Figulus rossi Gahan, 1900

Monte, Cinzia, Zilioli, Michele & Bartolozzi, Luca, 2016, Revision of the Australian species of Figulus MacLeay, 1819 (Coleoptera: Lucanidae), Zootaxa 4189 (3), pp. 447-484 : 470-473

Figulus rossi Gahan, 1900

( Figs. 20–24 )

Figulus rossi Gahan, 1900: 96 ; Van Roon 1910: 53; Boileau 1913: 265; Didier & Séguy 1953: 182; Benesh 1960: 27; Maes 1992: 40; Moore & Cassis 1992: 10; Krajcik 2001: 12; Krajcik 2003: 83; Maes 2014; Schoolmeesters 2015.

Type material. Figulus rossi : Lectotype here designated: Lectotype: “SYN- / TYPE [printed]”, “TYPE [printed]”, “Camp II /Christmas I. / C.W.Andrews. / 98-20. [printed]”, “ Figulus / rossi Gahan / Type [handwritten]”, “BMNH(E) / # 607443 [printed]”, [NHM]; Paralectotypes: 1♀, “SYN- / TYPE [printed]”, “Christmas I. / C.W.Andrews / Dec.1897 / 98-20. [printed]”, “Near / Flying Fish Cove [printed, handwritten]”, “ Figulus / rossi / Gahan / Co-type [handwritten]”, “BMNH(E) # 607442 [printed]”, [NHM]; 1♀, “SYN- / TYPE [printed]”, Christmas I. / C.W.Andrews / 1898 / 98-20. [printed]”, “North part / of Island / Jan.1898 [printed]”, “ Figulus / rossi / Gahan / Co-Type [handwritten]”, “BMNH(E) # 607441 [printed]”, [NHM];1Ƌ, “SYN- / TYPE [printed]”, “Flying Fish / Cove / Christmas I. / Hugh Ross / 1900. 28 [printed]”, “ Figulus / rossi / Gahan / Co-Type [handwritten]”, “BMNH(E) # 607444 [printed]”, [NHM].

Diagnosis. The general morphology of Figulus rossi is close to that of F. sulcicollis from which it mainly differs by the less punctate head and prothorax, and the much larger size of the punctures on the elytra being subcircular instead of suboval.

Redescription. Measurements: size range (n = 15): TL: 11.0– 14.33 mm; PL: 3.25–4.08 mm; EL: 6.25–7.71 mm; PW: 3.79–5.16 mm; EW: 3.6–4.87 mm.

Male ( Fig. 20 ). Body elongate, with subparallel sides, black to dark brown, glossy; antennae reddish brown.

Head: transverse, approximately twice as wide as long. Frontoclypeal region slightly concave at the anterior margin sparsely and finely punctate and 2 large, glossy areas situated before the eyes. Labrum broad, short, with anterior margin feebly bilobed and with long, golden setae. Vertex inclined anteriorly with a shallow medial elevation and 2 small, transversal elevations between eyes. Two moderately developed, longitudinal carinae are present along the inner margin of eyes. Eyes large, divided into 2 parts by the canthi, the upper part smaller than the lower, with distinct facets. Canthus protruding, evenly rounded laterally, more angled behind; upper surface slightly depressed, with coarse punctures that are smaller and sparse on the lateral margin. Head surface sparsely and finely punctate, with minute punctures on canthi and longitudinal carinae. Mandibles slightly shorter than head, strong and asymmetrical; outer margins rounded; apices slightly blunted and feebly bent upwards; upper surface slightly elevated at base. Internal margin of the right mandible with a moderately developed basal tooth and a medial strong tooth, with apex blunted directed inwards. Internal margin of the left mandible with a moderately developed basal tooth, a well-developed medial tooth, and a preapical slight angulation. Antenna with 10 antennomeres, with scape as long as the remaining antennomeres combined; club of last three antennomeres, which are flatter and broader than the remaining antennomeres of the funicle. Mentum subrectangular ( Fig. 21 ), slightly concave medially; anterior margin slightly bilobed; sides slightly rounded and feebly elevated at midlength, where a small tubercle directed downwards is present; base feebly depressed in the middle; surface punctate basally and at sides, rugose medially and distally.

Thorax: pronotum slightly wider than long with subparallel sides; anterior margin slightly convex and elevated, with a small, blunt median tubercle; posterior margin slightly bisinuate; anterior angles produced and rounded; posterior angles rounded. Deep longitudinal medial groove on pronotal disc, with large, circular punctures. Pronotal surface glossy, with dense, small, superficial punctures; punctures slightly larger at sides and with patch of large, close punctures at the anterolateral margin; each puncture with a short, erect, golden seta in the middle. Scutellum long, wedge shaped; surface smooth and glossy. Elytra about twice as long as pronotum. Base concave, subparallel sides, apex regularly rounded. Humeral angles, with a small, acute tubercle. Elytral surface glossy, with 9 visible, subparallel striae, the dorsal striae deeper than the lateral striae; each stria formed by a row of large, subcircular punctures that are well separated from each other, except for the first stria, where the punctures are confluent. Stria 1 is the only stria reaching apex; on the declivity, stria 2 curves outwards, and it sometimes converges with stria 9; striae 4, 5, 6 formed by a row of punctures slightly broader than those of the striae 2 and 3; stria 6 begins just after base; striae 3‒6 end slightly before the declivity; striae 7 and 8 narrow, formed by a row of punctures smaller than those of other striae. Dorsal interstriae much broader than the lateral interstriae, slightly convex and finely punctate; interstria 2 slightly larger on declivity, where it looks glossy and scarcely punctate; interstriae 3‒8 converging on the declivity. Elytral lateral margins strongly punctate, with short, erect, red setae; elytral apex slightly punctate. Wings present. Legs: thin and straight. Protibiae with elongate apical fork, and a long, strong spur internally at apex; lateral margin with 4‒5 small teeth, increasing in size distally. Mesotibiae with 4 long, acute, apical teeth, and 2 apical spurs, 1 larger than the other; lateral margin with strong submedial tooth, preceded by 1‒2 smaller teeth. Metatibiae with 4 acute apical teeth, and 2 long, apical spurs, 1 larger than the other; lateral margin with strong submedial tooth, preceded by a smaller tooth. Prosternum subpentagonal in shape behind the coxae; surface with large and deep punctures at anterior edge and with smaller punctures medially and at posterior edge. Metasternum smooth on disc, with superficial medial groove, deeper at posterior edge, slightly punctate at sides.

Abdomen: first abdominal ventrite with mixed, horse-shoe shaped, superficial hollows and simple punctures, each with short, golden seta. The remaining ventrites smooth with sparse, small punctures; punctures denser medially, each with short, golden seta. Last ventrite with 2 feeble depressions at sides near the posterior margin, surface with some punctures.

Male genitalia: penis tubular, shorter than parameres, completely covered by a dorsal translucid, membranous extension of the basal piece; in lateral view moderately curved, more curved proximally close to articulation with basal piece ( Figs. 22–23 ). Permanently everted internal sac drawn out into a long and broad, colorless or yellow flagellum tapering towards apex; from which a short, curved ejaculatory duct emerges; edge of flagellum serrulate toward apex ( Fig. 24 ). Parameres about as long as basal piece, broad in dorsal view, thick at base in ventral view, with marginal fringe of setae entirely enclosed in the cuticle (not represented in the figure). Basal piece usually parallel sided, sometimes slightly rounded; ventrally largely membranous; dorsally with a moderately broad sclerotic area along midline. A pair of long, slender struts run along basal piece from penis articulation, not reaching the base of basal piece ( Figs. 22–23 ).

Female. All external morphological characters as in male.

Female genitalia: hemisternites elongate, subtriangular, apically with long, golden setae surrounding the styli; moderately broad, narrower apically; outer edge almost straight or slightly sinuose; styli slender with apex obliquely directed outwards, slightly longer than wide. Bursa copulatrix represented by a slight expansion of the wall of spermathecal duct near junction with median oviduct. Spermathecal duct moderately short, ending in a bulbous, pear-shaped expansion that is pigmented distally.

Intraspecific variation. The examined specimens do not show significant morphological variability.

Additional material examined. CHRISTMAS ISLAND: 1 specimen, Christmas Island , I‒IX.1933, 6571, Brit. Mus 1934-32, BMNH (E) # 607445 ( NHM) ; 1 specimen, Christmas Island, I‒IV.1933, Brit. Mus 1934-32, BMNH (E) # 607446 ( NHM) ; 1 specimen, Christmas Island, The Cove , 16.X.04, R.Anitsch, labeled Sci. Mus.: K.L., ex F.M.S. Museum B.M. 1955-354, BMNH (E) # 607447 ( NHM) ; 1 specimen, Christmas Island, 12- 20.I.2003, A.I.Knight ( QMB) ; 1 specimen, Christmas Island, M.W.F. Tweedie, Collection Raffles Mus., VIII– IX.1932, ex F.M.S. Museum B.M. 1955-354, BMNH (E) # 607448 ( NHM) ; 1 specimen, Christmas Island, 10.29ºS, 105.37-38ºE, near Central area Workshop , 13-28.IV.1989, J.Lawrence, in rotten wood, ANIC Coleoptera, Voucher No 87-0243 ( ANIC) ; 1Ƌ, 1♀, Christmas Island, 18–26.XI.1999, M.Moulds & M.Humphrey (AMS) ; 1 specimen, same locality and data, (RKC).

Distribution. This species is known only from Christmas Island, Australia.

Natural history data. The examined specimens were collected from November to January and from August to September, but there are also records from April. Two specimens found in rotten wood, yet no further information about them is available. The larvae and host plant(s) are unknown.

Remarks. The species is endemic to Christmas Island.

Figures

FIGURES 20‒24. Figulus rossi Gahan. 20, dorsal view of adult (scale bar: 5 mm); 21, mentum; 22, male genitalia, dorsal view (scale bar: 0.5 mm); 23, male genitalia lateral view; 24 apex of flagellum (scale bar: 200 µm).