Ancyronyx longiparamerus, Freitag & Kodada, 2017

Freitag, Hendrik & Kodada, Ján, 2017, A taxonomic review of the genus Ancyronyx Erichson, 1847 from Sulawesi (Insecta: Coleoptera: Elmidae), Journal of Natural History (J. Nat. Hist.) 51 (9 - 10), pp. 561-606 : 583-586

Ancyronyx longiparamerus sp. nov.

( Figures 2 (a); 10(a–c); 18; 19(c))

Type locality

Mountain river ‘ Salu Maiting’ flowing through pine forest/paddy fields, 17.5 km northwest Rantepao, ca . 02°49′21′′ S, 119°51′17′′ E, 1510 m a .s .l ., South Sulawesi, Indonesia ( Figure 19 (c)) .

Type material

Holotype ♂ ( NMW [ FR115 ]): ‘ INDONESIA: S Sulawesi, 17.5 km NNW Rantepao 1510 m a.s. l., mount. riv. ’ Salu Maiting‘ , pine forest/paddy fields, run; submerged wood, c. 02°49′21′ ′ S, 119°51′17′′ E 31 Dec.1997 leg. Freitag (Sul4f)’, terminal parts of abdomen including aedeagus and right antenna glued separately, right metatarsus absent . Paratypes: 1♂ ( CFM [ FR113 ]) with same data as holotype; 1♂ ( CKB): ‘ INDONESIA: S Sulawesi, 17.5 km NNW Rantepao 1570 m a .s .l., small mount. river ’Salu Malarak‘, pine forest, run/riffle; submerged wood, c. 02°48′51′′ S, 119°51′21′′ E 31 Dec.1997 leg . Freitag (Sul 7f) ’.

Description

Body 1.55–1.58 mm long, 2.2–2.3 times as long as wide (BL/EW), EW: 0.68–0.71 mm.

Colouration Figure 2 (a). Predominantly very dark brown to black; elytra with conspicuous anterior pair of patches extending obliquely from humeri to first interval; posterior patches oblique and distinct. Pronotum and head black; entire femora dark brown; lighter areas of tarsomere 5, tibiae and antennal segments 1–8/9 paler brown to yellowish.

Head. HW: 0.35–0.37 mm; ID: 0.19–0.21 mm; labrum and clypeus laterally with longitudinal granules; frons and vertex with moderately densely arranged short longitudinal granules. Gena and gula transversally microstriate; gular suture indistinct.

Thorax. Pronotum slightly wider than long, widest at about posterior 0.3; posterolateral grooves moderately deep; posterior margin slightly trisinuate; PL: 0.45–0.48 mm, MW: 0.48–0.49 mm; pronotal surface appears reticulated. Prosternum densely punctate and granulose; anterior portion narrow; prosternal process distinctly wider than long, broadly subpentagonal, anteriorly with a shallow transverse groove. Metascutellum subtriangular. Elytra 1.6–1.7 times as long as wide; EL: 1.14–1.16 mm, EW: 0.68–0.71 mm; punctures moderately large and moderately deeply impressed on disc, rather small and shallow on elytral declivity; intervals with small granules, latest less prominent posteriorly. Mesoventrite narrow, anteriorly transversely microstriate, remaining portion irregularly punctate and granulose. Metaventrite longer than combined length of pro- and mesoventrite, with transverse impression anteriorly; disc with moderately deep, almost glabrous longitudinal impression, surrounding area with irregular granules and dense punctures; anepisternum 3 narrow, glabrous, with one row of punctures. Hind wings present in all specimens examined.

Legs slightly longer than body; pro- and mesocoxae large, subglobular; metacoxae obtuse and moderately elevated at mesal portion, obliquely conoidal; only procoxae visible in dorsal view; trochanter short, broadly lanceolate, invisible in dorsal view, pointed at distal end. Femora and tibiae with elongate, dense granules (appear striated in low magnifications); tarsomeres with several moderately long hair-like setae, setae more conspicuous ventrally; combined length of tarsomeres 1–4 approximately as long as terminal tarsomere; claws long, moderately broad, strongly bent, base of each with three teeth; distal tooth distinctly largest.

Abdomen. Ventrite 1 with intercoxal process short (about as long as remaining portion of ventrite 1), mesally almost glabrous. Ventrites 2–4 with surface similar as in ventrite 1; combined length of ventrites 3 and 4 as long as ventrite 1; ventrite 2 of intermediate size; ventrite 5 long, with cordiform granules; granules denser towards apex. Male sternite IX ( Figure 10 (a)) 460 μm long; apical margin concave; with fewer than 10 moderately short setae on lateral portion; paraprocts short, not reaching apical margin; anterior strut moderately long, evenly tapering.

Aedeagus ( Figure 10 (b,c)) broad, elongate, 475 µm long. Median lobe moderately long and broad (100 µm), slightly tapering towards base and almost regularly tapering in apical fifth, with small knob-like rounded tip, entirely slightly bent ventrad; ventral sac weakly sclerotized, simply plicate, reaching apical 0.08; fibula lightly sclerotized, apically enlarged; corona inconspicuous. Phallobase strongly sclerotized, rather simply shaped, asymmetrical, reaching 0.27 length of aedeagus. Parameres long and robust, regularly tapering in apical fourth; dorsolateral margin slightly concave; ventral margin slightly sinuous, with few very short basolateral setae and with more than 20 short setae in apical half.

Distribution

So far known from two localities in South Sulawesi ( Figures 18 ; 19 (c)).

Etymology

The species epithet ‘ longiparamerus ’ refers to the comparably long parameres which allow us to distinguish the species most clearly from its congeners, and particularly from Ancyronyx breviparamerus .

Comments

The species is characterized by the very long and robust parameres, while it most resembles Ancyronyx breviparamerus in the external characters. These two species may be distinguished by the distinctly shorter parameres reaching only up to apical 0.6 of the median lobe in A. breviparamerus , as well as by the anterior elytral patches being faint and brownish in the latter species versus the more distinct, large and pale patches in A. longiparamerus .

This species was exclusively found on submerged wood in small to medium-sized mountain rivers at altitudes at c. 1550 m a.s.l. ( Figure 19 (c)). The collection sites were surrounded by secondary vegetation (pine forest) and paddy fields.

Figures

Figure 2. Habitus of Ancyronyx species from Sulawesi, (a) Ancyronyx longiparamerus (total length 1.80 mm), (b) Ancyronyx toraja (total length 1.75 mm), (c) Ancyronyx konjo (total length 1.95 mm), (d) Ancyronyx breviparamerus (total length 1.80 mm).

Figure 10. Ancyronyx longiparamerus from Rantepao (Sul7f); (a) male sternite IX, ventral; (b) aedeagus, lateral; (c) aedeagus, ventral; (Scale bars = 0.1 mm).

Figure 18. Map of Sulawesi with collecting site of Ancyronyx species based on their label data.

Figure 19. Habitats of Ancyronyx species in Sulawesi, (a) the eastern slopes of the Pegunungan Fennema Mountains from where Ancyronyx breviparamerus, Ancyronyx henningi and Ancyronyx tobada were collected, (b) a small mountain creek in the Pegunungan Fennema Mountains (A), type locality of Ancyronyx breviparamerus and collection site of Ancyronyx tobada, (c) Salu Maiting River in North Toraja, type locality of Ancyronyx longiparamerus and collection site of Ancyronyx