The Elachistinae (Lepidoptera: Gelechioidea, Elachistidae) of Thailand, with description of eight new species

First records of Elachistinae are given from Thailand. Ten species of Elachistinae are reported, eight of which are described as new: Urodeta longa Sruoga & Kaila sp. nov., Elachista buszkoi Sruoga & Kaila sp. nov., E. oryx Sruoga & Kaila sp. nov., E. pellineni Sruoga & Kaila sp. nov., E. capricornis Sruoga & Kaila sp. nov., E. phichaiensis Sruoga & Kaila sp. nov., E. loeiensis Sruoga & Kaila sp. nov. and E. siamensis Sruoga & Kaila sp. nov. The new species are diagnosed and illustrated with photographs of the adults and genitalia. One species remains unidentified to species level.


Introduction
The subfamily Elachistinae Bruand, 1850 (family Elachistidae Bruand, 1850) belongs to the megadiverse lepidopteran superfamily Gelechioidea Stainton, 1854 and contains presently 805 described species considered valid (Kaila 2019). The moths are small, with wingspan of 4-20 mm (Kaila 2011). The head is smooth-scaled with a weakly raised neck tuft, and a short, basally scaled haustellum. The antenna extends to about ⅔ of the forewing. The forewing pattern often consists either of a white fascia and spots on a dark background, or fuscous marks on a light background; or the moths can be more or less unicolorous (white, yellowish white, or creamy). The moths rest in a characteristic posture: the antennae are directed backwards along the costal margin of the forewing and the tornal area of the forewing is produced above the dorsum. The male genitalia are symmetrical, usually with a spinose distal knob of gnathos and bilobed uncus. Larvae are obligate leaf miners, species of the largest genus of the subfamily, Elachista Treitschke, 1833 feed on monocots (almost solely grasses or sedges); species belonging to the smaller genera Perittia Stainton, 1854, Stephensia Stainton, 1858and Urodeta Stainton, 1869 with known life history feed on dicotyledonous plants (Traugott-Olsen & Nielsen 1977;Parenti & Varalda 1994).
Although the Elachistinae are cosmopolitan in distribution, only the Holarctic and Australian faunas can be considered to have been relatively well investigated (Braun 1948;Traugott-Olsen & Nielsen 1977;Bland 1996;Sinev & Sruoga 1997;Sugisima 2005aSugisima , 2005bSugisima & Kaila 2005;Kaila 1995Kaila , 1996Kaila , 1997Kaila , 1999bKaila , 2011Kaila , 2015aKaila , 2015bKaila , 2017Kaila et al. 2015;Sruoga et al. 2017;Kaila & Nupponen 2017, 2018. However, many regions are still very poorly known in terms of elachistine species composition. One such place is the Thailand, from where no data on Elachistinae were hitherto published. Investigation of the material from the Finnish Museum of Natural History of the University of Helsinki, Finland and from the Zoological Museum of University of Copenhagen, Denmark has resulted in the discovery of ten species, eight of which are described as new. Following the classifi cation of Kaila & Sugisima (2011), the species are grouped as follows: one species is attributed to the genus Urodeta, the rest to Elachista: one to the E. orba species group, four to the E. saccharella species group sensu lato, one to the E. praelineata species group and three to the E. freyerella species group.

Material and methods
Adult specimens were examined externally using a MBS-10 and Euromex Stereo Blue stereo microscopes. The forewing length was measured along the costa from wing base to the apex of the terminal fringe scales. For a wingspan, the forewing length was doubled and thorax width added. The width of the head was measured between the inner edges of the antennal bases. Genitalia were prepared following the standard method described by Robinson (1976) and Traugott-Olsen & Nielsen (1977). The genitalia were studied and some morphological structures were photographed in glycerol before permanent slide-mounting in Euparal. The male genital capsule was stained with fuchsin and the abdominal pelt and female genitalia with chlorazol black (Direct Black 38/Azo Black). The genital morphology was examined using Novex B and Leica DM 2500 microscopes. The photographs of adults were taken using a Leica S6D stereo microscope and Leica DFC290 digital camera. The photographs of genitalia were made using a Leica DM2500 microscope and a Leica DFC420 digital camera. The descriptive terminology of morphological structures follows Traugott-Olsen & Nielsen (1977), Kaila (1999aKaila ( , 2011, and Kristensen (2003). The specifi c epithets of the new species are nouns in apposition.
Urodeta species, U. noreikai Sruoga & De Prins, which is known from Nepalese Himalayas (Sruoga & De Prins 2013). The female genitalia are highly distinctive with a very large antrum having large internal spines. As such, U. longa Sruoga & Kaila sp. nov. cannot be confused with any other known species of Urodeta.

Etymology
The species name is derived from the Latin 'longa' (long) in reference to the unusually long papillae anales.  (Figs 1-2). Forewing length 2.3 mm; wingspan 4.9 mm (n = 1). Head: frons, vertex and neck tuft white, mottled with light brown tipped scales; labial palpus straight, very short, white; scape white, mottled with light brown, pecten white; fl agellum greyish brown annulated with paler rings, serrate distally. Thorax, tegula and forewing strongly mottled with scales basally white and distally creamy brown; light brown-tipped scales forming two small blurred spots, one at 2/5 and another at ⅔ of wing; fringe scales creamy white with some blackish brown tipped scales. Hindwing brownish grey, its fringe scales somewhat paler. FEMALE GENITALIA (Figs 3-6). Papilla analis sclerotized, longer than wide, sparsely covered with long setae. Apophysis posterioris very short. Apophysis anterioris weakly sclerotized except at apices, extending from central part of segment and spreading apart laterad. Ostium bursae situated in membrane between sterna 7 and 8. Sternum 8 membranous, with sclerotized, posteriorly curved band. Antrum large, oval, strongly sclerotized, with about 24 large and several small internal spines. Colliculum shorter than antrum, membranous, with minute internal spines. Ductus bursae about 3.8 times as long as antrum, membranous, without internal spines. Corpus bursae without signum or internal spines.

Male
Unknown.

Biology
Unknown.

Flight period
The only known specimen was captured in March by artifi cial light.

Distribution
So far this species is known only from northern Thailand. We have decided to describe and name it in spite of the paucity of the material. We made this decision as this record considerably extends the known distribution of the genus, fi lling a large gap between Nepal and Australia that are the closest known occurrences for this genus.   . Forewing length 2.6-2.7 mm; wingspan 5.8-6.0 mm (n = 2). Head: frons shiny, brownish white; vertex and neck tuft brownish black; labial palpus upwards curved, slightly longer than width of head, blackish brown except second segment white above; antenna blackish brown, very weakly annulated with paler rings, somewhat serrate, without pecten; densely ciliated, length of cilia about ½ diameter of shaft. Thorax, tegula and ground colour of forewing brownish black, with two silvery grey, weakly outwardly bent, transverse fasciae at ¼ and ½ of wing; fringe scales greyish brown, fringe line brownish black. Hindwing greyish brown, its fringe scales somewhat paler.
MALE GENITALIA (Figs 9-13). Uncus lobes short, narrow, with broad U-shaped gap between them, bottom of gap reinforced, ventral surface with few short, thin scales. Basal arms of gnathos short, strongly sclerotized; spinose knob of gnathos divided into two large oval lobes. Valva 3.5 times as long as wide, evenly bent, broadest medially, basal fold of costa extended to ½ length of valva, beyond it broad hump; cucullus rounded; sacculus with very small distal spine. Digitate process about 1/5 length of valva, broadest at base, apex with few small setae. Median plate of juxta with prominent dorsally directed pockets in lateral margin (Fig. 13); juxta lobes small, median margin straight, apical margin somewhat convex, with few small setae laterally. Vinculum V-shaped, without median ridge, tapered to short saccus. Phallus 0.8 length of valva, strongly bent at basal 2/5; basal opening posteriorly directed, without caecum; no cornuti present.

Female
Unknown.

Biology
The mined leaves of an unidentifi ed Poaceae sp. were collected in early November. All other known species of the E. orba species group feed on plants belonging to Zingiberales Grisebach or Commelinales Mirb. ex Bercht. & J.Presl. This is the fi rst record of a Poaceae Barnhart feeding species in this group.

Flight period
Based upon the two specimens available, adults fl y in late November.

Distribution
So far this species is known only from northern Thailand. Parenti, 1983 Material examined

Remarks
Elachista amamii is illustrated by Parenti (1983) and Sugisima (2005a). It belongs to the Elachista praelineata species group as defi ned by Kaila (1999b). It is similar to E. brachyplectra Meyrick, 1921, which has a more southern distribution (Sri Lanka, Indonesia). Elachista amamii can be separated from it by the absence of the digitate process in E. brachyplectra (Sruoga 2005

Etymology
The species name is derived from the Latin 'oryx' (a kind of antelope or gazelle) in reference to the long, horn-like spines of valvae.

Description
Male EXTERNAL CHARACTERS (Figs 14-15). Forewing length 2.6 mm; wingspan 5.8 mm (n = 1). Head: frons shiny whitish; vertex and neck tuft brownish grey, some scales with dark brown tips; labial palpus upwards curved, about 1.7 times as long as width of head, creamy white, third segment medially with few dark brown scales on outer side; scape creamy white, without pecten; fl agellum greyish brown, basal articles weakly annulated with paler rings. Thorax dark grey brown. Forewing: ground colour light greyish brown, costa narrowly dark except at 1/5 where indistinctly delimited oblique white streak and at 2/5 where larger oblique white streak almost reaches fold; in the middle of wing at fold dark brown spot formed of slightly raised scales; tornal area whitish; narrow longitudinal blackish brown stripe to apex of wing; fringe scales greyish, fringe line blackish brown. Hindwing and its fringe scales greyish brown.
MALE . Uncus lobes widely apart from each other, narrow, elongate, basally weakly dilated, distally distinctly broadened, ventral surface densely covered with long, hair-like scales. Tegumen short, anterior margin dorsomedially strongly and widely indented, almost meeting posterior margin. Basal arms of gnathos very long, basally strongly melanized, and strongly bent towards posterior direction, apically fused and covered with several tiny spines; spinose knob small, spinose area directed apically. Costa of valva weakly concave; from distal fold of costa long, strongly sclerotized spine, length of which almost ⅓ of that of valva. Cucullus divided into two lobes: wide triangular lobe where sacculus meets cucullus, and another slightly longer, narrow lobe in costal side. Digitate process short and wide, triangular, devoid of setae. Median plate of juxta with two pockets: anteriorly directed small, triangular pocket at ventral side, and posteriorly directed large and wide one at dorsal side. Juxta lobes long and narrow, tapering to apex, median margin straight and distinctly sclerotized, distal margin with few tiny setae and dorsally directed large group of long hair-like scales. Vinculum long, v-shaped, saccus short, blunt-tipped. Phallus about 1.4 length of valva, basally dilated, straight except apex slightly bent; caecum short, rounded with sclerotized ridge forming two small lobes; vesica with group of minute spines, distally joined with two sclerotized longitudinal plates; one long bent cornutus.

Female
Unknown.

Biology
Unknown. The specimen was collected by artifi cial light.

Flight period
The only known specimen was captured in mid-January.

Distribution
So far this species is known only from northern Thailand.   (Figs 24-25). Forewing length 2.6-2.8 mm; wingspan 5.8-6.2 mm (n = 2). Head: frons shiny, creamy white; vertex and neck tuft brownish white, some scales with dark brown tips; labial palpus upwards curved, about 1.7 times as long as width of head, creamy white, third segment medially with few dark brown scales on outer side; scape creamy white below, with few dark brown scales above, without pecten; fl agellum creamy white below, greyish brown above, annulated with paler rings, last fl agellomere creamy white. Thorax grey brown. Forewing: ground colour greyish brown, costa narrowly dark except at 1/5 where indistinctly delimited oblique white streak and at 2/5 where larger oblique white streak almost reaches fold; in the middle of wing at fold dark brown spot formed of raised scales; tornal area whitish; narrow longitudinal blackish brown stripe to apex of wing; fringe scales brownish grey, fringe line blackish brown. Hindwing and its fringe scales brownish grey.
MALE . Uncus lobes widely apart from each other, elongate, basally dilated, distally distinctly broadened, ventral surface densely covered with long, hair-like scales. Tegumen short, anterior margin dorsomedially strongly and widely indented, almost meeting posterior margin. Basal arms of gnathos very long, basally strongly melanized, and strongly bent towards posterior direction, apically fused and covered with several tiny spines; spinose knob small, spinose area directed apically. Costa of valva weakly concave; from distal fold of costa long, strongly sclerotized spine, length of which about 2/5 of that of valva. Cucullus divided into two lobes: wide triangular lobe where sacculus meets cucullus, and another longer, distally expanded lobe in costal side. Digitate process very long and narrow, more than 8 times as long as wide, distally slightly wider than in narrowest point, with a few setae. Median plate of juxta with posteriorly directed large and wide pocket at dorsal side. Juxta lobes medially strongly produced, median margin straight and distinctly sclerotized, distal margin with few  tiny setae and dorsally directed group of long hair-like scales. Vinculum long, v-shaped, tapered to broad saccus. Phallus about 1.5 length of valva, basally dilated, weakly bent; caecum short, rounded with sclerotized ridge forming two small lobes; vesica with one large, bent cornutus, and with large group of slender spines, increasing in size distally.

Biology
Unknown.

Flight period
Based upon three specimens available, adults fl y in May and September.

Distribution
So far this species is known only from northern Thailand.  (Figs 40-41). Forewing length 2.5-2.8 mm; wingspan 5.6-6.2 mm (n = 4). Head: frons shiny, creamy white; vertex and neck tuft brownish white, some scales with dark brown tips; labial palpus upwards curved, about 1.6 times as long as width of head, creamy white, third segment medially with few dark brown scales on outer side; scape creamy white below, with few dark brown scales above, without pecten; fl agellum creamy white below, greyish brown above, weakly annulated with paler rings, somewhat serrate in distal ½, last fl agellomere creamy white. Thorax and tegula intermixed with greyish brown and dark brown scales. Forewing: ground colour greyish brown, costa narrowly dark except at 1/5 where indistinctly delimited oblique white streak and at 2/5 where larger oblique white streak almost reaches fold; in the middle of wing at fold dark brown spot formed of slightly raised scales; tornal area whitish; narrow longitudinal blackish brown stripe to apex of wing; fringe scales brownish grey, fringe line blackish brown. Hindwing and its fringe scales brownish grey.

Elachista capricornis
MALE GENITALIA (Figs 42-50). Uncus lobes widely apart from each other, elongate, basally dilated, distally distinctly broadened, ventral surface densely covered with long, hair-like scales. Tegumen short, anterior margin dorsomedially strongly and widely indented, almost meeting posterior margin. Basal arms of gnathos very long, basally strongly melanized, and strongly bent towards posterior direction, apically fused and covered with several tiny spines; spinose knob small, spinose area directed apically. Costa of valva weakly concave; from distal fold of costa long, strongly sclerotized spine, length of which nearly ½ of that of valva. Cucullus divided into two lobes: wide triangular lobe where sacculus meets cucullus, and another slightly longer, narrow lobe in costal side. Digitate process short and wide, triangular, devoid of setae. Median plate of juxta with two pockets: anteriorly directed very small, triangular pocket at ventral side, and posteriorly directed large and wide one at dorsal side. Juxta lobes medially strongly produced, median margin straight and distinctly sclerotized, distal margin with few tiny setae and dorsally directed large group of long hair-like scales. Vinculum long, v-shaped, tapered to short and broad saccus. Phallus about 1.25 length of valva, basally dilated, bent at basal ¼ and more distinctly bent at apical 1/10; caecum short, rounded; proximal part of phallus with sclerotized ridge forming two lobes, one small, nipple-shaped at basal end of phallus, and larger one, prolonged at basal 1/10 of phallus; vesica with group of minute spines and one long, bent cornutus.

Female
Unknown.

Biology
Unknown. The specimens have been attracted by artifi cial light.

Flight period
Based upon specimens available, adults fl y in January.

Distribution
So far this species is known only from northern Thailand.  (Figs 51-52). Forewing length 2.7 mm; wingspan 6 mm (n = 1). Head: frons shiny, creamy white; vertex and neck tuft whitish brown, some scales with dark brown tips; labial palpus upwards curved, diverging, about 1.4 times as long as width of head, creamy white, third segment with few dark brown scales; scape creamy white below, with few dark brown scales above, without pecten; fl agellum creamy white below, greyish brown above, weakly annulated with paler rings. Thorax and tegula intermixed with greyish brown and creamy brown scales. Forewing: ground colour varying from creamy to a mixture of rusty and dark grey scales, costa dark brown except medially from where oblique pale ochreous streak extend to fold, and in distal ¾ where it is creamy to varying extent; in the middle of wing at fold dark brown spot formed of slightly raised scales; fringe scales brownish grey, fringe line blackish brown. Hindwing and its fringe scales brownish grey. MALE GENITALIA (Figs 53-58). Uncus lobes widely apart from each other, elongate, relatively short, slightly longer than its width, ventral surface densely covered with short, thick scales. Basal arms of gnathos very long, basally strongly melanized, and strongly bent towards posterior direction, apically fused; spinose knob medium sized, oval. Costa of valva weakly concave; basal fold of costa meets distal fold at 2/5 from base. Cucullus medially deeply incised, thus divided into two lobes: wide triangular lobe where sacculus meets cucullus, and another very large distal lobe. Digitate process long and slender, ⅓ length of valva and about 13 times as long as its width, distally with few short setae. Juxta lobes large, about 2/5 length of valva, medially produced as curved horn, median margin with short setae, distal margin with row of very long dorsally directed hair-like scales. Vinculum with broad median ridge, tapered to short and broad saccus. Phallus about 1.26 length of valva, evenly bent from basal ⅓; vesica with group of minute spines and three long, bent cornuti.

Female
Unknown.

Biology
Unknown. The specimen was collected by artifi cial light.

Flight period
The only known specimen was captured in November.

Distribution
So far this species is known only from northern Thailand.

Remarks
The wings in the holotype is somewhat rubbed, therefore the description of external characters is approximate.  (Figs 59-60). Forewing length 3.4 mm; wingspan 7.3 mm (n = 1). Head: frons shiny, creamy white; vertex and neck tuft brownish white, some scales with dark brown tips; labial palpus upwards curved, diverging, about 1.8 times as long as width of head, creamy white, third segment medially with few dark brown scales; scape creamy white below, with few dark brown scales above, without pecten; fl agellum creamy white below, greyish brown above, annulated with paler rings, last fl agellomere creamy white. Thorax grey brown. Forewing: ground colour greyish brown with scattered rusty brown scales, costa narrowly dark except at ⅓ where indistinctly delimited oblique creamy white streak and at ⅔ where larger oblique creamy white streak almost reaches fold; in the middle of wing at fold blackish brown spot formed of raised scales; tornal area creamy white; narrow longitudinal blackish brown stripe to apex of wing; fringe scales brownish grey, fringe line dark brown. Hindwing and its fringe scales brownish grey. FEMALE GENITALIA (Figs 61-62). Papilla analis longer than wide, setose. Apophysis posterioris slightly longer than apophysis anterioris. Ostium bursae situated at posterior margin of sternum 7, occupying 2/5 of the space between apophyses anteriores, dorsal wall covered with minute spines. Antrum large, about 1.5 times longer than wide, inwardly densely covered with small spines. Colliculum weakly sclerotized, as long as antrum. Ductus bursae membranous, gradually widened towards corpus bursae with which it is incepted without distinct border; corpus bursae without internal spines. Signum long, narrow, almost straight, with a few rows of teeth.

Male
Unknown.

Biology
Unknown. The specimen was collected by artifi cial light.

Flight period
The only known specimen was captured in December.

Distribution
So far this species is known only from northern Thailand.

Remarks
This female singleton externally resembles several other species found at the same site. It may be conspecifi c with some other species of Elachista albrechti-heteroplaca species group, now only known from males. Therefore, this taxon is documented but not named pending availability of additional male material. Sruoga & Kaila sp. nov. urn:lsid:zoobank.org:act:C7B51906-9FE4-4AA2-9220-C91DB0BF31F7 Figs 63-66

Diagnosis
The wing pattern of this species is hardly distinguishable from many others of the Elachista freyerella species group. It is one of the six known eastern Palaearctic or Oriental species of the E. freyerella species group whose phallus contains a cornutus. These species can be divided into two groups: species with the cornutus elongate, and species with the cornutus short and arrow-shaped. Elachista spiculifera Meyrick, 1922 described from India, E. cornutifera Sruoga, 1995 (Figs 63-64). Forewing length 2.6 mm; wingspan 5.8 mm (n = 1). Head: frons shiny, creamy white; labial palpus upwards curved, diverging, about two times as long as width of head; antenna greyish brown, basal articles weakly annulated with paler rings; pecten present as a few short stiff seta-like scales at base of scape. Forewing ground colour pale greyish white, powdered with greyish brown-tipped scales; distal half of wing darker than basal; fringe scales greyish brown. Hindwing and its fringe scales greyish brown.
MALE GENITALIA (Figs 65-66). Uncus lobes narrow and long, apically curved and tapered to pointed apex; ventral surface covered with mixture of short and thick, and long and slender setae. Basal arms of gnathos reinforced, spinose knob about 1.7 times as long as wide. Valva broadest in basal part; sacculus weakly concave medially, distally with stout spine; cucullus neither expanded nor produced towards costa, tip almost right-angled; basal fold of costa extended to ⅔ of valva, where it meets distal fold forming broad indistinct hump. Median plate of juxta about 2.3 times as long as broad, proximal end formed as rounded sac; medial margin of juxta lobes strongly sclerotized; lobes elongate, broadest medially, tapered distally; ventral surface with few long and short setae. Digitate process ⅓ length of valva, narrow, distally somewhat dilated and setose. Vinculum produced into very long parallel-sided blunt-tipped saccus. Phallus about 0.9 length of valva, narrow, broadest basally, curved at basal ¼ and more strongly at distal ⅓; caecum dorsally with cusp-like lobe whose anterior margin is concave; vesica with one stout straight cornutus, about 1/6 length of phallus.

Female
Unknown.

Biology
Unknown.

Flight period
The only known specimen was captured in October.

Distribution
So far this species is known only from northeastern Thailand.

Remarks
The holotype is in poor condition; the forewing and head are somewhat rubbed, the antennae are partly broken and therefore the description of external characters is incomplete.   (Figs 67-68). Forewing length 2.6-2.8 mm; wingspan 5.8-6.3 mm (n = 5). Head: frons shiny, creamy white; vertex and neck tuft whitish brown, powdered with dark browntipped scales; labial palpus upwards curved, diverging, as long as width of head, creamy white above, whitish brown below; antenna greyish brown, weakly annulated with paler rings, somewhat serrate in distal ½; pecten present as a few short stiff seta-like scales at base of scape. Thorax, tegula and ground colour of forewing formed from basally shortly creamy white and distally dark greyish brown making mottled appearance; plical spot elongate, blackish brown, at ½ wing length on dorsal side of fold; discal spot elongate, blackish brown, at ⅔ wing length in middle; fascia present as indistinct, creamy white, somewhat oblique band at ⅓ wing length; creamy white costal and tornal spots indistinctly delimited; fringe scales grey-brown, fringe line blackish brown. Hindwing grey-brown, its fringe scales somewhat paler. MALE GENITALIA (Fig. 69). Uncus lobes narrow and long, apically curved and tapered to pointed apex; ventral surface covered with mixture of short and thick, and long and slender setae. Basal arms of gnathos reinforced, spinose knob about 1.6 times as long as wide. Valva broadest in basal part; sacculus weakly concave medially, distally with stout spine; cucullus neither expanded nor produced towards costa, tip rounded; basal fold of costa extended to ⅔ of valva, where it meets distal fold forming broad distinct hump. Median plate of juxta two times as long as broad, proximal end formed as rounded sac; medial margin of juxta lobes strongly sclerotized; lobes short, broadest medially, tapered distally; ventral surface with few short setae. Digitate process ⅓ length of valva, narrow, distally somewhat dilated and setose. Vinculum produced into long and narrow saccus. Phallus about 0.9 length of valva, narrow, broadest basally, almost straight; caecum dorsally with cusp-like lobe whose anterior margin is concave; vesica with one short cornutus that consists of weakly sclerotized elongate plate with one acute tooth.  (Figs 70-71). Forewing length 2.8 mm; wingspan 6.3 mm (n = 1). Otherwise as male, but forewing more brightly coloured with ground colour dark blackish brown; fascia, costal and tornal spots white. FEMALE GENITALIA (Figs 72-73). Papilla analis setose, triangular. Apophysis posterioris slightly longer than apophysis anterioris. Ostium bursae in posterior margin of sternum 7, dorsal wall spinose. Ventral margin of ostium bursae deeply incised, narrow and V-shaped. Antrum rather short, approximately as long as apophysis posterioris and nearly three times as broad as colliculum. Inner side of antrum with minute spines. Anterior margin of sternum 7 reinforced. Colliculum as long as antrum, bent, more sclerotized on one side. Corpus bursae oval, covered by minute internal spines except caudally; signum oval sclerotized plate with pair of large apposite teeth and two small accessory teeth.

Biology
Unknown.

Flight period
Based upon specimens available, adults fl y in September and October.

Distribution
So far this species is known only from northeastern and central Thailand.

Remarks
The putative association of male and female is based on similar appearance and on the occurrence at the same locality. Moths were caught at the same site and time.
The gnathos is slightly wider in two paratypes (slide numbers L. Kaila 1500 and 1504). In the absence of other reliable differences, we consider this as minor variation of the same species.

Discussion
With the description of Urodeta longa Sruoga & Kaila sp. nov., the genus Urodeta is recorded for the Asia only for the second time. The occurrences of the new species, along with Urodeta noreikai Sruoga & De Prins, 2013 recently described from Nepal and two species, Urodeta inusta Kaila, 2011, Urodeta sp. from Australia, suggest a wider distribution of this enigmatic genus in the Oriental region than actually recorded. Unfortunately, there are still no documented data available on the biology of the Urodeta species in Asia.
All known species related to E. albrechti and E. heteroplaca and with known life histories feed on bamboos. In Asia, the diversity of bamboos is huge, with hundreds of species. If Elachista species specializing in them even marginally match this diversity, one may assume that a vast diversity of elachistines are is awaiting discovery.
In conclusion, our knowledge of the subfamily Elachistinae in Thailand is far from complete, leaving a large gap in our understanding of these moths. A great amount of work still needs to be done -from collecting to the description of new taxa and recording the natural history of species.
We are aware that describing new species on the basis of one or very few specimens can cause problems. However, the species presented here are characteristic each. Moreover, given how few specimens in total are known from Thailand or from the Oriental region in general so far, one can assume that it may take considerable time before further material is available. Eventual barcoding -unfortunately not possible for the authors at present -of these specimens will likely reduce the risk of future problems with taxonomy.