Zootaxa 3619 (1): 079–100 ISSN 1175-5326 (print edition) www.mapress.com/zootaxa/ Article ZOOTAXA Copyright © 2013 Magnolia Press ISSN1175-5334(online edition) http://dx.doi.org/10.11646/zootaxa.3619.1.6 http://zoobank.org/urn:lsid:zoobank.org:pub:95DE82C1-D18A-446E-A369-1C289A784651 Chrysomelid males with enlarged mandibles: three new species and a review of occurrence in the family (Coleoptera: Chrysomelidae) C. A. M. REID & M. BEATSON Department of Entomology, Australian Museum, 6 College Street, Sydney, NSW 2010, Australia. E-mail: [email protected] ; [email protected] Abstract Three new species of Chrysomelidae with extraordinary extensions of the male mandibles are described: Scaphodius drehu sp. nov. and S. ferox sp. nov. (Cryptocephalinae), from New Caledonia, and Chaloenus gajah sp. nov. (Galerucinae), from Borneo. Designation of the type species of Chaloenus Westwood, 1861, is clarified. Synonymy of Scaphodius Chapuis, 1874, with Nyetra Baly, 1877, is supported. Four species of Ditropidus Erichson, 1842, described from New Caledonia, but hitherto regarded as nomina nuda, are shown to be available and are placed in Scaphodius:S. aeneus (Fauvel, 1907), comb. nov., S. nitidus (Fauvel, 1907) comb. nov., S. striolatus (Fauvel, 1907) comb. nov., S. sulcatus (Fauvel, 1907) comb. nov. Ditropidus opacicollis Fauvel, 1907, is also transferred to Scaphodius, as S. opacicollis (Fauvel) comb. nov. The genus Ditropidus does not occur on New Caledonia. Male mandible enlargment in the Chrysomelidae is reviewed: it is common in Cryptocephalinae, but otherwise restricted to a few species of Chrysomelinae, Eumolpinae and Galerucinae. Possible reasons for its distribution in the Chrysomelidae are discussed. Key words: leaf beetle, Cryptocephalinae, Galerucinae, taxonomy, sexual dimorphism, mandible, agonistic behaviour, Borneo, New Caledonia Introduction For several years the senior author (CAMR) has been ‘sitting on’ specimens of unusual species of leaf beetle discovered in museum collections. Originally it was intended to include these species within generic revisions, but it seems unlikely that these objectives will be realised, as discussed below. Therefore, we describe the species here and summarise the distribution of similar features in Chrysomelidae. One species was discovered as a unique specimen in the Zoological Museum, Bogor (ZMB), while CAMR was employed to sort the Coleoptera collection in 1999. It belongs to the south-east Asian genus Chaloenus, unusual for the sexual dimorphism displayed by some species and the non-alticine appearance of these flea-beetles. The senior author had collected several new species of Chaloenus in Borneo 1996–1997, and was considering a generic revision. Since then many new species have been described, especially from Borneo, and two generic revisions published (Medvedev 2002, 2004, 2007; Takizawa 2012). The ZMB specimen, with its unique mandibular horns, remains unknown to both these authors and is described below. Another species was discovered amongst material of Scaphodius loaned from the Bishop Museum, Hawai’i, for CAAMR’s doctorate on Cryptocephalinae (awarded more than 20 years ago). This species is remarkable for the asymmetric mandibular horn in the single male specimen. The senior author’s original intention was to revise Scaphodius, endemic to New Caledonia, but what at first appeared to be a relatively small genus has become greatly expanded by availability of additional material from other sources. We are aware of at least 50 species in Scaphodius, requiring a major study for which time is lacking. A few of these species have been described recently (Schöller 2009). Scaphodius shows extreme sexual dimorphism in some species, perhaps more than any other taxon in the Cryptocephalinae. The new species is described below together with another unusual species, recently collected. Accepted by P. Divakaran: 21 Jan. 2013; published: 26 Feb. 2013 79 Mandibular sexual dimorphism is frequent in Chrysomelidae, but has not been reviewed. It is particularly associated with clytrine Cryptocephalinae (Monrós 1953; Agrain, Roig-Junent & Dominguez 2007; Agrain & Roig-Junent 2011), but occurs more widely, for example in Chrysomelinae (Figs 1–2). The distribution of mandibular sexual dimorphism in Chrysomelidae is reviewed below and its function discussed. Methods Genitalia were dissected from abdomens washed in water after being soaked in cold 10% KOH overnight. After examination they were stored in glycerol in a microvial, pinned with the rest of the specimen. Morphological terminology is based on Lawrence, Beutel, Leschen & Slipinski (2010). Abbreviations: BPBM (Bernice P. Bishop Museum, Hawai’i); c. (circa); MHNP (Natural History Museum, Paris); WUP (Wroclaw University, Poland); QMB (Queensland Museum, Brisbane); ZMB (Zoological Museum, Bogor). FIGURES 1–2. Callidemum cornutum Baly. 1, male head, dorsal; 2, female head, dorsal. Taxonomy Subfamily Galerucinae Chaloenus Westwood 1861: 216 Type species: Chaloenus latifrons Westwood, by subsequent designation (Wilcox 1973) Diagnostic description (based on Takizawa, 2012, and examination of 12 species). Small to medium sized alticine, length 3–8mm; head deflected at antennal insertions, especially in males, with genae and clypeus elongated; genae long, 0.5–2.0x eye length; male frontoclypeus without pits, setose foveae, tubercles or spines; postantennal calli well-defined, adjacent, convex, triangular to rectangular; antennal insertions close, separated by less than socket diameter; first antennomere greatly elongated, much longer than eye, second short, third elongated; labrum with truncate or convex apical margin; apical maxillary palpomere conical, shorter and narrower than pre- apical; pronotum strongly transverse, width 1.5–2x length, broadest at anterior half (usually at anterior angles); pronotum with or without discal depressions (not sharply defined); anterior pronotal border usually absent; procoxae strongly protruding, adjacent; prosternal process narrow but present between coxae; procoxal cavities closed by insertion of hypomera into apex of prosternal process; elytra non-striate to striate, rarely partially costate; elytra glabrous or with scattered erect setae; epipleuron broad at base (0.15–2x elytral width), gradually narrowed, upper and lower margins fusing well before elytral apex; mesoventrite process almost triangular, with truncate 80 · Zootaxa 3619 (1) © 2013 Magnolia Press REID & BEATSON apex; metaventrite without posterior lobes between hind coxae; metafemur 1.5–2x width mesofemur, with internal folded extensor endosclerite for jumping; tibiae rarely sharply ridged externally, without apical spurs; length of first metatarsomere slightly shorter to slightly longer than 2+3; third tarsomere deeply bilobed; tarsal claws appendiculate with basal lobe large and acute; ventrites not laterally ridged; male last ventrite trilobate, with two slots defining median apical lobe; female last ventrite simple; penis elongate-cylindrical with expanded basal foramen, apex symmetrical. Notes.The original paper erecting Chaloenus was published in issue ‘IV’ of the Journal of Entomology, dated December, 1861 (Westwood 1861). The statement that Medvedev “erroneously dated it as 1861” (Konstantinov & Prathapan 2008: 391) is therefore incorrect. Furthermore, the genus was originally credited with two species, both new, one described by Westwood and one by Baly. A type species was not clearly designated and the genus was not monotypic, therefore the statement by Wilcox (1973: 656), that C. latifrons Westwood is the type species by monotypy, was erroneous. Ironically, Wilcox's statement constitutes a type species designation in itself (International Code of Zoological Nomenclature 1999, Art. 69.1.1), which is C. latifrons Westwood, by subsequent designation of Wilcox. This was overlooked by Konstantinov & Prathapan (2008), who uneccessarily made the same designation. Konstantinov & Prathapan (2008) synonymised Priostomus Jacoby, 1884, with Chaloenus. The genus Chaloenus has recently been revised (Takizawa 2012) with these two concepts, Chaloenus and Priostomus, retained as subgenera, separated primarily by antennal proportions. Chaloenus is one of many genera of the leaf beetle subfamily Galerucinae with greatest diversity on the Sunda Shelf of south-east Asia. There are 42 described species (Takizawa 2012), 36 of which are recorded from Borneo. The new species described below is also Bornean and belongs to the nominate subgenus. Chaloenus gajah sp. nov. (Figs 1–6) Material examined. Holotype: m/ [INDONESIA] East Borneo, Balikpapan, Wain River [c.1°06’S 116°49’E], 50m, xi.1950, A. M. R. Wegner/ (ZMB). Description [slightly teneral male; female unknown]. Length 6.5mm. Colour: entirely yellowish-brown to orange-brown, except antennomeres 8–11 white, mandibular teeth, lateral edges of buccal cavity, antennomeres 1–7, elytra (but not edges of basal half), tibiae, tarsomeres 1–3 dark brown to almost black (elytra and antennomeres 4–7 darkest). Abdominal ventrites densely and finely setose. Head (Figs 1–3): impunctate or almost so, vertex shining, not microsculptured, frontoclypeus dull with fine microreticulation; head glabrous, except trichobothrium between postantennal callus and eye, short recumbent setae between antennae and buccal cavity and on upper surface of mandibles; frontoclypeus slightly ridged between antennae, otherwise almost flat with truncate apical margin; antennal cavities large, separated from each other and from eyes by about 0.75x socket diameter; postantennal calli elevated, well-defined, transverse, adjacent for entire length; eyes small, situated dorsally on head not laterally, oval, separated by c. 3x eye length; gena long, equal to eye length; antennae c. 0.75x body length, reaching apical third of elytra if reflexed, all segments elongate but decreasingly so from 3–10, and 8–11 moniliform in shape, antennomere 1 greatly elongated (length 2x eye length) and expanded at apex; relative lengths of antennomeres 1–11, as ratios of the shortest (10): 5, 1.25, 2, 1.9, 1.75, 1.5, 1.35, 1.25, 1.15, 1, 1.35; labrum large, semicircular, with 2 pairs of large setae; mandibles symmetrical, upper surface setose, elongated, laterally swollen at base, with vertical blunt tipped horn in middle of base and three apical teeth (visible ventrally); apical maxillary palpomere elongate-conical, about half length of penultimate. Thorax: pronotum and hypomera shining, unmicrosculptured, minutely and sparsely punctured, glabrous except trichobothrium in each angle; pronotum transverse, broadest anterior to middle, width c. 2x length, all angles slightly produced; pronotal disc convex but with pair of small circular depressions at sides; anterior edge truncate, not margined, sides strongly margined, sinuate, hind edge strongly margined, shallowly convex; prosternum glabrous, prosternal process reduced to a thin ridge between coxae, triangularly expanded at apex; MANDIBLE DIMORPHISM IN CHRYSOMELIDAE Zootaxa 3619 (1) © 2013 Magnolia Press · 81 FIGURES 3–8. Chaloenus gajahsp. nov., male holotype. 3, habitus; 4, head, antero-lateral; 5, head, dorsal; 6, apical ventrite; 7, penis lateral, ventral; 8, tegmen dorsal. 82 · Zootaxa 3619 (1) © 2013 Magnolia Press REID & BEATSON procoxal cavities closed, by elongate hypopleural lobes reaching apex of prosternal process; scutellum triangular; elytra shining but outer half finely microreticulate, glabrous except 5–6 setae at apices; each transversely depressed a third from base, from suture to slightly more than half width, with groove from this to base at inner margin of humerus; elytra impunctate except: finely punctured sutural striole, 4 short striae of large punctures in transverse depression, the fourth reaching elytral base; epipleura with upper margin elevated, broad at base, narrowing to a single elytral edge before apex; mesoventrite glabrous, other ventral mesothoracic sclerites finely and densely setose; mesoventrite process elongate triangular (but appearing slightly shrivelled); ventral metathoracic sclerites finely and densely setose (metaventrite shrivelled); procoxae globular, strongly projecting; femora glabrous or almost so on basal half, remainder of leg densely and finely setose; pro- and mesofemora almost parallel-sided, metafemora elongate-ovate, width c. 1.5x mesofemur; pro- and mesotibiae externally weakly ridged in basal half, metatibiae expanded at middle and sharply ridged for basal 2/3; length hind tarsus c. 0.5x hind tibia; first metatarsomere slightly shorter than 2+3, fifth as long as first; claws appendiculate, small right-angled basal lobe. Abdomen (Figs 5–8): ventrites weakly sclerotised, without lateral keels; male: apex of last ventrite weakly medially lobed, shallowly excavate either side of lobe; penis basal foramen circular, thick lipped, shaft cylindrical, sharply reflexed at base then straight, to semi-circular apex; endophallic sclerite thin with poorly defined base; tegmen thin, elongated, Y-shaped. Notes. Etymology: from the Malay for elephant (gajah), a noun in apposition, referring to the two tusk-like mandibular tubercles. Chaloenus gajah is the only species of Chaloenus with male mandibular horns and therefore easily distinguishable from all other males (Medvedev 2004; Takizawa 2012). In other Chaloenus species the female has a simple unmodified head and narrower prothorax; this is likely to be true of C. gajah. Apart from its unique mandibles, Chaloenus gajah is separated from similar Chaloenus species, as keyed and described by Takizawa (2012), as follows: C. brunneus Bryant, 1943, is small (4.8mm), yellowish with black margins to the elytra, and with flat apex to penis in profile; C. lanjakensis Takizawa, 2012 (female unknown), has black elytra, abdomen and legs, and broadly explanate lateral elytral margins; C. yukikoae Takizawa, 2012, has more elongate antennae and penis expanded at apex and flattened in lateral view. The type locality is probably the Wain River Forest Reserve, just north of the city of Balikpapan. This isolated 10,000 hectare reserve of lowland forest (maximum elevation 110m) has been seriously degraded in the last 15 years, with approximately 30% lost to fire, logging and cultivation (Craven 2002; Cleary & Priadjati 2005; Google Earth, images accessed July 2010). Some of the larger species of Chaloenus with sexually dimorphic males are known to aggregate at flowers of Araceae subfamily Aroideae (Kumano-Nomura & Yamaoka 2009; C. Darling pers. com. 2010; Takizawa 2012), and it is possible that C. gajah shows this behaviour. Aroideae are particularly diverse in Borneo (Mayo, Bogner & Boyce 1997). Chaloenus gajah appears to be the first record of this genus from Indonesian Borneo (Kalimantan) (Takizawa 2012), however the senior author has collected an additional 8 species from there. Subfamily Cryptocephalinae Scaphodius Chapuis 1874: 179 Type species: Scaphodius comptus Chapuis 1874, by monotypy. Diagnostic description (based on examination of c. 50 species). Small to medium sized cryptocephalines, length 1–6mm. Head: eyes small, convex, without a distinct internal canthus; male usually with elongated or laterally enlarged mandibles; clypeal area not sharply delimited, or if so, transversely triangular with obtuse upper angle and widely splayed raised margins for holding antennae in repose; antennae not serrate, longer than head width, antennomeres 7–11 elongate and expanded, each with dense basiconic sensilla in apical circular pit. Thorax: front angles pronotum not abruptly constricted as a collar; pronotum with triangular posterior lobe, usually medially notched for retention of scutellum; hind margin pronotum with row of teeth, usually hidden by base of elytra; hind angles of pronotum posteriorly produced; prosternal process broad, sides parallel and usually ridged; scutellum MANDIBLE DIMORPHISM IN CHRYSOMELIDAE Zootaxa 3619 (1) © 2013 Magnolia Press · 83 abruptly raised from mesoscutum, fusiform or oval, and anteriorly stepped; mesoscutum on either side of scutellum with narrow strip of microchaetae; elytra striate; elytral suture not serrate; elytral epipleuron entirely visible in lateral view, expanded at humerus, with sinuate lower margin; tibiae without spurs; claws appendiculate. Abdomen: ventrites III, IV and V fused; penis with distinct apical setae; vaginal palpi flat, semi-ovate; spermatheca falciform; dorsal transverse sclerites of kotpresse extending beyond sides of rectum. Notes.The genus Scaphodius is endemic to New Caledonia and was recently redescribed by Schöller (2009), with several new species. We have revised the description here, based on a larger sample of species. Schöller also included Nyetra Baly 1877 as a junior synonym of Scaphodius, with which we concur. Nyetra was described for a large species, with dorsal pubescence and extreme sexual dimorphism, in contrast to the type species of Scaphodius, small, dorsally glabrous and with slight sexual dimorphism, but there are intermediates in size and structure between these extremes, as noted by Schöller. Schöller listed 12 species in Scaphodius but this figure excludes species wrongly placed in the Australo- Papuan genus Ditropidus Erichson, 1842 (Schöller 2009). Schöller treated the five species of Ditropidus described by Fauvel (1907) as either belonging to that genus (D. opacicollis only) or nomina nuda, because they lacked detailed descriptions. However, these latter names were partially described by Fauvel (1907) as part of a key written to differentiate the species, which therefore makes them available (ICZN 1999, Art 12.1), although the species are unidentifiable from the key. Fauvel seems to have placed his species in Ditropidus based on size and colour, neither of which is valid, and faulty biogeography, influenced by Chapuis (1875a, b). Chapuis had listed D. punctulum Chapuis, 1875a, from Sydney, Adelaide and Fiji, and D. tibialis Chapuis, 1875a, from Sydney, Clarence River, Brisbane and Fiji. Chapuis also described Cryptocephalus fraterculus Chapuis, 1875b, from Fiji. All three of these species are Australian, absent from Fiji (Bryant & Gressitt 1957; types examined by CAMR) and the specimens from Fiji examined by Chapuis must have been wrongly labelled. Note that D. punctulatus of Bryant & Gressitt (1957) is a misidentification. Fauvel was therefore misled in believing that Ditropidus occurred in “Polynesia” (Fauvel 1907: 152). We have examined the male holotype of D. opacicollis. This is a small but otherwise typical species of Scaphodius, with ovate eyes, laterally expanded mandibles, strongly divergent facial antennal grooves and strigose pronotum (= S. opacicollis (Fauvel), comb. nov.). We have not seen any Ditropidus species in abundant material of Cryptocephalinae from New Caledonia. Fauvel’s generic diagnoses are clearly incorrect. We therefore feel justified in placing all of the other Fauvel names in Scaphodius: S. aeneus (Fauvel, 1907), comb. nov., S. nitidus (Fauvel, 1907) comb. nov.,S. striolatus (Fauvel, 1907) comb. nov.,S. sulcatus (Fauvel, 1907) comb. nov. The only species of Scaphodius supposedly from outside New Caledonia, S. compactus Sharp, 1881, was described from New Zealand. This is an Australian species of Ditropidus, either mislabelled from New Zealand or adventitive but no longer extant in that country (Leschen & Reid 2004; Schöller 2009). The net result of these changes is that Scaphodius is endemic to New Caledonia and Ditropidus is confined to Australia and New Guinea. Two new species in the material available to us show particularly bizarre sexual dimorphism and are described below. This brings the total number of valid Scaphodius species to 19. Scaphodius drehu sp. nov. (Figs 7–18) ♂ Material examined. Holotype: /Loyalty Is, Ouvea, Fayaoue, 0–50m, xii.1968/ N. L. H. Krauss collector Bishop ♀ Museum/ Nyetra sp., G. A. Samuelson det. 1971/ (BPBM); paratype: , same data as holotype except i.1969 (BPBM). Description. Length: 5mm (male = female), greatest width 3mm (male), 3.5mm (female). Colour: reddish- brown, except (i) antennomeres 8–11, female mandibles, disc of pronotum and elytral humeri, distal half female tibiae, darker brown; (ii) antennomeres 1–5, labiomaxillary complex, frontoclypeus of female, legs paler brown; (iii) labrum, posterior angles pronotum (dorsal and ventral), prosternal and mesoventrite processes, anterior margin metaventrite, mesanepisternum, mesepimeron, deep yellow to orange. Dorsal pubescence: head, pronotum [except disc—rubbed off?] and elytral striae with dense recumbent silvery setae. Head: roughly circular, broadest at genae below eyes (male) or at eyes (female); male frontoclypeus diamond 84 · Zootaxa 3619 (1) © 2013 Magnolia Press REID & BEATSON shaped, convex, except reflexed anterior edge which is produced apically and bilobed; female frontoclypeus not anteriorly produced, apical margin flat, shallowly triangularly excavate; sides frontoclypeus bounded by oblique antennal grooves from antennal sockets to lateral margins buccal cavity; head densely and finely punctured (punctures separated by their diameters, about eye facet sized) and clothed in silvery recumbent setae, except antennal grooves, antennal tubercles and shallowly depressed centre of vertex impunctate and glabrous; eyes oval (female larger than male), inner margin feebly concave; interocular space 2.5x (male) or 2x (female) length of eye; gena long, minimum length 0.4–0.45x eye length; antennae much longer than width of head (male) or slightly longer than width of head (female), all segments elongate, 1–5 sparsely setose and thin, almost parallel-sided, 6–10 densely setose and triangular with apical sensory patch, 11 elongate oval (10 & 11 absent in male); antennomere 1 longest, greatly elongated, length 0.8x eye length (male) or 0.35x (female); labrum transverse with convex apex, apically swollen in male, flat in female; mandible apices normal in both sexes, with two interlocking teeth; male with massive horn arising from base of left mandible, curving across face and upwards in front of right eye; apical maxillary palpomere flattened-cylindrical in male, elongate conical in female (apex narrowly truncate). Thorax: pronotum: strongly transverse, width male 1.7x length, width female 1.8x length, anteriorly strongly laterally arched, front angles almost hidden by curvature; strongly and closely punctured on disc (puncture diameters c. 2x head punctures, generally separated by one puncture diameter, some coalescent), but basal half midline smooth and impunctate (slightly raised in male), becoming finer and slightly sparser at sides; pronotum with dense recumbent silvery setae except disc [irregularly setose, possibly worn off] and trichobothrium at each angle; anterior and lateral edges finely margined, posterior edge presumed to have row of small teeth as in other Scaphodius species (not seen in entirety); anterior angles rounded, posterior angles posteriorly produced, 90° in perpendicular view; pronotal basal lobe triangular with slightly bilobed apex, basal margin hidden by raised anterior edge of elytra; hypomeron glabrous, impunctate, except densely setose posterior lobe; prosternum closely setose and punctate, anterior margin reflexed; prosternal process transverse, ventral surface flat, laterally bounded by parallel ridges, apex evenly arcuate; scutellum smooth, glabrous and impunctate, minute, length equal width 3rd elytral interval, elliptical; elytra almost quadrate but apices rounded with c. 45° sutural angle; basal margin elytra smooth, slightly overlapping basal margin pronotum; elytra striate, with striole and 10 striae (10th adjacent to epipleuron) but each ‘stria’ consisting of confused fine punctures, with recumbent setae (similar to head), in a straight groove with convex glabrous impunctate interstiae (except base of 9th interval); striae 4 and 5 anastomised before apex, striae 3 and 6, and 7 and 8, at apex; humeri prominent, swelling divided by base of 9th stria; epipleura sparsely and minutely setose, ventrally produced at humeri, broad at base (= width third elytral interval), abruptly narrowed at postcoxae, then narrowing to a single edge before elytral apex; mesoventrite process similar to prosternal process, but shorter, with convex anterior and laterally projecting apical angles; mesanepisternum and mesepimeron glabrous, impunctate, but densely microsculptured; fully winged; metaventrite densely punctured and pubscent at sides, glabrous and transversely strigose (more so in male) at middle; metepisternum densely setose; femora elongate-ovate, similar sized; tibiae gradually expanded to rounded apices, pro- and mesotibiae finely grooved on basal half outer edge; hind tarsi 0.75x length hind tibiae, length metatarsomere 1 < 2+3; male first pro- and mesotarsomeres expanded, width 3/5 length, female first tarsomeres not expanded, width 2/5 length; claws appendiculate, lobe large, right-angled. Abdomen: paired patches of wing-folding spicules on each tergite except pygidium, patches increasing in size from II-VII; pygidium entirely punctured and pubescent with dense recumbent setae, without median ridge; ventrites without lateral ridges, densely punctured and recumbent-setose; ventrite V with truncate apex in both sexes, male with median sparsely setose shallow depression, female ventrite V with deep hemispherical transversely strigose depression and median excavation of apical margins of ventrites III and IV. Male genitalia: spiculum Y-shaped; penis in lateral view with apical half constricted at base, bent towards acute apex; penis dorsally parallel-sided to right-angled apex with blunt tip, pair of setae at base of ostium and c. 11 pairs of setae on apical margin; tegmen broadly Y-shaped, with deep internal keel; endophallic sclerite roughly trident-shaped in dorsal view with oval apical lobes. Female genitalia: vaginal palp elongate-triangular, with darkly sclerotised anterior margin; spermatheca falcate, twisted at base, with uncoiled duct; rectum with well-developed kotpresse: dorsum with rectangular sclerites, simply rounded at their laterally projecting apices, and ovate patch of microspicules; venter with narrow parallel-sided transverse bar, projecting apices greatly expanded; sides with posteriorly directed sclerotised strip. MANDIBLE DIMORPHISM IN CHRYSOMELIDAE Zootaxa 3619 (1) © 2013 Magnolia Press · 85 FIGURES 9–13. Scaphodius drehu sp. nov. 9, male, habitus; 10, male head, anterior; 11, male head, lateral; 12, female, habitus; 13, female head, anterior. 86 · Zootaxa 3619 (1) © 2013 Magnolia Press REID & BEATSON FIGURES 14–18. Scaphodius drehu sp. nov. 14, penis lateral, dorsal, endophallic sclerite; 15, tegmen lateral, dorsal; 16, vaginal palp; 17, spermatheca and duct; 18, rectal kotpresse, dorsal (left), ventral (right) (lighter shading = internal spicule patches). MANDIBLE DIMORPHISM IN CHRYSOMELIDAE Zootaxa 3619 (1) © 2013 Magnolia Press · 87 Notes.Etymology: named for the major endemic language of the island of Ouvea, Drehu (Anonymous 2010), a noun in apposition. Sensory organs on the head are sexually dimorphic in size, as compared against body length, measured from anterior margin of pronotum to apex of elytra: greatest diameter of eye 14.5% (male) or 13.5% (female) body length; antennal length approximately 66% (male) or 50% (female). Amongst described species of Scaphodius, S. drehu is nearest to S. amieus Schöller, 2009, which differs by colour, mandibular structure, frontoclypeal margin and penis shape. The female of Scaphodius drehu is most similar to an undescribed species with only females available, from the nearby island of Livou (Loyalty Islands; in BPBM), but S. drehu differs by denser punctures on pronotum, more elongate hind angles of pronotum and broader lines of setae on elytra. Scaphodius ferox sp. nov. (Figs 19–28) ♂ Material examined. Holotype: / Mandjelia (summit), 20:23:09S 164♀:31:09E, 750–780m, beating montane rainforest, 12.i.2007, M. Wanat & R. Dobosz (MHNP); paratypes (4): / Mandjelia (subsummit), 20:23:09S ♀ 164:32:00E, 700–750m, night beating, 11.i.2007, M. Wana♀t (WUP); / Mandjelia, summit, 20:24S 164:32E, 780m, beating rainforest, 13.xii.2004, G. Monteith (QMB); / Mandjelia, lower creek, 20:24S 164:31E, 550m, ♀ malaise, 29.xi.2003–31.i.2004, G. Monteith (QMB); , same data, except ‘580m, beating rainforest, 12–13.xii.2004” (MNHP). Description. Length: 2.5mm (male = female), greatest width 1.3mm (male), 1.5mm (female). Colour: black, except (i) labrum, labiomaxillary complex, pale yellow; (ii) antennomeres 1 up to 6, apices trochanters, middle of thoracic venter, sometimes brown [probably slightly teneral examples]. Dorsal pubescence: almost entirely glabrous. Head: male anterior half with sides produced and middle deeply cleft, head almost circular in female, broadest at genae below eyes in both sexes; vertex with minute (much smaller than eye facet) and sparse punctures with minute recumbent setae; frontoclypeus similar but strongly microreticulate and genae coarsely microreticulate; male frontoclypeus deeply bilobed, median cleft almost reaching antennal sockets, but lateral triangular lobes projecting beyond genae; female frontoclypeus flat, semi-ovate, apical margin narrowly concave; sides frontoclypeus bounded by oblique antennal grooves from sockets to lateral margins buccal cavity (male), or flat with almost vertical sutures which may be raised as fine ridges [teneral examples]; eye oval, inner margin feebly concave; interocular space 1.4x (male) or 1.2x (female) length of eye; gena long, minimum length 0.6x (male) or 0.8x (female) eye length; antennae 1.5x (male) or 1.3x (female) width head, all segments elongate, 1–6 sparsely setose and thin, almost parallel-sided; male antennomere 7 triangular with scattered setae, 8–10 triangular and densely setose, 11 elongate-oval and setose, female similar but 7–10 elongate-oval in shape; antennomeres 7–11 with apical sensory patch; antennomere 1 longest, greatly elongated in male (1.1x eye length) less so in female (0.7x eye length); male labrum massive, flat, elongate rectangular, apex almost truncate, female labrum small, slightly swollen, transverse; male mandibles greatly elongated, apices with 3 interlocking teeth and middle with elongate semi-circular horn curving inwards; female mandibles normal, extending just beyond labrum with 2 visible interlocking teeth; labio-maxillary complex elongated in male, normal in female, apical maxillary palpomere elongate-cylindrical in both sexes, much longer than pre-apical. Thorax: pronotum: strongly transverse, width 1.6x length (both sexes), anteriorly strongly laterally arched, front angles hidden by curvature; impunctate and glabrous except trichobothrium at each angle; anterior and lateral edges finely margined; anterior angles rounded, posterior angles posteriorly produced, 75° in perpendicular view; pronotal basal lobe shallowly triangular with bilobed apex, posterior margin finely and evenly toothed; hypomeron glabrous, impunctate; prosternum with large close punctures and erect setae, anterior margin reflexed; prosternal process strongly transverse, ventral surface flat, laterally bounded by parallel ridges, apex feebly concave to truncate; scutellum smooth, glabrous and impunctate, minute, length shorter than width 3rd elytral interval, elliptical; elytra tapered from humeri to rounded apices with c. 45° sutural angle; basal margin elytra smooth, slightly overlapping basal margin pronotum; elytra glabrous, striate, with striole and 10 striae (10th adjacent to 88 · Zootaxa 3619 (1) © 2013 Magnolia Press REID & BEATSON