Nesocaedius borneensis sp. n. (Tenebrioninae Latreille, 1802: Opatrini Brullé, 1832) from Borneo is described. For some species already cited in a previously published checklist, exact data are given for Borneo for the first time. New locality data are provided for rarely found species.
The genus Nesocaedius was established by Kolbe (1915). According to Grimm & Lillig (2020), the genus included six species until now. In this paper, a new species is described from Kalampunian Beach in north-eastern Borneo, near the “Tip of Borneo”, Malaysia. Its congeners are psammophilic seashore tenebrionids and might feed on seaweed fungi or scavenge on seaside plants, but no detailed information has been reported (Ando & Yamasako 2015).
In the present ninth part of the series concerning new and little known species of Tenebrionidae from Borneo, exact data for some species cited from Borneo by Grimm & Schawaller (2021) are given for the first time, and new locality data are provided for rarely found species.
Material and methods
Acronyms of depositories
Dr. Roland Grimm collection, Neuenbürg, Germany (now in SMNS);
Museum Zoologi Bogor, Indonesia; obtained by Royal Ontario Museum (ROM), Toronto, Canada (Dr. D. Chris Darling);
Natural History Museum, London, UK (Mr. Maxwell Barclay);
Staatliches Museum für Naturkunde, Stuttgart, Germany (Dr. Arnaud Faille and Dr. Wolfgang Schawaller);
Zoologische Staatssammlung Munich, Germany (Dr. Michael Balke).
Tenebrioninae Latreille, 1802
Amarygmini Gistel, 1856
Amarygmus (Amarygmus) elegans Bremer, 2002
Amarygmus (Amarygmus) genalis Bremer, 2009
Sabah, Danum Valley, 4°58′N/117°48′E, M. D. F. Ellwood, “Parashorea tementella, Asplenium nidus”, Tembaling, 2: FogTray 4, 19.X.1999, 2 ex. (NHMUK).
Amarygmus (A.) genalis was described from W. Malaysia (Bremer 2009) and was cited also from Sabah (Bremer 2010). No exact data from Borneo had been previously published.
W. Malaysia, E. Malaysia/Sabah (Bremer 2010).
Amarygmus (Amarygmus) silvester Bremer, 2004
Sabah, Mt. Kinabalu Nat. Park, Poring Hot Springs, 9–11.III.2007, R. Grimm leg., 1 ex. (CRG). – Sarawak, Kubah Nat. Park, Matang Wildlife Centre, 19–22.IX.2008, R. Grimm leg., 1 ex. (CRG). – Sarawak, Gunung Gading Nat. Park, 100–300 m, 4–7.IV.2016, R. Grimm leg., 1 ex. (CRG). – W. Kalimantan, Gunung Palung Nat. Park, Cabang Panti Res. Sta., 1e rainforest, 100–400 m, 1°15′S/110°05′E, 15.VI.–1.VII.1991, Darling, Rosichon & Sutrisno leg., 1 ex. (ROM).
W. Malaysia, Sumatra, Borneo (Bremer 2010).
Diaperinae Latreille, 1802
Diaperini Latreille, 1802
Ceropria caesarea Gebien, 1925
Sabah, Mt. Kinabalu Nat. Park, Poring Hot Springs, 525 m, 8–10.IV.2013, R. Grimm leg., 1 ♂, 1 ♀ (CRG).
Malaysia, Borneo (Masumoto 1995).
Hypoplaeini Billberg, 1820
Corticeus (Cnemophloeus) cephalotes (Gebien, 1913)
Sabah, E Keningau, Bingkor, 30.III.2007, R. Grimm leg., 2 ex. (CRG). – Sabah, Tenom, 300 m, 24–25.I.2007, R. Grimm leg., 1 ex. (CRG).
Corticeus (C.) cephalotes was already mentioned in the checklist of darkling beetles of Borneo (Grimm & Schawaller 2021), but up to now no exact data from Borneo had been published.
India including Andaman Islands, Thailand, Vietnam, Taiwan, Philippines: Luzon, Palawan; Indonesia: Sumatra, Lombok; Australia, Comoros (Bremer 1999); E. Malaysia/Sabah (new record).
Tenebrioninae Latreille, 1802
Opatrini Brullé, 1832
Nesocaedius borneesis sp. n.
Holotype ♂: Kalampunian Beach, near “Tip of Borneo”, 22.II.2014, leg. R. Grimm (CRG, now SMNS).
Paratypes: Same data as for holotype, 21 ex. CRG, 3 ex. SMNS. – Same locality as holo-type, but 22–23.I.2010, leg. R. Grimm, 3 ex. (CRG, now SMNS).
Named after Borneo, where the type series was collected.
Ovoid, distinctly convex above; body dark reddish brown to black; setae yellowish brown. Body length 2.8–3.2 mm, width 1.3–1.6 mm.
Head widest across genae, transversely elliptical, weakly convex, with granules dense, large and flat; clypeus deeply notched at apex, devoid of fronto-epistomal suture; genae basally arcuate at lateral ends. Apical maxillary palpomeres distinctly securiform, with external margin about three times as long as inner margin. Antenna (Fig. 3) 11-segmented, feebly clavate, compactly articulate; antennomeres 8–9 widest, 10th subquadrate, with dense sensory hairs at apex. Eyes constricted by genal canthus; each in narrowest part one facet wide. Mentum reverse trapezoidal. Gula deeply depressed.
Pronotum transverse, width/length ratio 1.59–1.92, widest near middle, anterior margin straight; lateral margins straight in the middle, arcuately narrowed to basal corners, basal margin entirely arcuate; anterior angles rounded; basal angles obtusely arcuate; disc distinctly convex, with compact, flattened granules. Scutellum invisible. Prosternal process rhombic, depressed in middle, irregularly tuberculate.
Elytra oval, strongly convex, weakly rounded at sides, widest near middle; disc irregularly and densely granulate, bearing short and irregular setae apically at posterior end; granules almost subtriangular and moderately erect; lateral margins with irregularly serrate granules throughout.
Ventral side densely granulate, irregularly setiferous; prothoracic hypomera unevenly flattened, sparsely and minutely tuberculate, with dense and long setae along lateral margins. Mesoventrite lower than coxae. Metaventrite short, as long as first abdominal ventrite, weakly convex, irregularly granulate, and longitudinally depressed in the middle. Abdominal ventrites densely granulate.
Legs of fossorial type, robust. Tibiae irregularly tuberculate; protibiae dilated, explanate and flattened, with sinuate and setiferous outer margin and shallowly arcuate inner margin. Femora short and very thick, irregularly setaceous.
Aedeagus: see Fig. 4.
The known species of the genus are quite similar. Of the six hitherto known species, four occur in Southeast Asia (Grimm & Lillig 2020): N. insularis Ando & Yamasako, 2015 (Bali), N. schultzei Kolbe, 1915 (Philippines), N. taiwanus Shibata, 1979 (Taiwan) and N. vermiculatus Shibata, 1979 (Taiwan). According to Ando & Yamasako (2015), N. schultzei and N. taiwanus have eye at narrowest part of the combined width of two facets. Nesocaedius insularis is characterized, among other characters, by the obviously produced genal process (Ando & Yamasako 2015: fig. 1). Nesocaedius vermiculatus has, according to Shibata (1979), the elytra with irregular striae that are rather distinct on the basal half, formed by vermiculate granules.
Stenochiinae Kirby, 1837
Cnodalonini Gistel, 1856
Borneocamaria laticornis (Waterhouse, 1882)
Sabah, Poring Hot Springs, 380 m, 9–11.III.2007, leg. R. Grimm, 1ex. (CRG). – Sabah, Tenom, 300 m, 25.I.2010, leg. R. Grimm, 1ex. (CRG). – Sabah, Kinabalu Nat. Park, Headquarter, 1600 m, 20.VIII.1998, leg. D. Bartsch & C. Häuser, 1 ex. (SMNS). – Sabah, Tawau Hillls Park, Tawau River, 8.VI.1998, J. Kodada & F. Ciampor, 1 ex. (SMNS).
Borneo, Indonesia: Sumatra (Masumoto 1993).
Cerocamptus malayanus (Fairmaire, 1893)
Sabah, SW Sandakan, Kuamat, 700 m, 5°13′N/117°30′E, 10.IV.2014, leg. S. Chew [Bosuang], 1 ex. (CRG).
Borneo (Masumoto 1993).
Hoploedipus bidentulus Fairmaire, 1898
Sarawak, Santubong Penisula, Permai Rainforest Resort, 30–150 m, 10–14.II.2012, R. Grimm leg., 1 ex. (CRG). – Same locality, but 29.III.–3.IV.2016, R. Grimm leg., 1 ex. (CRG).
Singapore, E. Malaysia/Sarawak (Kaszab 1984).
Picocamaria geniculata (Pic, 1915)
Sabah, Crocker Mts., Gunung Emas, 500–900 m, 6–21.V. 1986, leg. I. Jenis, 1 ex. (ZSM). – Sabah, Mt. Trus Madi, 1100 m, 1–15.IV.2005, leg. K. Martini, 2ex. (CRG). – Sabah, Crocker Range, Gunung Emas Highland Resort, 11–13.V.2002, leg. T. Kothe, 1 ex. (CRG). – Sabah, Mt. Kinabalu Nat. Park, headquarter, 1550 m, 7–9.I.2010, leg. R. Grimm, 1 ex. (CRG). –Sabah, Kinabalu Nat. Park, headquarter, 1500 m, 19–28.III.2001, leg. S. Löffler, 1 ex. (SMNS).
E. Malaysia/Sabah (Masumoto 1993b).
Picocamaria subparallela (Pic, 1915)
Sabah, Mt. Trus Madi, 1100 m, 1–15.IV.2005, leg. K. Martini, 2 ex. (CRG). – Sabah, 16 miles point from Keningau, 7–8.IV.1991, leg. O. Furata, 1 ex. (ZSM). – Sabah, Crocker Range, 24.IV.2005, leg. S. Chew [Bosuang], 1 ex. (SMNS).
Borneo (Masumoto 1993b).
Robustocamaria andoi (Masumoto, 1989)
Sabah, Crocker Range, Gunung Alab, V.2005, leg. S. Chew [Bosuang], 2 ex. (CRG). – Sabah, vic. Ranau, 22.IV.2007, leg. S. Chew [Bosuang], 1 ex. (CRG). – Sabah, Crocker Range, Kimanis Road, 1100–1300 m, 2–4.IX.1998, leg. D. Bartsch & C. Häuser, 1 ex. (SMNS).
Borneo (Masumoto 1993b).
Robustocamaria tibialis (Kulzer, 1954)
Sabah, Mt. Trus Madi, 14.V.2007, leg. S. Chew [Bosuang], 2 ex. (CRG). – Sabah, SW Sandakan, Kuamat, 700 m, 5°13′N/117°30′E, 10.IV.2014, leg. S. Chew [Bosuang], 2 ex. (CRG).
Borneo (Masumoto 1993b).
I am grateful to Edgar Müller (Saarwellingen) for producing the photographs, Dr. Martin Lillig (Saarbrücken) for dissecting the aedeagus and other parts of the new species, and Dr. Wolfgang Schawaller for providing the data of the SMNS material. Cordial thanks for loans of specimens are due to Drs. Michael Balke (Munich), Arnaud Faille and Wolfgang Schawaller (both Stuttgart). Thanks are also due to Prof. Dr. Hans J. Bremer (Osnabrück) for information on Amarygmus (A.) elegans and A. (A.) genalis.