Sphaeridium sundense Suzumura, van Berge Henegouwen, and Budi, 2022

Suzumura, Alyssa Lee, Henegouwen, Arno van Berge & Budi, Anang Setyo, 2022, A New Species of Sphaeridium Fabricius, 1775 (Coleoptera: Hydrophilidae) from Indonesia, The Coleopterists Bulletin 76 (1), pp. 85-94 : 87-93

Sphaeridium sundense Suzumura, van Berge Henegouwen, and Budi , new species

zoobank.org/ urn:lsid:zoobank.org:act:806E15E1-6F1C-48D1-9EC2-675A0D582980 ( Figs. 1–3 , 4A , 5A, C, E , 6 )

Type Material. Holotype. “[ SM-03-MO-012 ]/ 09°40′17′′S 120°21′43′′E /[Sumba: Indonesia]/ Desa Watumbaka,/ Kecamatan Pandawai ,/ Kabupaten Sumba Timur ,/ Propinsi Nusa Tenggara /Timur (NTT), 28.Jan.2003,/ M.Ôhara and S. Hartini ” (1♂) . Paratypes. Kei: (= “Insel Key”), Coll. Régimbart (4♂♂, MNHN); (= “ Kai Isl ”), (1♂, ZMHB) . Wetar: (= “Wetter Insel”), Apr.1901, S.quinquemaculatum d’Orchymont det. (15♂♂, 9♀♀, ZMHB; 2♂♂, 2♀♀, ALBH; 1♂, RBINS); 19.Jun.1917, coll. Corporaal, S.quinquemaculatum d’Orchymont det. (1♂, RBINS); 1927, coll. C.H.Moore, S.quinquemaculatum J.Balfour-Browne det. (4♂♂, 3♀♀, NHMUK); Coll. Régimbart (1♂, MNHN). Timor : [TI-03-MO-002] Desa Penfui , Kecamatan central Kupang , Propinsi Nusa Tenggara Timur ( NTT), 10°10′01′′S 123°39′49′′E, 23.Jan.2003, coll. M.Ôhara (2♂♂, 2♀♀, SEHU); [ TI-03-MO-003 ] Desa Baumata ( Fenonisa ), Kecamatan central Kupang , Propinsi Nusa Tenggara Timur ( NTT), 10°11′49′′S 123°40′20′′E, 23.Jan.2003, coll. M.Ôhara (1♀, SEHU); [ TI-03-MO-025 ] Desa Camplong Il , Kecamatan Fatuleu , Kabupaten Kupang , Propinsi Nusa Tenggara Timur ( NTT), 10°00′58′′S 123°59′02′′E, 1.Feb.2003, coll. M.Ôhara (2♂♂, SEHU); [ TI-03-MO-027 ] Desa Boentuka , alt. 100m, Kecamatan Batuputih , Kabupaten Timor Tengah Selaten, Propinsi Nusa Tenggara Timur ( NTT), 10°57′34′′S 123°09′01′′E, 1.Feb.2003, coll. M.Ôhara (1♂, 1♀, SEHU); [ TI-03-MO-029 ] Desa Oekabiti , Kecamatan Amarasi , Kabupaten Kupang , Propinsi Nusa Tenggara Timur ( NTT), 10°10′30′′S 123°49′46′′E, 2.Feb.2003, coll. M.Ôhara (1♂, SEHU). Flores: [ FL-03-MO-006 ] Desa Baramari, Kecamatan , Nanguala , Kabupaten Ende , Flores , Propinsi Nusa , Tenggara Timur ( NTT), 08°47′88′′S 121°33′58′′E, 25.Jan.2003, coll. M.Ôhara (1♂, 2♀♀, SEHU); [ FL-03-MO-009 ] Desa Labolewa , Kecamatan Aesesa , Kabupaten Ngada , Flores, Propinsi Nusa Tenggara Timur ( NTT), 08°39′64′′S 121°19′49′′E, 25.Jan.2003, coll. M.Ôhara (1♀, SEHU); Woloare , Desa Roworena ca 5 km N of Ende, sea level, 09.Apr.1986, coll. A.L.van Berge Henegouwen & S.Pariwono 147 (4♂♂, 4♀♀, ALBH) from kerbau dung by hand in cultivated area (2♂♂, CNCI); Sikka 5 km W of Lela near junction with Ende road , sea level, 19.Apr.1986, A.L.van Berge Henegouwen & S.Pariwono 157 (66♂♂, 58♀♀, ALBH), from fresh kerbau dung by hand (2♂♂, 4♀♀, CNCI). Sumba: [SM-03-MO-012] Desa Watumbaka, Kecamatan Pandawai , Kabupaten Sumba Timur , Propinsi Nusa Tanggara Timur ( NTT), 09°40′17′′S 120°21′43′′E, 28.Jan.2003, coll. M.Ôhara and S. Hartini (1♂, SEHU); [SM-03- MO-013] Desa Lupah Watumbaka, Kecamatan Pandawai , Kabupaten Sumba timur, Propinsi Nusa Tenggara Timur ( NTT), 09°38′75′′S 120°24′14′′E, 29.Jan.2003, coll. M.Ôhara (FIT trap) (3♂♂, 2♀♀, SEHU); [SM-03-MO-014] Desa Watuhadang , Kecamatan Umalulu , Kabupaten Sumba timur, Propinsi Nusa Tenggara Timur (NTT), 09°56′16′′S 120°38′50′′E, 29.Jan.2003, coll. M.Ôhara (3♂♂, 2♀♀, SEHU); [SM-03-MO-021] Desa Makaminggit , Kecamatan Nggaha Ori Ango, Kabupaten Sumba timur, Propinsi Nusa Tenggara Timur ( NTT), 09°42′53′′S 120°01′76′′E, 30.Jan.2003, coll. M.Ôhara (1♀, SEHU). Sumbawa : [SB-00-MO-034], Desa Tatebal , Kecamatan Ropang, Kabupaten Sumbawa Besar, Propinsi Nusa Tenggara Barat ( NTB), 08°48′50′′S 117°19′45′′E, 9.Nov.2000, coll. M.Ôhara (2♂♂, 1♀, SEHU); [SB-00-MO-037], ca. 5 m. Desa Sukajaya , Kecamatan Plampang, Kabupaten Sumbawa Besar , Propinsi Nusa Tenggara Barat ( NTB), 08°45′48′′S 117°50′15′′E, 11.Nov. 2000, coll. M.Ôhara (1♂, 1♀, SEHU); [SB-00-MO-039], Desa Tolonggeru , Kecamatan Bolo, Kabupaten Bima, Propinsi Nusa Tenggara Barat (NTB), 08°29′48′′S 118°32′43′′E, 11.Nov.2000, coll. M.Ôhara (1♀, SEHU); Desa Belo 21 km S of Bima, sea level, 02.Apr.1986, coll. A.L.van Berge Henegouwen & S.Pariwono (13♂♂, 11♀♀, ALBH); Lape ca 35 km E of Sumbawa Besar, 200 m, 29.Mar.1986, coll. A.L.van Berge Henegouwen & S.Pariwono (16♂♂, 15♀♀, ALBH). Lombok : [LO-00-MO-026], alt. 55m. Desa Betek, Kecamatan Pamenang , Propinsi Nusa Tenggara Barat ( NTB), 08°26′40′′S 116°05′07′′E, 6.Nov.2000, coll. M.Ôhara (1♂, SEHU). Bali: Banyuwedang, 2.Jul.1976, coll. van Zon, (1♂, 3♀♀, RMNH); Lalanglingah (= Lalang Linggah) near Lalian Beach , 08°30′04′′S, 114°58′13′′ E, hill side near beach, from Bos sondaicus dung, coll. R.T.A.Schouten (6♂♂, 5♀♀, ALBH). Java: [JA-05-MO-58] West Java: Ds. Sukaresmi, 400m alt., Kec. Sukamakmur , Kab. Jonggol , 27.XI.2005, 06°32′22′′S 107°03′66′′E, coll. M.Ôhara leg., collected from cow dung (Bali sapi in cowshed) (2♂♂, SEHU). Kota Batoe , coll. v.de Poll, (5♂♂, 6♀♀, ALBH; USNM); Java, S.quinquemaculatum d’Orchymont det. (1♂, RBINS); Java, coll. Horsfield, (1♂, NMHUK); Slawi Tegal , 1909 coll. Valck Lucassen (1♂, RBINS); Baluran Nature Reserve near Bekol, 16.Jun.1976, coll. van Zon, Bos javanicus dung, (2♂♂, 1♀, RMNH). [ MZB. COLE.125.878] Banten: Ujung Kulon , Cidaon , XII.1958, coll. A.M.R. Wegner (1♀, MZB); [MZB.COLE.125.613] Central Java: Cilacap, V.1935, coll. Drescher (1♂, MZB). Sumatra: Balige, 10.Mar.1891, coll. Modigliani, S.quinquemaculatum d’Orchymont det. (1♀, RBINS); 10.1890, Balige, Oct.1890, coll. Modigliani (1♂, ZMUC); Fort de Cock (Bukitinggi) 1925, coll. Jacobson, from cow dung, S.quinquemaculatum d’Orchymont det. (1♀, RBINS); Medan, Tjinta Radja (= “Tjintaradja”), 19.Jun.1917, coll. Corporaal, S.quinquemaculatum d’Orchymont det. (1♂, RBINS); Padang , 1890, coll. Modigliani, (1♂, ZMUC); Padang Pandjang , 1896, coll. Kannegieter, S.quinquemaculatum d’Orchymont det. (2♀♀, RBINS); Padang Pandjang , 800m, 1.Apr.1896, coll. Kannegieter, S.quinquemaculatum var noire d’Orchymont det. (1♂, ZMAN); Tandjong Morawa / Serdang , coll. Hagen (1♀, RMNH) .

Description. Small, body length 3.0–5.0 mm, body width 2.0–3.0 mm. Body shape oval to slightly subquadrate, moderately compressed dorsoventrally.

Coloration not widely variable, usually as in Fig. 1 , head black, sometimes with a small indistinct reddish spot at middle behind level of eyes, labrum reddish, pronotum black with wide yellow stripe along lateral margins ( Figs. 1A, C , 4A ), continuing around anterior and posterior angles but not contacting posterior margin; elytra black to reddish in more freshly emerged adults, lateral margins with yellow border beginning slightly posterior to base, widening before midlength, continuing around posterior tip and ending abruptly at about 1/4 to 1/3 the length of elytral suture, border of this stripe indistinct posteriorly; lacking reddish humeral spots; epipleuron fulvous. Pygidium dark brown on anterior 1/2–1/4, yellow posteriorly. Ventral base color dark brown except narrow yellow stripe on gula, lateral portions of pronotum, and posterior margins of ventrites ( Fig. 1B ); legs yellow with brown spots at centers of femora. Mentum piceous-testaceous, maxillary palps yellow, antennae yellow with dark brown club.

Dorsal surface of head with dense, uniform punctures separated by less than their diameter except around smooth epicranial sutures, interstices with shallow microsculpture. Eyes of normal size, excised on anterior margin. Labrum exposed, anterior margin straight medially, with dense, flat, golden pubesence anteriorly, surface covered in dense transverse microrugae. Mentum ca. 0.6 times as long as wide, slightly bisinuate on anterior margin, lateral margins gently curved, surface with deep, coarse setiferous punctures, interspaces with dense, conspicuous microrugae ( Fig. 2A ); gula parallel-sided or slightly wider posteriorly, of normal width, not distinctly wide or narrow.Antennal club symmetrical, compact.

Pronotum with bisinuate posterior margin; lateral margins evenly curved, with irregular row of small blunt spines along posterior 2/3 ( Fig. 2B ); marginal beading wide, flat, continued along anterior margin, ending at posterior margin; posterolateral corners forming an oblique angle. Surface covered in dense punctures separated by less than their diameter, slightly larger than those on head, interspaces with dense, granulate microsculpture ( Figs. 2B, F ). Proventral process convex, weakly tectiform posteriorly between coxae, forming a large spine at posterior apex, and bearing 2−4 strong spines along longitudinal median line, the anterior of which is flanked by several weaker spines, golden setae, and sparse pubesence ( Fig. 2C ).

Scutellar shield about twice as long as wide, sides almost parallel-sided anteriorly, gently curved posteriorly ( Fig. 1A ); surface densely punctured, consistent with surrounding punctation on elytra, interspaces without discernable microsculpture.

Elytra ovoid, sides strongly rounded, apices rounded separately; sutural interval slightly raised, surface flat, continuous with marginal beading which is distinct along lateral margins and around posterior apices ( Figs. 1C, D ). Surface covered in dense, uniform punctures separated by less than their diameter, interspaces with distinct granulate microsculpture and sparse microrugae throughout; striae distinct, though larger strial punctures not evenly aligned, without grooves, interspaces flat ( Fig. 1A ). Mesoventral process as in Figs. 2D and 3F , anterior protrusion triangular, distinctly longer than wide, with a distinctive symmetrical pattern of long, strong spines: four rows of strong spines of increasing size numbering 3-6-4-2 from anterior to posterior. Posterior lip slightly convex, slightly shorter than protrusion, separated from lateral areas of mesoventrite by posterolateral angles of protrusion, distinctly raised above level of metaventrite, lacking pubesence on surface ( Figs. 2D , 3F : pml).

Metaventrite with metaventral field slightly raised as in Fig. 2E , convex, longer than wide, lateral margins not distinctly separated from surrounding lateral areas, median furrow weakly continuing posterior to transverse furrows which are only distinct centrally, curved laterally, meeting at an oblique angle; posterior margin between metacoxae gently curved, emarginate medially; surface covered in deep uniform punctures, separated by about 2× their diameter, interspaces with dense microrugae ( Fig. 2G ), central area posterior to transverse furrow with fewer punctures but microrugae strong throughout.

Procoxae with strong spines and sparse short indistinct setae, lacking long golden pubesence interspersed among the spines, with dentiform process at internal posterior apex. Posterior margin of trochanters with a row of spines continuing along posterior margin of femora. Male protarsus modified, with tarsomeres 1–4 shortened and slightly widened and tarsomere 5 almost as long as segments 1–4 combined, tarsomere 5 a little wider than tarsomere 4, with apical outer margin straight to slightly curved, slightly longer along ventral margin, without pointed angular process ( Fig. 3E ). Hind tibia with one small, moderately strong spine on ventral surface ( Fig. 1B ).

Pygidium weakly tectiform, apex obtusely pointed; abdominal ventrite 5 with apex evenly rounded, surface bare, without fringe of short setae.

Abdominal apex simply rounded, without emargination.

Male genitalia as in Figs. 3A–D . Ratio of median lobe:tegmen = 1.73. Median lobe with sides parallel on basal half, slightly constricted at about apical 1/3–1/4, slightly widened before tip, with truncate apical process; parameres about half the length of median lobe, rather wide on ventral side, with rounded tips.Abdominal segment IX about half the length of the lateral struts, apex roundly pointed, median ridge short.

Etymology. The specific epithet “ sundense ” is an adjective taken from the geographical name Sundaland, the former landmass that fell apart into the many islands including what is now called the Lesser Sundas.

Distribution. Indonesia: Sumatra, Java, Bali, Lombok, Sumbawa, Sumba, Flores, Timor, Wetar, Kei ( Fig. 6 ). AVBH recorded it from Sumatra, Bali, Wetar, and Pulau Kei based on material in museum collections. This indicates that as far as we know, the new species reaches eastwards to what is known as Lydekker’s Line.

Remarks. While there are several small (> 8 mm in length) species of Sphaeridium recorded from the Indonesian archipelago, S. sundense can be easily differentiated from most of the others by the following characters: ventral coloration dark, base color black to dark brown, never yellow (as in S. flavomaculatum and S. huijbregtsi ); posterior angles of pronotum without emargination (as in S. dimidiatum and the larger species S. discolor ); and with distinct elytral striae (lacking in S. flavomaculatum and S. huijbregtsi ).

Perhaps the most morphologically similar species to S. sundense is S. quinquemaculatum , particularly in size and often coloration. Sphaeridium sundense can, however, be easily separated from the former by the structure of the mesoventral process, of which the anterior protrusion is distinctly longer than wide, bears a unique pattern of strong spines on the ventral surface, and the posterior lip lacks pubescence ( Figs. 2D , 3F , 5C ). In S. quinquemaculatum , the anterior protrusion is about as wide as long and the posterior lip is sparsely but distinctly pubescent ( Fig. 5D ). Additionally, the procoxae of S. sundense lack the abundant long yellowish pubescence interspersed among the strong spines as is seen in S. quinquemaculatum ( Fig. 5B ). Sphaeridium quinquemaculatum shows remarkable variation in color pattern, and some specimens are rather dark and quite similar to S. sundense . Differences in the extent of yellow on the lateral margins of the pronotum, however, are highly constant, with S. quinquemaculatum having a yellow border which does not continue around anterior and posterior angles, whereas the yellow border of S. sundense does continue around the angles and reaches some distance inward from both anterior and posterior margins ( Fig. 4 ).

Figures

Fig. 1. Sphaeridium sundense, new species, habitus. A) Dorsal, B) Ventral, C) Lateral, D) Posterior.

Fig. 2. SEM of Sphaeridium sundense, new species. A) Head, ventral, inset shows microrugae on surface of mentum, B) Pronotum, dorso-lateral, inset shows microsculpture on surface, C) Proventrite, D) Mesoventral keel, ventral oblique, E) Metaventral field. F–G) Detail of types of microsculpture: F) Granulate microsculpture on pronotum, G) Rugose microsculpture (microrugae) on metaventral field.

Fig. 3. Sphaeridium sundense, new species. A–D) Male genitalia:A) Abdominal tergite IX, dorsal, B) Median lobe and tegmen, C) Ventral detail of apex of median lobe, D) Lateral profile of median lobe and tegmen. E) Male protarsus, F) Mesoventral process, ventral.Abbreviations: bs = basal segment of tegmen; cor = corona; ls = lateral struts of tergite IX; mkp = mesoventral protrusion; ml = median lobe; mr = median ridge of ventrite IX; oc = outer claw; par = paramera; pml = posterior mesoventral lip; S5 = tarsomere 5; T10 = tergite X; V9 = sternite IX.

Fig. 4. Pronotal coloration, left lateral view. A) Sphaeridium sundense, new species, B) S. quinquemaculatum.

Fig. 5. Morphology of Sphaeridium species.A, C, E) Sphaeridium sundense, new species, B, D, F) S. quinquemaculatum. A–B) Procoxae, C–D) Mesoventral keel, ventral view, E–F) Mesoventral keel, oblique view.

Fig. 6. Map of locations from which Sphaeridium sundense, new species was collected in Indonesia.