Cyclosomus flexuosus (Fabricius)

Kavanaugh, David H. & Cueva-Dabkoski, Mollie, 2023, A Review of Genus Cyclosomus Latreille (Coleoptera: Carabidae: Lebiinae: Cyclosomini) in Asia., Proceedings of the California Academy of Sciences 67 (21), pp. 493-537 : 503-507

Cyclosomus flexuosus (Fabricius)

Figures 5 , 6 , 14B , 15B , 16B , 17B , 20

Carabus flexuosus Fabricius, 1775:246 . LECTOTYPE, here designated, a male, deposited in ZMUK, labeled: “ Scolytus flexuosus “ [handwritten]/ “ LECTOTYPE Carabus flexuosus Fabricius 1775 design. by D.H. Kavanaugh & M. Cueva-Dabkoski 2022” [red label]. Type locality: eastern India.

Scolytus flexuosus (Fabricius) , Fabricius (1790:221; 1792:180).

Cyclosomus flexuosus (Fabricius) , Andrewes (1921:153 and 166, 1924a:464, 1927:105, 1930:365); Heller (1923:302); Csiki (1932:1295); Lorenz (2005:452); Kavanaugh (2015).

Cyclosomus dytiscoides Nietner, 1857:312 . LECTOTYPE, here designated, a female, deposited in MFNB, labeled: “ Ceylon, Nietner ” [handwritten]/ “ Type ” [red label]/ “ SYNTYPUS Cyclosomus dytiscoides Nietner 1857 ” [red label]/ “ LECTOTYPE Cyclosomus dytiscoides Nietner 1857 design. by D.H. Kavanaugh & M. Cueva-Dabkoski 2023” [red label]. Paralectotypes examined: one female, also in MFNB, labeled: “ Cyclosomus dytiscoides Nietner ” [handwritten]/ “Type” [red label]/ “ SYNTYPUS Cyclosomus dytiscoides Nietner 1857 labeled by MNHUB 2013” [red label]/ “ PARALECTOTYPE Cyclosomus dytiscoides Nietner 1857 design. by D.H. Kavanaugh & M. Cueva-Dabkoski 2023” [yellow label]. Type locality: Sri Lanka, Western Province, Negombo. Chaudoir (1876:31); Bouchard (1903:174); Andrewes (1921:154, 1927:105); Csiki (1932:1295); Kavanaugh (2015:281). Synonymy proposed by Andrewes (1921:154)

Notes on types and nomenclature. We follow Andrewes (1921:31) in recognizing the Fabrician specimen at ZMUK as the type of C. flexuosus and provide lectotype designations for both C. flexuosus and C. dytiscoides to promote nomenclatural stability.

Diagnosis. Adults of C. flexuosus can be distinguished from those of other Cyclosomus species in Asia by the following combination of character states: Body size larger for genus, BL males = 8.2 to 9.4 mm, females = 8.3 to 9.8 mm; body form ( Figs. 5A, 5C , 6A, 6B ) slightly elongate ovoid; pronotum ( Fig. 14B ) relatively broader (ratio PWM/PL = 2.45 to 2.69), disc light reddish brown to rufopiceous, with lateral pale bands moderately broad but not sharply defined, anterior angles broad and broadly rounded apically, lateral margins smoothly arcuate, not sinuate near anterior angles; elytra with pattern of dark maculae more extensively developed than average in most specimens ( Figs. 5C , 6A ) but highly varied and less than average ( Figs. 5A , 6B ) in a few specimens, preapical dark spot present; elytral epipleuron with long setae over entire length (although many of these are broken off in many specimens); male median lobe with apical lamella slightly recurved dorsally in relation to ventral curvature of shaft in lateral aspect ( Fig. 16B ), apical lamella broadly triangular with a distinct, more narrowly-rounded projection apicomedially in dorsal aspect ( Fig. 17B ).

In describing C. flexuosus, Kavanaugh (2015) incorrectly stated “Male with middle tarsomeres 1 to 3 not laterally expanded and without ventral pads of adhesive setae.” In fact, C. flexuosus males, like those of all the other Cyclosomus species represented in Asia for which males are known, have middle tarsomeres 1 to 3 distinctly expanded in comparison with those in females and have two longitudinal rows of squamatous adhesive setae ventrally on tarsomeres 1 to 3. In contrast, most (four of six) species in the Afrotropical Region have the male middle tarsi similar to those of females in form (i.e., more slender) and in the absence of ventral adhesive setae.

This species demonstrates the greatest range of variation in elytral dark color pattern seen among all species in the Asian fauna. The extremes are represented in Fig. 6 , with the most broadly developed dark pattern ( Fig. 6A ) covering more than 50% of the elytral surface, and the least developed pattern ( Fig. 6B ) restricted to the basal dark band, a typical longitudinal dark band, a relatively narrow middle dark band extended only to interval 4, and a small preapical spot. The patterns seen in the type specimens of C. flexuosus ( Fig. 5A ) and its junior synonym, C. dytiscoides ( Fig. 5B ), are close to the opposite extremes for the species, so it is certainly understandable that they would have been described as distinct species on the basis of different color patterns.

Members of this species share epipleura having relatively long setae throughout their length only with those of C. philippinus ; but they differ from the latter in having a prepical pale spot present and pronota with the pale lateral bands less well-defined medially. Males of the two species differ markedly in the curvature of the male median lobe in lateral aspect (compare Fig. 16B with Fig. 16E ) and shape of the apical lamella in dorsal aspect (compare Fig. 17B with Fig. 17E ). The elytra color pattern of darker specimens of C. flexuosus is most similar to that seen in C. sumatrensis ( Fig. 11 ) and some C. suturalis ( Fig. 12C ) specimens; but members of both of these species have long epipleural setae only on the humeral and subhumeral regions and progressively and distinctly shorter setae to toward the apex. Also, males of these species have the male median lobe less curved in lateral aspect ( Figs. 16F, G ) and the apical lamella of distinctly different shape (compare Fig. 17B with Figs. 17F and 17G ).

Habitat distribution. Not yet reported, but presumed to be restricted to sandy substrates in the vicinity of streams or other water bodies and any associated dune systems, and likely also to occur in such sandy areas along ocean shores. Several localities from coastal areas both on the Indian Subcontinent and in Sri Lanka likely represent occurrences in coastal sand beach or dune habitats. The apparent elevational range of this species extends from at or near sea level (3 m on Mannar Island, Sri Lanka) to at least 500 m (near Kurseong in West Bengal, northern India).

Geographical distribution. We have examined a total of 176 specimens (90 males and 86 females) from the following localities: BANGLADESH / INDIA: “Bengala” ([one female; MFNB]). INDIA ([two males and one female; IRSNB]): Arunachal Pradesh: Bhalukpong (27.0333°/92.5833°, 150 m, 26 May-3 June 2006, P. Pacholátko collector [two females; NHMUK]) ; Gujarat: Kinara ([one female; NHMUK]); Karnataka: Belagavi ([one female; NHMUK]) ; Shivamogga ([one male; NHMUK]); Kerala: Malabar ([16 males and 17 females; IRSNB], [two females; NHMUK]) ; Madhya Pradesh: Barwai ([one males and three females; IRSNB]) ; Odisha: Brahmapur ([one female; NHMUK]) ; Puducherry: Karaikal ( Karaikal , July 1962, P.S. Nathan collector [eight male and four females; EMEC], August 1955 [one male; NMNH]) , July 1956 [16 males and seven females; CAS] , [one male and two females; MFNB]), ( Nedungadu , June 1931 [one female; NHMUK], 10 May 1932 [one male and one female; NHMUK]) , Mahé ( Malabar Coast , July 1951, M. Maindron collector [12 males and three females; IRSNB]) ; Tamil Nadu: Anaimalai Hills ( Cinkona , 1070 m, May 1966, P.S. Nathan collector [five males and ten females; MFNB]) , Chennai ([one male and one female; NHMUK]) , Coimbatore (October 1958 [three males and two females]; NHMUK]) , Ramanathapuram ([one male; IRSNB]) , Tiruchirappalli (1905, P. du Breuil collector [one male and four females; IRSNB] , R.P. Castets collector [one male and two females; IRSNB],([two males and two females; IRSNB], [one female; MFNB]) ; Uttarakhand: Kumaon Division ( West Almora , November 1918, H.G. Champion collector [two females; NHMUK]) ; West Bengal: Kurseong (1904 [three males and one female; IRSNB]) ; “ Ind. Or. ” ([one female; MFNB]) ; “ Inde Meridionale ” ([one female; IRSNB]) ; “ South India ” ([one female; NHMUK]) . NEPAL ([one female; NHMUK]) : Bagmati Province: Chisapani Garhi District ( Hetauda , 540 m, 26 September 1960, H. Brydon collector [one male and one female; CAS]) ; Lumbini Province: Bardiya National Park ( Babi River , 200 m, 28 June 2000, T.W. Harman collector [one female; NHMUK]) . SRI LANKA ([one female; MFNB]), ([two males and one female; NHMUK]) : Sabaragamuva Province: Kitulgala (Kitulgala Rest House, 150 m, 24-26 October 1977, K.V. Krombein, T. Wijesinhe, M. Jayaweera, and P. A. Panawatta collectors [one male; NMNH]), Uggalkaltota (150 m, 10-14 October 1970, O.S. Flint, Jr. collector [two males; NMNH]) ; North Central Province: Polonnaruwa (4 May 19080, W.N. Mathis, T. Wijesinhe, and L. Jayawickrema collectors [one female; NMNH]) ; Northern Province: Kondachchi ( Ma Villu , 11-12 April 1981, K.V. Krombein, L. Weeratunga, and P. Leanage collectors [one female; NMNH] , Mannar Island (3.2 km W of Pesalai, 3 m, 24 March 1970, Davis and Rowe collectors [six males and one female; NMNH]) ; Western Province: Colombo ([one female; NHMUK]) , Negombo ([two females; MFNB]) . Specimens without or with illegible locality data: (5 July 1909 [one male; NHMUK]) ([one male; NHMUK]) .

The known geographical range of C. flexuosus ( Fig. 20 ) covers most of the Indian Subcontinent, from the southern base of the Himalayan Mountains in the north to Sri Lanka in the south. We have examined specimens from Arunachal Pradesh, Gujarat, Karnataka, Kerala, Madhya Pradesh, Odisha, Puducherry, Tamil Nadu, Uttarakhand, and West Bengal states in India, as well as Nepal, and Sri Lanka. Kavanaugh (2015) reported on a disjunct record of this species from “Nubia” (historical name for the area including southern Egypt and northern Sudan centered on the Nile River valley ) and commented on that occurrence.

Geographical variation. Although there is evident individual variation ( Figs. 5A, 5C , 6 ) in development of the dark color pattern of the elytra throughout the range of this species, we could not discern any particular geographic component to that variation.

Geographical relationships with other Cyclosomus species. This species has been found synotopic only with C. acutangulus (in Arunachal Pradesh, India) at the northwesternmost known locality for the latter species. The range of C. flexuosus overlaps that of C. vespertilio sp. nov. in northern India and Nepal, but these two species have not yet been found together. Known localities for C. flexuosus in northern West Bengal and C. suturalis in southernmost Sikkim are less than 30 km apart, so at least some overlap in their ranges is likely. Because of uncertainty with respect to the respective geographical ranges of C. inustis , C, marginatus , and C. suturalis (see discussions below), it is possible but not yet confirmed that one or more of these overlap with C. flexuosus at least in the eastern part of its range.

Figures

FIGURE 5. Cyclosomus flexuosus Fabricius. A. Holotype male, dorsal habitus; B. Labels associated with C. flexuosus holotype; C. Cyclosomus dytiscoides Nietner, lectotype female, dorsal habitus; D. Labels associated with C. dytiscoides lectotype. Scale lines = 1.0 mm.

FIGURE 6. Cyclosomus flexuosus Fabricius, dorsal habitus. A. Dark male (Cinkona, Anaimalai Hills, Tamil Nadu, India); B. Pale female (Tiruchirappalli, Tamil Nadu, India). Scale lines = 1.0 mm.

FIGURE 14. Pronota, Cyclosomus spp., dorsal aspect. A. C. acutangulus Kavanaugh and Cueva-Dabkoski (Bhalukpong, Arunachal Pradesh, India); B. C. flexuosus (Fabricius) (Hetauda, Bagmati Province, Nepal); C. C. inustus Andrewes, holotype (Hong Kong, China); D. C. marginatus Motschulsky (India); E. C. pallidus Kavanaugh and Cueva- Dabkoski sp. nov. (Karachi, Sindh Province, Pakistan); F. C. philippinus Heller (Pili, Zambales Mountains, Luzon, Philippines); G. C. sumatrensis Bouchard (Taman Negra National Park, Pahang, Malaysia); H. C. suturalis (Wiedemann), lectotype (“Bengala”, India); I. C. vespertilio Cueva-Dabkoski and Kavanaugh sp. nov. Scale lines = 0.5 mm.

FIGURE 15. Prosternal intercoxal process, Cyclosomus spp., left lateral aspect. A. C. acutangulus Kavanaugh and Cueva-Dabkoski (Longchuan Jiang at Longjiang Bridge, Wuhe Township, Tengchong County, Yunnan, China); B. C. flexuosus Dejean (Cinkona, Anamalia Hills, Tamil Nadu, India); C. C. sumatrensis Bouchard (Taman Negara, Pahang, Malaysia); D. C. verspertilio Cueva-Dabkoski and Kavanaugh sp. nov. (New Delhi, Delhi, India). Scale lines = 0.5 mm.

FIGURE 16. Male genitalia, Cyclosomus spp., left lateral aspect. A. C. acutangulus Kavanaugh and Cueva-Dabkoski (Longchuan Jiang at Longjiang Bridge, Wuhe Township, Tengchong County, Yunnan, China); B. C. flexuosus Dejean (Karaikal, Puducherry, India); C. C. inustus Andrewes (“China”); D. C. marginatus Motschulsky (“Bengal”, India); E. C. philippinus Heller (Pili, Zambales Mountains, Luzon, Philippines); F. C. sumatrensis Bouchard (Taman Negara, Pahang, Malaysia); G. C. suturalis (Wiedemann), lectotype (“Bengala”, India); H. C. verspertilio Cueva-Dabkoski and Kavanaugh sp. nov. (New Delhi, Delhi, India). Scale lines = 0.5 mm.

FIGURE 17. Male genitalia, Cyclosomus spp., dorsal aspect. A. C. acutangulus Kavanaugh and Cueva-Dabkoski (Longchuan Jiang at Longjiang Bridge, Wuhe Township, Tengchong County, Yunnan, China); B. C. flexuosus Dejean (Karaikal, Puducherry, India); C. C. inustus Andrewes (“China”); D. C. marginatus Motschulsky (“Bengal”, India); E. C. philippinus Heller (Pili, Zambales Mountains, Luzon, Philippines); F. C. sumatrensis Bouchard (Taman Negara, Pahang, Malaysia); G. C. suturalis (Wiedemann), lectotype (“Bengala”, India); H. C. verspertilio Cueva-Dabkoski and Kavanaugh sp. nov. (New Delhi, Delhi, India). Scale lines = 0.5 mm.

FIGURE 20. Map showing distribution of locality records for Cyclosomus specimens examined. Yellow circles = C. acutangulus Kavanaugh and Cueva-Dabkoski; white triangles = C. flexuosus Dejean; yellow triangle = locality where C. acutangulus and C. flexuosus have been found together; white squares = C. inustus Andrewes. Modified from Wikimedia Commons, World Atlas of the World, at URL: <http://upload.wikimedia.org/wikipedia/commons/8/8f/ Whole_world_land_and_oceans_12000.jpg>. Scale line = 500 km.

FIGURE 11. Cyclosomus sumatrensis Bouchard, dorsal habitus. A. Dark male (Kras, Kediri, East Java, Java, Indonesia); B. Pale male (Taman Negara, Pahang, Malaysia). Scale lines = 1.0 mm.

FIGURE 12. Cyclosomus suturalis (Wiedemann). A. Scolytus suturalis Wiedemann, lectotype male, dorsal habitus; B. Labels associated with lectotype; C. Dark male ((Longchuan Jiang at Nongkan village, Zhefang Township, Mangshi, Yunnan, China). Scale lines = 1.0 mm.