Ancyronyx skalei, 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 : 576-578

Ancyronyx skalei sp. nov.

( Figures 1 (b); 7(a–d); 18; 19(e))

Type locality

1 km west of Toraut , Dumoga Bone National Park, 0°34′17′′ N, 123°54′19′′ E, 200–300 m a .s .l ., northern Sulawesi, Indonesia .

Type material

Holotype ♂ ( NMW): ‘ INDONESIA N Sulawesi 1 km W Toraut, Dumoga Bone NP. 200–300 m, 0°34′17′′ N, 123°54′19′′ E 1.-2.II.2006 leg. A. Skale’, terminal parts of abdomen with aedeagus and left antenna glued separately . Paratypes: 9♀♀ ( CSH, NMW, CFM, CKB): same data as holotype; 2♂♂ ( CSH, CFM), 1♀ ( CFM: [ FR125 ]): ‘ INDONESIA: S Sulawesi, T . Toraja, Salu Toriu River , 810 m a .s .l., c. 02°56′38′′ S, 119°52′24′′ E 02 Jan.1998 leg . Freitag (Sul8Ag) ’.

Diagnostic description

Body 1.35–1.43 mm long, 2.0–2.2 times as long as wide ( BL / EW); EW: 0.62–0.68 mm.

Colouration Figure 1 (b). Elytra with extensive yellowish pattern on dark brown ground: a pair of always separated oblique oval patches posteriorly, not reaching sutural, lateral nor apical margins; a pair of median short and broad longitudinal parallel lines usually extending to anterior patches; anterior patches extending from humeri to first row of punctures. Yellow areas in pale specimens extended to dark suture and elytral margins and so a U-shaped median dark pattern on yellow ground is apparent only. Pronotum and head black. Foreleg yellowish to light brown; areas around articulations, proximal half of tibiae, tarsomeres 1–4 and distal half of terminal tarsomeres dark. Middle and hind leg with similar pattern but generally darker up to almost dark brown femora; claws dark yellowish to pale brown. Terminal segment of maxillary palps and antennal tips dark brown, remaining antennal segments yellowish, ventral side dark brown.

Head. HW: 0.35–0.38 mm, ID: 0.19–0.21 mm, frontoclypeal suture rather inconspicuous; antennae approximately as long as width of head.

Thorax. Pronotum widest at about posterior 0.35, posterior margin slightly trisinuate; PL: 0.40–0.43 mm, MW: 0.45–0.50 mm; surface with dense small irregular punctures, interstices raised and shiny, giving the surface reticulation-like pattern. Elytra. EL: 0.95– 1.03 mm, EW: 0.62–0.70 mm, almost parallel-sided in anterior 0.05–0.65; accessory scutellary row of punctures reaching anterior 0.2 of elytral length.

Abdomen. Male sternite IX ( Figure 7 (a)) 400 μm long; apical margin almost straight; apical portion moderately broad, with four moderately long setae; paraprocts short, distinctly not reaching apical margin; anterior strut moderately long, evenly narrowed.

Aedeagus ( Figure 7 (b,c)) elongate, 455 µm long. Median lobe moderately long and broad (110 µm wide), almost parallel-sided in basal half then evenly tapering towards apex; evenly bent ventrad; ventral sac weakly sclerotized, irregularly plicate, reaching apical 0.15; fibula slightly sclerotized, distinctly enlarged and curved inwards at proximal end, sides subparallel; corona inconspicuous. Phallobase almost symmetrical, moderately strongly sclerotized, reaching about one-third of aedeagus length (in lateral view). Parameres long, narrowest near middle, not inflated near apex, with more than 20 moderately long setae at apical third.

Ovipositor ( Figure 7 (d)), total length 570 µm. Stylus moderately long, subcylindrincal, with few apical setae. Coxite long and slender; setae moderately short, peg-like, slightly acute, comparably densely dispersed all over distal and basal portion; mesal margin of coxite moderately densely pubescent; basal portion c.0.6 times as long as distal portion. Valvifer c.1.4 times as long as coxite.

Distribution

The species is known from two localities in North and South Sulawesi ( Figures 18 , 19 (e)).

Etymology

The species is named for André Skale (Hof, Germany), collector of this species.

Comments

The darker specimens, externally most resemble Anxyronyx schoedli and differ in the median yellow patches on the elytra being more extensive; the profemora are distinctly paler near the middle; the parameres are proportionally shorter, narrower and gradually narrowed in the apical portion and the apex of male sternite IX is shallowly emarginated only. The pale specimens with extensive yellow elytral pattern are easily distinguished from all other Ancyronyx species described herein.

Ancyronyx skalei was found syntopically with A. schoedli at its southern collection site (Sul8Ag; Figure 19 (e)).

Figures

Figure 1. Habitus of Ancyronyx species from Sulawesi, (a) Ancyronyx schoedli (total length 1.65 mm), (b) Ancyronyx skalei (total length 1.60 mm), (c) Ancyronyx tobada (total length 1.65 mm), (d) Ancyronyx hafti (total length 1.70 mm).

Figure 7. Ancyronyx skalei from Dumoga; (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