Syntype. Male (BMNH), Borneo. Syntype. Female (BMNH), Lundu, Sarawak, G. E. Bryant, 6. 1. 14.

Platerodrilus paradoxus belongs to a group of Bornean species with robust and long parameres. The male of Platerodrilus paradoxus resembles Platerodrilus foliaceus but differs in the slender apex of parameres. Additionally these species differ in larval morphology (Figs 34, 40).

Male. Body 7 mm, dark brown, only humeri and elytral suture slightly lighter. Head small, with hemispherically prominent eyes, head with eyes wider than frontal margin of pronotum, eye diameter 1.9 times frontal interocular distance. Antennae compressed, covered with long, erected, dense pubescence. Pronotum flat, without carinae, 1.8 times wider than long at midline, frontal margin widely rounded anteriorly, frontal angles obtuse, lateral margins almost straight, posterior margin bisinuate. Elytra flat, parallel-sided, elytral costae inconspicuous, elytra 2.6 times longer than width at humeri. Legs slender, compressed, densely pubescent. Male genitalia with robust parameres, phallus slightly curved with bulbous tip. Parameres stout with hooked tip, apical half of ventral edge serrate. Phallobase wide, deeply emarginate.

Female larva. Body flat and wide (Fig. 34), pronotum parallel-sided at base, then gradually tapering to front, triangular, without any glabrous tubercles in disc, only small tubercles in middle part of posterior margins of thoracic segments, in middle of anterior pronotal margin four subequal tubercles; mesothorax strongly transverse, with rounded lateral margins and straight posterior margin, posterior angles obtuse, metathorax similar in shape with more acutely projected posterior angles. Abdomen with short, robust lateral processes.

Male. BL 6.9 mm, PL 1.0 mm, PW 1.9 mm, HW 2.0 mm, Edist 0.85 mm, Ediam 0.44 mm. Larva. BL 53.0 mm, PL 8.7 mm, PW 13.4 mm.

Malaysia: Sarawak. Known only from the type locality.

Holotype. Male (LMBC, UPOL 000589), Borneo, Central Kalimantan Prov., 60 km SE Muara Teweh, 1°20'25"S, 115°20'16"E, 24.–28. Jun. 2001, 150 m. Paratypes. 12 females, same locality data (LMBC, UPOL 000588).

Platerodrilus foliaceus belongs to the Platerodrilus paradoxus group and the male resembles Platerodrilus paradoxus in general appearance. Platerodrilus foliaceus differs in the rounded apex of parameres (Figs 46–47). The female larvae of Platerodrilus foliaceus are very flat and have much slenderer lateral processes of abdominal segments than Platerodrilus paradoxus (Figs 34, 40).

Male. Body small-sized, brown, head, antennae, legs except bases of femora and apical three fifths of elytra dark brown (Fig. 4). Head small, with hemispherically prominent eyes, head with eyes slightly wider than frontal margin of pronotum, eye diameter 1.7 times frontal interocular distance. Antennae compressed, covered with long, erected, dense pubescence, length of antennomere 3 0.7 times antennomere 2. Pronotum flat, without carinae, 1.7 times wider than long at midline, frontal margin slightly projected anteriorly, frontal angles obtuse, but apparent, lateral margins rounded, posterior margin slightly bisinuate (Fig. 22). Elytra flat, parallel-sided, elytral costae inconspicuous, elytra 2.9 times longer than width at humeri. Legs slender, compressed, densely pubescent. Male genitalia with robust parameres, phallus slightly curved with bulbous tip. Parameres stout with hooked tip, apical half of ventral edge serrate. Phallobase wide, deeply emarginate (Figs 46–47).

Female larva. Body extremely flat and wide (Fig. 40), pronotum triangular, without any glabrous tubercles, in middle of anterior margin four subequal tubercles; mesothorax strongly transverse, with rounded lateral margins and moderately projected posterior angles, metathorax similar in shape with more acutely projected posterior margins. Abdomen with very slender and long lateral processes.

Male. BL 6.0 mm, PL 0.9 mm, PW 1.5 mm, HW 1.7 mm, Edist 0.78 mm, Ediam 0.46 mm. Larva. BL 19.3 mm, PL 5.1 mm, PW 11.2 mm.

Indonesia: Kalimantan. Known only from the type locality.

The specific epithet refers to the flat body shape of the female larva.

The males and female larvae were identified as conspecific on the basis of highly similar sequences of rrnL (Fig. 1).

Holotype. Male (LMBC), Sumatra Utara, Brastagi, Gn. Sibayak, 19–23. Feb. 1998, 700–2000 m.

Platerodrilus wongi is a single species of the Platerodrilus paradoxus group occurring in Sumatra. It resembles Platerodrilus curtus from the Philippines in the uniformly yellow elytra, but has relatively shorter parameres (Figs 44–45).

Body brown, head, pronotum, mesoscutellum and elytra yellow (Fig. 5). Head small, with eyes is slightly wider than frontal margin of pronotum, antennal tubercles deeply separated. Eyes hemispherically prominent, frontal interocular distance 2.4 times eye diameter. Antennae slender, compressed, reaching two thirds of elytra length, antennomere 3 1.1 times antennomere 2. Head and antennae covered with short dense pubescence. Pronotum transverse, 1.6 wider than length at midline. Anterior margin only slightly projected, anterior angles well marked, lateral margins almost straight, posterior margin shallowly bisinuate (Fig. 28). Elytra parallel-sided, with inconspicuous carinae. Elytra 3.0 times longer than width at humeri, elytra widest in apical sixth. Legs compressed, densely pubescent. Male genitalia with laterally compressed, slightly curved phallus with bulbous tip, parameres stout, long, with hooked tip, apical half of ventral edge serrated, phallobase wide, deeply emarginate (Figs 44–45).

BL 7.4 mm, PL 1.0 mm, PW 1.6 mm, HW 1.9 mm, Edist 0.91 mm, Ediam 0.38 mm.

Indonesia: Northern Sumatra.

The specific epithet is a patronym in honour of Alvin T. C. Wong.

Holotype. Male (LMBC), Singapore, Bukit Timah and Central Water Catchment, 19.–22. May 2013, 50–100 m, E. Jendek and O. Šauša leg. Paratypes. Female larvae, 6 spec., Malaysia, Pahang, Tioman, Kg. Tekek–Juara trail, 50–300 m, 2°49'10"N, 104°10'21"E, 29. Mar.–2. Apr. 2013, same locality data, 4.–16. Mar. 1998, L. Dembicky and P. Pacholatko (LMBC); 1 spec., Singapore, Sime Road swamp, 30. Oct. 2008 (ZRCS);1 spec., Singapore, Bukit Timah Nature Reserve, A. T. C. Wong 1993 (ZRCS); 1 spec., Singapore, Sime Road, C. Lee (ZRCS, #6.20969, 1993.7277, 1993.7278).

Platerodrilus ngi is the only representative of the Platerodrilus major group known from Singapore and Tioman. It differs in dark red colouration of the pronotum and humeral two thirds of elytra from Platerodrilus atronotatus from the Malay Peninsula. Platerodrilus atronotatus has the black pronotum. Additionally, the phallus of Platerodrilus atronotatus is slender and antennomeres 3 and 4 short and much wider.

Male. Body small, dark brown to black, head, prothorax, mesoscutellum and basal two thirds of elytra dark red; whole body with dense, short, pubescence. Head small, including eyes slightly wider than frontal margin of pronotum. Eyes hemispherically prominent, frontal interocular distance 1.8 times eye diameter. Antennae robust at base, compressed, reaching two thirds of elytral length, antennomere 3 0.6 times antennomere 2, antennomere 3 as long as wide at apex. Pronotum flat, 1.7 times wider than long at midline. Anterior margin almost straight, anterior angles sharply marked, posterior margin bisinuate. Elytra slightly wider posteriorly, elytra 2.8 times longer than width at humeri; only slightly widened posteriorly, elytral costae conspicuous. Legs compressed, densely pubescent. Male genitalia with straight phallus and setose parameres, short phallobase slightly shorter than parameres.

Female larva. Body slender, parallel-sided (Fig. 43), pronotum triangular, with two basal, dark coloured, glabrous tubercles; mesothorax slightly transverse, without projected posterior angles, metathorax similar in shape. Abdomen with robust, short lateral processes and fixed urogomphi.

Male. BL 6.9 mm, PL 0.9 mm, PW 1.6 mm, HW 2.1 mm, Edist 0.86 mm, Ediam 0.48 mm. Larva. BL 30.2 mm, PL 5.7 mm, PW 5.6 mm.

Singapore, Malaysia: Pahang. Biology and female specimens collected in Singapore were reported by Lok (2008).

The species name is a patronym in honour of Peter Ng.

Holotype. Male (LMBC), Java, K. O. Blawan, Ijen Plateau, Jul. 1940, 900–1500 m, H. Lucht coll.

Platerodrilus wittmeri is the only bicoloured species from the Platerodrilus major group in Java. It resembles Platerodrilus major from Northern Sumatra in colouration but differs in the shorter phallobase (Figs 48–49, 50–51).

Male. Body medium-sized, dark brown, head, prothorax, mesoscutellum and basal half of elytra testaceous; antennae, legs, apical half of elytra dark brown to black (Fig. 17). Head small, including eyes slightly wider than frontal margin of pronotum. Eyes hemispherically prominent, frontal interocular distance 1.9 times eye diameter. Antennae slender, compressed, reaching two thirds of elytral length, antennomere 3 0.7 times antennomere 2. Head and antennae with dense, short, pubescence. Pronotum flat, 1.9 times wider than long at midline. Anterior margin slightly projected anteriorly, anterior angles sharply marked, prominent, posterior margin bisinuate (Fig. 30). Elytra almost parallel-sided, 3.5 times longer than width at humeri; only slightly widened posteriorly, elytral costae inconspicuous. Legs compressed, densely pubescent. Male genitalia with straight phallus and setose parameres, short phallobase slightly shorter than parameres (Figs 50–51).

BL 10.1 mm, PL 1.1 mm, PW 2.0 mm, HW 2.6 mm, Edist 0.95 mm, Ediam 0.49 mm.

Indonesia: Java.

The specific epithet is a patronym in honour of the late W. Wittmer, who donated the specimen to the senior author in 1992.

Holotype. Male (LMBC, 000586), Java, Ijen N. P., 12 km W of Sodora, 3–5. May 2001, 1000 m.

Platerodrilus ijenensis is the only Javanese species of Platerodrilus sinuatus group with bicoloured elytra. It resembles in colour pattern the Sumatran species Platerodrilus corporaali, which differs in the reddish coloured head and basal antennomeres, and the very short antennomere 3.

Body and head dark brown to black, pronotum, mesoscutellum and elytra in humeral half orange, apical part of elytra dark brown to black (Fig. 14). Head small, including eyes narrower than pronotum at posterior angles, antennal tubercles slightly prominent. Eyes hemispherically prominent, eye diameter 1.8 times frontal interocular distance. Antennae slender, compressed, length of antennomere 3 1.2 times antennomere 2. Pronotum transverse, 1.8 wider than long at midline, anterior margin slightly projected forward, anterior angles marked, lateral margins almost straight, posterior margin bisinuate (Fig. 18). Elytra 3.3 times longer than width at humeri, elytra parallel-sided, elytral costae inconspicuous. Legs slender, compressed, densely pubescent. Male genitalia with slender, curved phallus and small rounded parameres bearing slender membranous process, phallobase wide, narrowly and deeply emarginate (Figs 64–65).

BL 7.2 mm, PL 0.9 mm, PW 1.6 mm, HW 1.8 mm Edist 0.70 mm, Ediam 0.40 mm.

Indonesia: Java.

The specific name refers to the type locality.

Lectotype (hereby designated). Male (BMNH), Sumatra, Korinchi, 4500 ft, N. 1914, K. G. Blair. Paralectotype. Female (BMNH), same locality data.

The male genitalia are missing. Therefore, only information on external morphology can be compared. The orange pronotum and humeral part of elytra resemble Platerodrilus corporaali or Platerodrilus maninjauensis, but no similar species is known from the Kerinci massif.

Male. Body black, head dark brown, pronotum and basal quarter of elytra orange; antennae, and legs dark brown to black. Head small, antennal tubercles weak, eyes hemispherically prominent, frontal interocular distance 2.3 times maximum eye diameter. Antennae slender, compressed, densely pubescent, antennomere 3 as long as antennomere 2. Pronotum transverse, 1.5 times wider than long, anterior margin almost straight, frontal angles conspicuous, lateral margins almost straight, posterior angles acute, surface mat at margins, slightly glabrous in middle. Elytra parallel-sided, elytral costae weak, covered with dense pubescence. Male genitalia missing.

PL 1.3 mm, PW 1.9 mm, HW 2.6 mm, Edist 0.84 mm, Ediam 0.36 mm.

Indonesia: Sumatra, Jambi, Kerinci massif.

The lectotype is damaged (the apical half of elytra and abdomen are missing). Platerodrilus korinchianus differs in the shape of pronotum and colouration of elytra from Platerodrilus tujuhensis and Platerodrilus robinsoni. The paralectotype, a female larva, is very similar to the female larva of Platerodrilus tujuhensis from the same locality and might not be conspecific with the male specimen. As larvae are generally difficult to identify without DNA data, we prefer to designate a lectotype to keep status and preserve the validity of the name. The species can be misidentified as high diversity of neotenic net-winged beetles in the region was documented (Malohlava and Bocak 2010) and further species of Platerodrilus can occur in this locality.

Holotype. Male (LMBC, UPOL 001379), Sumatra, Jambi Kersik Tua, Gn. Kerinci, 19.–22. Jan. 2005, 1600–2200 m.

Platerodrilus luteus resembles in general appearance the syntopically occurring Platerodrilus robinsoni, but these species are distantly related according to the recovered molecular phylogeny (Fig. 1). The male of Platerodrilus luteus differs from similarly coloured Sumatran Platerodrilus in the very wide and broadly emarginate phallobase (Fig. 67).

Body black, head dark brown, pronotum and elytra orange; antennae, and legs dark brown to black (Fig. 8). Head small, antennal tubercles weak, eyes hemispherically prominent, frontal interocular distance 2.8 times maximum eye diameter. Antennae slender, compressed, densely pubescent, antennomere 3 1.5 times longer than antennomere 2. Pronotum transverse, 1.7 times wider than long, frontal angles inconspicuous, lateral margins slightly convex, posterior angles acute (Fig. 23). Elytra parallel-sided, 3.7 times longer than width at humeri, elytral costae weak, covered with dense pubescence. Male genitalia with curved phallus; parameres short, rounded, with slender membranous processes; phallobase wide, deeply emarginate (Fig. 67–68).

BL 10.1 mm, PL 1.1 mm, PW 1.8 mm, HW 2.3 mm, Edist 0.83 mm, Ediam 0.45 mm.

Indonesia: Sumatra.

The specific epithet refers to yellow colouration of the body.

Holotype. Male (LMBC, UPOL 001386), Sumatra, Barat Lake Maninjau, E coast, 12.–23. Jan. 2005, 800 m. Paratype. Male (LMBC, UPOL 001374), Sumatra, Barat Lake Maninjau, E coast, 12.–23. Jan. 2005, 800 m. Paratypes. Male, 2 females (LMBC, UPOL 001377), Sumatra, Barat, Pasaman, Gn. Talamau, 14.–15. Jan. 2005, 1000 m; female larva (LMBC, UPOL VP2303), Sumatra, Barat Lake Maninjau, E coast, 12.–23. Jan. 2005, 800 m.

Platerodrilus maninjauensis is a sister species to Platerodrilus tujuhensis from Northern Sumatra. These species differ in the colouration (Figs 7, 12) and the shape of the phallus and phallobase (Figs 56–57, 60–61). The female larvae of both species are similar and differ only in the relative size of the mesonotal tubercles, which are smaller in Platerodrilus tujuhensis (Figs 32, 41).

Male. Body medium-sized, dark brown; head, prothorax, mesoscutellum and basal three fifths of elytra orange; antennae, legs, apical two fifths of elytra dark brown to black (Fig. 7). Head small, including eyes narrower than frontal margin of pronotum. Eyes hemispherically prominent, eye diameter 2.2 times frontal interocular distance. Antennae slender, compressed, reaching two thirds of elytral length, antennomere 3 0.9 times antennomere 2. Head and antennae with dense, short, pubescence. Pronotum flat, 1.1 times wider than long at midline. Anterior margin widely rounded, anterior angles inconspicuous, posterior margin bisinuate (Fig. 20). Elytra almost parallel-sided, 3.5 times longer than width at humeri; slightly widened posteriorly, widest at apical fourth. Elytral costae inconspicuous. Legs compressed, densely pubescent. Male genitalia with short rounded parameres bearing slender membranous process. Phallus curved, phallobase wide, widely emarginate (Figs 60–61).

Female larva. Body flat, wide (Fig. 32), pronotum triangular, with two glabrous rounded tubercles postero-laterally, another two tubercles in middle of anterior margin; mesothorax strongly transverse, with rounded lateral margins and weakly projected posterior angles, laterally with four tubercles, upper rounded, lower transverse, metathorax similar in shape with more acutely projected posterior margins. Abdominal segments with slender and long lateral processes.

BL 7.0 mm, PL 0.9 mm, PW 1.6 mm, HW 1.7 mm, Edist 0.84 mm, Ediam 0.38 mm. Larva. BL 24.1 mm, PL 5.4 mm, PW 10.3 mm.

Indonesia: Sumatra.

The specific epithet refers to the type locality of the holotype.

Holotype. Male (LMBC, UPOL 001371), Sumatra Utara, Brastagi, Gn. Sibayak, 26. Jan.–1. Feb. 2005, 1600–2200 m. Paratype. Female larva (LMBC, UPOL VP2308), Sumatra Utara, Brastagi, Gn. Sinabung, 29.–30. Jan. 2005, 1400–2000 m.

Platerodrilus montanus and Platerodrilus sinabungensis are the only Sumatran species with the dark coloured pronotum. These species differ in the shape of the phallobase, when Platerodrilus montanus has the narrowly emarginate base (Figs 58–59, 66). The larva of Platerodrilus montanus has pronotum without any glabrous tubercles in the disc (Fig. 33).

Body medium-sized, dark brown to black, only basal half of elytra orange and pronotum with irregular light coloured patches in disc (Fig. 13). Head small, including eyes slightly narrower than frontal margin of pronotum. Eyes hemispherically prominent, eye diameter 2.4 times frontal interocular distance. Antennae compressed, length of antennomere 3 1.1 times antennomere 2. Head and antennae with dense, short, pubescence. Pronotum transverse, 1.9 times wider than long at midline; anterior margin slightly projected, lateral margins almost straight, anterior angles weakly marked, posterior margin of pronotum slightly bisinuate (Fig. 21). Elytra almost parallel-sided, elytra 3.5 times longer than width at humeri; slightly widened posteriorly, widest at apical fourth, elytral costae inconspicuous. Legs compressed, with dense pubescence. Male genitalia with short rounded parameres bearing slender membranous processes. Phallus curved, phallobase wide, deeply emarginate (Fig. 66).

Female larva. Body flat, wide (Fig. 33), pronotum triangular, without glabrous tubercles except two tubercles in middle of posterior margin; mesothorax strongly transverse, with rounded lateral margins and weakly projected posterior angles, laterally with four tubercles, upper rounded, lower only slightly transverse, metathorax similar in shape with more acutely projected posterior margins. Abdominal segments with slender and long lateral processes.

BL 8.2 mm, PL 0.9 mm, PW 1.8 mm, HW 2.1 mm, Edist 0.94 mm, Ediam 0.39 mm. Larva. BL 32.3 mm, PL 7.7 mm, PW 13.0 mm.

Indonesia: Sumatra, North Sumatra Province, Gn. Sibayak.

The specific epithet is derived from the Latin adjective montanus (mountainous) referring to the habitat of the species.

Holotype. Male (LMBC, UPOL 001382), Philippines, Palawan, Tanabak river, 150 m, 10°02'49"N, 118°58'31"E, 2.–5. Jan. 2007, Bolm lgt. Paratypes, 8 males (LMBC), same locality data, 22. Dec. 1991; 3 paratypes. Males (KMTC), Philippines, Palawan, Brooke's point, 8. Dec. 2002, leg. F. A. Dacasin. Paratype. Male (KMTC), Philippines, Palawan, Brooke's point, 18. May 2003, leg. F. A. Dacasin. Paratype. Male (KMTC), Philippines, Palawan, Brooke's point, 15. Jan. 2005, leg. F. A. Dacasin.

Platerodrilus palawanensis sp. n. resembles Platerodrilus borneensis in flabellate antennae and these species differ in colouration. Platerodrilus borneensis is dark brown and Platerodrilus palawanensis bicoloured (Fig. 16). Additionally Platerodrilus palawanensis has the very short pronotum and straight frontal pronotal margin (Fig. 31).

Body medium-sized, dark brown to black, only pronotum, mesoscutellum and humeral two thirds of elytra orange; apical third of elytra and two thirds of elytral suture dark brown to black. Head small, including eyes apparently narrower than frontal margin of pronotum, antennal tubercles robust, deeply separated. Eyes hemispherically prominent, eye diameter 1.9 times frontal interocular distance. Antennae flabellate, antennomere 3 with long process, pubescent, length of antennomere 3 1.6 times antennomere 2. Pronotum strongly transverse, 1.5 times wider than long at midline, anterior margin straight, with prominent anterior angles, lateral margins almost straight, posterior margin bisinuate, surface of disc mat, finely punctuate, with dense short pubescence. Elytra 2.9 times longer than width at humeri, elytra almost parallel-sided; slightly widened posteriorly, widest at apical fourth, elytral costae inconspicuous. Legs compressed, with dense pubescence. Male genitalia with curved phallus, short rounded parameres bearing slender membranous processes; phallobase wide, deeply emarginate (Figs 69–70).

BL 7.1 mm, PL 1.0 mm, PW 1.6 mm, HW 1.9 mm, Edist 0.66 mm, Ediam 0.34 mm.

Philippines: Palawan.

The specific epithet refers to the type locality of the holotype.

Holotype. Male (LMBC, UPOL 000587), Sumatra, SW coast of Ranau Lake, 1–4. Jun. 2001, 1200 m.

Platerodrilus ranauensis was found as a sister species to Platerodrilus talamauensis (Fig. 1) and these species differ in the extent and shape of the orange part of elytra and in the shape of the posterior margin of phallobase (Figs 54–55).

Body medium-sized, dark brown to black, only pronotum testaceous to brown and basal quarter of elytra orange (Fig. 9). Head small, including eyes slightly narrower than frontal margin of pronotum, antennal tubercles small. Eyes hemispherically prominent, eye diameter 2.3 times frontal interocular distance. Antennae compressed, pubescent, length of antennomere 3 1.1 times antennomere 2. Pronotum transverse, 1.7 times wider than long at midline, anterior margin widely rounded, semicircular, without prominent anterior angles, posterior margin of pronotum bisinuate, surface of disc glabrous, with sparse long pubescence (Fig. 24). Elytra almost parallel-sided, 3.0 times longer than width at humeri; slightly widened posteriorly, widest at apical fourth. Elytral costae inconspicuous. Legs compressed, with dense pubescence. Male genitalia with short rounded parameres bearing slender membranous processes; phallus curved, phallobase wide, deeply emarginate (Figs 54–55).

BL 6.0 mm, PL 0.8 mm, PW 1.3 mm, HW 1.7 mm, Edist 0.79 mm, Ediam 0.35 mm.

Indonesia: Sumatra.

The specific epithet refers to the type locality of the holotype.

Holotype. Male (LMBC, UPOL 001389), Sumatra Utara, Brastagi, Gn. Sibayak, 26. Jan.–1. Feb. 2005, 1600–2200 m. Paratypes. 2 males (LBMC), Sumatra, SW of Brastagi, Gn. Sinabung, 22. Feb. 1991, 1300–1800 m. Paratype. Male (LBMC), Sumatra, SW of Brastagi, Gn. Sinabung, 19.–23. Feb. 1991, 1300–1800 m. Paratype. Male (LBMC, UPOL 001372), Sumatra, Utara, Brastagi, Gn. Sibayak, 26. Jan.–1. Feb. 2005, 1600–2200 m. Paratype. Male (LBMC), Sumatra, Sinabung, Mar. 1998.

Platerodrilus sibayakensis and Platerodrilus angustatus were recovered as sister species (Fig. 1) and they share the pronotum with acutely projected posterior angles. Platerodrilus sibayakensis differs in the 4.1 times longer antennomere 4 than its width in the middle and the more robust phallus tapering gradually from the base to apex (Figs 71–72).

Body medium-sized, dark brown to black, pronotum testaceous to brown and basal third of elytra orange (Fig. 10). Head small, including eyes slightly narrower than frontal margin of pronotum, antennal tubercles small. Eyes hemispherically prominent, eye diameter 1.7 times frontal interocular distance. Antennae compressed, pubescent, length of antennomere 3 0.7 times antennomere 2. Pronotum transverse, 1.9 times wider than long at midline, anterior margin almost straight, with marked anterior angles, lateral margins straight, posterior margin of pronotum bisinuate, posterior angles acutely projected, surface of disc weakly glabrous, finely punctuate, with long pubescence (Fig. 25). Elytra almost parallel-sided, elytra 3.5 times longer than width at humeri; slightly widened posteriorly, widest at apical fourth, elytral costae inconspicuous. Legs compressed, with dense pubescence. Male genitalia with short rounded parameres bearing slender membranous processes; phallus curved, phallobase wide, deeply emarginate (Figs 71–72).

BL 8.5 mm, PL 0.9 mm, PW 1.8 mm, HW 2.0 mm, Edist 0.73 mm, Ediam 0.44 mm.

Indonesia: Sumatra.

The specific epithet refers to the type locality of the holotype.

Holotype. Male (LMBC), Sumatra, SW of Brastagi, Gn. Sinabung, 22. Feb. 1991, 1300–1500 m. Paratypes. 2 males (LBMC), Sumatra, SW of Brastagi, Gn. Sinabung, 22. Feb. 1991, 1400–1900 m.

Platerodrilus sinabungensis resembles Platerodrilus montanus in the dark coloured pronotum. These species differ in the shape of the phallobase (Figs 58–59, 66).

Body medium-sized, dark brown to black, only basal two fifths of elytra orange testaceous (Fig. 11). Head including eyes slightly wider than frontal margin of pronotum. Eye hemispherically prominent, their diameter 2.3 times frontal interocular distance. Antennae compressed, antennomere 3 as long as antennomere 2. Head and antennae with short dense pubescence. Pronotum transverse, 1.7 wider than long at midline, anterior and lateral margins weakly rounded, posterior margin of pronotum simply rounded to straight in middle, disc bare in middle, pubescent along lateral margins (Fig. 26). Elytra with inconspicuous carinae. Elytra 3.4 times longer than width at humeri, elytra widest posteriorly. Legs compressed with dense pubescence. Male genitalia with curved phallus and short rounded parameres bearing slender membranous processes with basal part serrate; phallobase wide, widely emarginate (Figs 58–59).

BL 8.9 mm, PL 1.0 mm, PW 1.7 mm, HW 2.1 mm, Edist 0.89 mm, Ediam 0.4 mm.

Indonesia: Sumatra.

The specific epithet refers to the type locality of the holotype.

Holotype. Male (LMBC, UPOL 001376), Sumatra Barat, Pasaman, Gn. Talamau, 14.–15. Jan. 2005, 1000 m. Paratype. Male (LMBC, UPOL 001375), Sumatra Barat, Pasaman, Gn. Talamau, 14.–15. Jan. 2005, 1000 m.

Platerodrilus talamauensis and Platerodrilus ranauensis are closely related (Fig. 1) and they differ in the extent and shape of the orange part of the elytra (Figs 9, 15) and in the shape of posterior margin of phallobase (Figs 52–55).

Male. Body medium-sized, dark brown to black, only pronotum, mesoscutellum and basal three fifths of elytra orange (Fig. 15). Head small, with eyes slightly wider than frontal margin of pronotum. Eyes hemispherically prominent, eye diameter 2.4 times frontal interocular distance. Antennae compressed, reaching two thirds of elytral length, antennomere 3 0.9 times antennomere 2. Head and antennae densely pubescent. Pronotum transverse, 1.2 wider than long at midline. Anterior margin of pronotum rounded, anterior angles inconspicuous, posterior margin bisinuate (Fig. 29). Elytra with inconspicuous carinae, parallel-sided, 2.9 times longer than width at humeri, widest posteriorly. Legs compressed with dense pubescence. Male genitalia with curved phallus, phallus twice longer than apical processes of parameres, phallobase widely emarginate. (Fig. 52–53).

BL 6.5 mm, PL 1.0 mm, PW 1.6 mm, HW 1.9 mm, Edist 0.88 mm, Ediam 0.36 mm.

Indonesia: Sumatra.

The specific epithet refers to the type locality of the holotype.

Holotype. Male (LMBC, UPOL 001385), Sumatra, Jambi Kersik Tua, Gn. Kerinci, 19–22. Jan. 2005, 1600–2200 m. Paratype. Female (LMBC, VP2305), Sumatra, Jambi prov. Kerinci Seblat N. P., 7 km E Kayuaro, Mt. Tujuh, 1°45'S, 101°25'E, 25. Feb.–2. Mar. 2003, 1750 ± 250 m.

Platerodrilus tujuhensis resembles in the uniformly light coloured head, pronotum and elytra Platerodrilus robinsoni, which differs in the more robust basal part of the phallus. The molecular phylogeny suggests the sister relationships of Platerodrilus maninjauensis and Platerodrilus tujuhensis. These species differ in colouration (Figs 7, 12) and the shape of the phallus and phallobase (Figs 56–57, 60–61). The female larvae of both species are similar and differ only in the relative size of mesonotal tubercles, which are smaller in Platerodrilus tujuhensis.

Body dark brown to black; head, pronotum and elytra yellow to orange, apical margins of elytra infuscate (Fig. 12). Head including eyes narrower than pronotum, antennal tubercles slightly prominent. Eyes hemispherically prominent, frontal interocular distance 2.6 times eye diameter. Antennae compressed, slender, length of antennomere 3 0.9 times antennomere 2. Pronotum transverse, 1.8 wider than long at midline, anterior margin widely rounded, anterior angles inconspicuous, posterior margin bisinuate (Fig. 27). Elytra 3.7 times longer than width at humeri, widest posteriorly, elytral costae inconspicuous. Legs slender, compressed with dense pubescence. Male genitalia with slender, curved phallus and small rounded parameres bearing slender membranous processes, phallobase wide, narrowly and deeply emarginate (Figs 56–57).

Female larva. Body flat, wide, dark brown, only margins of tergites lighter, pronotum triangular (Fig. 41), with two glabrous rounded tubercles postero-laterally, another two tubercles in middle of anterior margin; mesothorax strongly transverse, with rounded lateral margins and weakly projected posterior angles, laterally with four tubercles, upper rounded, lower transverse, metathorax similar in shape with more acutely projected posterior margins. Abdominal segments with slender and long lateral processes.

BL 8.1 mm, PL 0.9 mm, PW 1.6 mm, HW 1.9 mm, Edist 0.81 mm, Ediam 0.31 mm. Larva. BL 32.7 mm, PL 6.6 mm, PW 10.2 mm.

Indonesia: Sumatra.

The specific epithet refers to the locality of the paratype.

Holotype. Sumatra, Sungei Kumbang, Korinchi, 4500 ft, Apr. 1914 (BMNH). Other material examined. Male (LMBC, UPOL 001378), Sumatra, Jambi Kersik Tua, Gn. Kerinci, 19.–22. Jan. 2005, 1600–2200 m.

Platerodrilus robinsoni resembles Platerodrilus luteus in general appearance, but differs in the shape of the phallobase and phallus (Figs 62–63, 67–68).

Body black; head and mesoscutellum dark brown, pronotum and elytra orange yellow; antennae, and legs dark brown to black (Fig. 6). Head small, antennal tubercles separated by deep groove. Eyes hemispherically prominent, frontal interocular distance 2.1 times maximum eye diameter. Antennae slender, compressed, densely pubescent, antennomere 3 1.1 times longer than antennomere 2. Pronotum transverse, 1.6 times wider than long, anterior margin rounded, frontal angles obtuse, lateral margins slightly convex, posterior angles approximately rectangular (Fig. 19). Elytra parallel-sided, elytra 3.3 times longer than width at humeri, elytral costae weak, covered with dense pubescence. Male genitalia with curved phallus; parameres short, rounded, with slender membranous process; phallobase wide, deeply emarginate (Figs 62–63).

BL 7.8 mm, PL 1.0 mm, PW 1.6 mm, HW 2.0 mm, Edist 0.85 mm, Ediam 0.40 mm.

Indonesia: Sumatra.

Platerodrilus robinsoni differs from Platerodrilus korinchianus in the colouration; but both species are syntopic. Therefore, the species rank is proposed for Platerodrilus robinsoni stat. n.

Holotype, male, Presqu'ile Malaise (MNHP).

Wong (1996) described and illustrated Duliticola hoiseni. During the recent search in the Paris Museum we found that Pic (1942) described the same species as Falsocalochromus ruficollis and placed in the relationships with Calochromus despite that fact that the species perfectly fits in his own concept of Platerodrilus. Therefore, we propose Duliticola hoiseni as a junior subjective synonym of Platerodrilus ruficollis.

Platerodrilus testaceicollis was placed in Platerodrilus by Kazantsev, 2009, but the abdomen of the type is missing and the species cannot be placed in any species group unless further specimen is available. The redescription was given by Wong (1998).

The type series contains just female larvae judging from the illustrations might include two species. The adult is unknown.