Caryocolum tricolorella (Haworth, 1812)

Huemer, Peter, 2022, Underestimated cryptic diversity in the Caryocolum tricolorella species complex (Lepidoptera, Gelechiidae), ZooKeys 1103, pp. 189-209 : 189

Caryocolum tricolorella (Haworth, 1812)

Tinea tricolorella Haworth 1812: 338. Syntypes, UK: England (NHM) [not traced].

Recurvaria contigua Haworth 1828: 552. Lectotype ♀, UK: England (NHM). Designated by Huemer (1988).

Gelechia acernella Herrich-Schäffer 1855: 185, pl. 77, fig. 580. Syntypes, Austria, Germany [not traced].

Other material.

[ Austria] • 10 ♂; Burgenland, Jois 1.5 km NE; 200 m; 3 Aug 2021; [DNA barcode ids] TLMF Lep 30932, TLMF Lep 30933; P. Huemer leg.; • 1 ♂; Wien, Haschberg ; 28 Jul 1915; all TLMF; [ Germany] • 2 ♂, 1 ♀; Württemberg, Burgstall / Murr; 9-15 Jun 1973 e.l. ( Stellaria holostea ); L. Süssner leg ; • 2 ♂; Württemberg, Kirchberg / Murr; 24 Jun 1963 e.l. ( Stellaria holostea ); [genitalia slide number] GU 86-032 ♂, P. Huemer ; L. Süssner leg ; • 2 ♂, 3 ♀; Württemberg, Markgröningen; 18-30 May 1961 e.l. ( Stellaria holostea ); L. Süssner leg ; • 1 ♂; Württemberg, Markgröningen; 21 Jun 1963 e.l. ( Stellaria holostea ); L. Süssner leg ; • 2 ♂; Württemberg, Markgröningen; 4-5 Jun 1964 e.l. ( Stellaria holostea ); L. Süssner leg ; 2 ♂; Württemberg, Gronau, Kurzach Tal; 11-16 Jun 1973 e.l. ( Stellaria holostea ); [genitalia slide number] GEL 1092 ♀, P. Huemer ; L. Süssner leg ; 3 ♀; Württemberg, Schwarzwald, Sprollenmühle; 560 m; 18-22 Jun 1968 e.l. ( Stellaria holostea ); [genitalia slide number] GU 86-031 ♀, P. Huemer ; L. Süssner leg ; 1 ♂; Württemberg, Schwarzwald, Sprollenmühle; 550-580 m; 8 Jun 1967 e.l. ( Stellaria holostea ); L. Süssner leg ; 1 ♂; Württemberg, Schwarzwald, Sprollenmühle; 560 m; 22 Jun 1969 e.l. ( Stellaria holostea ); L. Süssner leg ; 5 ♂, 1 ♀; Württemberg, Schwarzwald, Bad Liebenzell; 450 m; 9-11 Jun 1971 e.l. ( Stellaria holostea ); [genitalia slide number] GEL 1288 ♂, P. Huemer ; L. Süssner leg ; all TLMF; [ France] • 1 ♂; Midi-Pyrénées, Soulom ; 31 Jul 2002; J. Nel leg. ; TLMF; [ Denmark] • 1 ♂, 2 ♀; Bótó; 22 Jul 1967 ; • 1 ♂; SZ, Vemmetofte ; 9 May 1987 (larva) ( Stellaria holostea ); O. Karsholt leg. ; all TLMF.

Diagnosis.

Caryocolum tricolorella differs from other species of the complex by its larger size and the extension of ochreous-orange scales on the dorsum and in the middle of the forewing. The male genitalia are characterized by the particularly long valva and sacculus, and the nearly straight posterior margin of the vinculum with indistinct lateromedial projections. The female genitalia differ from all other species by the distinctly smaller antrum.

Description.

Adult (Fig. 2 ). Forewing length. ♂ 5.4-6.6 mm ( ø = 5.92 mm, n = 5), ♀ 6.1-6.3 mm ( ø = 6.20 mm, n = 5). Head with fuscous vertex, frons cream-white; second segment of labial palpus cream-white on inner and upper surface, predominantly grey-brown on outer surface, third segment dark brown with a few white scales particularly at apex; antenna black, weakly ringed whitish. Thorax and tegula dark brown anteriorly, posterior part intermixed ochreous. Abdomen dorsally grey, ventrally whitish, pale grey at margins. Forewing predominantly ochreous-orange with scattered white scales, costal and terminal area fuscous, distinct subtriangular black patch from fold to costa at about one-third and black dash distad of cell, dorsum ochreous-orange with concolorous extension towards costa at 1/5 and in middle at 3/4, inwardly lined with irregular white suffusion, larger white costal spot and smaller tornal dash separated by ochreous patch or by fuscous scales; cilia light grey with fuscous ciliary line, buff beyond line. Hindwing light grey, cilia greyish buff.

Variation: the wingspan varies from 10.0-14.5 mm [forewing length not stated] ( Bland et al. 2002) showing a much greater variation than in the above examined material.

Male genitalia (Fig. 6 ). Uncus long, suboval, posterior edges rounded; gnathos with large mesial sclerite, culcitula small; posterior third of tegumen slender, anterior part strongly widened towards broadly rounded pedunculi of about twice size of uncus, anterior margin with deep concave emargination; transtilla membranous with few microtrichia; valva basally curved ventrad, long, slender, apical part weakly broadened, apex with group of stiff setae; sacculus long, slightly shorter than valva but about same width, apex knife-shaped; vinculum wide and short, posterior margin moderately sclerotized, nearly straight, with shallow medial incision and hardly developed lateromedial projections, anterior margin with strongly sclerotized concave ridge; saccus slender, basally weakly widened, gradually narrowing towards pointed apex, about length of apex of valva to anterior margin of vinculum; anellus with pair of needle-shaped sclerites; phallus stout, almost straight, coecum weakly inflated, longitudinal ridge from about middle to apex, two small sclerotized hooklets at apex.

Female genitalia (Fig. 10 ). Apophysis posterior about 4.5 times length of apophysis anterior; segment VIII smoothly sclerotized, with small dorsolateral flaps, posterior and inner edge strongly sclerotized, membranous ventromedial part with numerous microtrichia; apophysis anterior about three-quarters length of segment VIII; antrum comparatively short and small, about 4/5 length and 1/3 width of segment VIII between bases of apophyses anteriores, funnel-shaped; ductus bursae about twice length of apophysis anterior; corpus bursae semi-oval, signum with a large basal plate with long and slender hook.

Molecular data.

BIN: BOLD:AAF1506. The intraspecific average distance of the barcode region is 0.17%, the maximum distance 0.77% (p -distance) (n = 12). The minimum distance to the nearest neighbour, C. olekarsholti sp. nov., is 4.12%.

Distribution.

Caryocolum tricolorella is widely distributed from north-western Europe to Russia, extending to the central parts of the continent in the south, but most probably absent from the Mediterranean. All records from this area require verification and probably refer to other species.

Bionomics.

The biology of this species was described in detail by Stainton (1867), supplemented by several other authors ( Sorhagen 1886; Schütze 1931; Hering 1935-1937). The young larva produces a gallery-like leaf-mine on Stellaria holostea or rarely on other Stellaria spp. ( Caryophyllaceae), later feeding between spun shoots. Cerastium arvense requires confirmation as another suspected hostplant. The larva has been observed from September to mid-April ( Huemer 1988). Moths are on the wing from June to mid-September. The species prefers thermophilous forests and hedgerows at low elevation. This species is easily attracted to artificial light sources.

Remarks.

Tinea tricolorella was described from an unspecified number of specimens from England ( Haworth 1812) and is considered undisputed ( Huemer 1988). The two junior synonyms are of taxa originating outside the geographic range of sibling species, namely Recurvaria contigua from England ( Haworth 1828), and Gelechia acernella described from Central Europe (Germany, Austria) and figured in detail in the original description ( Herrich-Schäffer 1855).

Figures

Figures 2 - 5. Adults 2 Caryocolum tricolorella, male, Germany 3 C. fibigerium, male, paratype, Spain 4 C. herwigvanstaai sp. nov., male, holotype, Italy 5 C. olekarsholti, male, holotype, Greece.

Figures 6, 7. Male genitalia 6 Caryocolum tricolorella, Germany, slide GEL 1218 P. Huemer 7 C. fibigerium, Spain, slide GEL 1211 P. Huemer.

Figures 10, 11. Female genitalia 10 Caryocolum tricolorella, Germany, slide GEL 1092 P. Huemer 11 C. fibigerium, Spain, slide GEL 1095 P. Huemer.