Istrianis nilssoni, Bidzilya, Oleksiy & Karsholt, Ole, 2015

Bidzilya, Oleksiy & Karsholt, Ole, 2015, Revision of the genus Istrianis Meyrick, 1918 (Lepidoptera, Gelechiidae) with special regard to the Palaearctic region, Zootaxa 4059 (3), pp. 401-445 : 417-421

4. Istrianis nilssoni sp. nov.

Material examined. Holotype ♀, Greece, Arkanania, 10 km E. Mesolongi, 25.vii.1998, 20 m (Skule & Nilsson) (gen. slide 5519, H. Hendriksen) ( ZMUC). Paratypes: 3♂, 9♀, same data as holotype (gen. slide 5543♂, 6147♀, H. Hendriksen; 254/ 14♂, O. Bidzilya) ( ZMKU, ZMUC).

Adult ( Figs 19–21 ). Wingspan 10.5–11.8 mm. Head, thorax and tegulae covered with grey, brown-tipped scales, frons light grey; labial palpus light grey with black medial and subapical rings; scape brown mottled with grey; antennal segments brown with narrow grey rings. Forewing comparatively broad, greyish black; three diffuse black spots at base, 1/3 and 2/3 on costal margin; subcostal vein mottled with yellow; indistinct narrow black streak from the base of cell towards 2/3 at dorsal margin; a yellow spot at ½ below costal margin; paired yellow spots surrounded with some black slightly raised scales in the middle and in the corner of the cell; termen black-spotted; cilia grey, brown-tipped; hindwing and cilia grey.

Variation. The degree of expression of the yellow spots and black pattern vary within the specimens from the type series.

Male genitalia ( Fig. 62 ). Distal portion of tergite VIII tongue-shaped, narrowed distally, apex rounded, anteromedial emargination subtriangular, its distal portion quadrate, lateral lobes broad; posteriolateral projections of sternite VIII short, rounded; uncus elongated, slightly shorter then gnathos, weakly narrowed in middle, distal portion of even width nearly to rounded apex; gnathos gradually narrowed towards strongly sclerotized rounded apex, apical hook very small; tegumen subtriangular, lateral lobes broad, anteromedial emargination comparatively narrow; cucullus straight, apex rounded, weakly inflated, slightly longer than phallus; phallus tubular, apex tapered.

Female genitalia ( Figs 88, 89 , 117, 118 ). Segment VIII trapezoidal, slightly longer than broad; apophyses anteriores 1.5 times longer than segment VIII; anterior margin of sternite VIII straight, posterior margin strongly emarginated in middle; posterior sclerite rounded, lateral corners with well-developed posteriorly curved projections; anterior sclerites comparatively broad; subostial folds indistinct; ductus bursae long, evenly broadened towards globular corpus bursae; signum subhexagonal, about as broad as long, margins distinctly serrate, medial ridge constricted in middle.

Variation. Posterior sclerite varies from small weakly flattened to large, rounded.

Diagnosis. I. nilssoni may be confused externally with I. myricariella and I. arenicolella , but basal 1/5–1/4 is not black-edged, the forewing is comparatively broad and more uniformly coloured grey, with a less well expressed black pattern and weaker ochreous brown dots; it is also very similar to I. kravchenkoi but has broader forewings with a well expressed orange dot in middle under costal margin. The male genitalia are very similar to those of I. myricariella and I. pseudomyricariella , but differ in the uncus which is weakly narrowed in middle and its distal portion of even width nearly to apex, whereas uncus in related species is gradually tapered apically; the male sternite VIII with short posteriolateral projections may be considered as an additional feature that separates I. nilssoni from the related species. The female genitalia are very similar to those of I. pseudomyricariella , but the posterior sclerite is smaller, its lateral projections are upturned, the anterolateral sclerites broader and the apophyses anteriores are shorter.

Biology. Host plant unknown. Adults have been observed in July, at low altitude. Distribution. Greece.

Etymology. I. nilssoni is named after one of the collectors, Danny Nilsson, Denmark.

Figures

FIGURES 1 – 21. Adults of Istrianis species. 1 — I. myricariella, ♂, LT, Germany (B. M. gen. slide 7302); 2 — I. myricariella, ♂, Germany (gen. slide 98 / 13, O. Bidzilya); 3 — I. myricariella, ♂, Bulgaria (gen. slide 270 / 14, O. Bidzilya); 4 — I. myricariella, ♂, Greece (gen. slide 197 / 14, O. Bidzilya); 5 — I. myricariella, ♀, Spain (gen. slide 255 / 14, O. Bidzilya); 6 — I. myricariella, ♂, Spain (gen. slide 260 / 14, O. Bidzilya); 7 — I. myricariella, ♀, Tunisia (gen. slide 271 / 14, O. Bidzilya); 8 — I. arenicolella, ♂, PLT, Algeria (gen. slide 99 / 13, O. Bidzilya); 9 — I. arenicolella, ♀, Algeria; 10 — I. arenicolella, ♀, France; 11 — I. arenicolella, ♀, Spain (gen. slide 263 / 12); 12 — I. arenicolella, ♂, Spain (gen. slide 268 / 12, O. Bidzilya); 13 — I. arenicolella, ♂ (amilcarella, HT), Tunisia (gen. slide 374 c, K. Sattler); 14 — I. arenicolella, ♂, Tunisia (gen. slide 276 / 14, O. Bidzilya); 15 — I. arenicolella, ♀, Spain (gen. slide 269 / 14); 16 — I. pseudomyricariella, ♀, HT, Kyrgyzstan (gen. slide 70 / 11, O. Bidzilya); 17 — I. pseudomyricariella, ♀, PT, Kyrgyzstan (gen. slide 11 / 13, O. Bidzilya); 18 — I. pseudomyricariella, ♂, Greece (gen. slide 96 / 592, P. Huemer); 19 — I. nilssoni, ♀, HT, Greece (gen. slide 5519, H. Hendriksen); 20 — I. nilssoni, ♂, PT, Greece (gen. slide 254 / 14, O. Bidzilya); 21 — I. nilssoni, ♂, PT, Greece (gen. slide 5543, H. Hendriksen).

FIGURES 57 – 62. Male genitalia of Istrianis species. 57 — I. myricariella, Tunisia (gen. slide 276 / 14, O. Bidzilya); 58 — I. myricariella, Turkey (gen. slide 6112, H. Hendriksen); 59 — I. myricariella, Spain (gen. slide 260 / 14, O. Bidzilya); 60 — I. arenicolella, Spain (gen. slide 268 / 12, O. Bidzilya); 61 — I. pseudomyricariella, Greece (gen. slide 96 / 592, P. Huemer); 62 — I. nilssoni, Greece (gen. slide 5543, H. Hendriksen).

FIGURES 87 – 89. Female genitalia of Istrianis species. 87 — I. pseudomyricariella, PT, Kyrgyzstan (gen. slide 11 / 13, O. Bidzilya); 88 — I. nilssoni, HT, Greece (gen. slide 5519, H. Hendriksen); 89 — I. nilssoni, PT, Greece (gen. slide 6147, H. Hendriksen).

FIGURES 108 – 125. Female genitalia of Istrianis species, sternite VIII. 108 — I. myricariella, Germany (B. M. gen. slide 6255); 109 — I. myricariella, Bulgaria (gen. slide 179 / 14, O. Bidzilya); 110 — I. myricariella, Tunisia (gen. slide 271 / 14, O. Bidzilya); 111 — I. arenicolella, PLT, Algeria (gen. slide 64 / 13, O. Bidzilya); 112 — I. arenicolella, Spain (gen. slide 263 / 12, O. Bidzilya); 113 — I. arenicolella, Spain (gen. slide 269 / 14, O. Bidzilya); 114 — I. pseudomyricariella, PT, Kyrgyzstan (gen. slide 11 / 13, O. Bidzilya); 115 — I. pseudomyricariella, HT, Kyrgyzstan (gen. slide 70 / 11, O. Bidzilya); 116 — I. pseudomyricariella, PT, Tadzhikistan (gen. slide 351 / 14, O. Bidzilya); 117 — I. nilssoni, HT, Greece (gen. slide 5519, H. Hendriksen); 118 — I. nilssoni, PT, Greece (gen. slide 6147, H. Hendriksen); 119 — I. kravchenkoi, PT, Greece (gen. slide 5947, H. Hendriksen); 120 — I. wachtlii, Egypt (gen. slide 62 / 10, O. Bidzilya); 121 — I. brucinella, Egypt (gen. slide 266 / 12, O. Bidzilya); 122 — I. brucinella, Pakistan (gen. slide 185 / 14, O. Bidzilya); 123 — I. sattleri, PT, Pakistan (B. M. gen. slide 14359); 124 — I. armatus, PT, Pakistan (gen. slide 568 / 14, O. Bidzilya); 125 — I. femoralis, Kyrgyzstan (gen. slide 100 / 13, O. Bidzilya);