Kostalius sylvaticus Borovec, 2025

Borovec, Roman, 2025, Two new and one enigmatic genus of Oosomini from South Africa with description of seven new species (Coleoptera: Curculionidae: Entiminae), Zootaxa 5642 (2), pp. 101-126 : 123-124

Kostalius sylvaticus Borovec , sp. nov.

http://zoobank.org/ urn:lsid:zoobank.org:act:ED14DBEC-4BF5-4F70-8CD2-5E059D7E1F64

Figs (11, 12, 46, 47, 51, 54, 56)

Type locality. South Africa, Eastern Cape, Hogsback State Forest .

Type material. Holotype: ♂, RSA, Eastern Cape, Hogsback State Forest, Contour track env., 32°35.2′ S, 26°56.6′ E, 1495 m, 11.xi.2023, Sifting of litter, indigenous forest, R. Borovec lgt. ( NMPC) . Paratypes: 16 specs., same data as holotype ( MKŠS, RBSC) ; 18 specs., South Africa, Eastern Cape, Hogsback State Forest Contour track env., 32°35.2′ S, 26°56.6′ E, 10.i.2015, J. Janák lgt. ( BMNH, JJRC, SANC) ; 5 specs., ditto, but 18.i.2018 ( JJRC) ; 1 spec., ditto, but 5.i.2018, 1300 m ( JJRC) ; 1 spec., South Africa, Eastern Cape, W of Keiskammahoek , indig. forest, 32°40.7′ S, 27°4.0′ E, 18.i.2016, P. Bulirsch lgt. ( RBSC) ; 1 ♂, South Africa, Eastern Cape, Cata env., ind. forest, 32°34.7′ S, 27°06.3′ E, 19.i.2016, J. Janák lgt. ( JJRC) ; 1 spec., South Africa, Eastern Cape, Silaka NR, 31°38.9- 39.3′ S, 29°30.3-4′ E, ind. forest, 20-80 m, 9.i.2018, P. Bulirsch lgt. ( RBSC) ; 2 specs., S.Afr. [ South Africa, Eastern Cape], Ciskei Amatole, Pirie for., 32.43 S – 27.17 E, 8.xii.1987; E-Y: 2560, indig. forest litter, leg. Endrödy-Younga ( TMSA) ; 20 specs., South Africa: Eastern Cape, Hogsback, above Contour Track , 1335m, 32°35.2’S 26°56.6’E, 3 Feb 2004, afromontane forest litter, A. Solidovnikov, M. Thayer et al., FMNH 2004-037 ( CMNC, FMNH, SANC) ; 10 specs., South Africa: Eastern Cape, Hogsback, above Contour Track , 1335m, 32°35.2’S 26°56.6’E, 3 Feb 2004, forest litter, D. Clarke, FMNH 2004-038 ( CMNC, FMNH, SANC) ; 3 specs., South Africa: Eastern Cape, Hogsback, above Contour Track , 1340m, 32°35.1’S 26°56.4’E, 3 Feb 2004, leaf and log litter, D. Clarke, FMNH 2004-042 ( CMNC, FMNH, TMSA) .

Diagnosis. Odd elytral interstriae with short, inconspicuous, narrow, subspatulate setae, setae on pronotum forming three irregular transverse rows; rostrum from base evenly enlarged anteriad, widest at apical portion; antennal scape in ventral side glabrous, smooth; funicle with 6 articles; all tibiae in short apical part asquamose.

Description. Body length holotype 2.19 mm, paratypes 1.91–2.53 mm. Integument ( Figs 11, 12 ) brown reddish, antennal funicles with clubs and tarsi paler, yellowish. Body covered by sparse, short, perpendicularly erect, greyish piliform setae, at short apical part slightly curved, not hidden integument; only frons and lateral parts of head with rostrum densely covered with small, oval, appressed scales. Odd elytral interstriae with sparse row of erect, subspatulate, apically rounded, finely longitudinally striate scales, slightly longer than half width of interstria; distance between two setae about three times longer than length of one seta. Pronotum with identical erect setae as those on elytra, forming three irregular transverse rows, on anterior and posterior margin and across middle of pronotum. Head and rostrum with about half as long erect setae, mainly along margins of epifrons. Antennal scapes with short and fine, piliform appressed setae, inner margins with short, slender, semi-erect subspatulate setae; funicles with short and fine, translucent, hardy visible setae; clubs finely and densely setose in apical half. Femora with narrow, semi-appressed subspatulate scales; tibiae with short, semi-appressed setae, lateral margin with semi-erect narrowly subspatulate scales; tarsi with short and sparse setae. Majority of specimens have dorsal part of body densely encrusted with hardly visible erect scales.

Rostrum ( Figs 46, 47 ) 1.45–1.51× as wide as long, from base abruptly evenly enlarged anteriad with straight sides, widest at apical third to quarter, apically broadly rounded, at base 0.83–0.89× as wide as at widest apical part; rostrum in lateral view distinctly vaulted. Epifrons evenly tapered apicad with straight sides, at base 1.22–1.29× as wide as at apex, dorsally flat, posteriorly with narrow transverse sulcus with ill-defined margins before eyes, completely hidden under vestiture and encrustation. Antennal scrobes in dorsal view visible as very narrow furrow along the whole length, curved laterally before eyes; in lateral view reaching eye, furrow-shaped, slightly curved, with dorsal margin directed almost to dorsal margin of eye and ventral margin directed slightly below eye. Eyes small, in dorsal view visible, not prominent from outline of head; in lateral view subcircular, positioned in middle of head.

Antennae ( Figs 11, 12 ) with scape 3.4–3.6× as long as wide and 1.2× as long as funicle, at apex 1.4–1.6× as wide as club, scape in ventral side glabrous, smooth. Funicle with 6 articles; article 1 2.1–2.2× as long as wide and 1.8–2.0× as long as article 2, this is 1.6–1.8× as long as wide; article 3 1.6–1.7× as long as wide; articles 4 and 5 1.4–1.5× as long as wide; article 6 1.2–1.3× as long as wide; clubs 2.0–2.1× as long as wide.

Pronotum ( Figs 11, 12 ) 1.56–1.69× as wide as long, distinctly narrower than elytra, distinctly constricted behind anterior margin, widest at midlength; disc under vestiture smooth, very finely and sparsely punctuate, with distinct narrow and moderately deep transverse incision across whole width at anterior third, often hidden by encrustation. Pronotum in lateral view vaulted, at anterior third flattened.

Elytra ( Figs 11, 12 ) 1.08–1.12× as long as wide, almost globular, with distinctly and regularly rounded sides, widest at middle, in lateral view vaulted. Striae roughly punctured; interstriae narrow, flat, smooth.

Abdominal ventrites 1.18–1.24× as long as wide.

Protibiae 4.2–4.3× as long as wide, anteriorly obliquely subtruncated with fringe of pale, yellowish fine setae; meso- and metatibiae with apical surface densely fringed by yellowish setae; all tibiae in short apical part asquamose, glabrous, smooth. Tarsi with tarsomere 2 1.7–1.8× as wide as long; tarsomere 3 1.4× as wide as long and 1.3× as wide as tarsomere 2; onychium 0.8–0.9× as long as tarsomere 3; claws distinctly divaricate.

Penis ( Fig. 51 ) slender and moderately long, widest near base, evenly slightly tapering apicad, apically broadly rounded; in lateral view weakly regularly curved, subequal in width along entire length, evenly tapering apicad in short apical portion; temones almost twice as long as body of penis; endophallus with one long oval, irregularly shaped sclerite. Tegmen with slender ring lacking parameres; manubrium almost twice as long as ring diameter. Sternite IX anteriorly curved and tapered, posteriorly with fused basal arms.

Female sternite VIII ( Fig. 56 ) with plate about as long as wide, apically broadly rounded; apodeme 4.3–4.6× longer than plate, forming basal margin of plate. Gonocoxites slender, tube-shaped, subparallel-sided; styli apical, slender. Spermatheca ( Fig. 54 ) with slender and curved cornu; ramus and collum slightly longer than wide, apically narrowly rounded, collum longer and wider than ramus.

Derivation of name. This species is named from the Latin sylvaticus , meaning occurring in the forest, in reference to the circumstances of collection.

Biology. All type material was sifted from litter in indigenous forest.

Distribution. South Africa, Eastern Cape, collected in five proximate localities.

Differential diagnosis. Both new species described in Kostalius are very easily distinguished by the following characters: Kostalius rotundisetis : Erect elytral setae conspicuous, wide, regularly rounded; pronotal setae forming one conspicuous transverse row; rostrum subparallel-sided; funicle with 7 articles; scape on ventral side densely squamose; oval elytra with sparse, low bumps on odd interstriae; pronotum with four bumps forming transverse row; all tibiae in apical parts densely squamose; penis with small apical tip in dorsal view and spine visible in lateral view; female sternite VIII with plate subtriangular. Kostalius sylvaticus : Erect elytral setae inconspicuous, narrow, subspatulate; pronotal setae forming three inconspicuous transverse rows; rostrum distinctly enlarged apicad; funicle with 6 articles; scape on ventral side glabrous, smooth; globular elytra with regularly flat interstriae; pronotum irregularly domed; all tibiae in short apical part asquamose; penis lacking apical tip in dorsal view and small spine in lateral view; female sternite VIII with plate broadly rounded.

Figures

FIGURES 9–12. Dorsal habitus.9. Kostalius rotundisetis, encrustated. 10. K.rotundisetis, cleaned. 11. K.sylvaticus, encrustated. 12. K. sylvaticus, cleaned. Not to scale.

FIGURES 44–57. 44–47: Head including rostrum in dorsal and lateral view. 44, 45. Kostalius rotundisetis. 46, 47. K. sylvaticus. 48: Right protibia. K. rotundisetis. 49: Abdominal ventrites. K. rotundisetis. 50, 51: Penis in dorsal view. 50. K. rotundisetis. 51. K. sylvaticus. 52: Tegmen. K. rotundisetis. 53, 54: Spermatheca. 53. K. rotundisetis. 54. K. sylvaticus. 55, 56: Female sternite VIII. 55. K. rotundisetis. 56. K. sylvaticus. 57: Ovipositor. K. rotundisetis. Scale 1.00 mm for 49; 0.50 mm for 44–48; 0.25 mm for 50–57.