Coptodisca lucifluella, Clemens, 1860

Takacs, Attila, Szaboky, Csaba, Toth, Balazs, Bozso, Miklos, Kutas, Janos, Molnar, Szilard & Richter, Ignac, 2020, Nearctic walnut leafminers invade Europe: first Coptodisca lucifluella (Clemens, 1860) and now Coptodisca juglandiella (Chambers, 1874) (Lepidoptera, Heliozelidae), Nota Lepidopterologica 43, pp. 77-93 : 77

Coptodisca lucifluella

Morphology and recorded host plants.

Adult. External characters (Figs 2 , 4 ). Length of forewing 1.5-1.8 mm including fringe. Head silvery grey, rest of body dark silvery grey. Basal half of forewing silvery grey, with two triangular patches present at distal thirds of costa and dorsum, white with black border on each side. Area between silvery grey basal field and tornal patch dark fuscous. Tornal patch broad, especially at base (Fig. 2 ).

Genitalia (Figs 7 , 8 ). Male genitalia with five sensilla on pectinifers of both valvae (n = 2; right valva of an additional specimen lost, left valva with five teeth), elsewhere 5-7 sensilla ( Bernardo et al. 2015, see fig. 7). Phallus with two rows of spines. Female genitalia with six oviscapt teeth, a pair of large ones anteriorly, posterior ones forming a wide, slightly indented apex (Fig. 8a ). Corpus bursae rather pyriform, with neither scobinations nor signum (Fig. 8b ).

Mine. This species prepares blotch mines visible on both sides of the leaf (Figs 9 , 10 ). Mines are always situated between lateral veins and never traverse them. The shape of mines is rather elongate and angular (Fig. 10 ), average size 8 mm × 5 mm. Mines are positioned close to lateral veins, equally distributed from the midrib to the edge of the leaflet (Fig. 12 ). The frass of C. lucifluella is visible from both sides as it is dispersed in the mine (Fig. 9 ).

Larva. Mature larva 2.5 mm long, monochromatic rusty brown in colour (Fig. 14 ).

Case. Prepared from an oval-shaped area of the leaflet, severed from the leaf by chewing the epidermis on both sides around this piece (Fig. 19 ). Then the oval plates are attached with silk along the edges, forming an oval-shaped shield, which is somewhat more elongate than the original leaf pieces, 2.9 mm long and 1.3 mm wide (Fig. 18 ).

Pupa. Fresh pupa pale yellow, then becoming dark yellow, 2.7 mm long (Fig. 17 ).

Host plants. Host plants of C. lucifluella in Hungary are Juglans regia , Carya cordiformis and Pterocarya fraxinifolia (new hostplant record).

Remarks.

Genitalia images prepared by us have a resolution too low for publication, but the above-mentioned characters are still observable. We illustrate here the genitalia with images kindly sent by Erik J. van Nieukerken (Fig. 7a, b ; partly from Bernardo et al. 2015).

Figures

Figures 1 - 4. External morphology of Coptodisca species from Hungary. 1. Habitus of C. juglandiella male: Somogy county, Oereglak, reared from Juglans nigra (coll. Csaba Szaboky), 2. C. lucifluella female: Zala county, Zalaszentgrot, reared from Juglans regia (coll. HNHM). 3. Denuded right wings of C. juglandiella (TB 1903 f). 4. Denuded right wings of C. lucifluella (TB 1902 m). 1, 2: photo by Attila Takacs, 3, 4: photo by Balazs Toth. Scale bars: 0.5 mm.

Figures 7, 8. Genitalia of Coptodisca lucifluella. 7 a. Enlarged view of pectinifers of male genitalia, with five sensilla on left valva and six sensilla on right valva. Ventral view (from Bernardo et al. 2015, Italy, reared from J. regia, slide No. EvN 4462, coll. RMNH) 7 b. Male genitalia with six sensilla on left valva and seven sensilla on right valva, semi-ventral view, phallus at right in ventral view (photos of male genitalia provided by Erik van Nieukerken, photograph of phallus from Bernardo et al. 2015, U. S. A., moth reared from Carya tomentosa, slide No. EvN 4458, coll. USNM). 8 a. Enlarged region of oviscapt of female genitalia (Hungary, Pecs, 02. vi. 2018, slide No. GP 29762 IgR). 8 b. Female genitalia (data as 8 a). 7 a, 7 b: photo by Erik van Nieukerken, 8 a, 8 b: photo by Ignac Richter. Scale bars: 0.1 mm (7 a, 7 b, 8 b), 0.05 mm (8 a).

Figures 9 - 13. Blotch mines of Coptodisca species in Hungary. 9. Mine of. C. lucifluella with larva, frass dispersed. 10. Another mine of. C. lucifluella with larva, higher magnification than 9. Both mines on J. regia, Tornyiszentmiklos, 27. viii. 2017. 11. Mine of C. juglandiella with larva, frass covered by a small area of the upper parenchyma. On J. nigra, Fejer county, Alcsutdoboz, 21. v. 2018. 12. Vacated mines of C. lucifluella, scattered throughout the leaflet. On J. regia, Fejer county, Lovasbereny, 14. x. 2019. 13. Vacated mines of C. juglandiella, close to midrib. On J. nigra, Fejer county, Alcsutdoboz, 19. viii. 2019. Photos by Miklos Bozso. Scale bars: 2 mm (9 - 11), 20 mm (12, 13).

Figures 14, 15. Mature larvae of Coptodisca species from Hungary. 14. C. lucifluella, on J. regia, Fejer county, Lovasbereny, 15. x. 2019. 15. C. juglandiella, on J. nigra, Fejer county, Alcsutdoboz, 29. viii. 2018. Photos by Attila Takacs. Scale bars: 0.5 mm.

Figures 16 - 19. Parasitoid wasp, cases and pupae of Coptodisca species from Hungary. 16. Unidentified Closterocerus Westwood, 1833 species, female, reared from C. juglandiella. Alcsutdoboz, 22. vi. 2018. 17. Pupa of C. lucifluella, in an opened case from J. regia, Zala county, Tornyiszentmiklos, 27. viii. 2017. Photo by Miklos Bozso. 18. Case with exuviae, C. juglandiella, from J. nigra, Fejer county, Alcsutdoboz, 29. viii. 2019. 19. Case just finished, C. lucifluella, on J. regia, Zala county, Tornyiszentmiklos, 27. viii. 2017. Photos by Attila Takacs. Scale bars: 0.5 mm (16 - 18), 5 mm (19).