Stigmella longa Remeikis & Stonis, 2020

Stonis, Jonas R., Remeikis, Andrius, Diškus, Arūnas & Navickaitė, Asta, 2020, Documenting new and little known leaf-mining Nepticulidae from middle and southwestern areas of the Asian continent, Zootaxa 4881 (3), pp. 401-452 : 409-418

Stigmella longa Remeikis & Stonis , sp. nov.

( Figs 2, 3 , 16, 17 , 31, 32 , 122–129 )

urn:lsid:zoobank.org:act:5F63E3B8-7385-43A5-B1BE-B9AF82D830C5

Type material. Holotype: ♂, India, Uttarakhand, Dehradun Distr., Rishikesh , 30°07’52”N, 78°18’45”E, elevation ca. 700 m, mining larva on Ototropis elegans , 9.viii.2010, A. Remeikis and J. R. Stonis, genitalia slide no. RA264 ( ZIN).

Diagnosis. This new species is left unattributed to a species group, however it shows some similarity to the Stigmella betulicola group. Externally, S. longa sp. nov. can be confused with many other dark-speckled Stigmella species. In the male genitalia, the combination of long caudal processes of the uncus, unique, U- shaped gnathos ( Fig. 123 ), and phallus with two very long cornuti and wringled, thickened vesica ( Figs 127–129 ) distinguishes S. longa from all known congeneric species.

Male ( Figs 31, 32 ). Forewing length 1.7 mm; wingspan 3.8 mm (n = 1).

Head. Palpi cream; frontal tuft pale ochreous orange; collar rubbed in the holotype; scape yellowish cream; antenna slightly shorter than one half the length of forewing; flagellum with 24–25 segments, brown-grey, distally pale brown.

Thorax. Tegula, thorax and forewing with some purple iridescence, brownish grey, densely irrorated with dark, black-brown scales; fringe dark grey-brown. Hindwing dark grey. Legs yellowish cream, golden glossy, with some purple iridescence and grey-brown scales on upper side.

Genitalia ( Figs 122–129 ) with capsule about 305 µm long, 175 µm wide. Uncus ( Fig. 123 ) with long caudal processes laterally. Valva ( Figs 123–126 ) about 200 µm long; transtilla without sublateral processes ( Fig. 122 ). Juxta large, plate-like, basally contricted ( Figs 123, 125, 126 ). Vinculum large, without lateral lobes ( Fig. 12 ). Phallus ( Figs 124, 127–129 ) about 215 µm long, with two very long cornuti: a stout, horn-like cornutus and a slender, spine-like cornutus; vesica wringled, thickened.

Female. Unknown.

Bionomics ( Figs 2, 3 , 16, 17 ). Host plant is Ototropis elegans (DC.) H. Ohashi & K. Ohashi (= Desmodium elegans DC. ), Fabaceae ( Figs 2, 3 ). Larvae mine in leaves in August. The leaf mine is a slender, sinuous gallery; in the beginning it is fully filled with dark green frass; further on frass is greenish black to black; in the last quarter, frass with unfilled margins of the gallery ( Fig. 17 ). Adults fly in late August.

Distribution. Known from a single locality in the western Himalaya, Uttarakhand, Rishikesh, at the elevation of about 700 m ( Fig. 1 : wHi).

Etymology. The species name is derived from Latin longus (long), in reference to the long cornuti and processes of the uncus in the male genitalia.

Figures

FIGURES 1–6. A geographical map (courtesy of T. Patterson, USA) and new host plants of Nepticulidae. 1, localities in this study; 2, 3, Ototropis elegans (DC.) H. Ohashi & K. Ohashi, Fabaceae, a host plant of Stigmella longa sp. nov.; 4, Viburnum cotinifolium D. Don., Adoxaceae, a host plant of Acalyptris nasutus sp. nov; 5, Ototropis sp., Fabaceae, a host plant of Stigmella pyramidata sp. nov.; 6, Spiraea canescens D. Don., Rosaceae, a host plant of Ectoedemia orbiculata sp. nov.

FIGURES 16–28. Leaf mines of new species of Nepticulidae. 16, 17, Stigmella longa Remeikis & Stonis, sp. nov.; 18–21, Acalyptris brunipexus Stonis, Diškus & Remeikis, sp. nov.; 22–25, A. nasutus Diškus & Navickaitė, sp. nov.; 26–28, Ectoedemia orbiculata Diškus, Remeikis & Stonis, sp. nov.

FIGURES 29–38. Adults of new species of Nepticulidae. 29, 30, Stigmella alilediella Diškus & Navickaitė, sp. nov., holotype; 31, 32, Stigmella longa Remeikis & Stonis, sp. nov., holotype; 33, S. ziziphifolia Rocienė & Stonis, sp. nov., holotype, upper side; 34, same, underside; 35–37, S. damocles Remeikis, sp. nov., holotype; 38, S. latilobata Diškus & Navickaitė, sp. nov., holotype (ZIN)

FIGURES 122–129. Male genitalia of Stigmella longa Remeikis & Stonis, sp. nov., holotype, genitalia slide no. RA264 (ZIN). 122–126, capsule with phallus removed; 127–129, phallus

FIGURES 7–15. Leaf mines of new species of Nepticulidae. 7, 8, Stigmella ziziphifolia Rocienė & Stonis, sp. nov.; 9, 10, S. alilediella Diškus & Navickaitė, sp. nov.; 11–13, S. pyramidata Diškus & Navickaitė, sp. nov.; 14, S. latilobata Diškus & Navickaitė, sp. nov.; 15, S. paniculata Diškus & Navickaitė, sp. nov.