Revalidation and taxonomic revision of Teloneria Aczél (Diptera, Neriidae), with description of two new species

The genus Teloneria Aczél, 1954 is resurrected from synonymy with Chaetonerius Hendel, 1913 to include four species: Teloneria apicata (Edwards, 1919) comb. nov., Teloneria bimaculata (Edwards, 1919) comb. nov., Teloneria juceliae Sepúlveda & Souza sp. nov. and Teloneria ladyae Sepúlveda & Souza sp. nov. Lectotypes for Telostylus apicatus Edwards, 1919 and its junior synonym, Telostylinus apicalis Enderlein, 1922, and for Telostylinus ornatipennis Enderlein, 1922, junior synonym of Teloneria bimaculata comb. nov., are designated. An identification key to Chaetonerius, Telostylus Bigot, 1859 and Teloneria, with emphasis on the identification of the species of Teloneria, illustrations and distribution data are provided.


Introduction
Chaetonerius apicatus (Edwards, 1919) and Chaetonerius bimaculatus (Edwards, 1919) are Oriental species of Neriidae distributed across southeast Asia. The particular morphology of these species has made their classification controversial, with different authors placing them in Telostylus Bigot, 1859, Telostylinus Enderlein, 1922or Chaetonerius Hendel, 1913(Edwards 1919Enderlein 1922;Hennig 1937). Hennig (1937) expressed the difficulty of classifying these species among the known genera of Neriidae when, in the same work, he placed them provisionally in Telostylinus and included them in the identification key for Chaetonerius. Aczél (1954) proposed the genus Teloneria Aczél, 1954 to house these species, characterizing it by the following characters: arista brown, three dorsocentral setae and head almost as long as high, with the eye occupying a considerable part of its lateral surface. Subsequently, without providing any argumentation, Steyskal (1977) synonymized Teloneria under Chaetonerius.
Recent taxonomic reviews have shown that the morphology of C. apicatus and C. bimaculatus is fundamentally inconsistent with the diagnostic characters of Chaetonerius and Telostylus , supporting Azcél's (1954) hypothesis that these species should be classified in an independent genus. Thus, in this paper, we review the morphology of C. apicatus and C. bimaculatus and revalidate the genus Teloneria to allocate these and other two species herein described as new to science: T. juceliae Sepúlveda & Souza sp. nov. and T. ladyae Sepúlveda & Souza sp. nov. Additionally, seeking to stabilize the names of the species in Teloneria, we designate lectotypes for T. apicata comb. nov. and T. bimaculata comb. nov. and their synonyms and, in order to clarify the separation of Teloneria from Chaetonerius and Telostylus, we provide a key for these genera, with emphasis on the identification of the species of Teloneria.

Material and methods
This study is based on material from the following institutions: The type material of C. apicatus and C. bimaculatus was studied and both species were redescribed. Label information is provided for each specimen examined, followed by the depository institution along with an identification number, which is also included on the determination label pinned with each specimen. Information on labels of type material is written verbatim and each label is separated by double forward slashes '//'. Total length of the specimens is measured from the parafacial to the posterior margin of tergite 6. General morphological terminology follows Cumming & Wood (2017) and terminology used to describe male genitalia follows Ovtshinnikova & Galinskaya (2017).
Illustrations of genitalia were produced after removing the apical portion of the abdomen and clearing it in 10% KOH overnight at room temperature. After examination, the genitalia were neutralized using acetic acid and stored in a glass microvial containing fresh glycerin, which was pinned with the corresponding dissected specimen.
Photographs were made using a Leica DFC 500 digital camera mounted on a Leica MZ16 stereoscope and images were edited with the computer software Leica LAS 3D Viewer and LAS Montage ver. 4.7. New records are indicated by an asterisk in the 'Distribution' section of each redescription. The map with the geographic distribution of the species was generated using Google Earth ver. 7.1.1.1580 to obtain decimal coordinates and QGIS 3.10-A Coruña (QGIS Development Team 2019) was used to plot the distribution of the points. Insecta Linnaeus, 1758Order Diptera Linnaeus, 1758Suborder Brachycera Schiner, 1862Superfamily Nerioidea Hendel, 1916 Family Neriidae Westwood, 1840

Remarks
The genus Teloneria is restituted from synonymy with Chaetonerius based on the following distinctive features: i) arista brown with pubescence shorter at base and longer towards apex; ii) inner process of pedicel positioned at dorsal half of inner surface, with broad linear shape and rounded apex; iii) antennal base shiny and small but well-developed, visible laterally between the anterior margin of frons and parafacial; iv) parafacial, genal and postocular areas very narrow, with the eye occupying a considerable part of its lateral surface; v) posterior fronto-orbital seta positioned at mid length of the eye; vi) three well-developed and long dorsocentral setae (one presutural and two postsutural), and vii) the exclusive character of wing vein A2, ending abruptly before reaching the second third of the anal lobe. As the species of Teloneria were associated with Chaetonerius and Telostylus in the past, we redescribe the genus and provide a key to clarify the separation between the newly restituted genus and these genera.
Head ( Fig. 1A-B). Pedicel with one dorso-apical and one ventro-apical outstanding setae. Scape slightly longer than width. Anterior fronto-orbital seta positioned near anterior margin of fronto-orbital plate. Vertex and occiput joining in a curve that follows from close to posterior margin of eye until postgena. Parafacial and gena running very close to eye margin from genal seta towards antennal base. Postgena convex and narrow, with black setulae near occipital foramen.
abdomen. Homogeneously colored. Syntergite 1 + 2 with short and numerous setae in anterior half, followed by a bare medial area and posteriorly; with longer setae in lower density. Sternite 6 capeshaped, laterally elongate and narrower near lateral margin of tergite 6. Syntergosternite 8 with 3−5 long setae in proximal half of dorsal surface. Epandrium cylindrical and elongate, measuring approximately 1.5−2.0 times length of syntergosternite 8; cercus and surstylus variable in length and shape (Fig. 2); pregonite bare.

Diagnosis
Teloneria apicata and T. bimaculata can be differentiated from T. juceliae sp. nov. and T. ladyae sp. nov. by the general darker color and the inner vertical and outer vertical setae of almost the same length. All Teloneria species have the gena and postpronotal lobe yellow, but only T. apicata have the frontoorbital plate, occiput, mid coxa and femora black. Also, T. apicata and T. bimaculata bear a mostly black frontal vitta, with a small anterior area yellow. The head of T. apicata is at most slightly elongate and not evidently elongate as in T. bimaculata and T. juceliae sp. nov., and the anterior fronto-orbital seta is well-developed but less than half the length of the posterior fronto-orbital seta. Males of T. apicata bear an anteroventral row of long, spine-like setae.  Head (Fig. 1A). First flagellomere ovate, narrowing on distal half, with broad apex (Fig. 7J). Anterior margin of frons slightly convex, projecting over small antennal base without surpassing anterior margin of parafacial (Fig. 7N). Fronto-orbital plate broad and shiny, sometimes with three or four fronto-orbital setae. Parafacial pale brown. Vertex and median occipital sclerite blackish-brown; outer vertical seta aligned with four postocular setae, almost of same size; row of 2−5 occipital setae very short.

Lectotype of
THorax (Figs 1C; 8G). Dorsal longitudinal stripe of faint gray pruinescence; anterior notopleural seta subequal to posterior notopleural seta. Femora entirely brown; fore femur with several long anteroventral setae, diminishing in size distally and absent on distal third; ventro-apical surface of fore fourth tarsomere with four very thick setae.
abdomen. Dark brown with several long setulae laterally on posterior half of syntergite 1 + 2. Syntergosternite 8 protrudes basally, with two distal setae; epandrium twice the length of syntergosternite 8, reaching posterior half of third segment ventrally; surstylus narrow linear; cercus broad linear, slightly narrowing on distal third, with broad round apex; length of cercus half length of epandrium and twice length of surstylus; distiphallus partially sclerotized, flattened and bifurcated, with distal and coiled membranous area bearing a sclerotized spike ( Fig. 2A).

Female
Body length 4.6-5.6 mm. Fore femur and fourth tarsomere without thick ventral setae. Oviscape brown and shiny.

Remarks
Despite being a syntype labeled as TYPE, we are hereby designating the male specimen in the most complete condition of preservation as lectotype to stabilize the taxonomic concept of this species and its name. (Edwards, 1919)
Head (Figs 1b, 6C, e, 7o). First flagellomere ovate, narrowing on distal half, with broad apex (Fig. 7K). Anterior margin of frons convex, projecting over small antennal base without surpassing anterior margin of parafacial (or at most surpassing it very discreetly). Fronto-orbital plate broad and shiny. Parafacial pale brown to yellow. Vertex blackish-brown and median occipital sclerite paler; outer vertical seta aligned with 2−4 postocular setae of almost same length; row of 2−4 very short and hair-like occipital setae.
abdomen. Dark brown, with several long setulae laterally on posterior half of syntergite 1 + 2. Syntergosternite 8 with three median setae; epandrium 1.5−2.0 times as long as syntergosternite 8, reaching anterior half of third segment ventrally; distal margin of epandrium extended laterally; surstylus narrow linear; cercus broad and spatulate; length of cercus ½ to ⅔ length of epandrium and three times length of surstylus; distal margin of cercus with conspicuously long and thick setae; distiphallus partially sclerotized, with median membranous area distally bifurcated in a sclerotized spike and a membranous coiled up tube (Fig. 2B).

Remarks
The abdomen of the holotype is lost. However, the basally infuscate wing cells r 1 and r 2+3 indicate that it is a female specimen. The cercus morphologically differentiated varies in length among specimens and presents conspicuously long distal setae. According to Van Steenis & Hippa (2012) Diagnosis Teloneria juceliae sp. nov. and T. bimaculata have the head elongate and mostly yellow, except for the black frontal vitta and pale brown ventral half of occiput of the latter. Teloneria juceliae sp. nov. and T. ladyae sp. nov. are very similar in general color, both having the thorax yellowish-brown subshiny with dorsal brown and yellow areas; postpronotal lobe, notopleura, anepisternum, anepimeron and katepisternum partially yellow; and femora yellow with distal fourth black. These two species also have the inner vertical seta one third or more shorter than the length of the outer vertical seta. Exclusive characters of T. juceliae sp. nov. include having the first flagellomere pear-shaped with the distal half slightly twisted up (Fig. 4A), two well-developed fronto-orbital setae, a broad median dark brown line on the dorsal scutum (Fig. 4D) and the male fore femur with three rows of short and thick ventral setae.

Etymology
The specific epithet 'juceliae' is dedicated to D.S. Souza's mother, Jucelia Pereira de Santana Souza. Head (Fig. 4A). Anterior margin of frons straight; anterior fronto-orbital seta absent; middle fronto-orbital seta positioned near anterior margin of eye and as long as inner vertical seta; posterior fronto-orbital seta lost; outer vertical seta aligned with two subequal postocular setae; occipital setae inconspicuous. THorax (Fig. 4B). Sub-shiny and partially brown with yellow areas; broad median presutural dark brown line, medially divided near transverse suture; broad median brown postsutural line narrow near transverse suture, widening toward scutellum; scutellum brown dorsally and yellow laterally; anterior notopleural seta subequal to posterior notopleural seta; proepisternum yellow; ventral katepisternal seta hair-like and short. Fore and mid coxae yellow, hind coxa brown. Femora yellow with dark brown distal fourth, slightly paler on fore femur; fore tarsomeres without ventral setae; mid tibia cylindrical and thin; mid tarsomeres without ventral setae; hind trochanter without ventral patch of setulae.

Material examined
abdomen. Dark brown with several long setulae laterally on posterior half of syntergite 1 + 2. Syntergosternite 8 not protruded basally and without marginal setae; epandrium only slightly longer than syntergosternite 8, reaching anterior half of third segment ventrally; surstylus narrow linear; cercus broad linear, narrowing distally; length of cercus half length of epandrium and ⅔ length of surstylus (Fig. 2C).
Variation (males) Body length 4.6-6.6 mm. Wing length 5.2-6.5 mm and width 1.3-1.7 mm. Inner process of pedicel broad linear to slightly triangular. Anterior margin of frons straight to slightly convex; posterior frontoorbital seta longer than inner vertical seta; postocular setae vary from three long setae to one short plus three long setae or one short seta plus two long setae. Yellow parts of body slightly darker and dorsal longitudinal lines of thorax vary in intensity, especially on anterior half, where these can be yellow to black. Proepisternum brown. Specimens from India (TAUI 674,681,672,675) and two from Thailand (TAUI 1023, 1003) with thorax and pleuron mostly brown. Distiphallus partially sclerotized and flattened, with distal half divided by median membranous area and apex branched in two short membranous spikes.

Female
Body length 4.5-6.3 mm. Ventral katepisternal seta inconspicuous to absent in most females. Fore femur without ventral setae. Oviscape shiny, with dorsal line brown and laterally yellow to entirely brown.

Distribution
India, Thailand. Diagnosis Teloneria ladyae sp. nov. and T. juceliae sp. nov. are very similar in general color, both with thorax yellowish-brown sub-shiny with dorsal brown and yellow areas; postpronotal lobe, notopleura, anepisternum, anepimeron and katepisternum partially yellow; and femora yellow with distal fourth black. These species also bear an inner vertical seta one third or more shorter than the length of the outer vertical seta. Exclusive characters of T. ladyae sp. nov. include anterior margin of frons very convex, three well-developed fronto-orbital setae, hind trochanter with ventral patch of setulae and thorax mostly yellow, with two suprahumeral dark brown spots and one presutural median brown line. Within Neriidae, T. ladyae sp. nov. is the only species in which males bear strong mid legs, represented in the mid tibia thickening distally and mid tarsomeres with ventral setae.

Arista
The arista in Teloneria is apically brown, with shorter pubescence at the base and longer towards the apex. In Telostylus, the arista is apically white, densely pubescent and, in Chaetonerius, it is usually subapically, brown and micropilose.

1868) and
Chaetonerius obscurus (Brunetti, 1913)  . In Teloneria, the antennal base is clearly well-developed and surrounds the antennal socket in all the extension of its circumference with clear limits (Fig. 6E), whereas, in Chaetonerius, the limits of the antennal base and upper face vanish in the inner margin (Fig. 6F).

Inner process of pedicel
The inner process of pedicel is a diagnostic character for Neriidae (Buck 2010) and the differences in its shape have been broadly used as diagnostic for generic identification (Aczél 1961;Buck 2010;Sepúlveda & Souza 2020). Two main shapes have been described for Neotropical species of Neriidae: broad triangular, characteristic of Nerius Fabricius, 1805 (Fig. 7A) and narrow triangular to finger-like for the other genera ( Fig. 7B−H). A third shape, broad linear and positioned on the dorsal half, was described for Telostylus   (Fig. 7I), and is similarly observed in the species of Teloneria (Fig. 7J-K).

Fronto-orbital setae
Species of Chaetonerius bear three equally spaced fronto-orbital setae (Figs 6F, 7M) and most of the Telostylus species lack anterior and middle fronto-orbital seta (Figs 6A, 7L) (only present in Telostylus decemnotatus Hendel, 1913). In both Chaetonerius and Telostylus, the posterior fronto-orbital seta is positioned at the level of the posterior third of the eye, whereas in Teloneria, it is positioned at the level of the mid length of the eye (Fig. 7N-O). Moreover, the middle fronto-orbital seta in Teloneria is positioned at the anterior third of the eye, near the anterior fronto-orbital seta, which is positioned almost at the level of the anterior margin of eye.

Dorsocentral setae
The number of dorsocentral setae is a taxonomically informative character for the determination of the genera in Neriidae (Aczél 1961;Sepúlveda & Souza 2020). The presutural dorsocental seta is only present in Chaetonerius, Eoneria Aczél, 1951, Odontoloxozus Enderlein, 1922, Nipponerius Cresson, 1926, Protonerius de Meijere, 1924and Stypocladius Enderlein, 1922, and the number of postsutural dorsocentral setae is accurately constant amongst the genera of Neriidae Cerantichir Enderlein, 1922, Glyphidops Enderlein, 1922, Gymnonerius Hendel, 1913, Longina Wiedemann, 1830, Loxozus Enderlein, 1922 (Fig. 8G-H). These are different from the three equally spaced setae in Chaetonerius and the two prescutellar setae in C. latifemur, which likely represent a secondary loss within the genus. Likewise, the presutural dorsocentral seta, common in Chaetonerius and other genera with two or more postsutural setae, is also present in Teloneria. The position of this seta in Teloneria is only similarly found in Protonerius, being differently placed medially on the presutural scutum, when compared with other genera bearing this seta near the transverse suture. Barraclough (1993) referred to the 'scapular seta' as a very small seta positioned just lateral to the dorsocentral line, at the anterior margin of the presutural scutum ( Fig. 8D-E). This seta was described as a diagnostic character for Chaetonerius by  and for the Neotropical Cerantichir (Sepúlveda et al. 2013) and it is not known to be present in any other Oriental or Austral-Oceanic group of Neriidae. The scapular seta is also absent in Teloneria.

Wing
Morphological similarities are evident among the species of Telostylus and Teloneria, such as the wing being distally infuscate (Fig. 8H-J). Notwithstanding, patterns of wing infuscation can be differentiated by the highly defined limits on Teloneria and the darker infuscation on the apex of cell r1 in Telostylus.

Male genitalia
The male genitalia of representatives of Telostylus are uniform and taxonomically uninformative , whereas in Chaetonerius, they are the most accurate source of information for the identification of many species (Barraclough 1993). The male genitalia of Teloneria are similar to those of Chaetonerius. Both genera have an elongate and cape-shaped sternite 6 and, in some cases, the cercus is very elongate and has dense setae. However, differently from Chaetonerius, the epandrium, cercus and surstylus in Teloneria do not present conspicuous transformations.