Ancyronyx toraja, 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 : 586-588

Ancyronyx toraja sp. nov.

( Figures 2 (b); 11(a–c); 18)

Type locality

Small mountain river ‘ Salu Malarak’ flowing through pine forest, 17.5 km NNW Rantepao, 1 570 m a .s .l., ca. 02°48′51′′ S, 119°51′21′′ E, South Sulawesi, Indonesia .

Type material

Holotype ♂ ( NMW): ‘ INDONESIA: S Sulawesi, 17.5 km NNW Rantepao 1570 m a.s.l., small mount. river ’ Salu Malarak‘ , pine forest, run/riffle; bottom gravel, c. 02°48′51′′ S, 119°51′ 21′′ E 31 Dec.1997 leg. Freitag (Sul7c)’, terminal parts of abdomen including aedeagus and right antenna glued separately, right metatarsus lacking . Paratypes: 3♂♂, 2♀♀ ( NMW, CKB, CFM [FR124]): with same data as holotype.

Diagnostic description

Body 1.50–1.63 mm long, 2.1–2.3 times as long as wide ( BL / EW), EW: 0.65–0.78 mm; body form elongate, convex dorsally.

Colouration Figure 2 (b). Elytra with anterior patches less distinct; patches pale brown/ yellowish with central portion darker so each patch appears divided into two spots; posterior patches dark and inconspicuous. Remaining portions of elytra, head and pronotum black. Lighter portions of legs brown, dark portions almost black.

Head. HW: 0.38–0.40 mm; ID: 0.19–0.21 mm; labrum and clypeus glabrous, with moderately dense pubescence; antennae slightly shorter than head width; gular sutures visible.

Thorax. Pronotum. PL: 0.45–0.49 mm, MW: 0.50–0.53 mm; surface anteriorly of transverse groove slightly vaulted; posterior margin slightly trisinuate; prosternal process posteriorly slightly depressed. Elytra 1.5–1.7 times as long as wide; EL: 1.10–1.23 mm, EW: 0.65–0.78 mm; punctures moderately large and deeply impressed in anterior portion, especially behind humeral area, smaller and less impressed on posterior elytral declivity. Mesoventrite anteriorly microreticulate; posteromedian impression and anterior notch more or less fused into a deep furrow. Metaventrite with rather broad, rugulose median longitudinal impression.

Legs slightly longer than body.

Abdomen. Ventrites 1–5 without extended glabrous areas, submedian areas nearly rugulose; setiferous granules almost evenly distributed, flatter at median portions.

Aedeagus ( Figure 11 (a,b)) 490 µm long. Median lobe 106 µm wide, slightly tapering apicad along basal three-quarters; tip rounded and extended ventrad; ventral sac simply plicate, reaching apical 0.09; fibula distinctly tapering basally, slightly bent. Phallobase slightly asymmetrical, reaching 0.28 length of aedeagus. Parameres long and slender, narrowest medially; dorsal margin slightly emarginated near apex; surface with about 14 moderately long ventroapical setae and a few very short basolateral setae.

Ovipositor ( Figure 11 (c)), total length 505 µm. Stylus subcylindrincal; apex with rather small setae. Coxite long and slender; all setae elongately peg-like, mesal pubescence very distinct; basal portion more than half as long as distal portion. Valvifer about 1.1 times as long as coxite.

Distribution

So far known from the type locality in South Sulawesi ( Figure 18 ) .

Etymology

The species is named after an ethnic group of Sulawesi highland people, the Toraja, and their homeland Tana Toraja from where this species was collected. Toraja is used as noun in apposition.

Comments

The species is similar to Ancyronyx longiparamerus in size and in the shallow elytral punctures. It can be distinguished from the latter by the clearly divided anterior elytral patches, the shorter and narrower parameres and by the setae near the ventral margin of the parameres, which are longer than the width of the paramere.

The species was solely collected from bottom gravel at the type locality. Ancyronyx longiparamerus occurred in the same stream, but on wood.

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 11. Ancyronyx toraja from Rantepao (Sul7c); (a) aedeagus, lateral; (b) aedeagus, ventral; (c) ovipositor, ventral; (Scale bar = 0.1 mm).

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