Research Article |
Corresponding author: Niladri Hazra ( nhazra@zoo.buruniv.ac.in ) Academic editor: Martin Husemann
© 2022 Somnath Chatterjee, Gouri Sankar Pal, Niladri Hazra.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Chatterjee S, Pal GS, Hazra N (2022) Descriptions of two new species of Culicoides Latreille from Sundarbans, India with an adult key to the ornatus species group of the Oriental region (Diptera, Ceratopogonidae). Evolutionary Systematics 6(1): 89-102. https://doi.org/10.3897/evolsyst.6.84170
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Two new species of biting midges, Culicoides cornatus sp. nov. and Culicoides pileus sp. nov. are described based on adults. The new species are compared to their congeners with close similarity. All specimens were collected from the Indian Sundarban Mangrove Forests, few specimens were mounted in glass slides and few were prepared for SEM study. Total 78 species under the genus Culicoides Latreille including the two new ones (6 species from ornatus species group) are described from India. An adult key of the ornatus species group from the Oriental Region is provided.
Adult Key, India, New species, ornatus group, Sundarbans, Taxonomy
Culicoides Latreille, 1809 is one of the most species rich genera of the family Ceratopogonidae with approximately 1368 valid species, 32 subgenera, 38 species groups, and 176 unplaced species described worldwide (
The ornatus species group of this genus comprises of 33 species worldwide (
Distribution of the species of ornatus group of the genus Culicoides Latreille reported from the Oriental region.
Sl. No. | Name of the species | Distribution |
---|---|---|
1. | C. aequalispinus Nandi, Mazumdar & Das Gupta, 2013 | India |
2. | C. circumbasalis Tokunaga, 1959 | Indonesia, Malaysia, Papua New Guinea, Philippines, Thailand |
3. | C. cordiger Macfie, 1934 | Australia, Papua New Guinea, Malaysia, Philippines |
4. | C. corti Causey, 1938 | Malaysia, Thailand, Vietnam |
5. | C. damnosus Delfinado, 1961 | Indonesia, Malaysia, Philippines |
6. | C. flumineus Macfie, 1937 | Indonesia, Malaysia, Philippines |
7. | C. fuscitibialis Nandi, Mazumdar & Das Gupta, 2013 | India |
8. | C. garciai Wirth & Hubert, 1989 | Malaysia |
9. | C. griffithi Wirth & Hubert, 1989 | Laos, Thailand |
10. | C. hewitti Causey, 1938 | Malaysia, Philippines, Thailand, Vietnam |
11. | C. hollandiensis Tokunaga, 1959 | Indonesia |
12. | C. infulatus Delfinado, 1916 | Indonesia, Philippines |
13. | C. cornatus sp. nov. | India |
14. | C. maai Wirth & Hubert, 1989 | Malaysia |
15. | C. mcdowelli Delfinado, 1961 | Indonesia, Philippines |
16. | C. niphanae Wirth & Hubert, 1989 | Thailand |
17. | C. okinawensis Arnaud, 1956 | Indonesia, Japan, Laos, Taiwan, Thailand, Vietnam |
18. | C. palawanensis Delfinado, 1961 | Indonesia, Malaysia, Philippines |
19. | C. pampangensis Delfinado, 1961 | Indonesia, Malaysia, Philippines, Sri Lanka, Thailand |
20. | C. pangkorensis Wirth & Hubert, 1989 | Indonesia, Malaysia |
21. | C. papuensis Tokunaga, 1962 | Brunei, Indonesia, Papua New Guinea, Philippines |
22. | C. pateli Nandi, Mazumdar & Das Gupta, 2013 | India |
23. |
C. peliliouensis Tokunaga, in |
Kiribati, Indonesia, Malaysia, Philippines, Thailand, Vietnam, India |
24. | C. pileus sp. nov. | India |
25. | C. pongsomiensis Chu, 1986 | Cambodia |
26. | C. ornatus Taylor, 1913 | Australia, Papua New Guinea, Indonesia, Malaysia, Singapore |
27. | C. quatei Wirth & Hubert, 1989 | Indonesia, Malaysia |
In this paper we describe two new species of the genus Culicoides Latreille belonging to the ornatus species group from the Indian Sundarban Deltaic region and provide a key to the adults of the species of the ornatus group of the Oriental Region.
Adults of both sexes of Culicoides pileus sp. nov. and C. cornatus sp. nov. were caught using ultraviolet light trap with an 8W UV light operated besides the cow shed adjoining to mangrove forest area in Sundarbans (Fig.
A–C. Collection site. A. Outline map of India; B. Google map of West Bengal (Source: maps.google.com); C. Collection site of Culicoides cornatus sp. nov. and C. pileus sp. nov.
Morphology and terminology of adults follow
Type specimens are now in the Entomological collections of the Department of Zoology, University of Burdwan (India) and will be deposited to the National Zoological Collections (NZCI), Kolkata (India) in due course.
Abbreviations of morphological terms used in the text and/or figures: Adult. AR – antennal ratio; SCh – sensilla chaetica; SCo – sensilla coeloconica; P/H – proboscis to head ratio; PR – palpal ratio; CR – costal ratio; WL – wing length; WW – wing width; TRn – tarsal ratio; BUENTD – Burdwan University Entomology Division; NZCI – National Zoological Collections of India.
Genus Culicoides Latreille, 1809
Subgenus unplaced, ornatus species group
Holotype : male, labelled as ‘Holotype Culicoides cornatus Chatterjee, Pal and Hazra, India, West Bengal, South 24 Parganas, Balibazar [22°08'88"N, 88°75'72"E], 16.04.2019, Coll. S. Chatterjee’ (NZCI). Paratypes: 1 male and 3 females, data as holotype (BUENTD).
Eyes with interfacetal hair, wing with inconspicuous pale marking, pale spot on cell r3 occupying greater than half of the entire cell, tips of veins pale; horn shaped appearance of anterior portion of parameres.
Female (n = 3). Head. Brown, eyes with interfacetal hair (Fig.
A–H. Adult male and female of Culicoides cornatus sp. nov. A. Female maxillary palp; B. Female antenna; C. Female legs (femur and tibia); D, Female hind tibial comb; E. Female spermatheca; F. Paramere of male genitalia; G. Aedeagus of male genitalia; H. Male genitalia. Scale bar: 0.05 mm.
A–E. Adult male and female of Culicoides cornatus sp. nov. A. Female wing (Photograph); B. Female thorax (Photograph); C. Female Eye (SEM Photograph); D. Female maxillary palp (SEM Photograph); E. Female hind tibial comb. (SEM Photograph).
Thorax
(Fig.
Wing
(Fig.
Leg
(Fig.
Abdomen. Brown; two large, subequal, roughly rounded functional spermathecae with sclerotised necks, measuring one 55.20–57.50 (55.35) µm by 46.00–48.30 (47.00) µm, another one 52.90–55.20 (54.05) µm by 41.40–43.70 (42.55) µm; both with slender, moderately long neck, rudimentary third one and faintly sclerotised ring present (Fig.
Male (n = 1). Same as female with the usual sexual differences.
Head. Brown. Eyes with interfacetal hair, separated by distance of 2 ommatidia; frontovertex with 28 SCh; palpus pale, palpal segment III moderately swollen with apical shallow sensory pit; PR 2.5.
Thorax. Dark brown.
Wing. Similar with female except morphometric characters. Distribution of macrotrichia in cells; wing length 0.89 mm, width 0.34 mm.
Leg. Brown in colour, all legs uniformly dark without any pale region; hind tibial comb with 4 spines and nearest to spur longest, spur tip frayed.
Abdomen. Ninth sternum with shallow caudomedial excavation; ventral membrane not speculated; ninth tergum with lateral margin more or less straight.
Genitalia
(Fig.
New species shows similarities with C. aequalispinus and C. fuscitibialis but differs from the former in wing pattern and spine structure of hind tibial comb (second nearest the spur longer in C. aequalispinus). Culicoides fuscitibialis differs from the new species in disposition of some pale spots of wing and structure of third palpal segment. New species shows similarities with C. circumbasalis Tokunaga, 1959 and C. cordiger Macfie, 1934 in wing pattern but differs in many attributes such as eyes with interfacetal hair and pale spots on wing inconspicuous in Culicoides cornatus sp. nov. Culicoides cornatus shows similarities with C. cordiger Macfie, 1934 in wing pattern but differs in attributes like eyes (eyes with interfacetal hair in new species but eyes are bare in C. cordiger), antennal ratio, mandibular teeth number and distribution of SCo on antennal segments. The new species shows similarities with C. corti Causey, 1938 in some characters like eyes with interfacetal hair, disposition of some pale spots on wing but differs in characters like palpal ratio, distribution of SCo, and on antennal segments (SCo are present on I–XII in C. cornatus but SCo on I and XI–XIII in C. corti), P/H ratio, shape of the aedeagus and paramere. Distribution of SCo on antennal segments of Culicoides cornatus are similar with C. damnosus Delfinado, 1961 and C. flumineus Macfie, 1937 but differs in characters like eyes with interfacetal hair, antennal ratio, mandibular teeth, and number and disposition of pale spots on wing. Culicoides cornatus shows similarities with C. palawanensis Delfinado, 1961 in SCo distribution and hairy eyes but differs in disposition of pale spots on wing, shape of the parameres and aedeagus, P/H ratio (much less in C. cornatus), mandibular teeth number (17 in C. cornatus but 11–13 in C. palawanensis), and antennal ratio. Culicoides cornatus also shares similarities with C. papuensis Tokunaga, 1962 in disposition of some pale spots on wing but differs in the presence of interfacetal hair on eyes in Culicoides cornatus (bare in C. papuensis), distribution of SCo on the antennal segments, mandibular teeth number, antennal ratio and the shape of parameres. Culicoides cornatus differs with C. hollandiensis Tokunaga, 1959 in pale marking of wing (inconspicuous pale marking in C. cornatus whereas prominent pale marking present in C. hollandiensis) and shape of the aedeagus (terminally rounded in C. hollandiensis). Culicoides cornatus differs from C. pampangensis Delfinado, 1961 in structure of paramere and pale marking of wing. Culicoides cornatus is different from C. paragarciai Dyce, 1996 in pale marking on wing (pale marking absent in C. paragarciai) and structure of hind tibial comb (hind tibial comb with 5 spines and 2nd from the spur is longest in C. paragarciai whereas 4 spines and 1st from the spur longest in C. cornatus). Culicoides quaterifasciatus Tokunaga, 1959 differs in presence of densely spread macrotrichia on wing and also some pale marking is different from C. cornatus.
The name ‘cornatus’ refers to Latinised version of cow horn shaped appearance of anterior portion of parameres.
The species was collected in adjacent to Indian Sundarbans Deltaic region, a world heritage site (West Bengal state). Adult midges were collected from a cowshed using an ultraviolet light trap in the type locality, situated in the vicinity of Datta River. The type locality is at an altitude of 7.50 m above sea level.
Holotype : male, labelled as ‘Holotype Culicoides pileus Chatterjee, Pal and Hazra, India, West Bengal, South 24 Parganas, Balibazar [22°08'88"N, 88°75'72"E], 16.04.2019, Coll. S. Chatterjee’ (NZCI). Paratypes 2 males and 5 females, data as holotype (BUENTD).
Eyes bare; wing with one distal pale spot in cell r3 separated from wing margin; cell m1 with two pale spots, distal one away from wing margin; anal cell with one distal pale spot with slight medial constriction; SCo present on flagellomeres I–VII and IX–XII; parameres basally fused, cap shaped basal knob, mid portion wide, distally slender, abruptly bent laterad with pointed end.
Description. Female (n = 5). Head. Brown. Eyes bare (Fig.
A–H. Adult male and female of Culicoides pileus sp. nov. A. Female maxillary palp; B. Female antenna; C. Female legs (femur and tibia); D. Female hind tibial comb; E. Female spermatheca; F. Paramere of male genitalia; G. Aedeagus of male genitalia; H. Male genitalia. Scale bar: 0.05 mm.
A–E. Adult male and female of Culicoides pileus sp. nov. A. Female wing (Photograph); B. Female thorax (Photograph); C. Female Eye (SEM Photograph); D. Female hind tibial comb (SEM Photograph); E. Female mandible (SEM Photograph).
Thorax
(Fig.
Wing. Wing pattern as in figure 5A, costa moderately long; cell r2 moderately broad with distinct lumen, macrotrichia sparse, arranged from middle to distal most portion of wing; wing length 0.77–0.80 (0.78) mm; width 0.38–0.42 (0.40) mm; CR 0.64–0.65 (0.645). wing spots moderately distinct, second radial cell completely in dark region; pale spot over r-m cross vein moderately large, extending from vein M1 to costal margin; post stigmatic pale spot obliquely placed with slight medial constriction; cell r3 with distal large pale spot away from wing margin; cell M1 with two pale spots, distal one separated from wing margin; cell m2 with narrow pale streak connecting pale spot at basal arculus, pale spot behind medial fork and distal pale spot; distal pale spot touching wing margin; cell cua1 with moderately large, roughly round pale spot touching CuA1 vein and broadly touching wing margin; anal cell with one medially constricted distal pale spot, proximal one extended to pale spot at arculus.
Leg
(Fig.
Abdomen. Brown; two large subequal roughly rounded functional spermathecae with sclerotised necks, measuring one 46.00–50.60 (48) µm by 41.40–43.70 (42.55) µm, another one 43.70–48.30 (46.00) µm by 39.10–41.40 (40.25) µm; both with slender, moderately long neck, rudimentary third one, and faintly sclerotised ring present (Fig.
Male (n = 3). Same as female with the usual sexual differences.
Head. Brown. Eyes bare, separated by distance of 1–2 ommatidia, frontovertex with 18–21 SCh. Palpus pale; palpal segment III moderately swollen with apical shallow sensory pit; PR 2.00.
Thorax. Dark brown.
Wing. Similar with female except distribution of macrotrichia in cells; macrotrichia sparse, mostly arranged on distal one third portion of wing; wing length 0.81–0.83 (0.82) mm, width 0.36–0.38 (0.37) mm.
Leg. Light brown in colour, hind tibial comb with 4 spines and nearest to spur longest, spur tip frayed.
Abdomen. Ninth sternum with shallow caudomedial excavation; ventral membrane not speculated; ninth tergum with lateral margin more or less straight.
Genitalia
(Fig.
New species shows similarities with C. aequalispinus in bare eyes and mandibular teeth number but differs in attributes like distribution of SCo on antennal segments, and presence of two equal length spines nearest to the spur in C. aequalispinus. The new species shares a few similarities with C. peliliouensis Tokunaga in
The name ‘pileus’ refers to Latinised version of cap shaped basal knob of parameres.
The species was collected from Sundarbans Mangrove Forest in India (West Bengal state). Adult midges were collected from a cowshed using an ultraviolet light trap in the type locality situated in the vicinity of Datta River. The type locality is at an altitude of 7.50 m above sea level.
Distribution of Oriental species of ornatus group has been presented in Table
Distribution of the Oriental species of ornatus group of the genus Culicoides Latreille. The number(s) in the bubbles of the respective countries depicts the species (Sl. nos.) presented in Table
We convey our sincere thanks to Dr P. K. Chaudhuri, former Professor, Department of Zoology, The University of Burdwan, for critically going through the manuscript and rendering valuable suggestions. The authors thank Mr. Basudev Das, Senior Technical Assistant, University Science Instrumentation Centre (USIC), The University of Burdwan, for the fabrication and maintenance of the ultraviolet light trap. Authors are thankful to Dr. Shubhranil Brahma for sorting of specimens and slide preparation.The research is supported by West Bengal Biodiversity Board, Government of West Bengal, India [number 703/3K(Bio)–1/2016]. The authors are thankful to the Head, DST-FIST sponsored Department of Zoology, University of Burdwan and Ministry of Science and Technology (DST-PURSE Programme), New Delhi, India for providing research facilities. We are grateful to the Department of Forest, Govt. of West Bengal, for giving permission to carry out the fieldwork.