Figulus trilobus Westwood, 1838

Monte, Cinzia, Zilioli, Michele & Bartolozzi, Luca, 2016, Revision of the Australian species of Figulus MacLeay, 1819 (Coleoptera: Lucanidae), Zootaxa 4189 (3), pp. 447-484 : 478-481

Figulus trilobus Westwood, 1838

( Figs. 30–36 )

Figulus trilobus Westwood, 1838: 263 ; Westwood 1845: 26; Burmeister 1847: 439; Parry 1864a: 6; Parry 1864b: 99; Harold 1868: 966; Parry 1873: 343; Parry 1875: 15; Didier 1937: 30; Benesh 1943: 46; Didier & Séguy 1953: 184; Benesh 1960: 29; Maes 1992: 41; Moore & Cassis 1992: 11; Krajcik 2001: 13; Krajcik 2003: 84; Maes 2014; Schoolmeesters 2015.

Type material. Figulus trilobus Westwood holotype (♀): “Holo / type [printed]”, “Type [printed]”, “W. Imeson / N. Holland [handwritten]”, “Ent. Club. / 44-12. [printed]”, “BMNH(E) / # 607242 [printed]”, “ Figulus / trilobus Westw. [handwritten]”, [NHM].

Diagnosis. Figulus trilobus differs from the all other known members of the genus in Australia by the shape of prothorax, which is moderately elevated with anterior process trilobate, and by the shape of male genitalia.

Redescription. Measurements: size range (n = 41): TL: 16.0– 19.79 mm; PL: 3.92–5.42 mm; EL: 10.42– 11.50 mm; PW: 4.0– 6.75 mm; EW: 4.1–6.79 mm.

Male ( Fig. 30 ). Body elongate, with subparallel sides, dark brown, glossy.

Head: transverse, about twice as wide as long, slightly depressed. Frontoclypeal region slightly concave at the anterior margin, slightly produced anterolaterally, densely and coarsely punctate; surface smooth with some punctures before the eyes and in the middle. Labrum broad, short, strongly bilobed at anterior margin. Vertex slightly concave in the middle, inclined forwards, with 2 small, subcircular elevations. Two moderately-developed longitudinal carinae are present along the inner margin of eyes. Eyes small, divided into 2 parts by the canthi, the upper part smaller than the lower with distinct facets. Canthus largely protruding, rounded laterally and evenly rounded behind, slightly depressed upper surface, with dense and small punctures on the lateral margin. Head surface densely punctate with coarse umbilicate punctures; surface with some smooth areas on frons and on the subcircular elevations of vertex. Mandibles shorter than head, strong and asymmetrical, strongly curved, apices slightly acute; external margin of the superior side slightly elevated. Internal margin of the right mandible with a medial strong tooth, directed inwards and with a weaker subapical elevation. Internal margin of the left mandible with a medial tooth, directed inwards and with a subapical tooth more ventral and flatter, strong and directed forward and downwards. Antenna with 10 antennomeres, with scape as long as the remaining antennomeres together; club of last three antennomeres, which are flatter and broader than the remaining antennomeres of the funicle. Mentum subrectangular ( Fig. 31 ), slightly concave medially; anterior margin slightly bilobed and sides slightly rounded and anteriorly elevated. Surface strongly and regularly punctate.

Thorax: pronotum slightly wider than long with subparallel sides; anterior margin produced, convex, and moderately elevated with anterior process trilobate; medial tubercle more developed than the others; posterior margin slightly bisinuate; anterior angles slightly acute, the posterior angles largely rounded. Broad and superficial longitudinal medial groove on pronotal disc, with large, circular punctures. Surface of pronotal disc at optical microscope appearing microreticulate with sparse, minute punctures. With the SEM the surface appears formed by subcircular, imbricate facets with faint edges, progressively disappearing towards sides, where punctures conversely become larger and denser ( Figs. 35–36 ). Anterior margin of pronotum with large punctures; each puncture with short, erect, golden setae in the middle. Scutellum broad, wedge shaped, broad, with coarse punctation. Elytra about twice as long and as wide as pronotum. Base concave, sides subparallel, apex regularly rounded. Humeral angles acute, with a small tubercle. Elytral surface with 9 visible, subparallel striae; each stria formed by three rows of large, oval punctures that are well separated from each other; dorsal striae with the medial row formed by larger punctures than lateral striae; lateral striae formed by large and identical-sized punctures. Interstriae much narrower than striae. Elytral margins and apex strongly punctate, with short, erect, red setae. Wings present. Legs thin and straight. Protibiae with strong, elongate apical fork, and a long, strong spur internally at apex; lateral margin with 5‒6 small teeth, increasing in size distally. Mesotibiae with 4 acute, apical teeth, and 2 apical spurs, 1 larger than the other; lateral margin with strong submedial tooth, preceded by 2‒3 smaller teeth. Metatibiae with 4 acute apical teeth, and 2 apical spurs, 1 larger than the other; lateral margin with strong, submedial tooth, preceded by 1‒2 smaller teeth. Prosternum subpentagonal in shape behind the coxae; surface with large and deep punctures with long, golden setae in the middle. Metasternum punctate, with a long, medial groove that is deep at posterior edge.

Abdomen: first abdominal ventrite with some horse-shoe shaped, superficial hollows with a short, golden seta in the middle; the other ventrites with large and deep punctures, each puncture with a short, golden seta.

Male genitalia: penis tubular, short, broadened from base towards apex ( Figs. 32–34 ); only partially covered by a dorsal, translucid, membranous lobed extension of the basal piece not reaching the penis apex; in lateral view fairly curved, more strongly at base close to articulation with basal piece. Permanently everted internal sac drawn out into a long and broad, colorless or yellow flagellum tapering towards bifid apex ( Fig. 34 ). Parameres shorter than basal piece, with long, golden setae on ventral and lateral surface beside the marginal fringe of setae entirely enclosed in the cuticle. Basal piece long, sclerotized, about 1.5 times the length of parameres; in dorsal view slightly, evenly broadened from base towards apex; ventrally largely membranous, dorsally with a broad sclerotic area along midline and 2 weak protuberances just before the base. A pair of long, slender struts run along basal piece from penis articulation, not reaching the base ( Figs. 32–33 ).

Female. All external morphological characters as in male.

Female genitalia: hemisternites elongate, broad, parallel sided, inclined outwards apically at 2/3 of its length, medial edge moderately convex and indented towards base; styli slender, hook-shaped, directed outwards, slightly longer than wide. Bursa copulatrix represented by a slight expansion of the wall of spermathecal duct near junction with the median oviduct. Spermathecal duct moderately short, ending in a bulbous, helicoidal expansion proximally colorless, distally pigmented.

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

Additional material examined. Australia [state unknown]: 1♀, Comp. au Type, ex Collection v. de P., 5672, ex Collection Boileau, H.E. Bomans 1999-248 ( NHM) . AUSTRALIAN CAPITAL TERRITORY: 1 specimen, Black Mountain , 1.II.1968, light trap, M.S.Upton ( ANIC) . NEW SOUTH WALES: 1 specimen , New South Wales, MacLeay Museum, University of Sydney 2006 ( LBC) ; 1♀, Barrington Tops National Park, Upper Williams R., 26.I.1987, R.deKeyzer, 11929, H.E.Bomans 1999-248 ( NHM) ; 1 specimen, Barrington Tops National Park, Upper Williams River , 26.I.1987, R.deKeyzer, K 293320, R.deKeyzer Insect Collection (AMS) ; 1 specimen, Barrington Tops National Park , XII. 1996, 400 m ( MRST) ; 1♀, Mount Belmore State Forest , via Busby Flat, T. Ridge Road, 4.XII. 1998, 500 m, mv light, S.G.Watkins Collection donated 2001 ( ANIC) ; 1 specimen, Bimbi, 11.XII.1987, Wedding Bells State Forest , R.H.M., R.H. Mulder Collection, K 293095 (AMS) ; 1♀, Blaxland, 33°S, 146°E, 1970, D. Wallace (NBC); 1 specimen, Dingo State Forest, NW Wingham, Brown’s Look-out , 6.I.1990, mv light, S.G.Watkins Collection donated 2001 ( ANIC) ; 3Ƌ, Dingo State Forest, NW Wingham, Dingo Tops Forest Park, 14.I.1993, 93:146 Ƌ, 93:147 Ƌ, and 93:160 Ƌ, S.G.Watkins Collection donated 2001 ( ANIC) ; 1Ƌ, Dingo State Forest, Wadsworth Trail at Potoroo Road , 10.XI.1995, mv light, 95:1096 Ƌ, S.G.Watkins Collection, donated 2001 ( ANIC) ; 1Ƌ, Dingo State Forest, 5 km West on Potoroo Road , 10.XI.1995, 95:926 Ƌ, S.G.Watkins Collection, donated 2001 ( ANIC) ; 1Ƌ, Double Duke State Forest, WSW New Italy, Pyrocarpa Flora Reserve , 18.X. 1998, 140 m, 98:566 Ƌ, S.G.Watkins Collection, donated 2001 ( ANIC) ; 2ƋƋ, Fortis Creek State Forest , N Grafton, 13.XI.1996, mv light, 96:538 Ƌ and 96:539 Ƌ, Watkins, S.G. Watkins Collection donated 2001 ( ANIC) ; 1♀, South boundary Fortis Creek National Park, N of Grafton , 5.I.1999, 50 m, mv light, Watkins, S.G. Watkins Collection donated 2001 ( ANIC) ; 1 specimen, Grose Vale, 12.IV.1982, under log, D.P.Carne ( ANIC) ; 1 specimen, Lagoon Pinch Forest Park, Chichester State Forest , 26.I.1987, R.deKeyzer (RKC) ; 1♀, Lansdowne State Forest, Starrs Creek , 8.XII.1990, mv light, S.G.Watkins Collection, donated 2001 ( ANIC) ; 1♀, Ogilvie Trail, Banyabba State Forest, N of Grafton , 1.XI.1997, mv light, S.G.Watkins Collection, donated 2001 ( ANIC) ; 1♀, Powerful Owl Reserve Girard State Forest,W of Drake , 30.XII. 1998, 690 m, mv light, Watkins, S.G. Watkins Collection donated 2001 ( ANIC) ; 1 specimen, Sydney , Carter, H.J.Carter Collection, P. 20.4.22, COL-85978 ( NMVM) ; 1 specimen, Sydney , Nat. Mus. Victoria, C.French’s Collection 5.IX.08, COL-85996 ( NMVM) ; 1 specimen, Mount Victoria, 5.XII.1946, C.Oke, COL-85922 ( NMVM) ; 1 specimen, Wauchope, 31.27ºS, 152.44ºE, 72 km W on Oxley Highway , 4.I.70, wet sclerophyll, at light, Britton, Holloway & Misko ( ANIC) ; 1♀, Western boundary Yarratt State Forest , NE Wingham, 17.XII.1994, mv light, Watkins, S.G. Watkins Collection donated 2001 ( ANIC) ; 1 specimen, Yengo National Park, East side of transmission line along Howes Range Fire Trail , 27.XI.2010, R.deKeyzer & A.Scott, at mv light, K 293321 (AMS) . VICTORIA: 1 specimen , Victoria (French), Wagga, W.W. Froggatt Collection ( ANIC) .

Distribution. Australia: Australian Capital Territory to northeastern New South Wales in high rainfall or moderately high elevation areas. The single record from Victoria probably needs confirmation.

Natural history data. Several adults were collected from November to January, but there are single records of September, October, February, and April. Most specimens were collected at mercury vapor light; one specimen was collected under log (Grose Vale, IV.1982). The elevation ranges goes from 50 to 690 m. The larvae and host plant(s) are unknown.

Remarks. This is the largest Australian Figulus species.

Figures

FIGURES 30‒34. Figulus trilobus Westwood. 30, dorsal view of adult (scale bar: 5 mm); 31, mentum; 32, male genitalia, dorsal view (scale bar: 0.5 mm); 33, male genitalia, lateral view; 34, apex of flagellum (scale bar: 200 µm).

FIGURES 35‒36. Figulus trilobus Westwood. 35, microreticulate surface of pronotal disc (scale bar: 100 µm); 36, detail of microreticulation (scale bar: 50 µm).