The Neriidae (Diptera) of Southeast Asia: A taxonomic revision of the genus Telostylus

The Asian neriid fl y genus Telostylus Bigot (Diptera: Neriidae) is revised, including a key and illustrations of its species. Lectotype designations are proposed for four species: Telostylus babiensis de Meijere, T. decemnotatus Hendel, T. remipes (Walker) and T. trilineatus de Meijere. Two new species are described: Telostylus marshalli Sepúlveda & de Carvalho, sp. n., from Sarawak, Malaysia, and T. whitmorei Sepúlveda & de Carvalho, sp. n., from Masbate, Philippines. The morphology of Telostylus binotatus Bigot and T. remipes (Walker) is discussed in order to support their synonymy. Additionally, new country records are provided for four species: Telostylus babiensis de Meijere for Philippines, T. binotatus Bigot for Papua New Guinea, T. inversus Hennig for Malaysia and Indonesia, and T. trilineatus de Meijere for Malaysia and Philippines. ZooBank Article LSID: 1086131B-B958-4B0C-98C4-83E15E775739


INTRODUCTION
The genus Telostylus was proposed by Bigot (1859) for Telostylus binotatus Bigot, 1859, a species from Indonesia characterized by having an elongate conical fi rst fl agellomere, a tomentose arista placed apically and an elongate pedicel. Almost concurrently with Bigot's (1859) work, Walker (1860) proposed the genus Coenurgia to contain a new species from Makassar (Sulawesi, Indonesia), Coenurgia remipes Walker, 1860, using the same set of characters as used by Bigot (1859) to diagnose Telostylus.
A few years later, in a short publication seeking to address some inaccuracies in previous studies, Bigot (1881) synonymized Coenurgia under Telostylus, declaring: "Mon Telostylus bimaculatus, Leptopodidae? = Coenurgia remipes (Walker), à qui appartient la priorité". In this work, Bigot (1881) refers to T. bimaculatus as a species of his own authorship, but this was likely a lapsus for T. binotatus Bigot, 1859, the only species in that genus at that time.
When Hennig (1937) reviewed the Neriidae, the taxonomy of Telostylus began to be organized and its species catalogued. Hennig (1937) lists 11 species in Telostylus and provides a new diagnosis for the genus, adding several characters related to the number and size of setae on the head and thorax. The taxonomic changes proposed by Hen-was the only species of Telostylus sampled in Koch et al.'s (2015) analysis, no defi ning synapomorphies for the genus were indicated. Therefore, Steyskal (1966) remains the most important taxonomic reference for this genus. Thus, seeking to contribute to the taxonomy of Telostylus, herein we redescribe all of its valid species, describe two new species and provide a new diagnosis for the genus. Additionally, we provide a key for the identifi cation of the species of Telostylus and update the geographical distribution of its species.

MATERIAL AND METHODS
This study is based on material deposited in the following institutions (acronyms according to Evenhuis, 2019) The name-bearing type specimens of all species of Telostylus were examined, except for T. binotatus Bigot (MNHN − Muséum National d'Histoire Naturelle, Paris, France) and T. niger Bezzi (MSNM − Museo Civico di Storia Naturale, Milano, Italy). Redescriptions are based on type material, and variation recorded in the additional male and female material examined are included separately. Redescriptions and descriptions include the total length of primary type specimens and other material examined, measured from parafacial to posterior margin of tergite 6, and wings are measured from the insertion of setae on basicosta to the distal margin for length and from the costal vein perpendicularly across the midpoint of dm-cu to the posterior margin for width. General morphological terminology follows Cumming & Wood (2017) and terminology used to describe the male genitalia follows Ovtshinnikova & Galinskaya (2017). Male genitalia are described within the "Abdomen" section and are fully illustrated in Figs 8, 9 and 10 for T. latibrachium Enderlein, T. marshalli Sepúlveda & de Carvaho sp. n. and T. philippinensis Cresson. For all other species, the distiphallus is omitted as it is of uniform shape.
Illustrations of type material are included and the label information is provided for every specimen examined. When the specimens have more than one label, the order of labels from top to bottom is indicated between parentheses. When labels of different specimens share the same information but have different collection dates or museum catalogue numbers, all data are grouped together using m-dash and separated by commas. Each specimen examined in this study received a determination label that contains an identifi cation number. The depository institution and the identifi cation number of the specimens are provided between square brackets in the material examined section for each species. Information on distribution includes the region or province between parentheses when the locality is a large country or an mately 1.2−2.0 times width of syntergosternite 8. Cercus slightly tapering toward apex. Surstylus linear (Fig. 8). Ejaculatory apodeme slightly shorter than syntergosternite 8. Pregonite linear elongate, with sparse ventral setulae. Postgonite with distal rounded plate bearing irregular rows of 5−6 spines. Distiphallus partially sclerotized basally and distally, with median area completely membranous (Fig. 9); distally bifurcated into one sclerotized spine and one fl exible membranou s tube (Fig. 10); about twice length of epandrium and coiled up at base of epandrium when the genitalia are retracted.
Remarks. The number of diagnostic characters of Telostylus is increased from three characters of the antenna, as originally proposed by Bigot (1859), to more than fi fteen from the head and thorax, including several new antennal characters. Among the characters mentioned by Bigot (1859) as diagnostic of Telostylus, we have excluded the elongate pedicel as it is only slightly elongate and different from the conspicuously elongate pedicel in Gymnonerius Hendel, 1913, Longina Wiedemann, 1830and Loxozus Enderlein, 1922. Species of Telostylus are usually pale and have different patterns of contrasting spots along the body. The shape of the antennal base is similar to that found in Telostylinus, albeit smaller (as shown in Sepúlveda & de Carvalho, 2019, Figs 7, 8), contrary to Aczél (1961) and Steyskal (1966), who suggest that Telostylus lacks a modifi ed antennal base. Sexual dimorphism in species of Telostylus is manifested in the shape of the fore fi rst tarsomere, which is swollen in most males and cylindrical in females and some males. Diagnosis. Tegument mostly dark yellow; frontal vitta yellow with anterolateral black spot, without white pruinescence between it and anterior margin of fronto-orbital plate; vertex black from ocellar triangle to dorsal area of median occipital sclerite; supracervical setae yellow (Fig.  11); occiput blackish-brown, without differentiated yellow stripes or spots (Fig. 12); thorax with wide presutural black spot above postpronotal lobe and notopleuron, and wide postsutural black spot from near transversal suture to supra-alar area (Fig. 13); thorax dorsally with wide median blackish-brown stripe from anterior margin of scutum to scutoscutellar suture (Fig. 14); scutellum blackish-brown; Figs 6−10. Morphology of male Telostylus. 6-8 -T. latibrachium (specimen MZLU #1955): 6 -head anterolateral; 7 -fore tibia and tarsus lateral; 8 -genitalia lateroventral (specimen NHMUK #1918). 9 -T. marshalli sp. n., postabdomen lateral, arrow indicates median membranous area on distiphallus (specimen TAUI #992). 10 -T. philippinensis, distiphallus, arrow indicates fl exible membranous tube of distiphallus (specimen NHMUK #1960).

Key for identifi cation of the species of Telostylus
fore femur yellowish-brown on apical third; mid and hind femora with incomplete dorsal brown ring on distal third.
Remarks. Since we only examined two female specimens and the undissected male lectotype, male genitalia are not described. According to de Jong (2000), there are two syntypes (sex unknown) of this species housed in the RMNH. However, we only had access to one male from the Babi island (2°7´N, 96°40´E), southern sub-district of Simeulue Regency, Teupah Selatan. The specimens of T. babiensis examined by de Meijere (1916) are part of the material collected by the German-born Dutch naturalist Edward Richard Jacobson in 1913 on the Simeulue island and its satellite islet. In the original description of T. babiensis, de Meijere (1916) studied at least four specimens: one female from Labuan Badjau and three males from Babi island. The specimen housed in the RMNH, although it lacks any type label, is very likely the specimen examined by de Meijere (1916) because he was clear in declaring that among the three males he examined, the one with the swollen fore fi rst tarsomere was the specimen he used to describe the species. Diagnosis. Tegument mostly yellow; frontal vitta yellow; vertex with ovate black spot between ocellar triangle and postocellar setae; lateral occiput with one narrow ovate brown spot on ventral half; supracervical setae yellow; scutum mostly yellow dorsally except for one presutural black spot above postpronotal lobe (Fig. 18); pleuron completely yellow; scutellum yellow; all femora yellow with black tips, without brown or black rings; abdomen brownish-yellow; proximal extremity of ejaculatory apodeme expanded, forming fl attened fan-like membranous structure (Fig. 19).
Redescription. Male. Body length 7.9−8.5 mm. Mainly yellow, with black spots only on presutural scutum and abdomen. Head. First fl agellomere yellowish-brown, slightly darkening toward apex; twice as long as scape. Scape and pedicel brown. Anterior margin of frons concave. Frontal vitta yellow, with anterolateral black spot and dense white pruinescence between this and anterior margin of frontoorbital plate. Fronto-orbital plate yellow, with anterior third brown. Ocellar triangle black. Thorax. Coxae yellow. Femora without spine-like seta ventrally. Tibiae brown. Wing with slight infuscation on distal third; length 5.0 mm; width 1.2 mm. Halter stem white; knob blackish ( Fig.  18). Abdomen. Mostly yellow, with numerous small pale brown spots. Syntergosternite 8 brownish-yellow. Epandrium brownish-yellow; slightly longer than syntergosternite 8, reaching anterior half of abdominal segment 5 ventrally. Surstylus narrow and linear; half the length of cercus. Cercus tapering toward apex (Fig. 19); half the length of epandrium. Phallapodeme without marginal projections.
Remarks. Telostylus binotatus was redescribed by Aczél (1955), who distinguished it based on the medial third of the frontal vitta being blackish, a wide black spot in the supra-alar area and that this species only occurred in Borneo. Steyskal (1966) questioned the validity of Aczél's (1955) work, suggesting that the redescription was based on misidentifi ed material, since none of the features he mentions are present in T. binotatus and the distribution is incorrect. Today, it is known that T. binotatus occurs in Borneo, but the redescription provided by Aczél (1955) is certainly based on a misidentifi cation, since T. binotatus has only an ovate black spot on vertex behind the ocellar triangle and an entirely yellow postsutural scutum.
Following Hennig's (1937) classifi cation, Steyskal (1966) provided a key for the species of Telostylus based on features extracted from the species' original descriptions, recognizing both T. binotatus and T. remipes as independent species. The main feature mentioned by Steyskal (1966) differentiating T. binotatus from T. remipes is the colour pattern on the femora, i.e., dark brown with base and preapical ring yellow in T. binotatus, and yellowish with black apex in T. remipes. However, by differentiating T. remipes from T. binotatus based on the colour of the femora, it is clear that Steyskal (1966) misinterpreted the characteristic "Genubus nigris" used by Bigot (1859) in the original description of T. binotatus. "Genubus nigris" refers to the apex of the femora, which is blackish-brown to black.
After examining the type material of C. remipes and some additional material of T. binotatus, we verifi ed that both species have yellow femora with black tips, without brown or black rings. Moreover, T. binotatus and T. remipes are the only species of Telostylus that have a mostly yellow scutum, except for one presutural black spot above the postpronotal lobe, and an ovate black spot on the vertex between the ocellar triangle and the postocellar setae. Thus, based on these features, we return C. remipes to synonymy with T. binotatus, as previously proposed by Bigot (1881).
Telostylus binotatus is remarkably similar to T. marshalli in general morphology. The main differences between these species are the colour pattern on the vertex and femora and the postabdominal morphology. The ejaculatory apodeme in T. binotatus is unique amongst the species of Telostylus. The expanded proximal extremity of this structure is very similar to species of Micropezidae and it has never been described before in Neriidae.
Redescription. Female (lectotype). Body length 5.4 mm. Mostly yellow, with black spots on head and thorax. Head. First fl agellomere lost. Scape and pedicel yellow. Anterior margin of frons concave and wide. Frontal vitta with anterolateral black spot and dense white pruinescence between it and anterior margin of fronto-orbital plate. Fronto-orbital plate brown on anterior third. Thorax. Mostly yellow, shiny; without pruinose areas. Coxae yellow. Femora yellow, with brown tips; fore femur lost in lectotype; mid and hind femora without ventral spine-like seta. Tibiae brown. Wing without infuscation; length 4.5 mm, width 1.2 mm. Halter stem white; knob black. Abdomen. Pale brown. Oviscape pale brown, shiny; length twice its maximum width.

Distribution. Taiwan.
Remarks. This species was described by Hendel (1913) based on two female specimens from Taiwan: one is housed in the SDEI (designated here as lectotype) and one in the NMW (not examined in the present study). The label information for the paralectotype was transcribed from the original description published by Hendel (1913).
Telostylus decemnotatus is very similar to T. maccus, differing mainly as follows: (1) the vertex is completely brown in T. maccus, while in T. decemnotatus the vertex has an ovate black narrow spot between the ocellar triangle and the postocellar setae; (2) an additional wide median presutural brown stripe is present in T. maccus; (3) a black circular presutural spot is present between the suprahumeral black spot and the transverse suture in T. maccus; and (4) the scutellum is blackish-brown with a wide median yellow stripe in T. maccus, while in T. decemnotatus the scutellum is completely yellow. Diagnosis. Tegument mostly brown; thorax and abdomen shiny; anterior margin of frons straight (Fig. 28); frontal vitta yellow with black line surrounding fronto-orbital plate between anterior margin and posterior fronto-orbital seta; lateral occiput brown; vertex black from ocellar triangle to median occipital sclerite; supracervical setae black; parafacial black, with white pruinose spot ventrally toward narrowest point of gena; halter yellow; femora brown, with proximal area yellow; mid and hind femora yellow apically.
Redescription. Male (holotype). Body length 5.0 mm. Head and thorax brown, without black spots. Head. Round, not elongate anteriorly (Figs 28, 29); mostly dark brown, with fronto-orbital plate brown. First fl agellomere lanceolate and elongate, length three times its maximum width (Fig. 30). Frontal vitta and gena yellow anteriorly. Frontal vitta with black spot between anterior margin and fronto-orbital plate, without dense white pruinose spot; median cleft in frontal vitta slightly wider and deeper than in other species of Telostylus. Occiput narrow. Face in front of frontogenal suture forming lateral facial plate, brown and shiny. Thorax. Scutellum brown, sub shiny. Pleuron brown, shiny. Fore coxa pale brown. Mid and hind coxae brown. Fore femur with anteroventral spine-like setae on distal two thirds. Tibiae brown. Wing infuscate on distal third; length 5.0 mm; width 1.5 mm. Halter yellow. Abdomen. Brown, shiny. Syntergosternite 8 brown, shiny. Epandrium brown, shiny; twice as long as syntergosternite 8, reaching anterior half of abdominal segment 4 ventrally. Surstylus linear and narrow; slightly shorter than half the length of cercus. Cercus elongate, tapering distally with pointed apex; approximately half the length of the epandrium. Phallapodeme without marginal projections (Fig. 31) Diagnosis. Tegument mostly yellow; lateral occiput brownish-yellow, with two spots (one dorsal diffuse brown spot between inner and outer vertical setae and one wide ovate brown spot on ventral half, Fig. 36); vertex with oval black spot between ocellar triangle and postocellar setae; supracervical setae black (Fig. 37); scutum, scutellum and pleuron pale yellow to brownish-yellow, without pruinose or black spots on scutum and pleuron; hind femur with brown ring ventrally incomplete on distal third; abdomen brown.
Redescription. Male (holotype). Body length 6.9 mm. Mainly brownish-yellow, with small black spots dorsally on head. Head. First fl agellomere mostly blackish-brown, with small yellow proximal area; twice the length of scape. Scape and pedicel yellow. Anterior margin of frons concave (Fig. 37). Frontal vitta yellow, with anterolateral black spot and dense white pruinescence between it and anterior margin of fronto-orbital plate. Fronto-orbital plate yellow, with anterior third brown. Ocellar triangle black. Thorax. Mostly brownish-yellow, shiny. Presutural scutum with narrow median longitudinal blackish-brown stripe (Figs 38, 39). Coxae brownish-yellow. Femora yellow, with brown tips. Fore femur with short anteroventral setae; slightly increasing in size toward apex. Mid femur lost. Hind femur without spine-like seta ventrally. Tibiae brown. Wing slightly infuscate on apical third; length 6.2 mm; width 1.9 mm. Halter yellow. Abdomen. Syntergosternite 8 blackish-brown, shiny. Epandrium blackish, subequal to syntergosternite 8, reaching anterior half of abdominal segment 5 ventrally. Surstylus linear and narrow; slightly shorter than half of the length of cercus. Cercus ovate and wide, with pointed apex; almost half of the length of epandrium. Phallapodeme with rounded marginal projection on distal third, near base of postgonite (Fig. 8).
Variation. Body length 4.3-6.9 mm. Wing length 3.4-6.2 mm; width 1.0-1.9 mm. Occiput and thorax blackish to pale yellow. Thorax with median presutural longitudinal stripe dark yellow. Mid femur yellow, with brown tip; with incomplete brown ring on distal third.
Female. Body length 4.7-5.0 mm. Body setae in general weaker than in males. Femora without prominent anteroventral seta. Oviscape yellow, with small black area distally; length 2.5 times its maximum width. Diagnosis. Tegument mostly yellow; wide brown longitudinal stripe on ventral half of lateral occiput (Fig. 42); vertex black between ocellar triangle and postocellar setae (Fig. 43); supracervical setae yellow; two thoracic presutural black spots laterally (one above postpronotal lobe, and one smaller near transverse suture (Figs 44, 46); presutural scutum with wide median brown stripe; wide postsutural black spot in supra-alar area; scutellum brown with wide median yellow stripe (Fig. 47); pleuron with three black spots (one proepisternal, one katepisternal, and one covering meron and mediotergite); halter yellow; abdomen yellow with median brown longitudinal stripe.
Redescription. Female (holotype). Body length 4.9 mm. Mostly yellow, with several brown and black spots dorsally and laterally on head and thorax. Head. First fl agellomere blackish-brown, darkening towards apex; twice as long as scape. Scape and pedicel yellow. Anterior margin of frons concave. Frontal vitta yellow, with anterolateral black spot and dense white pruinescence between it and anterior margin of fronto-orbital plate. Frontal vitta yellow with black line surrounding fronto-orbital plate between anterior margin and level of posterior fronto-orbital seta. Fronto-orbital plate brown on anterior third. Median occipital sclerite yellow. Thorax. Mostly yellow, shiny; without pruinose areas. Coxae yellow. Femora yellow, with brown tips. Fore femur with short anteroventral setae; slightly increasing in width toward apex. Mid and hind femora without spine-like seta ventrally. Tibiae brown. Wing without infuscation; length 4.2 mm; width 1.5 mm. Halter lost. Abdomen. Abdomen yellow, with median wide longitudinal brown stripe. Tergite 6 completely yellow. Oviscape yellow, slightly darker than tergites, length twice its maximum width.

Distribution. Philippines (Leyte), Indonesia (Java).
Remarks. The types of T. maccus and T. decemnotatus are very similar but can be differentiated by the absence of the anterior and middle fronto-orbital setae in T. maccus. We did not have access to male specimens, but Wulp (1896) described a male from Java identifi ed as T. maccus (including its terminalia) which shows slight differences from the female described by Osten-Sacken (1882): "male genitalia very long and cercus with several long setae. Mid and hind femora with incomplete median rings and in fore and mid femora, anteroventral setae thickening distally". One female of T. maccus from Lake Danao, Philippines, photographed by Paul Bertner, lacks the third black spot posteriorly on the pleuron (Figs 1, 2). Diagnosis. Tegument mostly yellow (Figs 48,49); lateral occiput yellow, with one ovate brown longitudinal stripe on ventral half (Fig. 50); black spot on posterior third of frontal vitta, covering the vertex through ocellar triangle to behind postocellar setae (Fig. 51); supracervical setae black; scutum dorsally with presutural black spot above postpronotal lobe; coxae yellow; mid and hind femora yellow, with brown ring ventrally incomplete or complete on distal third (Fig. 48); abdomen brown.
Description. Male (holotype). Body length 6.9 mm. Mainly yellow, with a few black spots dorsally on head and thorax. Head. First fl agellomere blackish-brown dorsally, darkening towards apex; three times longer than scape (Fig. 50). Scape and pedicel yellow. Anterior margin of frons concave and wide (Fig. 51). Frontal vitta yellow, with anterolateral and mediolateral black spots and dense white pruinescence between this and anterior margin of fronto-orbital plate. Fronto-orbital plate yellow, with anterior third brown. Thorax. Pleuron yellow (Fig. 48). Scutellum yellow (Fig. 49). Coxae yellow. Fore femur yellow, with distal third brown. Femora without spine-like seta ventrally. Tibiae brown. Wing slightly infuscate on distal third; length 4.5 mm, width 1.5 mm. Halter yellow. Abdomen. Brown, shiny. Syntergosternite 8 blackish-brown, shiny. Epandrium dark yellow; twice as long as syntergosternite 8, reaching anterior half of abdominal segment 5 ventrally. Surstylus linear and narrow; slightly longer than half of the length of cercus. Cercus tapering toward apex; length slightly longer than half of that of the epandrium. Phallapodeme without marginal projections (Fig. 52).
Variation. Body 4.3-6.1 mm. Wing length 3.4-5.0 mm; width 1.0-1.5 mm. Supra-alar area slightly blackish, without black spots. Scutellum brownish-yellow to dark yellow, with narrow median yellow stripe. Katepisternum with anteroventral brown spot. Fore femur with brown tip and brown ring on distal third.
Female. Body length 4.7-5.0 mm. Setae in general thinner and shorter than in males. Oviscape yellow, with small black area distally; length 2.5 times its maximum width.
Etymology. This new species is dedicated to Dr. Steve Marshall in recognition of his many contributions to Diptera systematics.
Redescription. Male. Body length 5.3 mm. Head. Slightly elongate anteriorly; mostly dark brown, with gena yellow near anteroventral margin of eyes towards parafacial. First fl agellomere yellow at base, darkening dorsally. Pedicel and scape yellow. Face in front of the frontogenal suture forming lateral facial plate black and shiny (Fig. 56, indicated by the arrow). Occiput with dense white pruines-cence dorsally and behind the head. Thorax. Slightly pruinose dorsally and yellowish on postpronotal lobe, notopleuron and transverse suture. Scutellum brown, sub shiny. Fore femur without anteroventral spine-like setae. Tibiae yellow. Wing infuscate on apical third; length 5.0 mm; width 1.2 mm. Halter yellow. Abdomen. Syntergosternite 8 brown, shiny. Epandrium cylindrical, about 1.5-2 times longer than syntergosternite 8, reaching posterior half of abdominal segment 4 ventrally. Surstylus linear and short, length shorter than half of that of the cercus. Cercus lanceolate, length about half of that of the epandrium. Phallapodeme without marginal projections (Fig. 57).
Female. Body length 4.9-5.5 mm. Wing length 4.5-4.7 mm; width 1.2-1.3 mm. Oviscape blackish-brown, shiny, with brown tip; 2.5 times longer than its maximum width.  Hennig (1937) and, subsequently, revalidated by Sepúlveda et al. (2014) in Glyphidops Enderlein, 1922. The association between T. niger and G. vittatus suggested by Bezzi (1913) must have been a misinterpretation, since the author listed important characteristics for the identifi cation of T. niger, clearly different from those of G. vittatus: head black with frons velvety black with a yellow spot above the antenna; scutellum black; halter pale yellow; legs yellow with a narrow brown ring; wing as in T. maccus, but infuscate on apical third.
We did not have access to the type material of T. niger. However, the distinct morphology and the dark colour pattern of this species, along with the reference material determined by G. Steyskal, who studied material collected by Backer deposited in the USNM, apparently from the same collection as the holotype (Steyskal, 1966), allowed us to identify this species. Telostylus niger can be easily differentiated from the other dark species T. inversus by the colour pattern on the femora, which are mostly brown with yellow base in T. inversus, and yellow with brown ring on distal third in T. niger. Cresson, 1926 (Figs 10, 58−64) Telostylus philippinensis Cresson, 1926: 258. Diagnosis. Tegument mostly yellow; lateral occiput with two black spots (one on the point of insertion of outer vertical seta and one on ventral half, Fig. 58); vertex with ovate black spot between ocellar triangle and postocellar setae (Fig. 59); supracervical setae yellow; two thoracic presutural black spots laterally (one above postpronotal lobe and a smaller one near transverse suture, Figs 60, 62, 63); wide postsutural black spot in supra-alar area; scutellum yellow ( Fig. 63); pleuron mostly yellow, except for a black spot covering the proepisternum; femora yellow, with brown tip, without brown rings (Fig. 62); abdomen yellow.

Telostylus philippinensis
Redescription. Female (holotype). Body length 5.9 mm. Mainly yellow, partially black dorsally on head and thorax. Head. First fl agellomere yellow at base; blackishbrown at apex. Scape and pedicel yellow. Anterior margin of frons concave. Frontal vitta yellow, with anterolateral black spot; with white pruinescence between anterior margin and anterior margin of fronto-orbital plate. Fronto-orbital plate mostly yellow, with anterior third brown. Thorax. Mostly yellow, shiny; without pruinose areas. Coxae yellow. Fore femur without anteroventral line of setae. Mid and hind femora without ventral spine-like setae. Tibiae brown. Wing without infuscation (Figs 62, 63); length 5.3 mm; width 1.2 mm. Halter stem yellow; knob brown. Abdomen. Yellow with dark median longitudinal stripe. Oviscape yellow, length twice its maximum width.
Male. Body length approximately 4.4-6.1 mm. Fore femur with anteroventral line of prominent setae. Synter-gosternite 8 brownish-yellow, shiny. Epandrium yellow; 1.5 times longer than syntergosternite 8, reaching posterior half of abdominal segment 4 ventrally. Surstylus linear and narrow; length slightly longer than half of that of the cercus. Cercus tapering toward apex; one third the length of the epandrium. Phallapodeme with rounded marginal projection on distal third, near base of postgonite (Fig. 61).
Variation. Body length 4.8-6.8 mm. Wing length 4.6-5.9 mm; width 1.0-1.4 mm. Scape blackish dorsally. Black spot on occiput, near insertion of vertical seta, wide or narrow and very faint in some specimens. Particular variation was observed in specimens from Philippines as follows: presutural scutum with median blackish longitudinal stripe in two specimens from Laguna (Pagsanjan, #1008) and Negros Oriental (Amlan, #1186); posterior presutural brown spot diffuse in two specimens from Masbate (Mobo, #1961 and #1185) and absent in one from Negros Oriental (Amlan, #1967). Presutural spot may also be well defi ned and joined with anterior spot over postpronotal lobe by narrow dark brown stripe (Fig. 60). Abdomen yellow with brown median longitudinal stripe in specimens from Negros Oriental (Amlan, #1967) and Masbate (Mobo, #1181), or completely pale brown in one female specimen from northern Kalinga (Balbalan, #1883).
phology, but can be readily differentiated by the pattern and number of black spots and blackish areas on the scutum and pleuron. In the description of this species, Cresson (1926) differentiated T. philippinensis from T. decemnotatus by the absence of katepisternal black spots, and from T. binotatus by the presence of supra-alar and proepisternal black spots, but then drew attention to a possible synonymy between these species. While it is true that T. binotatus, T. decemnotatus, T. philippinensis and T. maccus are morphologically similar, T. binotatus is more similar to T. latibrachium and the new species T. marshalli in lacking the black postsutural and pleural spots. Diagnosis. Tegument mostly dark yellow; frontal vitta yellow with black line around fronto-orbital plate between anterior margin and level of posterior fronto-orbital seta; vertex black between ocellar triangle and postocellar setae (Fig. 65); lateral occiput with one narrow ovate brown spot on ventral half (Fig. 66); supracervical setae black; presutural scutum without spots (Fig. 67); one black spot laterally between transverse suture and supra-alar seta (Fig. 68); scutellum blackish-brown laterally, with wide median yel-low stripe; halter yellow; mid and hind femora with brown ring on distal third.
Redescription. Male (lectotype). Body length 6.5 mm. Dark yellow, partially blackish dorsally on head and thorax. Head. First fl agellomere yellow basally; blackish-brown distally. Scape and pedicel yellow. Anterior margin of frons concave and wide (Fig. 65). Frontal vitta yellow, with anterolateral black spot; with white pruinescence between anterior margin and anterior margin of fronto-orbital plate. Fronto-orbital plate brown on anterior third. Thorax. Dark yellow. Coxae dark yellow. Femora yellow, with brown tip. Fore femur with diffuse brown ring on distal third. Fore femur with short anteroventral setae; slightly increasing in size toward apex. Mid and hind femora with brown ring on distal third. Tibiae brown. Wing slightly infuscate on apical third; length 4.0 mm; width 1.0 mm. Abdomen. Blackish-brown, with lateral yellow spot on syntergite 1+2 (Fig. 69). Tergite 6 pale brown. Syntergosternite 8 yellow, shiny. Epandrium dark yellow; slightly longer than syntergoternite 8, reaching posterior half of abdominal segment 4 ventrally. Surstylus linear and short, shorter than half of cercus. Cercus tapering toward apex; length slightly shorter than half of that of the epandrium. Phallapodeme with rounded marginal projection on distal third, between distal margin and base of postgonite (Fig. 70). Variation. Body length 5.5−7.6 mm. Wing length 4.0−5.7 mm; width 1.0−1.5 mm. Tegument with variable tones of dark yellow (Figs 71−84); ventral proepisternal brown stripe very pale or absent; median yellow scutellar stripe narrow. Darkest spots are present on specimens from India, with black spots on thorax wider and dorsal blackish stripes wider and darker (Figs 77,78). Proepisternum dark yellow, with ventral brown stripe. Katepisternum with ventral brown spot on specimens from , which is usually darker on specimens from India (Fig. 77), and varying from pale to absent on specimens from Philippines (Fig. 79). Additionally, on two specimens from Balabac (#1977, #1997) occipital ovate spot on ventral half absent and neither of the two specimens have brown ventral stripe on proepisternum (Fig. 79). Scutellum yellow on specimens from Philippines (Fig. 80). Halter stem white; knob brown. Abdomen with yellow lateral stripe on syntergite 1+2 extending posteriorly to tergite 6 on two specimens from India (#669 and #680; Fig. 77) and several specimens from Philippines and Palawan (#1975, #1993); abdomens of specimens from Philippines completely yellow, Balabac (#1977, #1997).
Female. Same as male, differing in having 5.8-6.6 mm body length. Oviscape yellow to yellowish-brown, darkening towards apex with black tip; length almost three times maximum width.
Remarks. We had the opportunity to study males and females of T. trilineatus from several localities in the Oriental Region and conclude that it is one of the most variable species of Telostylus in terms of colouration. Two structures in particular vary greatly in colour in T. trilineatus: the anterior portion of the katepisternum and abdomen. The variation in the black spot on the katepisternum is only comparable with the variation in the spot on the meron and mediotergite of T. maccus. In the case of T. trilineatus from different localities, it is possible to track these differences in the colouration of pleural structures, which vary from well-defi ned to pale and diffuse on continental specimens from India and Thailand, or varying from pale to absent on specimens from Indonesia and Philippines. Diagnosis. Tegument mostly brown; anterior margin of frons wide and concave (Fig. 85); frontal vitta mostly black, except for circular yellow spot near anterior margin; fronto-orbital plate yellow; supracervical setae black; lateral occiput narrow, with dorsal half yellow and ventral half brown; thorax and abdomen brown, slightly pruinose; thorax with dorsal white pruinescence; proepisternal lobe and notopleuron yellow; halter yellow; femora brown; fore tibia brown; mid and hind tibiae yellow.
Etymology. The species name honours Dr. Daniel Whitmore (Staatliches Museum für Naturkunde Stuttgart, SMNS), in acknowledgement of his support of our studies on Neriidae, which made this publication possible.

Distribution. Philippines.
Remarks. Telostylus whitmorei sp. n. is one of the most distinct species in the genus. Morphologically similar to other dark species, T. inversus and T. niger, this new species can be easily differentiated by yellow bands contrasting with the dark brown tegument. Moreover, T. whitmorei is the only species of Telostylus with sub shiny tegument and a yellow fronto-orbital plate, and males have long anteroventral setae on the fore femur.