Echinoaesalus cechovskyi Huang, Bartolozzi

Huang, Hao, Bartolozzi, Luca & Chen, Chang-Chin, 2015, Notes on the genus Echinoaesalus Zelenka, 1993 (Coleoptera: Lucanidae), with the description of a new species from the Malay Peninsula, Zootaxa 4039 (4), pp. 553-565 : 563-564

Echinoaesalus cechovskyi Huang, Bartolozzi , & Chen, new species

( Figs. 6–7 , 14–15, 50–51 , 56, 69, 75 , 88, 101, 108, 111–123)

Type material. Holotype ( Figs. 6 , 14, 50 , 69 , 88, 101, 111–117): MALAYSIA: ♂, Johor, 15 km NW of Kota Tinggi, Muntahak Mts., 200 m, 14–16.IV.2001, P. Cechovsky, L28, in coll. Cechovsky, to be deposited in MZUF. Paratype: SINGAPORE: 1 ♀ ( Figs. 7 , 15, 51 , 56, 75 , 108 , 118–123 ), no detailed collecting data, deposited in USNM, labeled: a) Singapore / Coll. Baker; b) 1H26H; c) Curimus / Arrow; d) Nosodendron / sp./ Det. / P.J. Johnson 1988.

Holotype description. Length of pronotum-elytra measured from apex of pronotum to the caudal end of elytra: 4.0 mm.

Ground color of the entire body on both surfaces dark reddish brown. Scattered scale-like bristles and clumps of the scale-like bristles on dorsal surface of the body black. Bristles on ventral surface of the body bright yellow. Dorsal surface of the body with bristle clumps placed exactly as in E. timidus and E. sabahensis .

Head: Width approximately half as wide as pronotum. Interocular width about 9 times as wide as eye. Anterior portion of head in front of eye nearly as long as eye in dorsal view. Intermandibular projection broadly rounded and not protruding. Canthus present, with end rounded and a little beyond eye. Left mandible with a subapical dorsal tooth and a subapical ventral tooth. Right mandible with a subapical dorsal tooth but without ventral tooth. Both mandibles with mola well developed and massive in inner lateral view, and each with a setose prostheca along medial edge. Labrum setose, movable and about 1/4 times as wide as head. Galea of maxilla with setae on apex regularly curved and brush-like. Lacinia of maxilla free and large. Ligula of labium bilobed and setose. Base of labial palpomere 1 concealed by mentum. Palpus insertions on prementum separated by a distance equal to 2.5 times the width of first palpomere. Antenna partially geniculate and composed of ten antennomeres. Antennal scape without longitudinal groove. Antennal club composed of the last three antennomeres and entirely pubescent. Antennomere 3 elongate, nearly 1.5 times as long as wide. Mentum nearly oblong, transverse, with anterolateral corners produced, setose, microsculptured, with a transversal frontal sulcus that is bent backwards at lateral ends (hooked laterally).

Thorax and abdomen: Ratio of pronotum-elytra-length to elytra-width: 1.40. Ratio of thickness to length of elytra: 0.72. Dorsal line of elytra in lateral view weakly produced at summit, not evenly convex. Pronotum and elytra densely punctate, with punctures irregularly distributed and not serially in longitudinal lines. Scutellum wider than long. Intercoxal process of prosternum plate-like, a little longer than wide, not strongly convex in lateral view, with posterior margin strongly arched at middle and almost as far as procoxae, without a step-like projection posteriorly. A pair of deep and triangular furrows present on the anterolateral corner of the metasternum along and behind mesocoxae. Metasternum with long sulci at lateral sides to receive mesotibia and mesotarsi. Abdominal ventrites 1-3 with long sulci to receive metatibia and metatarsi. Posterior margin of the last visible abdominal ventrite flat. Semicircular punctures along the anterior margin of the abdominal ventrites 3–5 nearly the same as those of the abdominal ventrites 1–2. Hindwing as in E. timidus : veins 3dA1 and 3dA2 well defined; vein 3dA2 almost reaching the margin of wing; origin of vein 3dA1 close to base of vein 3dA2; vein 3dA1 nearly in parallel with vein 2dA3.

Surface structures: Vestiture of pronotum and elytra consisting of three types of elements: the slender scalelike bristles, the stout scale-like bristles, and the irregularly branched tomenta. All bristles longitudinally ribbed, with the cross section branched. Slender bristles sparsely distributed, inserted centrally in the smaller punctures, erect, and not forming clumps. Stout bristles concentrated into clumps, inserted anteriorly in the wall of the larger punctures. Tomenta arising anteriorly in the wall of the punctures and branched. All punctures with margins sharply defined. Punctures of the stout bristles and tomenta with floor raised and polygonally sculptured. Puncture of bristle not associated with a tubercle outside of puncture.

Legs: Protibia gradually broadened from base to apex, with a minute inner terminal spur, a large outer apical spine, and 2 smaller spines on outer lateral margin, and with a small setal-tuft at inner apex. Apical spine curved and almost half as long as the maximum width of protibia. Mesotibia and metatibia contracted in width from middle toward tip as in other species of the E. timidus group. All tarsi short, with the combined length nearly half as long as tibia.

Ninth abdominal segment and male genitalia (Figs. 88, 101): 9th abdominal segment stout, nearly as long as that of E. gedeensis ; basal lobe well marked and nearly twice as long as wide; paired pleurites slender and protruding ventrally; ventral plate sclerotized and nearly as wide as basal lobe. Basal piece short. Parameres nearly 1/3 times as long as the sclerotized part of median lobe. Median lobe stout, weakly curved and broadened from base to apex, asymmetric and broadly membranous at lateral surfaces near tip, with two broad distal plates on dorsal and ventral surfaces respectively; lateral membranous portion at apex occupying the distal half of the entire penis; dorsal plate broadly rounded at tip; ventral plate contracted toward tip; a free distal sclerite appeared at tip of median lobe which has not been found in other species of the E. timidus group.

Description of female paratype ( Figs. 118-123 ). Sexual dimorphism in external morphology is slight. Differences are found in the following characters. Head about 0.47 times as wide as pronotum, slightly thinner than in male. Labrum nearly 1/5 times as wide as head, thinner than in male. Galea of maxilla thinner than in male, with setae on apex not brush-like. Ligula obsolete and not large and bilobed as in male. Palpus insertions on prementum separated by a distance nearly equal to width of first palpomere. Mentum ( Fig. 15) shorter than in male ( Fig. 14) and rather trapezoidal. Intercoxal process of prosternum ( Fig. 75 ) thinner than in male ( Fig. 69 ), with a slightly shorter anterior margin. Apex of metatibia with outer lateral margin a little more broadly convex than in male, as in E. timidus . Last abdominal ventrite with a central projection on anterior margin, which is absent in male. No difference found in shape of posterior margin of last visible abdominal ventrite from male.

Female genitalia ( Fig. 108 ): Hemisternites well sclerotized and setose near rounded apex, with styli elongate, sclerotized, non-setose, and pointed outwards. Accessory gland rooted on bursa copulatrix at lateral side, closer to terminal end of bursa copulatrix than to entrance of bursa copulatrix. Bursa copulatrix rather long and wide, twisted at end, full of sclerotized spines on outer surface and easily separable from bursal duct. Bursal duct rather short and wide. Spermatheca and its duct rooted on bursa copulatrix very near the terminal end of bursa copulatrix. Spermathecal duct long, nearly as long as bursa copulatrix.

Diagnosis. This new species is most similar to E. timidus , but can be distinguished by the following combination of characters: 1) eye narrower in dorsal view; 2) posterior margin of pronotal plate more arched at middle; 3) mentum slightly broader; 4) protibia slightly broader; 5) 9th abdominal segment of male markedly larger and longer; 6) aedeagus markedly larger, with parameres no more than 1/3 times as long as median lobe, and with a free distal sclerite at terminal tip; 7) hemisternite of female genitalia markedly wider at base; 8) bursa copulatrix of female genitalia more than twice longer than in E. timidus , with markedly more spines on surface, and with terminal end strongly twisted; 9) accessory gland of female genitalia rooted on a position rather remote from the terminal end of bursa copulatrix; 10) spermathecal duct of female genitalia nearly three times as long as in E. timidus .

This species can be distinguished from E. sabahensis by the following combination of characters: 1) eye narrower in dorsal view; 2) third antennomere less elongate; 3) pronotal plate wider and shorter; 4) 9th abdominal segment of male with a markedly shorter basal lobe; 5) median lobe of male genitalia with a narrower ventral plate and with an extra free terminal sclerite.

This species can be distinguished from E. gedeensis by the following combination of characters: 1) eye narrower in dorsal view; 2) third antennomere less elongate; 3) pronotal plate more arched at posterior margin; 4) 9th abdominal segment of male with a markedly narrow ventral plate; 5) median lobe of male genitalia with shorter lateral colorless splits and with an extra free terminal sclerite; 6) parameres of male genitalia longer and narrower.

Within the E. timidus group, only E. javanus Krikken, 2008 is unknown in male genitalia. The unique holotype of E. javanus from Java is a female, which is separable from the female of E. cechovskyi by the broadly rounded frontal angles of mentum ( Fig. 19) and the markedly shorter posterior margin of pronotal plate ( Fig. 76 ).

Distribution. Southern Malay Peninsula.

Etymology. This new species is named in honor of Mr. Petr Cechovsky, Czech Republic, who collected the holotype of this new species.

Figures

FIGURES 1 – 7. Antenna. 1, Echinoaesalus hidakai, L 12, western Malaysia; 2, E. borneoensis, L 11, Borneo; 3, E. timidus, L 19, western Malaysia; 4, E. sabahensis, L 14, Borneo; 5, E. gedeensis, holotype, Java; 6, E. cechovskyi, holotype, western Malaysia; 7, E. cechovskyi, paratype, Singapore. Arrow directed to end of third antennomere.

FIGURES 35 – 52. Protibia (left), mesotibia (middle), and metatibia (right), or just protibia. 35, Echinoaesalus hidakai, L 12; 36, E. hidakai, L 10; 37, E. borneoensis, L 11; 38, E. borneoensis, L 07; 39 – 48, E. timidus; 39, L 17; 40, L 13; 41, L 08; 42, L 02; 43, L 23; 44, L 21; 45, L 22; 46, L 18; 47, L 09; 48, L 06; 49, E. sabahensis, L 14; 50, E. cechovskyi, holotype; 51, E. cechovskyi, paratype; 52, E. gedeensis, holotype.

FIGURES 57 – 76. Prosternal process in ventral view. 57, Echinoaesalus hidakai, L 12; 58, E. hidakai, L 10; 59 – 62, E. borneoensis; 59, L 11; 60, L 01; 61, L 07; 62, L 16; 63, E. gedeensis, holotype; 64 – 67, E. timidus; 64, L 08; 65, L 02; 66, L 17; 67, L 21; 68, E. sabahensis, L 14; 69, E. cechovskyi, L 28; 70 – 73, E. timidus; 70, L 09; 71, L 06; 72, L 20; 73, L 13; 74, E. sabahensis, after Krikken 2008; 75, E. cechovskyi, paratype; 76, E. javanus, after Krikken (2008), holotype.

FIGURES 107 – 110. Female genitalia under same scale (scale bar 1 mm). 107, Echinoaesalus timidus, L 09; 108, E. cechovskyi, paratype, Singapore; 109, E. timidus, L 25; 110, E. timidus, L 20. Abbreviations: st, stylus; lv, last abdominal ventrite; mo, median oviduct; bd, bursal duct; bc, bursa copulatrix; sd, spermathecal duct; s, spermatheca; sg, spermathecal gland; ag, accessory gland.

FIGURES 111 – 124. 111 – 123, Echinoaesalus cechovskyi, habitus and characters; 111 – 117, male holotype; 118 – 123, female paratype; 111, 118, dorsal view; 112, 119, lateral view; 113, 120, head in oblique view; 114, 121, head in dorsal view; 115, part of metasternum to show a small furrow near mesocoxae; 116, 122, scutellum in dorsal view; 117, abdominal ventrites, showing pair of large sulci to receive legs; 123, metasternum and ventrites, showing furrows and sulci; 124, E. timidus, holotype in lateral view (photograph by Jan Krikken).