franzen leg.; https://observation.org/observation/327389394/ GoogleMaps . • 2 mines; Rheinland-Pfalz, BIT Messerich ; 49.94597°N, 6.45992°E; 17 Sep. 2023; Alexander Franzen leg.; https://observation.org/observation/288425626/ GoogleMaps . • 1 larva (Fig. 32 View Figures 32–39 ); Thüringen ,, KYF Ochsenburg ; 51.3873°N, 11.0389°E; 27 Jul. 2024; Alexander Franzen leg.; https://observation.org/observation/321525068/ GoogleMaps . – HUNGARY • 1 mine; Budakeszi, Hársbokorhegy ; [47.535°N, 18.922°E]; Aug. 1952; L. Gozmány leg. GoogleMaps ; Budapest. • 9 mines [on 3 herbarium sheets]; Nadap ; [47.26°N, 18.61°E]; 12–13 Aug. 1951, 14 Sep. 1951, 12 Oct. 1951; L. Gozmány leg.; HNHM GoogleMaps .

Additional observation. – SLOVAKIA • Larva, leafmines; Banská Bystrica, Šiatorská Bukovinka ; [48.1653°N, 19.7957°E]; 07 Sep. 2023, A. Laštůvka & Z. Laštůvka leg. GoogleMaps