Tischeria decidua siorkionla Kozlov

Stonis, Jonas R., Diškus, Arūnas, Rocienė, Agnė, Sruoga, Virginijus & Davis, Donald R., 2014, New and little known Coptotriche and Tischeria species (Lepidoptera: Tischeriidae) from Primorskiy Kray, Russian Far East, Zootaxa 3884 (2), pp. 141-155 : 148-151

Tischeria decidua siorkionla Kozlov

( Figs 25–29 , 31, 33, 35 , 44, 46, 47 )

Tischeria decidua Wocke, 1876: 41 –43

Tischeria decidua siorkionla Kozlov, 1986: 25

Material examined. 4♂, RUSSIAN FAR EAST, Primorskiy Kray (= Primorskiy Territory), 20 km E Ussuriysk, Gornotayezhnoe, Biological Station, 43º41'38"N, 132º09'07"E, 27.vii–20.viii.2011, leg. V. Sruoga, genitalia slide no. AD581 ( ZIN); 4♂, same locality, 23.vii–20.viii.2011, leg. A. Rocienė, genitalia slides nos AD582, AD589 ( ZIN).

Diagnosis. So far this is the only Tischeria species with a phallus possessing a caudal transverse bar ( Figs 34, 35 ). The colour of the scaling of T. decidua has usually little or no diagnostic value. However, compared with some other Tischeria species, T. decidua usually is a brighter yellow, with less or almost no brown scales.

Male ( Fig. 25 ). Forewing length: 3.8–4.0 mm. Wingspan: 8.3–8.6 mm. Head: palpi and face cream to yellowish cream; frontal tuft and collar comprised of yellowish cream to ochreous cream slender lamellar scales; antenna with long piliform sensillae, cream on upper side and brownish on underside, slightly shorter than half the length of forewing. Thorax yellowish cream; tegulae ochreous cream, usually with ochre to brown scales. Forewing ochreous cream with many sparsely distributed yellowish ochre to brown-ochre scales which most prominent in the apical half of forewing and in narrow area along costal margin. Underside of forewing uniformly greyish brown. Cilia ochreous cream. Hindwing narrow, greyish cream, without androconia; its cilia grey-cream. Legs ochreous cream, with greyish brown darkenings on upper side (particularly intensive on forelegs, but little on hindlegs). Abdomen greyish brown on upper side, yellowish ochre on underside; anal tufts moderately short (about 1/3 of width of abdomen), composed of slender, greyish ochre or cream lamellar scales; genital plates (valvae) very distinct, broad, covered with ochreous cream scales.

Female. Antenna half the length of forewing, whitish cream or greyish cream on upper side and underside, without long sensillae. Otherwise as in male.

Male genitalia ( Figs 26–29 , 31, 33, 35 ). Capsule 660–720 µm. Uncus with long and very slender lateral lobes ( Figs 27, 28 ). Socii small, membranous, densely covered with fine spines. Tegumen broad and long. Valva 480–530 µm long, broad basally (190 µm), with median bulge (170 µm), narrowed on apical third (65 µm), without dorsal process ( Fig. 27, 28 , 31 ); distally valva covered with large chaetae; sublateral process of valva moderately short (90–100 µm), transtilla (transverse bar) absent. Ventral plate of vinculum large (185 µm long), triangular, anteriorly narrowed ( Fig. 28 ) or merely pointed ( Fig. 27 ). Juxta comprising two, 235 µm long bent elements connected with membranous joint ( Fig. 33 ). Phallus 475 µm long, medially strongly broadened (160 µm in width), apically bifid and with 80 µm long transverse bar; connected with juxta by membranous joint and forming a complex structure ( Fig. 26, 29 ).

Female genitalia. Females of the European subspecies posses an angular antrum with long, slightly curved anterior processes. Distal part of bursa narrow and slightly folded, densely scobinated with tiny granules; basal part of corpus bursae 1.7–2 times longer than posterior apophyses, and 3–3.3 times broader than the distal part, with no pectinations nor signa. Accessory sac strongly wrinkled, very small and narrow. Ductus spermathecae very slender and short, with 2–2.5 coils and round distal plate. Utriculus unknown (possibly undeveloped). Females of the East Asiatic subspecies T. decidua siorkionla Kozlov are poorly studied. Apophyses and distal part of bursa are illustrated in Sato 1993: 551–552: fig. 4 F.

Bionomics. Host-plants: Quercus spp., incl. Quercus mongolica Fisch. ex Turcz. (section Quercus ), Q. serrata Thunb. ex Murray and Q. dentata Thunb. (section Mesobalanus) ( Fagaceae ). Larvae mine in July, producing whitish or yellowish irregular or oval blotch. The leaf-mines with a round central spot of concentric blackish to greyish green or brown arcs (a firm, silk-lined nidus inside of the mine in which larva rests during feeding pauses); the leaf-mine contains little or no frass. According to Sato (1993), circular nidus distinct even in the early mine, outlined by a dense ring of silk at prepupal stage, swollen like a thick disc on the leaf surface, then falling off the leaf on the ground. Adults fly in late July–August.

Distribution. This subspecies occurs in deciduous, predominantly broadleaf forest ( Figs 46, 47 ) of the southern Primorye (Primorskiy Kray, Russian Far East) at altitudes of 160–180 m ( Fig. 44 ), also Japan (Hokkaido, Honshu and Tsushima, with occasional outbreaks) ( Sato 1993).

Remarks. The polytypic concept of Tischeria decidua Wocke was first raised by Kozlov (1986, 1997) who described the East Asiatic subspecies T. decidua siorkionla . In the material we studied, the apex of the valva is broader or as twice as broad in T. decidua siorkionla (65 µm) ( Fig. 31 ) compared with T. decidua decidua (30 µm). The median bulge on the valva of T. decidua siorkionla is longer but less prominent, the inner margin of the valva is nearly straight, while in T. decidua decidua it is distinctly sinuous, and the apex of the valva is bent proximally, i.e. towards dorsal side of the capsule ( Figs 30, 31 ). The chitinized basal part of the phallus tends to be less developed and the transverse bar is shorter in T. decidua siorkionla ( Fig. 35 ) compared with those structures in T. decidua decidua ( Fig. 34 ). The ventral plate of the vinculum in T. decidua decidua is transformed into a narrow lobe, while in T. decidua siorkionla it usually remains almost triangular. Finally, the geographical distribution of the host-plant genus ( Quercus ) is broadly disrupted (disjunct) because of the last glaciation and the aridity of Central Asia.

Figures

FIGURES 25 – 29. Tischeria decidua siorkionla Kozlov. 25, male adult. Scale 1 mm; 26, male genitalia, phallus and juxta, genitalia slide no. AD 582 (ZIN); 27, same, capsule; 28, capsule with phallus inside, genitalia slide no. AD 581 (ZIN); 29, phallus and juxta, genitalia slide no. AD 582 (ZIN). Scale bar 100 µm.

FIGURES 30 – 35. Comparision male genitalia of two subspecies of Tischeria decidua Wocke. 30, valva, T. decidua decidua Wocke, genitalia slide no. AD 590 (ZIN); 31, same, T. decidua siorkionla Kozlov, genitalia slide no. AD 589 (ZIN); 32, juxta, T. decidua decidua Wocke, genitalia slide no. AD 590 (ZIN); 33, same, T. decidua siorkionla Kozlov, genitalia slide no. AD 589 (ZIN); 34, phallus, T. decidua decidua Wocke, genitalia slide no. AD 590 (ZIN); 35, same, T. decidua siorkionla Kozlov, genitalia slide no. AD 589 (ZIN). Scale bar 100 µm.

FIGURES 44 – 47. Maps and habitat. 44, map of the region (courtesy of T. Patterson, USA), showing the collecting locality (red dot) in Primorskiy Kray (= Primorskiy Territory) in August 2011 (see Methods and material); 45, currently known distribution of Tischeria sichotensis Ermolaev (red dots); 46, 47, habitat of Coptotriche minuta Diškus & Stonis, sp. nov., Tischeria unca Diškus & Stonis, sp. nov., T. decidua siorkionla Kozlov and T. sichotensis Ermolaev—dense deciduous, predominantly broadleaf forest near Gornotayezhnoe Biological Station, 20 km E Ussuriysk, Primorskiy Kray (Primorskiy Territory, Russian Far East).