Scaphodius ferox, Reid & Beatson, 2013

Reid, C. A. M. & Beatson, M., 2013, Chrysomelid males with enlarged mandibles: three new species and a review of occurrence in the family (Coleoptera: Chrysomelidae), Zootaxa 3619 (1), pp. 79-100 : 88-92

Scaphodius ferox sp. nov.

( Figs 19–28 )

Material examined. Holotype: 3/ Mandjelia (summit), 20:23:09S 164:31:09E, 750–780m, beating montane rainforest, 12.i.2007, M. Wanat & R. Dobosz ( MHNP) ; paratypes (4): Ƥ/ Mandjelia (subsummit), 20:23:09S 164:32:00E, 700–750m, night beating, 11.i.2007, M. Wanat ( WUP) ; Ƥ/ Mandjelia , summit, 20:24S 164:32E, 780m, beating rainforest, 13.xii.2004, G. Monteith ( QMB) ; Ƥ/ Mandjelia , lower creek, 20:24S 164:31E, 550m, malaise, 29.xi.2003 – 31.i.2004, G. Monteith ( QMB) ; Ƥ, 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 epipleuron), each stria consisting of single line of large punctures, increasing in size from stria 1 to 9, interstriae impunctate, flat, except slightly convex intervals 7–9; striae 4, 5, 7 and 8 abbreviated before apex, striae 3 and 6 anastomised at apex; humeri prominent, swelling divided by base of 9th stria; epipleura glabrous and impunctate, 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; mesanepisternum and mesepimeron glabrous, impunctate, but densely microsculptured; fully winged; metaventrite with median groove, distinctly but sparsely punctured and pubscent throughout; metepisternum with scattered setae; femora elongate-ovate, similar sized; tibiae gradually expanded in basal 2/3, then contracted to apex, outer margins basally ridged; hind tarsi 0.75x length hind tibiae, length metatarsomere 1 <2+3; male first pro- and mesotarsomeres feebly expanded, female first tarsomeres not expanded; claws appendiculate, lobe large, rightangled.

Abdomen: paired patches of wing-folding spicules on each tergite including pygidium, increasing in size from II–VII; pygidium entirely punctured with recumbent setae, but basal bi-arcuate patch of wingfolding spicules present, without median ridge; ventrites without lateral ridges, distinctly punctured and recumbent-setose; ventrite V with truncate apex in both sexes, male with median shallow depression, female ventrite V with moderately deep bowl-shaped transversely strigose depression and median excavation of apical margin of ventrite IV. Male genitalia: spiculum Y-shaped; penis in lateral view with swollen apical half, constricted at base, acute apex; penis dorsally parallel-sided to rounded apex with small mucronate tip, pair of setae at base of ostium and c. 9 pairs of setae on apical margin; tegmen narrowly Y-shaped, without deep internal keel; endophallic sclerite roughly rectangular in dorsal view with thin apical lobes. Female genitalia: vaginal palp ovate, with transparent anterior margin; spermatheca falcate, twisted at base, with long loosely coiled duct; rectum with well-developed kotpresse: dorsum with triangular sclerites, narrowly hooked at projecting apices, and triangular patch of microspicules; venter with narrow parallel-sided transverse bar, projecting apices not greatly expanded; sides with posteriorly directed sclerotised strip.

Notes. Etymology: named for the fierce (Latin: ferox ) appearance of the male.

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 16% (male) or 14–15% (female) body length; antennal length 76% (male) or 45–46% (female).

This is one of many species of Scaphodius with greatly modified mandibles and extended clypeal or genal lobes ( Schöller 2009; pers. obs. CAMR). Six of the 41 species with males available to us have a spine on the inner edge of the male mandible. However, S. ferox is the only species we are aware of with a smooth glabrous dorsum and an elongate dorsally directed tooth at the base of each mandible. There are several shining black undescribed species, but with relatively unmodified male mandibles and at least slightly punctate or strigose pronotum. The black head with contrasting yellow mouthparts also seems to be diagnostic for S. ferox .

Figures

FIGURES 19–23. Scaphodius ferox sp. nov. 19, male, habitus; 20, male head, anterior; 21, male head, lateral; 22, female, habitus; 23, female head, anterior.

FIGURES 24–28. Scaphodius ferox sp. nov. 24, penis lateral, dorsal, endophallic sclerite; 25, tegmen lateral, dorsal; 26, vaginal palp; 27, spermatheca and duct; 28, rectal kotpresse dorsal (left), ventral (right) (lighter shading = internal spicule patches).