Henicops tropicanus, Hollington & Edgecombe, 2004

Hollington, L. M. & Edgecombe, G. D., 2004, Two New Species of the Henicopid Centipede Henicops (Chilopoda: Lithobiomorpha) from Queensland and Victoria, With Revision of Species from Western Australia and a Synoptic Classification of Henicopidae, Records of the Australian Museum 56, pp. 1-28 : 10-16

Henicops tropicanus n.sp.

Figs. 7–11

Etymology. For the Wet Tropics of northeastern Queensland, where the species occurs.

Diagnosis. Member of Henicops dentatus Group with female gonopod having two (exceptionally three) large, elongate, bullet-shaped spurs; legs 14 and 15 relatively sparsely setose, with few setae on tibia and basitarsus of leg 15.

Type material. HOLOTYPE: ♀ QM S39941 ( Fig. 7A), from head of Roots Creek , 12km WNW Mossman, Queensland, 16°24'46"S 145°16'03"E, 1200 m, 28 Dec 1989 – 11 Jan 1990, ANZSES, pitfall . PARATYPES: 3 QM S39941 , from type locality, collection data as for holotype; S39869 , 3♀♀, S39873, 13, S39898 , 2♀♀ ( Figs. 8A–D, 10D–F,K, 11C,H,J), 13 ( Figs. 9B–D,F–J, 10A–C,G–H,J,M, 11D,E,I), S39934 , 2♀♀, Mossman Bluff Track, 5–10 km W Mossman, GBM, G. Thompson & ANZSES, 20 Dec 1989 – 15 Jan 1990 .

Other material. QUEENSLAND: QM: S22632 , 1♀, 14.4 km N Wudjl Wudjl, 15°52'S 145°19'E, R. & S. Raven, P. & E. Lawless, 28 Nov 1992 – 18 Apr 1993; S39861 , 2♀♀, 13, Mt Dalrymple, 21°03'S 148°38'E, 1200 m, ANZSES, 21 Dec 1992 – 10 Jan 1993; S39863, 1 3, Eungella, Pease’s Lkt, 21°07'S 148°31'E, 900 m, D. Cook & GBM, 17 Nov 1992 – Apr 1993; S39866 , 2♀♀, S39899 , Maalan Rd, 2 km S Palmerston Hwy, 17°36'S 145°42'E, 750 m, GBM & J. Hasenpusch, 10 Jan–7 Mar 1995; S39870 , 1♀, Wongabel SF, 17°19'30"S 145°29'45"E, R. Raven, P. & E. Lawless & M. Shaw, 23 Jul–26 Nov 1992; S39872 , 2 ♀♀, Longlands Gap SF, 17°27'30"S 145°28'45"E, R. Raven, P. & E. Lawless & M. Shaw, 23 Jul–26 Nov 1992; S39874 , 1 ♀, 13, S39875 , Karnak-Devils Thumb, 8–12 km NW Mossman, 1100 m, ANZSES, 26 Dec 1989 – 15 Jan 1990; S39884 , 2♀♀, 433, Hughes Rd, Topaz, 17°26'S 145°42'E, 650 m, GBM & Breeden, Sep–Dec 1993; S39930 , 1 3, same locality, GBM, D. Cook & H. Jantezki, 6 Dec 1993 – 25 Feb 1994; S39892 , 4 ♀♀, Kjelberg Rd turnoff, 17°32'S 145°36'E, 850 m, GBM & J. Hasenpusch, 7 Mar–15 May 1995; S39961, 2♀♀, same locality, 25 Nov 1994, 10 Jan 1995; S39896 , 4♀♀, Kjelberg Rd, Mt Fisher, 17°32'S 145°33'E, 1000 m, J. Hasenpusch, 1 Dec 1993 – 25 Feb 1994; S39902 , 1 ♀, S39962 , 1♀, Big Tableland, 15°43'S 145°17'E, 740 m,ANZSES, 20 Dec 1990 – 8 Jan 1991; S39906 , 1♀, Eungella NP, Mt William , 21°02'S 148°36'E, 1200 m, GBM ,

19 Apr 1979, rf; S39924 , 1♀, 13, Pandanus Ck , Cathu SF, 20°48'S 148°33'E, 80 m, GBM , 22 Apr 1979; S39925 , 433 ( Fig. 7C), 2.5 km S Mt Hartley , 15°47'S 145°19'E, L. Roberts , 8 Dec 1993 – 2 Feb 1994; S39927 , 2♀♀, 3 juveniles, Mt Fisher , 7 km SW Millaa Millaa, 17°33'S 145°33'E, 1000 m, GBM & D.K.Yeates , 3 May 1983, rf; S39928 , 3♀♀, 333, Westcott Rd , Topaz, 17°25'S 145°42'E, 680 m, GBM , Jul–Dec 1993; S39940, 1♀, 2 km SE Mt Spurgeon via Mt Carbine , 16°27'S 145°12'E, 1100 m, GBM & G. Thompson , 20 Dec 1988, rf; S39946 , 13, 2 juveniles, Mt Bartle-Frere , W base, 17°23'S 145°46'E, 700 m, GBM & J. Hasenpusch , 25 Nov 1994 – 10 Jan 1995; S39947 , 2 ♀♀, 13, Lamins Hill , 17°22'S 145°42'E, 880 m, GBM & J. Hasenpusch , 1 Dec 1993 – 25 Feb 1994; S39954 , 1 ♀, Eungella NP, Broken R, 21°10'S 148°30'30"E, P. Lawless, R. Raven & M. Shaw , 10 Nov 1991 – 29 Jul 1992; S39955, 1♀, same locality , 29 Jul–4 Dec 1992; S39956 , 1 ♀, Malaan SF, 17°35'30"S 145°36'45"E, R. Raven, P. & E. Lawless & M. Shaw , 25 Jul–26 Nov 1992; S39967 , 1 ♀, 1.5 km SE Mt William , 21°02'S 148°37'E, 1060 m, ANZSES , 21 Dec 1992 – 10 Jan 1993; S39973 , 1 ♀, Malaan SF, V.E. Davies & R. Raven , 20–24 Apr 1978.

AUSTRALIAN MUSEUM: 13, Eungella NP, Broken River campsite, G.D. Edgecombe, 18 Apr 1998, rf; 1♀, KS83631, 233 ( Figs. 9A,E,K–M, 10I,L, 11A,B,F,G,K), Eungella NP, Dalrymple Rd, 1.7 km and 2.9 km NE Snake Rd, G.D. Edgecombe, 21 Apr 1998, rf.

AUSTRALIAN NATIONAL INSECT COLLECTION: 2♀♀, 9 km ENE Mt Tozer (ex. Berl. 1059, 1062), 12°43'S 143°17'E, T. Weir, 10–16 Jul 1986 ; 2 ♀♀, juveniles, larval stadia LII–IV, 3 km NE Mt Webb (ex. Berl. 692, 721), 15°03'S 145°09'E, T. Weir, 1–3 Oct 1980, 3 May 1981 ; 1 ♀, 14 km W by N Hope Vale Mission (ex. Berl. 729), 15°16'S 144°59'E, A. Calder & J. Feehan, 7–10 May 1981 ; 2 ♀♀, 333, Mt Windsor Tableland (ex. Berl. 490), 16°18'S 145°05'E, 850 m, RWT, 20 Mar 1975 , rf; 1♀, Mt Tiptree (ex. Berl. 1006), 17°03'S 145°37'E, B. Halliday, 13 Jul 1984 , rf; 1♀, 3.2km N Atherton (ex. Berl. 275), 17°14'S 145°29'E, J.G. Brooks, 5 May 1970 , rf; 2♀♀, Mulgrave R (ex. Berl. 316), 17°15'S 145°46'E, 75 m, RWT & J. Feehan, 19 Jun 1971 , rf; 1♀, Barrine NP (ex. Berl. 486), 17°16'S 145°38'E, 760 m, RWT, 21 Mar 1975 , rf; 1♀, Eacham NP (ex. Berl. 484), 17°18'S 145°37'E, RWT, 23 Mar 1975 , rf; 1♀, 20 km S Ravenshoe (ex. Berl. 358), 17°45'S 145°32'E, 800 m, RWT & J. Feehan, 3 Jul 1971 , rf; 1♀, Paluma (ex. Berl. 207), 19°00'S 146°12'E, 810 m, E. Britton, 18 Jan 1970 , rf; 3♀♀, 433, c. 3 km S Eungella (ex. Berl. 487, 488), 21°09'S 148°29'E, 780 m, RWT, 26 Mar 1975 , rf; 1♀, 16 km N Eungella (ex. Berl. 493), 21°03'S 148°35'E, RWT, 13 Sep 1975 .

Distribution. Queensland: throughout Wet Tropics, south to Eungella, north to Mt Tozer, Cape York Peninsula ( Fig. 1), mostly in rainforest, 75–1200 m, mostly above 650 m.

Description. Length up to 24 mm; width of head shield up to 2.85 mm. Colour (based on specimens in absolute ethanol): antenna yellow to pale orange with several dark pigment spots occasionally present on dorsal side of articles in proximal third of antenna; head shield yellow with brown mottled network; tergites pale yellow to pale orange with dark (sometimes tinged with purple) mottling concentrated in longitudinal median band and near margins; dark pigment spots often present near tergal margins; maxillipedes pale orange; sternites pale yellow to pale orange with some faint purple mottling around margins; prefemur to tibia pale to moderate yellow with purple mottling, tarsi a slightly deeper orange; genital sternite and gonopods yellow.

Head shield smooth. Frontal margin with strong median notch; posterior margin transverse or weakly concave; border slightly wider posterolaterally than medially. Median furrow incised for about 1/6 length to transverse suture, shallow throughout. Antennal length 4.1–5.7 times width of head shield, usually extending back to tergite 5 ( Fig. 7A); 33–40 articles, majority of specimens examined with 36; basal two articles much larger than succeeding two; relatively gradual change in length of articles along rest of antenna ( Fig. 10G,H), articles 3 to 8–10 typically wider than long, gradually elongating along antenna with more distal articles up to twice as long as wide ( Fig. 10I); gradational increase in density of setae to about tenth article, then more or less constant. Ocellus moderately large, overhanging lateral margin of head ( Fig. 9A), usually translucent, sometimes whitish to dark purple, domed. Tömösváry organ small, deep, longitudinally elliptical, outer edge at anterolateral margin of cephalic pleurite ( Fig. 9D–F).

Small transverse seta projects medially from pit in labral sidepiece ( Fig. 9C). Labral margin with rounded shoulder beside midpiece, with pronounced break in curvature where branching bristles overhang margin; fringe composed of up to 30 densely grouped bristles with many short, spinelike projections along their length, a few longer spines at distal end ( Fig. 9G).

Maxillipede coxosternum trapezoidal to subsemicircular, dental margin broad, each half weakly convex ( Fig. 9H–K); median notch lacking; teeth moderately large, triangular projections, invariably 3+3, usually with a slightly wider space between the outer tooth and middle tooth ( Fig. 9K) but ranging from equidistant to space between outer and middle tooth nearly twice that between inner and middle tooth. Coxosternum bearing moderate number of large, scattered setae, usually with distinctly denser setation behind dental margin and anterolaterally ( Fig. 9I,K). Tarsungulum with long, slender pretarsal section, as much as twice length of tarsal section ( Fig. 9H,L). Setae on telopodite somewhat more abundant on inner part of femur, tibia and tarsal section of tarsungulum than on outer part, these setae moderately long.

Mandible: Four paired teeth on right mandible, left with smaller flattened fifth tooth adjacent to furry pad ( Fig. 10A,B). Approximately 20 aciculae differentiated into two rows ( Fig. 10C,D); aciculae in dorsal part of outer row with pronounced serrations on both margins along distal half, those in ventral part of outer row with a simple margin or with weak scalloping distally; aciculae of inner row with simple margin ( Fig. 10C,D). Fringe of branching bristles skirts aciculae, with transition to rows of scales with multifurcating spine fringes adjacent to midpoint of the second most ventral tooth; scales gradually shortening dorsally ( Fig. 10F) to terminate before reaching furry pad ( Fig. 10K); ventralmost bristles in fringe narrow-based, lacking spine-like projections on basal sixth to eighth of bristle, spine-like projections abundant and even along remainder of bristle ( Fig. 10E); bristles branching into a few spines distally. Accessory denticle field without grooves between rows of denticles or at margin of denticle field ( Fig. 10A,F); largest accessory denticles bluntly conical, grading into smaller triangular denticles then small elongate rods near fringe of scale-like bristles; band of unsculpted cuticle on dorsalmost tooth separates accessory denticles from furry pad; furry pad with many elongate, simple bristles ( Fig. 10K), some bristles with bifid terminations.

First maxilla: Minute wedge-shaped sternite ( Fig. 10L). Coxal process trapezoidal, with a few plumose setae and up to 10 simple setae on anteromedial edge ( Fig. 10J), this cluster slightly separated from a few simple setae on inner edge of coxal process; plumose setae with numerous short, spine-like branches along their distal third. Cluster of about six barb-like sensilla microtrichoidea on posterolateral part of coxal process ( Fig. 10J). Distal article of telopodite with two rows of about 15 plumose setae along inner margin; branches developed along distal half of these setae ( Fig. 10M); shorter simple setae on membranous strip alongside inner margin; main field of distal article of telopodite bearing a few setae anteriorly.

Second maxilla: Sternite small, fused with coxae. Band of 8–11 short setae along anterior part of coxa. Tarsus bearing numerous simple setae on outer surface, cluster of many plumose setae on membranous patch on inner surface ( Fig. 11D,E); branches on plumose setae mostly confined to distal half. Claw small, composed of five digits, median digit long, thick, with shorter, slender digit between median and each outer digit ( Fig. 11E).

Tergites weakly wrinkled. T1 generally trapeziform, smaller than T3, slightly narrower than head shield ( Fig. 7A), about 70% width of widest tergite (T8), posterior angles rounded, posterior margin transverse; lateral margins subparallel in T3, slightly convex in T5, posterior angles rounded in both, posterior margin faintly concave in TT3 and 5; TT1 and 3 bordered posteriorly; borders of TT5 and 7 incomplete posteriorly; posterior margin of T7 with transverse or convex medial sector, having independent curvature from lateral sectors, posterior angles gently triangular, rounded; lateral margins of TT4–14 convex, all bordered laterally; posterior margin of T8 weakly concave, posterior angle blunt, TT10 and 12 posterior margins gently concave, posterior angles with obtuse, blunt corners; TT6, 9, 11 and 13 embayed with transverse posteromedial third, posterior angle of T6 rounded, T9 blunt, TT11 and 13 with sharp triangular projections; posterior margin of T14 concave, with blunt posterior angles.

Short to moderate, slender setae along lateral borders of all tergites, often with 3–5 longer, thicker setae concentrated on anterolateral border; often cluster of several short setae on posterior angles of tergites; few short, slender setae scattered sparsely over surface of most tergites. A few moderate to long setae on margins of sternites, 1–3 setae at anterolateral corner most prominent anteriorly in trunk; setae along posterolateral and posterior margins more prominent in posterior segments; posterior margin fringed by 6–10 setae on sternites 13–15; consistently strong pair of setae on anteromedial part of sternites.

Legs: Strong, pointed distal projections with sclerotized tips on tibiae of legs 1–14. Prefemur of legs 1–13 with short to moderate setae scattered on anterior and posterior faces, some longer, thicker setae on ventral edge of prefemur, femur and tibia; longest setae on femur and tibia equal to ( Fig. 8B) or shorter than ( Fig. 8A) longest on prefemur; a few thickened setae encircling distal margin of femur; strong, pigmented seta at ventrodistal end of tibia on anterior face of legs 1–13; tarsus with combination of slender setae of fairly even length, and four pairs of thicker, divergent, pigmented setae on ventral side of legs 1–13 ( Fig. 11K), two of these just proximal to articulations between tarsomeres, one near midlength of distal tarsomere. Setae on legs 14 and 15 more uniformly slender and sparsely distributed than on preceding legs, especially sparse on tibia and basitarsus of leg 15. Three tarsomeres in legs 1–12 ( Fig. 8A), with divided basitarsus. Condyle at joint between basitarsus and distitarsus on legs 13–15 only. Four tarsomeres in legs 13 and 14, basitarsus and distitarsus with two parts each ( Figs. 8B,C, 11I); proximal tarsomere nearly 70% length of basitarsus and 55–60% length of distitarsus on leg 14. Leg 15 with five tarsomeres, basitarsus having two, distitarsus three ( Figs. 8D, 11H). Distitarsus 70–80% length of basitarsus on leg 15; basitarsus 12–14 times longer than broad; proximal tarsomere 55–65% length of basitarsus; three tarsomeres comprise about 45–50, 15–20 and 30–40% (proximal to distal) length of distitarsus. Pretarsal claws ( Fig. 11F,G) as described below for H. milledgei .

Coxal pores round or ovate ( Fig. 7B,C), commonly 5,6,6,6/5,6,6,6 in large males and females, males maximum 5,6,6,6/5,6,6,6, minimum 3,4,4,4/3,4,4,4; females maximum 7,7,7,7/7,7,7,7, minimum 3,4,5,5/3,4,5,5. Coxal pore field set in shallow groove, distal pore(s) partly concealed by anteroventral face of coxa. Anal pores large in both sexes.

Female ( Fig. 7B): Sternite of segment 15 transverse or convex posteromedially. Tergites of first genital segment and telson usually well sclerotized. Sternite of first genital segment large, posterior margin concave between condyles of gonopods except for small median projection, posterior two-thirds fairly evenly scattered with setae of varied length; short setae concentrated in a band along posteromedial margin.First article of gonopod bearing two (three in one specimen) large, bullet-shaped spurs, inner spur slightly smaller than outer; spurs gently curved such that tip points up ( Fig. 11C,J); first and second articles of gonopod with mix of many short, moderate and long setae, up to 56 on first article, up to 37 on second; third article with up to 10 setae, mostly moderate, one or two long ones ( Fig. 11J). Claw large, undivided.

Male ( Fig. 7C): Sternite of segment 15 rounded posteriorly. Sternite of first genital segment small, divided, with transverse posterior margin, bearing numerous moderately long setae, short setae concentrated in a band near posterior margin ( Fig. 11B). Gonopod of three articles and tapering, seta-like terminal process that bears many short spine-like projections ( Fig. 11A), the three articles each bearing numerous short to moderately long setae, typically about 15, 10–12 and 10 for first to third articles, respectively; extended penis approximately equal in length to first article of gonopod.

Larval stadia (identified by correspondence to leg and limb-bud pairs in Lamyctes emarginatus: Andersson, 1979, 1984 ) (ANIC Berl. 1062): Stadium LII with 8 pairs of legs and two pairs of limb-buds; 14 antennal articles. Stadium LIII with 10 pairs of legs and two pairs of limb-buds; 25 antennal articles. Stadium LIII with 12 pairs of legs and three pairs of limb-buds; 25 antennal articles. Stadia LII–IV all with 3+3 teeth on dental margin of maxillipede coxosternum.

Discussion. As discussed above under the Henicops dentatus Group, H. dentatus and H. tropicanus n.sp. share numerous characters distinguishing them from other species of Henicops , and they appear to be sister taxa. In spite of their geographic separation, the two species are remarkably similar. They can consistently and most readily be distinguished by the morphology of the female gonopod, in particular the size and shape of the spurs on the basal article. Henicops dentatus has two, small bullet-shaped ( Fig. 6G) or distally-truncated ( Figs. 4F, 6H) spurs, with the outer spur as much as 40% longer and 50% wider than the inner spur. In contrast, the gonopods of H. tropicanus ( Figs. 7B, 11C) bear spurs that are larger and more elongate (with the outer spur of H. tropicanus being approximately 40% the length of the inner margin of the first article of the gonopod, compared to approximately 20% in H.dentatus ) and both spurs are of more nearly equal size. Though the shape of the spurs varies within H. dentatus , they are consistently shorter and stouter than in H. tropicanus . In contrast to the distinction made possible by the female gonopods, the male gonopods of the three species of Henicops treated herein ( Figs. 4C, 7C, 12C) provide no obvious characters for specific distinction.

Two features of the mandibular gnathal edge permit distinction between Henicops tropicanus and H. dentatus . The Western Australian H. dentatus has a narrower fringe of branching bristles on the dorsal part of the mandible ( Figs. 5D,I versus 10F), this including the entire row of scale-like bristles. As well, the branching bristles on the ventral part of the fringe have a longer non-spinose (basal) extent ( Fig. 5H versus 10E). In both of these characters, the state in H. tropicanus is plesiomorphic, being shared with H. maculatus (Edgecombe et al., 2002: figs. 4A, 5C), H. milledgei ( Fig. 14H), H. brevilabiatus ( Fig. 2A,B,D) and outgroups.

Specimens of Henicops tropicanus often have a narrower medial sector to “n otched” tergites 7, 9 and 11 than does H. dentatus (compare Fig. 3 with Fig. 7A) but this difference is inconsistent. Setation of legs 14 and 15 often also serves to distinguish between the two species: H. tropicanus typically has fewer setae on legs 14 and 15 ( Fig. 8C,D) than H. dentatus ( Figs. 4C,D), most notably on the tibia and basitarsus of leg 15 ( Fig. 11H), and has gracile setae on the prefemur of leg 15 versus sometimes spine-like setae in H. dentatus .

Henicops tropicanus normally has two spurs on the female gonopod, only one specimen (QM S38899 ) having three spurs. Three-spur variants are also exceptional in other members of the Henicopinae . For example, specimens of Lamyctes mauriesi Demange, 1981 , are recorded as normally having two conical spurs on each gonopod, but single specimens from Tenerife and Gran Canaria have two such spurs on one gonopod and three on the other (Eason & Enghoff, 1992).