Psorosa desaturata, Tsvetkov, 2020

Tsvetkov, Eugene, 2020, Two new species of the genus Psorosa Zeller, 1846 (Lepidoptera: Pyralidae, Phycitinae) from South Kazakhstan, Zootaxa 4786 (4), pp. 546-554 : 547-549

Psorosa desaturata sp. nov.

( Figs 1, 2 , 5–7 , 11 )

Type material. Holotype ♂. Kazakhstan: Karatau Mts. , 6 km NE of vill. Ashisai, 950 m, N 43°36′26″, E 68°57′27″, 23.vi.2019, leg E. Tsvetkov. Deposited in Zoological Institute St. Petersburg ( ZISP).

Paratypes. 1 ♂, 1 ♀, same data as for holotype ; 1 ♀, Kazakhstan: Karatau Mts. , 5 km SW of vill. Ashisai, 700 m, N 43°30′31″, E 68°51′45″, 22.vi.2019, leg E. Tsvetkov, ( ZISP, ET) .

Description. Imago ( Figs 1–2 ). Head. Frons convex, its lower half white with two small black spots near eyes. Ash grey scales cover vertex and partly frons. Narrow white stripes adjacent to eyes decorate vertex and frons on the sides. Chaetosemata (whitish or light grey scales) present behind ocelli. Labial palps nearly 1.6–1.7× the diameter of eye, pointed up and ahead. The second segment twice as long as the first, the third segment equal to the first in length but much narrower. Labial palps white with large black or dark grey spots on the outer side (two spots on the second segment and a single spot on the first segment; the third segment entirely black). The inner side of labial palps light grey, sometimes with black spots. Maxillary palps very small, reaching the edge of clypeus. Segments ovoid, the second segment is the largest. Maxillary palps covered with light grey flat scales. Proboscis well developed. Antennae nearly 2/3 the length of the forewing. Cilia rather short and dense, about 2/5 of antenna diameter in males and much shorter in females. Scape nearly twice as long as wide. Base of male flagellum slightly sinuate, surrounded by raised grey scales. Flagellomeres 2–5 apically bear chitinous pointed projections. Projection of the second flagellomere is the smallest. Dorsal side of flagellum chequered. Scape and pedicel covered with light grey scales.

Thorax. Thorax and dorsal side of abdomen grey, ventral side of abdomen whitish. Legs grey, each tarsomere dark grey with white ring distally. Wings: venation corresponds to venation within the genus Psorosa . Forewing length 9–10 mm, elongate triangular with convex margins. A mixture of dark grey and whitish areas forms background of the forewing pattern. Antemedial line dull greyish orange, black spotted from the inner side, marked with angulate black line from the outer side. Postmedial light line rather thin, angled inwards at vein M2 and sharply angled inwards at A vein. The line is marked with black thin line from the inner side and with dull greyish orange stripe from the outer side. Two very small discal spots, suffused black spot in apical area crossed by postmedial line. Fringe grey, scales motley bicolour (whitish and brown). Forewing underside brown, narrow white costal streak reaches vein R2. Hindwing whitish with slight brown tinge, marginal area brown. Veins dusted with light brown scales. Fringe whitish. Underside of the hindwing whitish brown, sector from costal margin to vein M1brown.

Male genitalia ( Figs 5, 6 ). Uncus elongate trapezoidal with rounded apex, side margins angled in basal 1/3 and curved down (right margin shown unfolded in Fig. 5 ). Dorsal surface of uncus densely covered with bristles. Gnathos not large, slightly hooked and tapering distally. It bears a tiny spine in apical 1/4. Apex of gnathos flattened dorsoventrally. Branches of gnathos short ribbon-like and almost straight, the ends of branches abruptly broadened. Sacculus of valva well sclerotised, narrowing distally, occupying about 1/2 of ventral edge of valva. Costa gradually narrowing from the base to angulate apex of valva. A weakly sclerotised lobe (ampulla) present at the base of valva. Ampulla and cucullus covered with fine setae. Triangular area between sacculus and ampulla free of setae. Ventrocaudal edge of cucullus widely rounded. Juxta large with long cranially pointed projection. Lateral lobes of juxta short and stout. Transtilla arched, ribbon-like. Its sclerotised components divided by a small membranous gap in the centre. Vinculum V-shaped. Aedeagus relatively large, nearly cylindrical; very slightly narrowing distally. Caecum short, weakly sclerotised. Dorsal wall of aedeagus bears a sawtooth crest distally. Vesica armed with large distally located horn-like cornutus and several spine-like cornuti of different size located proximally ( Fig. 6 ). Posterior half of sternum VIII weakly sclerotised, anterior margin of the sternum rounded with small V-shaped central hollow. Culcita as a pair of dense scale tufts on the sides of the sternum ( Fig. 7 ).

Female genitalia ( Fig. 11 ). Papillae anales elongate tapering. Posterior apophyses thin, slightly sinuate at 1/2 of the length and about 2.5 times longer than papillae anales. Anterior apophyses about 0.7× the length of posterior apophyses, broadened basally and angularly curved at the base. Tergum VIII longer than broad, unmodified, with straight posterior margin and widely convex anterior margin. Antrum rather wide, membranous. Posterior ductus bursae sclerotised to form a ribbed funnel-shaped structure, anterior ductus bursae narrow, membranous. The funnel-shaped structure consists of a few heavily sclerotised longidudinal ribs and finely dentate (from inside) sclerotised surface. The ribs also finely dentate. An oval dentate plate at the posterior edge of this structure on ventral side. Corpus bursae elongate, membranous. Seminal duct arises from membranous bulb located posteriorly on corpus bursae.

Diagnosis. P. desaturata sp. nov. is similar to P. nucleolella and P. mediterranella . In the collected series of P. desaturata sp. nov. the forewing is rather dark with indistinct orange pattern elements. This external peculiarity probably can be helpful for diagnosing, but considering the variability of Psorosa spp. it may not be enough for separating it from similar species. Both P. nucleolella and P. mediterranella can be distinguished from the new species by the aedeagus in the male genitalia. In P. desaturata sp. nov. the dorsal wall of the aedeagus bears a sawtooth crest distally, the vesica is armed with large horn-like cornutus located distally and a group of several smaller and much thinner cornuti located proximally. In males of P. nucleolella the aedeagus bears 1–3 conical spines at the distal end of the dorsal wall, and the vesica lacks a distally located large cornutus. The aedeagus is quite different in P. mediterranella : a large cornutus is absent in the distal part, and the dorsal wall doesn’t bear a sawtooth crest. Besides, the juxta is smaller in P. mediterranella . Females of P. desaturata sp. nov. can be recognised by the ribbed sclerotised structure in the ductus bursae. Such structure is absent in the compared species.

Etymology. The name desaturata comes from “desaturated”. Psorosa species often show bright ochreous or yellowish elements in the forewing pattern. In the described species the antemedial and postmedial lines retain a faint shade of yellow, so the forewing pattern looks desaturated.

Biology. P. desaturata sp. nov. is probably a mountain species as no material was found in the plain adjacent to Karatau Mts. The specimens were collected in open mountain valleys ( Fig. 13 ).

Distribution. The species is so far known from Karatau Mts. in South Kazakhstan.

Figures

FIGURE 13. Typical habitat of P. desaturata sp. nov. and P. pseudoelbursella sp. nov., a mountain valley in environs of the village Ashisai, June 22, 2019.

FIGURES 1–4. Habitus of imago of Psorosa spp. 1–2 P. desaturata sp. nov. 3–4 P. pseudoelbursella sp. nov. 1. Holotype. 2. Paratype, female. 3. Holotype. 4. Paratype, male.

FIGURES 5–10. Male genitalia and eighth sternums of Psorosa spp. 5–7 P. desaturata sp. nov. 8–10 P. pseudoelbursella sp. nov. 5. Male genitalia (aedeagus extracted). 6. Aedeagus. 7. Eighth sternum. 8. Male genitalia (aedeagus extracted). 9. Aedeagus. 10. Eighth sternum. Scale bar: 1 mm.

FIGURES 11–12. Female genitalia of Psorosa spp. 11. P. desaturata sp. nov. 12. P. pseudoelbursella sp. nov. Scale bar: 1 mm.