Caryocolum improvisella (Rebel, 1936), 2020

Huemer, Peter, 2020, Integrative revision of the Caryocolum schleichi species group - a striking example of a temporally changing species concept (Lepidoptera, Gelechiidae), Alpine Entomology 4, pp. 39-63 : 39

Caryocolum improvisella (Rebel, 1936) stat. rev.

Lita improvisella Rebel 1936: 3, pl. 1, fig. 7. Lectotype ♂, Switzerland: Graubünden, Remüs (Unterengadin), 21.vii.1931, leg. Thomann (BNCH) [here designated, not traced].

Material examined.

Austria: 1 ♂, 3 ♀, Tirol, Zams, Steinseehüttenweg, 1000 m, 17 Sep. 1987, leg. Huemer; 1 ♂, Tirol, Vennatal, 1500 m, e.l. 2.viii.l956 ( Dianthus sylvestris ), leg. Burmann; 1 ♂, 4 ♀, same data, but 850 m, 13 Aug. 1988, leg. Burmann & Huemer; 1 ♂, same data, but 47°10'35"N, 10°36'14"E, 29 Jul. 1989, leg. Burmann; 1 ♂, Tirol, Fließ, Vögele Bichl, 47°6'57"N, 10°37'35"E, 23 Jul. 2014, DNA Barcode TLMF Lep 15322, gen. slide GEL 1256 ♂ P. Huemer; 2 ♂, Tirol, Umhausen, unterh. Farst, 1100 m, 47°9'25"N, 10°55'22"E, 5 Sep. 2013, DNA Barcode TLMF 13394, gen. slide in glycerin; 1 ♀, Tirol, Umhausen, 1500 m, 9 Jul. 1948 e.l. ( Dianthus sylvestris ), leg. Burmann, gen. slide GU 86-109 ♀ P. Huemer; 1 ♀, same data, but 10 Jul. 1948 e.l., gen. slide GU 86-109 ♀ P. Huemer; 1 ♀, same data, but 15 Jul. 1948 e.l.; 1 ♀, same data, but 19 Jul. 1948 e.l. Italy: 3 ♂, Südtirol province, Laas, 5 Jul. 1987 e.l. ( Dianthus ) leg. Huemer, gen. slide GEL 1290 ♂ P. Huemer; 1 ♂, same data, but 2 Jul. 1987 e.l. ( Dianthus ); 1 ♀, same data, but 14 Jul. 1987 e.l. ( Dianthus ); 1 ♀, Südtirol province, Laatsch, 1000 m, 19 Aug. 1972, leg. Burmann; 1 ♀, Südtirol province, Matschertal, Waalweg, 1750 m, 46°42'44"N, 10°38'32"E, 24 Aug. 2017, leg. Huemer, DNA Barcode TLMF Lep 23714 (all TLMF).

Diagnosis.

C. improvisella differs from C. schleichi by the brown rather than white head, thorax and tegulae. It is usually larger than C. arenariella and C. lamai but otherwise cannot be reliably separated from the other species of the complex by external characters. The male genitalia are characterized in particular by the distally widened valva with a moderately long, pointed dorsal process, a character which is only shared with C. arenariella , C. messneri , and C. lamai . However, this process is distinctly shorter than in C. arenariella and C. lamai . The species differs from C. messneri in several characters such as the broader valva with a longer dorsal process and the distinctly shorter latero-medial processes of the vinculum. The female genitalia are hardly discernible from several other species of the C. schleichi species group though the short crescent shaped base of the signum in combination with the moderately slender signum hook seem characteristic and differ from all other species except for C. messneri . However, the individual variation of these characters is insufficiently documented due to lack of material.

Description.

Adult (Figs 5 , 6 ). Forewing length ♂ 5.5-7.0 mm, ♀ 4.5-6.0 mm. Head with dark grey-brown vertex, mottled with white, frons cream-white; first segment of labial palpus dark brown, second segment cream-white on inner and upper surface, ventral and outer surface predominantly dark brown, dark brown mixed with few whitish scales on segment three; antenna black, weakly ringed paler. Thorax and tegula dark brown anteriorly, posterior half mixed cream with dark brown and some rusty brown mottling. Abdomen grey to whitish grey on ventral surface. Forewing dark brown, mottled with greyish white on dorsal margin; white transverse fascia from fold to costa at one-fifth; white medial spot occasionally extended towards costal and dorsal margin; white costal and tornal spots separate; fringes basally dark brown, distal part paler. Hindwing light grey.

Variation.

The extension of white markings of the forewings varies considerably.

Male genitalia

(Figs 15 , 16 , 23 , 24 ). Uncus broadly sub-quadrangular, posterior corners rounded; lateral sclerites of gnathos distinct, medial part with large minutely spined culcitula; tegumen weakly widened anteriorly, with slightly emarginated anterior margin; transtilla sclerotized, longitudinally folded; pedunculus large, sub-oval, with sclerotized inner edge; valva nearly straight, long, distal part broadly dilated with weakly curved dorsal and straight ventral edges, apex with two processes, moderately long and pointed dorsal process extended to about middle of uncus, broadly digitate ventral process at about right-angles to and about length of dorsal process; sacculus moderately long, slender, with parallel margins, apically pointed; posterior margin of vinculum deeply incised medially, with pair of moderately long digitate processes, pair of latero-medial processes broadly hump-like; saccus slightly longer than valva, slender, gradually tapered to apex; phallus long, slender, nearly straight, apically with area of small cornuti.

Female genitalia

(Figs 31 , 38 , 45 ). Apophysis posterior about four times length of apophysis anterior; segment VIII without processes, smooth; ostium bursae with short lateral folds; apophysis anterior about length of segment VIII; antrum short, about one-fifth length of apophysis anterior, funnel-shaped; posterior part of ductus bursae with pair of long lateral sclerites extending to about apex of apophysis anterior, membranous part of ductus bursae about length of segment VIII including apophysis anterior; signum on right side of entrance to sub-oval corpus bursae, with broad and shortly crescent-shaped base and moderately slender hook.

Molecular data.

BIN: BOLD:ACL3018. The intraspecific average distance of the barcode region is 0.31%, the maximum distance 0.46% (p-dist) (n = 3). The minimum distance to the nearest neighbor, C. messneri , is 3.05%.

Distribution

(Fig. 1 ). The species is currently only known from a small section of the Central Alps of Switzerland, Italy and Austria.

Bionomics.

The larva has been recorded feeding within shoots of Dianthus sylvestris Wulfen (Klimesch 1953; Burmann 1990; pers. obs.) and moths emerged from early July to the beginning of August. The species has been recorded along steep rock-surface on siliceous soil in the montane zone.

Remarks.

Lita improvisella was described from 1 ♂ and 1 ♀ collected at two different localities in Switzerland ( Graubünden) by Thomann, and a further incorrectly identified specimen probably of C. leucomelanella from Valais, with the genitalia figured in the original description ( Rebel 1936). Klimesch (1953) figured the male genitalia of a syntype from Remüs, which is here designated as the lectotype in order to fix the identity. The second specimen from Landquart, 1.vii.1922, leg. Thomann, probably belongs to C. habeleri , a species which has been collected nearby in the Swiss Rhine valley.

Figures

Figure 1. Distribution map of successfully sequenced material of the C. schleichi species group. Map created with SimpleMappr (http: // www. simplemappr. net).

Figures 3 - 8. Adults. 3 Caryocolum schleichi, male, Syria; 4 C. dianthella, male, Spain; 5 C. improvisella, male, Austria; 6 C. improvisella, female, Austria; 7 C. arenariella, male, Sweden; 8 C. arenariella, female, Sweden.

Figures 13 - 16. Male genitalia. 13 Caryocolum schleichi, Syria, slide GU 86 / 273 P. Huemer; 14 C. dianthella, Spain, slide GEL 1284 P. Huemer; 15 C. improvisella, Austria, slide GEL 1256 P. Huemer; 16 C. improvisella, Italy, slide GEL 1290 P. Huemer.

Figures 21 - 24. Male genitalia (details vinculum-valva-complex). 21 Caryocolum schleichi, Syria, slide GU 86 / 273 P. Huemer; 22 C. dianthella, Spain, slide GEL 1284 P. Huemer; 23 C. improvisella, Austria, slide GEL 1256 P. Huemer; 24 C. improvisella, Italy, slide GEL 120 P. Huemer.

Figures 31, 32. Female genitalia. 31 Caryocolum improvisella, Italy, slide GEL 1291 P. Huemer; 32 C. arenariella, Sweden, slide GEL 1292 P. Huemer.

Figures 36 - 39. Female genitalia (segment VIII). 36 Caryocolum schleichi, Syria, slide GU 86 / 277 P. Huemer; 37 C. dianthella, Spain, slide GEL 1285 P. Huemer; 38 C. improvisella, Italy, slide GEL 1291 P. Huemer; 39 C. arenariella, Sweden, slide GEL 1292 P. Huemer.

Figures 43 - 46. Female genitalia (signum). 43 Caryocolum schleichi, Syria, slide GU 86 / 277 P. Huemer; 44 C. dianthella, Spain, slide GEL 1285 P. Huemer; 45 C. improvisella, Italy, slide GEL 1291 P. Huemer; 46 C. arenariella, Sweden, slide GEL 1292 P. Huemer.