Argyresthia (Blastotere) brumella Pérez Santa-Rita, Baixeras & Karsholt, 2020

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 : 224-228

publication ID	https://doi.org/ 10.11646/zootaxa.4789.1.7
publication LSID	lsid:zoobank.org:pub:DC76AE3C-7DC2-4003-81FA-FF6398BB02DE
persistent identifier	https://treatment.plazi.org/id/612EC27A-FFC3-FF9B-77E8-520DFE7403FA
treatment provided by	Plazi
scientific name	Argyresthia (Blastotere) brumella Pérez Santa-Rita, Baixeras & Karsholt
status	sp. nov.

Treatment

Argyresthia (Blastotere) brumella Pérez Santa-Rita, Baixeras & Karsholt , new species

( Figs 2 View FIGURES 1–2 , 8 View FIGURES 3–8 , 21–23 View FIGURES 9–23 , 30–41 View FIGURES 30–37 View FIGURES 38–41 )

Type material. Holotype, ♀, Portugal, Azores, Terceira, Serra de Santa Bárbara , 900–1000m, 38°43’47.37”N; 27°19’16.04”W, 12 Jun 2018, O. Karsholt, ZMUC ( GS 20891 J.V. Pérez Santa-Rita) ( Fig. 8 View FIGURES 3–8 ). GoogleMaps

Paratypes (7♂, 7♀). Portugal: Azores, Flores, 3 km WNW Lajes das Flores, 300m, 39°23’33.24”N; 31°10’40.08”W, 07 Jul 2015 (1♂,) O. Karsholt, ZMUC ( GS 20890 J.V. Pérez Santa-Rita ); 5 km WNW Lajes das GoogleMaps Flores, 500m, 39°24’07.30”N; 31°13’29.31”W, 9 Jul 2015 (1♂) O. Karsholt; Terceira, Serra de Santa Bárbara, 900–1000m, 38°43’47.37”N; 27°19’16.04”W, 12 Jun 2018 (1♀), O. Karsholt, ZMUC ( GS 5368 O. Karsholt); Santa Barbara, near Centro de Interpretação Ambiental , 507m, 38°42’42.32”N; 27°19’27.91”W, 23 Jul 2017 (2♂, 2♀) J.V. Pérez Santa-Rita, ICBiBE; (6♂, 8♀) same data preserved in ethanol tubes ( JPS17 _0197 to JPS17_0210) GoogleMaps .

Material examined not included in the type series. Portugal: Azores, Terceira, Santa Barbara, near Centro de Interpretação Ambiental , 507m, 38°42’42.32”N; 27°19’27.91”W, 23 Jul 2017 (5♂, 6♀) J.V. Pérez Santa-Rita, ICBiBE. These specimens have been preserved in ethanol, mostly in moderate or poor condition after transportation, manipulation and dissection. Consequently, they have been excluded from the GoogleMaps type series.

Molecular characterisation. We were able to obtain 5 sequences (658 bp) for COI publicly available through GENBANK accession numbers MT050032 View Materials to MT050036 View Materials .

Diagnosis. Many Argyresthia species are superficially similar. In addition, the only sympatric species, A. atlanticella , is a highly variable species, making any clear discrimination in the field difficult. Although A. brumella ( Figs 8 View FIGURES 3–8 , 21–23 View FIGURES 9–23 ) is also to some extent a variable species, it shows a comparatively more simplified wing pattern, typically with two or three silvery whitish blocks on the forewing on a brownish background; one of the blocks basal, the medial trapezoidal as a band, and the distal (ca. level of CuP) subtriangular. Although these three blocks show variable degree of suffusion, the range of wing patterns in A. atlanticella is definitely broader, from uniformly matte brown, with no marking, to relatively complex patterns, rich in transversal elements ( Figs 9–20 View FIGURES 9–23 ). Some of the intermediate cases ( Fig. 12 View FIGURES 9–23 ) consequently may superficially overlap with the wing pattern of A. brumella and in worn specimens the distinction may be difficult. However, A. brumella can be distinguished from A. atlanticella by genitalia and associated pregenital segments and also by molecular characters. In males, segment VIII differs in both species, the coremata in A. atlanticella is robust and prominent while it is reduced and sinuous in A. brumella . The sternal plate of segment VIII is composed by a Y-shaped sternite in A. brumella ( Fig. 31 View FIGURES 30–37 ) while it is V-shaped in A. atlanticella ( Fig. 25 View FIGURES 24–29 ). The male genitalia of A. brumella differ from those of A. atlanticella by the number and distribution of the fringed scales of the socii ( Figs 27 View FIGURES 24–29 & 33 View FIGURES 30–37 ) and by the phallus ( Figs 26 View FIGURES 24–29 & 32 View FIGURES 30–37 ). The socii are covered by 9 scattered fringed scales in A. atlanticella while in A. brumella they are covered by a cluster of 15 imbricated scales. The phallus is clearly distinctive in both species, shorter in A. brumella than in A. atlanticella , with a dorsal double row of denticles (acanthae) on the distal part of the phallus in A. brumella ; these are absent in A. atlanticella . The endophallus differs in both species, A. atlanticella has long sclerotized plate (cornutus) covered by a membrane with folds ( Fig. 26 View FIGURES 24–29 ) while A. brumella has a reduced sclerotized plate at the basal part (cornutus) covered by a membrane with long spiniform teeth (acanthae) ( Figs 32, 34–35 View FIGURES 30–37 & 41 View FIGURES 38–41 ). The female genitalia of A. brumella differ from those of A. atlanticella by the ductus bursae and the signum. The ductus bursae in A. atlanticella is longer than in A. brumella , internally with micro-denticles (ctenidia), which are absent in A. brumella . The signum is T-shaped in A. atlanticella and bull horn-shaped in A. brumella . In the subgenus Blastotere the most closely related species is A. trifasciata . Argyresthia brumella has three incomplete whitish bands on the forewing, represented by dorsal blocks meanwhile A. trifasciata has three complete bands from dorsum to costa. The abdominal sternite in male segment VIII is scissors-shaped in A. trifasciata and Y-shaped in A. brumella . The general shape of the valvae is more rounded in A. trifasciata than in A. brumella . The double dorsal row of denticles on the phallus is apical in A. brumella and subapical in A. trifasciata . Females of A. trifasciata and A. brumella have a bull horn-shaped signum, large and closed in A. brumella , smaller and open in A. trifasciata .

Description. Head: frons with appressed dark brown scales, forwardly directed; vertex with light yellowish brown erected scales, 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; antennae indistinctly ringed with 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 6.8–7.7 mm (x = 7.1; n = 3) in males, 6.7–7.1 mm (x = 6.8; n = 3) in females. Venation typical for Argyresthia (Blastotere) species ( Fig. 2 View FIGURES 1–2 ). Forewing with Sc to ca. 0.5 of costa; pterostigma poorly developed, close to R 1; R 1 arising from ca. 0.5 of discal cell; chorda and M-stem undetectable; R 4 and R 5 stalked; CuA 1 and CuA 2 undetectable; rest of venation variably obsolescent. Upperside forewing pattern simplified ( Fig. 8 View FIGURES 3–8 ) consisting of light to golden brown background with three silvery whitish irregular blocks, surrounded by ochre scales ( Figs 21–22 View FIGURES 9–23 ); one of blocks basal to subbasal, a second one nearly medial, trapezoidal, sometimes as band ( Fig. 21 View FIGURES 9–23 ), and one distal (ca. level of CuP). These three blocks may be suffused, especially in the dorsal edge, with the background. Consequently, the basal block may practically disappear or just be represented by some few scattered scales ( Fig. 23 View FIGURES 9–23 ). Fringes brownish in apical part, grey towards tornus, in one specimen with distinct black fringe line. Hindwing upperside and underside grey including fringe.

Abdomen: General colour brownish. Males with complex segment VIII formed by lateral lobes projected posteriorly over the valva. Coremata developed as pocket between external side of valvae and internal side of segment VIII occupied by tuft of long scales three times longer than width of valva. A ventral Y-shaped sclerite as sternite is present ( Fig. 31 View FIGURES 30–37 ). Segment VII in females unmodified.

Male genitalia (based on 7 preparations) with tegumen well sclerotized ( Figs 30, 32–33 View FIGURES 30–37 ); pedunculi projected ventro-anteriorly into pair of apodemes; another pair of short apodemes projected anteriorly at level of dorso-caudal angles of valvae (appendices angulares); uncus undeveloped; anal cone membranous, broad; socii complex, covered by 15 scales clustered on inner edge; gnathos linear, weakly sclerotized; transtilla not detected; valva rounded, suboval, slightly sclerotized; costa almost straight with slit approximately in the middle; cucullus rounded, with sparse hairs; sacculus convex, glabrous; no appreciable pulvinus; vinculum as rectangular plate, ventral edge strongly sclerotized; juxta simple, irregular sclerotized plate; saccus reduced; phallus long ( Fig. 32 View FIGURES 30–37 ) and slender, twice length of valva, coecum penis reduced, distal part of phallus with double dorsal row of denticles (acanthae) ( Figs 35 View FIGURES 30–37 , 38 & 41 View FIGURES 38–41 ); endophallus tightly covered by spiniform teeth (acanthae) ( Figs 34 View FIGURES 30–37 & 40 View FIGURES 38–41 ), basal cornutus ( Fig. 41 View FIGURES 38–41 ) as long-sclerotized plate (no deciduous cornuti detected in corpus bursae).

Female genitalia (based on 7 preparations) with simple sterigma ( Fig. 36 View FIGURES 30–37 ); antrum funnel-shaped; lamella postvaginalis with reduced presence of micro-denticles (acanthae); colliculum as ventrally incompletely sclerotized ring; ductus bursae long (approximately 1.3 mm) and narrow, distal half smooth, proximal half roughened, without micro-denticles; ductus seminalis originating from middle of ductus bursae; bulla seminalis not detected. Corpus bursae subspherical, roughened (single spermathopore extracted from corpus bursae); spermatophore corpus irregular, rather strong. Signum bull horn shaped ( Fig. 37 View FIGURES 30–37 ) formed by diffusely sclerotized circular dorsal plate projected laterally into two hollow curved horns, basal plate and surrounding membrane profusely covered by microdenticles (ctenidia), microdenticles on horns simple; anal papillae with sparse hairs, anterior apophysis about same length as posterior apophysis.

Biology. The early stages are unknown. Adults were collected in June (n = 2) and July (n = 31). We suppose that the larva feeds on Juniperus brevifolia (Seub.) Antonie (Cupressaceae) (see Discussion). The collecting sites are laurisilva.

Distribution. Endemic to the Azores Islands. Specimens were collected from Terceira and Flores. Nunes et al. (2015) reported a huge number of specimens of A. atlanticella in their study of the biota of Juniperus brevifolia from the islands of Flores, Faial, Pico, São Jorge, Terceira and São Miguel, but it was not stated if these specimens actually fed on Juniperus or they were just found in connection with it.

Etymology. The specific epithet refers to the Portuguese word «bruma», which translates as a typical fog, common of the laurisilva, in which it lives. This forest is present in Azores islands and it has an enormous interest from a conservation perspective.