taxonID	type	description	language	source
03B38784FFCE066FFE7EFB00901EB0CB.taxon	description	urn: lsid: zoobank. org: act: 4 A 4 C 7 F 2 E- 0792 - 4 EBE-A 7 E 1 - 7 AD 822 D 5 A 903 Figs 1 – 3, 7 A – C	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFCE066FFE7EFB00901EB0CB.taxon	diagnosis	Diagnosis The species is well distinguished from morphologically similar species by a combination of the following features: scutum entirely black, without pruinose vittae in males (Fig. 1 A), or indistinct pruinose vittae sometimes present laterally in females (Fig. 3 A). The anterior half of the wing has a distinct yellowish brown infuscation (Fig. 1 A – B), indistinct in females (Fig. 3 A). The terga are mainly orange with a black posterior margin and median vittae on terga II – III (Figs 2 D, 3 D). In male, the ventral margin of the surstylus is sinuous at the middle (Fig. 7 C).	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFCE066FFE7EFB00901EB0CB.taxon	etymology	Etymology The species is named after Enrico Adelelmo Brunetti to honour his immense contribution to the Indian Diptera, especially Syrphidae. The specific name brunettii refers to his surname and should be treated as a noun in the genitive case.	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFCE066FFE7EFB00901EB0CB.taxon	materials_examined	Type material Holotype INDIA – West Bengal • ♂; Hooghly, Arambagh; 22.86355 ° N, 87.80362 ° E; 15 m a. s. l.; 20 Apr. 2024; B. Roy leg.; sweep netting; GenBank no.: PQ 615094; NZSI. Paratypes INDIA – West Bengal • 1 ♀; same collection data as for holotype; GenBank no.: PQ 615095; NZSI • 1 ♂, 3 ♀♀; same collection data as for holotype; NZSI • 1 ♀; Murshidabad, Malipara; 24.15341 ° N, 88.37381 ° E; 40 m a. s. l.; 8 Mar. 2020; Banerjee and party leg.; pan trap; GenBank no.: ON 421642; NZSI • 4 ♂♂, 3 ♀♀; Birbhum, Suri; 23.906383 ° N, 87.527732 ° E; 71 m a. s. l.; 7 Mar. 2024; B. Roy leg.; sweep netting; NZSI • 2 ♂♂, 3 ♀♀; Hooghly, Arambagh; 22.86355 ° N, 87.80362 ° E; 15 m a. s. l.; 26 May 2024; B. Roy leg.; sweep netting; NZSI.	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFCE066FFE7EFB00901EB0CB.taxon	description	Description Male MEASUREMENTS. Body length 6.0 – 8.5 mm, wing length 5.5 – 7.5 mm, FH 0.19 – 0.24, WM 2.08 – 2.31. HEAD (Fig. 2 A – B). Eye holoptic, yellow, with dark patches, pilose on the dorsal half, eye contiguity about 12 – 16 facets long; vertical triangle shining black, fully occupied by ocellar triangle, entirely covered with black pile, ocelli dark red; frons shining blueish black with black pile, lateral margin narrowly pruinose; face yellowish grey pruinose with shining blueish black median vitta, facial pilosity pale yellow; facial tubercle moderately developed, gena and subcranial cavity black; occiput black with greyish white pruinosity, pilosity black dorsally and greyish white ventrally; antennae yellowish orange, postpedicel about 1.9 × as long as wide, dorsal half dark brown, arista dark brown, bare. THORAX. Mesonotum shining black with blue reflection, covered with dense, erect black pile; scutum without pruinose vittae; postpronotum and anterolateral area of scutum before transverse sulcus with pale yellow pruinosity; pleura black, with greyish white pruinosity on posterior half of anterior anepisternum, anterodorsally on posterior anepisternum, posteriorly on anepimeron, anterodorsally on katepisternum and meron; pleural pilosity pale yellow mainly, intermixed with black pile on anterodorsal part of anepimeron; anterior anepisternum and meron bare; posterior anepisternum densely pilose anterodorsally, rest of pleura comparatively sparsely pilose (Fig. 2 C). Wings with distinct yellowish brown infuscation on anterior half, veins dark brown, pterostigma brown; calypters blackish grey (Fig. 1 A); haltere orange. Legs mainly black; pale yellow at apex of pro- and mesofemur, apical half of protibia, whole mesotibia, extreme apex of metatibia, apical 1 – 2 tarsomeres of pro- and mesoleg, and basitarsomere of metaleg; pile on leg black and yellow intermixed; yellow on basal ⅔ of meso­ and metafemur and basal ⅓ of profemur; black pile on rest of profemur, dorsally on pro- and mesofemur, entirely on metatibia, intermixed with yellow pile on pro- and mesotibia; pile on tarsomeres of all legs yellow and black intermixed, shorter and denser than those on femora and tibia; presence of black setulae at basolateral extreme of all tibia, and apico-laterally on all tarsomeres. ABDOMEN (Fig. 2 D). Abdomen yellowish orange; tergum I with shining black area at middle; terga II – III with black posterior margin and median black vittae; tergum IV with or without median black vitta and posterior margin narrower than that on terga II – III; tergum V completely black; pile on abdomen yellow, except on black part, laterally on terga II – III, and anterolateral corner oftergum II with black pile (Fig. 2 D); sterna I – III yellow, rest of sterna brownish black, pilosity on sterna yellow (Fig. 1 B). GENITALIA (Fig. 7 A – C). Cercus sub-triangular, wider than high; surstylus rounded on extreme apex with black reclinate setulae (Fig. 7 B), anteriorly with a few pile and scattered setulae, ventral margin of surstylus sinuate at the middle (Fig. 7 A); hypandrium curved, almost uniformly broad throughout its length, postgonite with 2 ventral projections, one apical and one sub-medial, nearly equal in length (Fig. 7 C). Female (Fig. 3) Body length 5.5 – 7.2 mm, wing length 5.8 – 7.0 mm, FH 0.27 – 0.30, WM 2.06 – 2.25. Similar to male except for normal sexual dimorphism and following characteristics: eye dichoptic, bare; postpedicel about 1.6 × as long as wide; area anterior to vertex, frons and face along eye margins greyish white pruinose, pile on frons black; mesonotal pile yellow intermixed with black ones; tergum III with incomplete posterior margin and a trace of black vitta, pile on anterolateral corner of tergum II yellow.	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFCE066FFE7EFB00901EB0CB.taxon	biology_ecology	Biology Eristalinus brunettii Roy, Naskar & Banerjee sp. nov. exhibits a preference for high­flying behaviour, typically frequenting the canopies of tall woody trees such as Mangifera indica L. (Anacardiaceae) and Syzygium cumini (L.) Skeels (Myrtaceae). The species also occurs occasionally on ground-cover vegetation and agricultural lands.	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFCE066FFE7EFB00901EB0CB.taxon	distribution	Distribution West Bengal (India).	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFCE066FFE7EFB00901EB0CB.taxon	discussion	Remarks Specimens identified herein as Eristalinus brunetti sp. nov. were previously treated as morphological variants of E. polychromata due to similarities in the general habitus and abdominal colouration. Detailed morphological examination, however, revealed consistent differences in the body pilosity, colouration, wing infuscation, and the structure of the surstylus and postgonite, separating these specimens from E. polychromata (Table 2). Additionally, the female specimen ON 421642 (NZSI), earlier identified as E. polychromata (Kar et al. 2024), was re-examined and found to exhibit the diagnostic characters defined for E. brunetti; molecular analysis further recovered this specimen within the E. brunetti clade. Accordingly, the specimen is here assigned to E. brunetti as a paratype.	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFC30668FE6DFACA9132B2A5.taxon	description	urn: lsid: zoobank. org: act: 36 EF 7774 - E 588 - 41 C 7 - B 886 - 6684 D 385 B 68 E Figs 4 – 6, 7 G – I	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFC30668FE6DFACA9132B2A5.taxon	diagnosis	Diagnosis Eristalinus sapphirinus Roy, Naskar & Banerjee sp. nov. can be distinguished from other resembling Eristalinus by a combination of the following features. The body is shining blueish black. In male, a sharply triangular head in the lateral view, with a smooth face profile and a weakly developed facial tubercle (Fig. 5 A). Wing vein R 4 + 5 with an appendix on the loop (Fig. 5 D). The abdomen has yellowish brown maculae on tergum II and blueish grey on terga III – IV (Figs 5 C, 6 D). The male genitalia has the ventral margin curved of surstylus outward at the middle and rounded posteriorly (Fig. 7 I).	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFC30668FE6DFACA9132B2A5.taxon	etymology	Etymology The specific name is from Latin sapphirinus (‘ sapphire-coloured’) and indicates the shining blueish black sheen of the species.	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFC30668FE6DFACA9132B2A5.taxon	materials_examined	Type material Holotype INDIA – West Bengal • ♂; Hooghly, Arambagh; 22.86474 ° N, 87.80363 ° E; 15 m a. s. l.; 22 Nov. 2022; B. Roy leg.; sweep netting; GenBank no.: PQ 622673; NZSI. Paratypes INDIA – West Bengal • 1 ♀; Hooghly, Arambagh; 22.86355 ° N, 87.80362 ° E; 15 m a. s. l.; 20 Apr. 2024; B. Roy leg.; sweep netting; GenBank no.: PQ 622674; NZSI • 1 ♂, 5 ♀♀; Hooghly, Arambagh; 22.86355 ° N, 87.80362 ° E; 15 m a. s. l.; 20 Apr. 2024; B. Roy leg.; sweep netting; NZSI • 4 ♂♂, 5 ♀♀; Hooghly, Arambagh; 22.86355 ° N, 87.80362 ° E; 15 m a. s. l.; 28 Mar. 2025; B. Roy leg.; sweep netting; NZSI • 1 ♀; Hooghly, Arambagh; 22.86309 ° N, 87.80278 ° E; 15 m a. s. l.; 13 Jun. 2025; B. Roy leg.; sweep netting; NZSI.	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFC30668FE6DFACA9132B2A5.taxon	description	Description Male MEASUREMENTS. Body length 9.9 – 10.2 mm, wing length 8.5 – 8.8 mm, FH 0.21 – 0.23, WM 2.10 – 2.20. HEAD. Head sharply triangular laterally, strongly tapering towards vertex (Fig. 5 A); eye greenish yellow with tiny purple maculae, pilose on dorsal half, eye contiguity about 19 – 22 facets long, eye facets larger on dorsal part; vertical triangle shining black with dark brown pile, ocelli reddish orange; frons and face with yellowish grey pruinosity, pilosity on frons black and pale yellow on face, facial tubercle poorly developed, black and bare; gena yellowish grey pruinose, subcranial cavity brown; occiput with greyish white pruinosity, with black pile dorsally and greyish white pile ventrally; antennae orange, postpedicel about 1.9 × as long as wide, orange-yellow with dark brown dorsal margin, arista bare, brownish orange, darker apically (Fig. 5 A). THORAX. Mesonotum shining blueish black, covered with yellowish brown pile, intermixed with black pile on notopleuron, lateral side of scutum after transverse sulcus, and lateral margin of scutellum, pile longer on pleura, sterna and posterior margin of scutellum; scutum with 5 longitudinal yellowish grey pruinose vittae (Fig. 4 A); pleura with greyish white pruinosity on postpronotum, notopleuron, posteriorly on anterior anepisternum, upper part of anepimeron and posterior anepisternum (Fig. 5 B); pleural pilosity pale yellow; anterior anepisternum and meron bare; posterior anepisternum densely pilose anterodorsally, remaining pleura comparatively sparsely pilose (Fig. 5 B). Wings hyaline, stigma pale, vein R 4 + 5 curved, with appendix at its extreme lower point (Fig. 5 D); upper and lower calypter blackish grey, with dark margins (Fig. 4 A); haltere pale yellow. Legs mainly black; pale yellow at the apex of all femora, basal ½ of pro­ and mesotibia, basal ⅓ of metatibia and 1 – 3 tarsomeres of all legs (Fig. 4 C); presence of black pile anteriorly on procoxa and trochanter, anteroventrally on mesocoxa and anteriorly on mesotrochanter; femora and tibiae with denser and longer black pile on black part and comparatively shorter and sparser pale yellow pile on pale yellow part; ventral surface of meso- and metafemur with longer pale yellow pile compared to rest of leg pilosity; black setulae present apically on all tibiae, apicolaterally on protarsomeres, ventrally and apicolaterally on mesotarsomeres, laterally on metatarsomeres. ABDOMEN. Ovate, shining blueish black, finely punctate on dorsal surface; tergum I shining black, grey pruinose; tergum II with transverse, yellowish brown maculae (Fig. 5 C) and dull black, arcuate fascia, reaching posterior margin laterally, leaving blueish grey posterior margin in middle; terga III – IV similar to tergum II, except shining blueish grey maculae; tergum V shining blueish grey; abdominal pilosity mainly yellowish white, more distinct laterally, black pile present posterolaterally on tergum II; sternum II pale yellow, with remaining sterna shining black, pilosity on sterna yellowish white. GENITALIA (Fig. 7 G – I). Cercus nearly square-like (Fig. 7 G), wider than high; apex of surstylus rounded with black reclinate setulae, anteriorly with a few pile and scattered setulae (Fig. 7 G – H), ventral margin expanded and curved outward at middle and rounded posteriorly; hypandrium curved, suddenly narrowing towards apex, postgonite with 2 ventral projections, one large hook-shaped projection apically and one small incurved hook, submedially (Fig. 7 I). Female (Fig. 6) Body length 8.9 – 9.7 mm, wing length 7.8 – 8.3 mm, FH 0.26 – 0.30, WM 2.05 – 2.23. Similar to males except for normal sexual dimorphism and following characteristics: eyes dichoptic, bare; postpedicel about 1.7 × as long as wide; maculae on tergum II dark brown (Fig. 6 D); all sterna shining blueish black (Fig. 6 B).	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFC30668FE6DFACA9132B2A5.taxon	biology_ecology	Biology The species was first recorded in November 2022, feeding on Mikania micrantha Kunth (Asteraceae) blooms along a roadside drainage channel in a locality of West Bengal. Subsequent observations in April 2024 and March 2025 in the same locality documented small aggregations, primarily of females, cooccurring with congeners — Eristalinus arvorum (Fabricius, 1787), E. megacephalus (Rossi, 1794), and E. brunettii sp. nov. — on a medium-sized Streblus asper Lour. (Moraceae) tree adjacent to a domestic drainage system and close to sesame (Pedaliaceae) cultivation. Females were frequently observed exhibiting slow hovering flight and prolonged floral visitation, making them more readily collectible than the agile males. Additionally, a solitary female was collected in June 2025 from a nearby sesame crop field.	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFC30668FE6DFACA9132B2A5.taxon	distribution	Distribution West Bengal (India).	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFC30668FE6DFACA9132B2A5.taxon	discussion	Remarks Eristalinus sapphirinus sp. nov. shows morphological affinities with several Indian congeners bearing a unicolourous (black, blueish black or aeneous) scutellum, but can be readily distinguished by its shining blueish black body with yellowish brown to dark brown maculae restricted to abdominal tergum II and the presence of an appendix on the loop of vein R 4 + 5. It differs from Eristalinus tarsalis (Macquart, 1855), which has conspicuous creamy white maculae or fasciae on the abdominal terga, by the complete absence of such markings and by its metallic blueish colouration. Among the aeneous-bodied species such as E. aeneus (Scopoli, 1763) and E. sepulchralis (Linnaeus, 1758), it is similar to them in lacking creamy abdominal markings, but differs by its vivid blueish sheen and the presence of yellowish brown to dark brown maculae on tergum II. The new species also exhibits a close affinity in the male genital morphology to E. polychromata and its allied species E. brunettii sp. nov., in the arched hypandrium and elongate, apicoventrally hooked postgonite with a distinct subventral projection; however, in E. sapphirinus, the ventral margin of the surstylus is curved outward medially and rounded posteriorly, while it is distinctly sinuous medially in E. brunettii and nearly straight in E. polychromata. Externally, E. sapphirinus can be further distinguished from E. polychromata and E. brunettii by its predominantly blueish black body with yellowish brown maculae confined to tergum II. In contrast, both E. polychromata and E. brunettii possess orange abdominal terga with black posterior margins and distinct or indistinct median vittae. Apart from this, the male genitalia of Eristalinus sapphirinus sp. nov. share similarities with those of E. megacephalus, particularly in the structure of the epandrium, surstylus, and the curvature of the hypandrium, but differ in the configuration of the postgonite, and exhibit a marked similarity with E. taeniops (Wiedemann, 1818) in the structure of the hypandrium and postgonite (Pérez-Bañón et al. 2003).	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFC40674FDBBF92495CCB2CD.taxon	description	Figs 8 – 11, 7 D – F	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFC40674FDBBF92495CCB2CD.taxon	diagnosis	Diagnosis Small to medium-sized species (5.0 – 7.2 mm). Male: eyes holoptic, pilose on dorsal half; postpedicel brownish orange, longer than wide with dark brown dorsal margin (Fig. 10 A – B); mesonotum shining black, scutum with four distinct pruinose vittae (Fig. 9 A); mesonotal pile yellow, intermixed with black ones (Fig. 9 C); pleural pilosity all yellow (Fig. 10 C); wing nearly hyaline (Fig. 9 A), without distinct infuscation, though brownish tinge sometimes may present; abdomen mainly orange, tergum II with black posterior margin and distinct median black vitta, terga III – IV with narrow posterior margin (compared to tergum II), without median vittae, sometimes traces of median vitta may present anteriorly on tergum III, tergum V black (Fig. 10 D); male genitalia (Fig. 7 D – F): mid-ventral margin of surstylus nearly straight (Fig. 7 D), hypandrium narrowing towards apex, postgonite with 2 ventral projections (Fig. 7 F). Female: eyes dichoptic, bare; tergum III with distinct, black posterior margin and median vitta (Fig. 11).	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFC40674FDBBF92495CCB2CD.taxon	materials_examined	Type material Holotype (Fig. 8) INDIA • 1 ♂; Calcutta; J. Bigot; NZSI, ZSI 1411 / 8. Other material examined INDIA – West Bengal • 2 ♂♂, 6 ♀♀; Hooghly, Arambagh; 22.86355 ° N, 87.80362 ° E; 15 m a. s. l.; 26 Jun. 2022; B. Roy leg; sweep netting; NZSI • 7 ♂♂, 4 ♀♀; Birbhum, Suri; 23.906383 ° N, 87.527732 ° E; 71 m a. s. l.; 7 Mar. 2024; B. Roy leg.; sweep netting; NZSI.	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFC40674FDBBF92495CCB2CD.taxon	description	Description of male genitalia Cercus squarish; surstylus rounded on extreme apex, with black reclinate setulae (Fig. 7 H), ventral margin of surstylus nearly straight at middle (Fig. 7 G); hypandrium curved, narrowing apically, postgonite with two ventral projections, apical one forms a crescent-shaped curve rather than hook, sub-medial projection hook-shaped (Fig. 7 I).	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFC40674FDBBF92495CCB2CD.taxon	biology_ecology	Biology The species exhibits predominantly ground-level activity and a strong association with low vegetation and crop fields. Individuals were frequently seen visiting plants, e. g., Phyla nodiflora (L.) Greene (Verbenaceae), Mimosa pudica L. (Fabaceae) and Croton bonplandianus Baill. (Euphorbiaceae). Occasional co-occurrence on ground-cover vegetation with E. brunettii sp. nov. was also observed.	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFC40674FDBBF92495CCB2CD.taxon	distribution	Distribution Bihar, Himachal Pradesh, Kerala, Odisha, Tripura, West Bengal (India).	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
03B38784FFC40674FDBBF92495CCB2CD.taxon	discussion	Remarks Both males and females of E. polychromata share similarities with E. brunettii sp. nov. in the general appearance of the body; mainly orange abdominal terga with black posterior margins and median vittae, the complete absence of creamy white markings on abdomen, and the shape of the hypandrium and projections of postgonite. However, the two species can be readily distinguished by the characters summarized in Table 2.	en	Roy, Bristi, Kar, Oishik, Naskar, Atanu, Sengupta, Jayita, Banerjee, Dhriti (2026): Two new species of the genus Eristalinus Rondani, 1845 (Diptera: Syrphidae) from the Gangetic Plains of Eastern India. European Journal of Taxonomy 1062: 1-33, DOI: 10.5852/ejt.2026.1062.3286, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3286/14493
