Argyresthia (Argyresthia) atlanticella Rebel, 1940

Pérez Santa-Rita, Jose V., Baixeras, Joaquin & Karsholt, Ole, 2020, The enigmatic case of the genus Argyresthia in the Azores Islands (Lepidoptera Argyresthiidae), Zootaxa 4789 (1), pp. 217-232 : 219-224

Argyresthia (Argyresthia) atlanticella Rebel, 1940

( Figs 1 , 3–7 , 9–20 , 24–29 )

Argyresthia atlanticella Rebel, 1940: 37 , pl. 2, figs 1–2.

Argyresthia (Argyresthia) minusculella Rebel, 1940: 38 , pl. 2, fig. 6, syn. n. (see the Discussion).

Tinea poecilella Rebel 1940: 46 , pl. 2, fig. 7, syn. n. (see the Discussion).

Type material examined. A. atlanticella Rebel. Lectotype (here designated) ♀:“ Azores Pico Madalena 6.-9.vii. Storå ” “3211” “ Argyresthia atlanticella ♀ Type Rbl.” “Mus. Zool. H:fors Spec. typ. No. 7253 Argyresthia atlanticella Reb. ” “genitalia slide ♀ no 4 Not ♂ [vii.1983 J. D. Bradley]” “Mus. Zool. Helsinki Loan No. L1150” “Mus. Zool. Helsinki Loan Nr. L 01 - 123” “photographed by A. Illum, 2018” ( MZH) ( Fig. 3 ).

Paralectotype, sex unstated (abdomen and hindwings missing): “Azores Flores Vales vi. Storå” ”4324” “Mus. Zool. H:fors Spec. Paratyp. No. Argyresthia atlanticella Reb ” “Mus. Zool. Helsinki Loan Nr. L 01 - 124” ( MZH) . Paralectotype, ♀, “Azores Flores Caldeira Seca 9. 21.vi. Storå” “3955” “ Argyresthia atlanticella Type Rbl” “Mus. Zool. H:fors Spec. typ. No. 7252 Argyresthia atlanticella Reb. ” “Mus. Zool. Helsinki Loan Nr. L 01 - 125” ( MZH) . Paralectotype, ♀, “Azores Flores Vales vi. Storå” “5284” “ Argyresthia atlanticella Type Rbl” “Mus. Zool. H:fors Spec. typ. No. 7251 Argyresthia atlanticella Reb ” “Mus. Zool. Helsinki Loan Nr. L 01 - 126” ( MZH). A. minusculella Rebel . Syntype, ♂: “Madeira Funchal 1.–8.v. Storå” “1057” “ Argyresthia minusculella Type Rbl” “Mus. Zool. H:fors Spec. typ. No. 7254 Argyresthia minusculella Reb ” “slide ♂ No. 8 [viii.1983 J. D. Bradley]” “Mus. Zool. Helsinki Loan No. L160” “Mus. Zool. Helsinki Loan Nr. L 01 - 122” ( MZH). Fig. 5 . Syntype ♀: “ Azores Pico Lagoa do Calado 7.vii. Frey ” “1569” “ Argyresthia minusculella Type Rbl ” “Mus. Zool. H:fors Spec. typ. No. 7255 Argyresthia minusculella Reb. ” “slide ♀ no 9 [viii.1983 J. D. Bradley]” “Mus. Zool. Helsinki Loan No. L159” “Mus. Zool. Helsinki Loan Nr. L 01 - 121” ( MZH). Fig. 6 . Tinea poecilella Rebel . Holotype ♀: “ Azor. S. Miguel Furnas 19.–24.v. Storå” “ Tinea poecilella Type + Rbl” “Mus. Zool. H:fors Spec. typ. No. 7266 Tinea poecilella Reb. ” “genit slide no 3 [vi.1983 J. D. Bradley]” “hindwings + abdomen glued!!” “Mus. Zool. Helsinki Loan No. L1157” “Mus. Zool. Helsinki Loan Nr. L 02 - 1” “photographed by A. Illum, 2018” ( MZH), ( Fig. 4 ) .

Non type-material examined. Portugal: Azores, Corvo, Caldeirão , 500m, 39°42’7.49”N; 31° 5’52.95”W, 10 Jul 2015 (1♂, 2♀), O. Karsholt, ZMUC . Faial, Caldeira, 4 Jul (1♂), Storå, MZH ; Horta , 40m, 38°31’52.08”N; 28°37’49.87”W, 13–14 Jul 2015 (1♂), O. Karsholt, ZMUC . Flores, 2km S Fajã Grande, Aldea da Cuada , 125m, 39°26’24.40”N; 31°15’26.55”W, 6–12 Jul 2015 (1♂), O. Karsholt, ZMUC ; 3km WNW Lajes das Flores, 300m, 39°23’33.24”N; 31°10’40.08”W, 07 Jul 2015 (3♂, 7♀) ; 09 Jul 2015 (3♂, 1♀), O. Karsholt, ZMUC . Graciosa , 3km NW São Mateus, 300m, 39° 3’22.09”N; 27°59’33.42”W, 16–18 Jun 2018 (10♂, 25♀), O. Karsholt, ZMUC ; São Mateus , 3m, 39°3’22.09”N; 27°59’33.42”W, 17 Jun 2018, (1♀), O. Karsholt, ZMUC . Pico , 5km NW Lajes do Pico, 20m, 38°23’52.20”N; 28°11’58.61”W, 03–05 Jul 2015 (1♂, 2♀), O. Karsholt, ZMUC ; 5 km W São Roque do Pico , 400 m, 38°30’49.20”N; 28°21’11.41”W, 29 Sep 2004 (2♂), L. Aarvik, M. Fibiger & D. Nilsson, NHMO ( GS 1411 Aarvik) ; 7 km E Madalena , 260 m, 38°31’19.12”N; 28°28’34.47”W, 26–27 Sep 2004 (1♂, 2♀), L. Aarvik, M. Fibiger & D. Nilsson, NHMO ; above São Caetano, 300m, 38°26’18.35”N; 28°25’21.90”W, 5 Jul 2015 (2♂, 1♀), O. Karsholt, ZMUC ; Landroal , 950 m, 28–30 Sep 2004 (1♂), L. Aarvik, M. Fibiger & D. Nilsson, ZMUC ; Redondo, 950 m, 26–30 Sep 2004 (7♂, 6♀), L. Aarvik, M. Fibiger & D. Nilsson, NHMO ( GS 1426 Aarvik). São Miguel, flow- ers of Morella faya , 04 Jun 1992 (1♂, 1♀), V. Vieira, ZMUC ; flowers of Vaccinium cylandriaceum , 15 Jun 2005 (2♂, 1♀), R.H. Heleno, ZMUC ; above Lagoa Azul , 300m, 37°51’29.21”N; 25°47’49.75”W, 04 Apr 2009 (2♂, 3♀), O. Karsholt, ZMUC ; Furnas, Lagoa das Furnas , 40m, 37°44’58.6”N; 25°20’23.7”W, 22 Jun 2017 (1♀), J.V. Pérez Santa-Rita, ICBiBE ; Lagoa de Santiago , 3–7 Jul 2008 (18♂, 55♀, 19 exx), B. Baungaard, ZMUC ; Lombadas at Serra Escuro , 550m, 37°46’32”N; 25°27’31”W, 16–18 Nov 2008 (1♂, 9♀), B. Skule, ZMUC ; Pico da Vara , Tron- queira, 05 Sep 1999 (2♀), H. Enghoff, ZMUC ; Planalto dos Graminhais , 800m, 37°48’0.68”N; 25°14’1.96”W, 05 Apr 2009 (1♂, 2♀), O. Karsholt, ZMUC ; Ponta Delgada , 3–7 Jul 2008 (1♂), B. Baungaard, ZMUC ; Serra da Tronqueira , 675m, 37°47’11”N; 25°11’39”W, 15 Nov 2008 (1♂, 2♀), B. Skule, ZMUC , Sete Cidades, 17 May (1♀), Storå, genitalia slide 1/ 23 Mar 2001 Kullberg, MZH . Santa Maria, above Maia , 240m, 36°56’19.52”N; 25° 1’24.04”W, 25 Jul 2010 (1♂), O. Karsholt, ZMUC ; Malbusca , 200m, 36°56’22.50”N; 25° 4’23.03”W, 26–28 Jul 2010 (1♂, 4♀), O. Karsholt, ZMUC ; Pico Alto , 550m, 36°58’53.02”N; 25° 5’31.01”W, 26 Jul 2010 (1♂), O. Kar- sholt, ZMUC ; Vila do Porto , 100m, 36°58’22.15”N; 25° 9’40.37”W, 22–27 Jul 2010 (7♂, 18♀), O. Karsholt, ZMUC . Terceira, Lagoa do Negro, Mistérios Negros , 637m, 38°44’04.3”N; 27°17’02”W, 02 Sep 2017 (6♂, 2♀), J.V. Pérez Santa-Rita, ICBiBE ; Angra do Heroísmo , near Monte Brasil, 29m, 38°39’01.84”N; 27°13’23.33”W, 30 Aug 2017 (3♂, 1♀), J.V. Pérez Santa-Rita, ICBiBE ; Serra de Santa Bárbara , 900–1000m, 38°43’47.37”N; 27°19’16.04”W, 12 Jun 2018 (2♂, 6♀), O. Karsholt, ZMUC (one female in Fig. 7 ) ; Santa Bárbara, near Centro de Interpretação Ambiental , 507m, 38°42’42.32”N; 27°19’27.91”W, 23 Jul 2017 (1♂, 2♀) J.V. Pérez Santa-Rita, ICBiBE ; Serreta, Miradouro do Raminho, 146m, 38°46’48.88”N; 27°21’24.33”W, 19 Nov 2017 (2♂, 1♀), J.V. Pérez Santa-Rita & M. Villar de Pablo , ICBiBE .

Molecular characterisation. We were able to obtain 12 sequences of COI. Accession numbers are compiled in Supplementary Table S1.

Redescription. Head: frons with appressed dark brown scales, forwardly directed; vertex with erected scales concolorous with mesonotum, darker between the eyes. Labial palpus slender, gently upcurved not surpassing vertex, smoothly scaled, concolorous with frons, sometimes light brown with some black, lighter scales in inner surface; vom Rath’s organ opening subterminal. Antennae indistinctly ringed black and dark grey to white. Proboscis developed.

Thorax: general colour brown; tegulae concolorous with forewing costal area, mesonotum from white to dark brown, concolorous with vertex and forewing basal dorsal block. Wingspan 7.0– 8.6 mm (x = 7.6; n = 20) in males, 7.0– 8.4 mm (x = 7.8; n = 10) in females. Venation typical for Argyresthia species but variable in forewing ( Fig. 1 ); Sc to ca. 0.5–0.4 of costa; pterostigma well developed, between Sc and R 1; R 1 arising from basal 0.5 to 0.3 of discal cell; chorda obsolescent or absent; R 2, R 3 and R 4 to costa; R 5 to costa or dorsum, separated or stalked with R 4; M-stem obsolescent; rest of venation slightly variable. Upperside forewing pattern ( Figs 9–20 ) highly variable, from practically unicolorous ( Fig. 18 ) to conspicuously banded and complex ( Figs 9–10 ); ground colour brown with scattered white, grey and black scales; costa (especially between Sc and R 1), dorsum and fringes often densely strigulated; pattern in basal third – from base of wing to point where Sc meets the costa – ill-defined, unicolorous ( Fig. 18 ) or variably brown anteriorly and white ( Fig. 11 ) or dark dorsally ( Fig. 17 ); two dark bands sometimes detectable on the wing; more basal band ( Fig. 10 ) between basal 0.3 of costa and basal 0.25 of dorsum; frequently this band medially suffused; more apical band extends between 0.6 of costa and 0.5 of dorsum, darker and broader than basal one, it is the most conspicuous element of the wing if completely expressed ( Figs 10–11 ); dorsal fragments remain more frequently than costal ones ( Figs 12–14 ) but may be also completely obliterated ( Figs 15–17 ); between these two bands a light narrow band may extend ( Fig. 10 ), although in many cases it is expressed as simply a dorsal strigulated white blotch ( Figs 9–10 & 12 ); a second light band poorly developed after the second dark band ( Figs 10–12 & 14 ); apical pattern ill-defined consisting of mixture of dark and light scales strigulated on fringes; all the elements of the wing pattern may diffuse being replaced by a rather longitudinal pattern ( Figs 15–17 ) dorsally white or unicolorous ( Figs 18–20 ); fringe from end of pterostigma to some point between CuP and 0.5 of dorsum. Underside brown, unicolorous, unmarked. Hindwing upperside and underside light grey, darker towards apex, with grey fringe.

Abdomen: dark brown, more or less concolorous with hindwings. Males with complex segment VIII formed by lateral lobes projected posteriorly over valvae. Coremata developed as a pair of lateroventral pockets between external side of valvae and internal side of lateral lobes of segment VIII, occupied by tuft of long scales eight times longer than width of valva. Ventral V-shaped sclerite developed ( Fig. 25 ). Females with segment VII unmodified.

Male genitalia (based on 10 preparations) ( Figs 24, 26–27 ) with tegumen well sclerotized; pedunculi long projected ventro-anteriorly into a pair of apodemes (peduncular appendices); another pair of short apodemes projected anteriorly at level of dorso-caudal angles of valvae (posterior appendices); uncus undeveloped; anal cone membranous, elongate, confluent with top of tegumen, broadest basally; socii complex, covered by nine fringed scales regularly distributed on surface; gnathos linear, weakly sclerotized; transtilla not detected; valva subsemicircular, upcurved, twice as long as wide, slightly sclerotized; costa straight with distal slit; cucullus rounded, covered with long hairs in disc; sacculus slightly convex, glabrous; no appreciable pulvinus; vinculum as rectangular plate, ventral edge strongly sclerotized; juxta subrectangular sclerotized simple plate; saccus reduced; phallus long, slender, more than 0.3 length of valva, coecum penis reduced, distal part of phallus without denticles (acanthae); endophallus with densely plicate membrane; long, narrow sclerotized plate as cornutus (no deciduous cornuti detected in corpus bursae).

Female genitalia (based on 5 preparations) with simple sterigma ( Fig. 28 ); antrum spiny, funnel-shaped; lamella postvaginalis covered with micro-denticles (acanthae); colliculum as ventrally incompletely sclerotized ring; ductus bursae long (approximately 1800 µm) and narrow, approximately posterior half internally smooth, anterior half strongly roughened, densely covered with micro-denticles (ctenidia); ductus seminalis originating from distal third of ductus bursae; bulla seminalis not detected; corpus bursae nearly ovate, moderately covered by micro-denticles (ctenidia) from cervix to surroundings of signum, continuous with anterior part of ductus bursae; a single spermathopore extracted from corpus bursae (n = 2); spermatophore corpus irregular, with rather strong walls; signum well developed, strongly sclerotized, T-shaped ( Fig. 29 ), formed by internally concave basal elongate plate oriented longitudinally, anterior end invaginated in hollow bifid transversal serrated process, posterior end of the plate as simple short straight hollow invagination; anal papillae sparsely covered by long hairs; length of anterior apophysis ca. 2.0 the length of posterior apophysis.

Biology. The life cycle has been described in detail by Silva et al. (1995). The larvae feed on Erica azorica Hochst ex Seub. and Vaccinium cylindraceum Sm. (both Ericaceae ) and Morella faya (Aiton) Wilbur (= Myrica faya Aiton ) ( Myricaceae ) which are all native to the Azores. The species is apparently multivoltine, and Silva et al. (op. cit.) stated that “Adults and larvae … were found throughout the year”. The moths examined by us were collected in April (n = 8), June (n = 47), July (n = 141), August (n = 4), September (n = 29) and November (n = 16), but that may reflect that few lepidopterists are active in the Azores during winter. The larvae seem to prefer feeding on flowers and green fruits of their host plants (Silva et al. op. cit.). In captivity, larvae accepted Potentilla erecta (L.) Raeusch. ( Rosaceae ) and Persicaria capitata (Buch.-Ham. ex D.Don) H.Gross ( Polygonaceae ) (Silva et al. op. cit.). Records of A. atlanticella larvae feeding on Juniperus brevifolia are probably referable to A. brumella sp. n. (see under that species). Argyresthia atlanticella occurs both in laurisilva habitats and in different kinds of disturbed habitats with Morella , Erica or Vaccinium .

Distribution. Endemic to the Azores Islands.

Remarks. Records from outside of the Azores are due to errors or mislabelling, e.g. five specimens in SMNK labelled “KANAREN St. Miguel v.69 leg. Pinker”. Also the paratype of A. minusculella labelled “Madeira” is considered mislabelled ( Aguiar & Karsholt 2006). When describing A. atlanticella and A. minusculella Rebel apparently retained a syntype of each. We did not examine these syntypes which, according to Lewis & Sohn (2015), are in the collection of the Natural History Museum in Vienna. Rebel (1940) did not indicate the exact number of syntypes. We now know that there were at least six specimens (mostly females) involved: one from São Miguel, one from Pico, one from Faial, and three from Flores. Females of Argyresthia show clear diagnostic characters, but the species shows great variability, new synonyms have been detected and it is more than likely that there will be new research on this interesting taxon. In this situation the designation of a lectotype contributes to the stability of nomenclature and has a taxonomic value. The selected specimen is genitalized, relatively well preserved ( Fig. 3 ) and allows precise identification of the species.

Figures

FIGURES 1–2. Venation of Argyresthia species from Azores. 1. A. atlanticella. 2. A. brumella. Scale bars = 1 mm. Dashed line indicates obsolescent veins. Dotted areas indicate the pterostigma.

FIGURES 3–8. Habitus of selected type material of Argyresthia species from Azores. 3. A. atlanticella Rebel, Lectotype, female. 4. A. poecilella (Rebel), Holotype, female. 5. A. minusculella Rebel, Syntype, male. 6. A. minusculella Rebel, Syntype, female. 7. A. atlanticella, female, Terceira, Serra de Santa Bárbara, 900–1000 m, 12 june 2018, O. Karsholt. 8. A. brumella n. sp. Holotype, female. Scale bars = 2 mm.

FIGURES 9–23. Forewing pattern variability of A. atlanticella (9–20) and A. brumella sp. n. (21–23). 9. ♀, Pico, above São Caetano. 10. ♂, Graciosa, 3km NW Praia de São Mateus. 11. ♀, Santa María,Vila do Porto. 12. ♀, Flores, Fajã Grande. 13. ♂, Graciosa, 3km NW Praia de São Mateus. 14. ♂, Santa María, Malbusca. 15. ♂, Pico, 5km NW Lajes do Pico. 16. ♂, Santa María, Pico Alto. 17. ♂, São Miguel, Serra da Tronquiera. 18. ♀, Pico, 5km NW Lajes do Pico. 19. ♀, Graciosa, 3km NW Praia de São Mateus. 20. ♀, Flores, 3km WNW Lajes das Flores. 21. ♀, Terceira, Santa Barbara. 22. ♂, Terceira, Santa Barbara. 23. ♂, Terceira, Santa Barbara. Scale bars 9–20 = 1mm, 21–23 = 3mm.

FIGURES 24–29. Morphological characters of A. atlanticella. 24. Male genitalia (GS 3753). 25. V-shaped sternite of segment VIII (GS 3757). 26. Phallus (GS 3768). 27. Detail of male genitalia (GS 3781). 28. Female genitalia (GS 3756). 29. Signum (GS 3756). Abbreviations. cl: colliculum; cm: coremata; co: cornutus; ds: ductus seminalis; gn: gnathos; lp: lamella postvaginalis; pe: peduncular appendices; po: posterior appendices; os: ostium; so: socius; ve: vesica. Scale bars 24 and 28 = 500 μm, 25, 27 and 29 = 200 μm, 26 = 100 μm.