Ancyronyx henningi, 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 : 593-596

Ancyronyx henningi sp. nov.

( Figures 3 (a,b) 5(a–g); 14(a–d); 18; 19(a,f))

Type locality

A mountain brook flowing through grassland with submerged wood, road km 32 Tentena-Gintu, ca. 1600 m a.s.l., ca. 01°48′10′′ S, 120°28′ 10 E, Central Sulawesi, Indonesia .

Type material

Holotype ♂ ( NMW): ‘ INDONESIA: C Sulawesi, Rd. Km 32 Tentena-Gintu ; mountain creek, grassland; submerged wood, c. 1600 m a.s.l., c. 01°48′10′′ S, 120°28′10′′ E 04 Jan.1998 leg. Freitag (Sul13f)’, terminal parts of abdomen and aedeagus glued separately, two tarsi lacking . Paratypes: 15 ♂♂, 12 ♀♀ ( NMW, CFM [FR123]): same data as holotype; 6 ♂♂, 7 ♀♀ ( CKB, CFM): ‘ INDONESIA: C Sulawesi, Rd . Km 29Tentena-Gintu; mountain creek; rock surface, boulders, c. 1380 m a.s.l., c. 01°47′50′′ S, 120°28′50′′ E 04 Jan.1998 leg . Freitag (Sul 12 g)’; 8 ♂♂, 3 ♀♀ ( NMW, CFM [FR122]): ‘ INDONESIA: C Sulawesi, 3.7 km N Tentena; calcerous Saluopa Falls ; limestone, sec . veget.; c. 520 m a.s.l., c. 01°44′ S, 120°39′ E 04 Jan.1998 leg . M . Henning (Sul 18 g)’.

Diagnostic description

Body 1.32–1.50 mm long, 2.1–2.2 times as long as wide ( BL / EW); EW: 0.61–0.70 mm.

Colouration Figure 3 (a,b). Very dark species. Elytra dark brown; pronotum and head black; elytral patches usually not discernible; if ever, hardly visible small paler spots are present at humerus and median anterior elytra ( Figure 3 (b)).

Head. ( Figure 5 (a,b)) 0.36–0.39 mm wide; ID: 0.20–0.22 mm; antennae about as long as head width, terminal segment with digitiform sensillum ( Figure 5 (g)); gular sutures separate.

Thorax. Pronotum 0.42–0.48 mm long ( PL), 0.47–0.50 mm wide ( MW); surface strongly rugulose ( Figure 5 (a)); punctures deeply impressed. Elytra 1.4–1.5 times as long as wide; EL: 0.92–1.05 mm, EW: 0.62–0.70 mm; punctures large and deeply impressed ( Figure 5 (e)). Mesoventrite anteriorly microreticulate/microstriate ( Figure 5 (b)). Anepisternum 3 rugulose. Legs slightly shorter than body.

Abdomen. Ventrites 1–4 with flat cordiform granules ( Figure 5 (c,d)); granules moderately dense, sparse and small in central portion, larger and denser on sides, interstices shiny; ventrite 5 densely covered with granules. Male sternite IX ( Figure 14 (a)) 390 μm long; apical portion narrow; apical margin emarginate, laterally with few short setae; paraprocts unequal in size, not reaching apical margin; anterior strut short.

Aedeagus ( Figure 14 (b,c)) broad, elongate, 425 µm long. Median lobe long and conical (105 µm wide basally, 85 µm wide near middle); lateral margins slightly convex, gently (at apex distinctly) bent ventrad; ventral sac prominent, reaching apical 0.1; fibula moderately sclerotized, broad; corona inconspicuous. Phallobase obliquely prolonged anteriad, strongly sclerotized. Parameres long, inflated in distal half, strongly narrowed near middle, with more than 25 moderately long setae in apical half.

Ovipositor ( Figure 14 (d)), total length 450 µm. Stylus moderately long, bent laterad, broader apically; apex with peg-like setae. Coxite moderately long and slender; setae dimorphic, elongate peg-like, pointed at distal portion and broad spine-like, acute at basal portion; cluster of spine-like setae at basal portion; mesal margin with dense, fine pubescence. Valvifer about 1.3 times as long as coxite.

Distribution

The species is known from localities in Central Sulawesi ( Figures 18 ; 19 (a,f)).

Etymology

The species is named for Matthias Henning (Bernburg, Germany), who collected this species.

Comments

This species somewhat resembles externally A. breviparamerus , but is smaller and darker (rarely with inconspicuous anterior elytral patches only). Generally it differs from all its congeners from Sulawesi by the peculiarly large and deeply impressed elytral punctures and the coarsely sculptured pronotum. In addition, its parameres are characterized by their short length as well as by the numbers and position of the setae.

The usual dark morph (from the type locality, c. 1600 m a.s.l.) is illustrated in Figure 3 (a). In Figure 3 (b), a slightly smaller specimen from a collection site at lower altitude (c. 520 m a.s.l.) is illustrated that displays the rarer colour morph with paler legs and faint elytral spots. However, the latter colour morph was also found at high altitude sites, while the trend of slightly smaller body size (1.32–1.39 mm) is evident for specimens of the lower site irrespective of their colouration.

Ancyronyx henningi seems to be less specialized to a certain microhabitat. It was collected from different microhabitats (submerged wood, rock surface), in presumably acidic (type locality) as well as alkaline, calcerous waters ( Figure 19 (f)) and at a comparably wide range of altitudes from 500 m to 1600 m a.s.l.

Figures

Figure 3. Habitus of Ancyronyx species from Sulawesi, (a) Ancyronyx henningi from Gintu (Sul13f) (total length 1.61 mm; BL: 1.45 mm!), (b) Ancyronyx henningi from Tentena (Sul18 g) (total length 1.58 mm; BL: 1.33 mm!), (c) Ancyronyx vincentarnoldi (total length 1.80 mm), (d) Ancyronyx raffaelacatharina (total length 2.15 mm).

Figure 5. Ancyronyx henningi, ventral (SEM photographs), (a) head, pronotum and scutellum, dorsal; (b) head and thorax, ventral; (c) metaventrite, ventrites 1–3, meso- and metacoxae and -trochanter; (d) ventrites 2–5; E: elytra; F: mouthparts; G: antenna.

Figure 14. Ancyronyx henningi from Gintu (Sul13f); (a) male sternite IX, ventral; (b) aedeagus, lateral; (c) aedeagus, ventral; (d) ovipositor, 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