Calvariomorphus sakaii, Ruta & Yoshitomi, 2022

Ruta, Rafał & Yoshitomi, Hiroyuki, 2022, Calvariomorphus-a new genus of marsh beetles (Coleoptera: Scirtidae) with remarkable elytral excitators, Zootaxa 5120 (1), pp. 65-82 : 78

Calvariomorphus sakaii sp. nov.

( Figs 1E–F , 7B , 13 , 14 )

Type material. Holotype, male ( EUM): “[MINDANAO] \ Eagle Centre, 1100m \ Baracatan north \ slope of Mt. Apo \ 4. VIII. 1985 M. Sakai ” . Paratypes, 6 males, 2 females ( EUM): same data as holotype . Paratype, male ( EUM): same data as holotype, but collected 5.VIII.1985 . Paratype, male ( EUM): “P. I., MINDANAO \ Bukindon, 1250m. \ Mt. Katanglad \ 26-x-1959 ”; “ L. W. Quate \ Collector” .

Diagnosis. Small species, on average larger than other members of the genus (TL ~ 2.0– 2.2 mm), body widest in the basal half of elytra, trigonium of penis as long as parameroids, elytra of females without excitators.

Description. Body small, TL 2.03–2.20 (mean 2.11, n=8) mm, TL/EW ~ 1.4–1.5 (1.4), oval, brownish black, legs and antennae lighter, yellowish, covered with dense, yellowish, erect setae. Head strongly transverse, punctation sparse, punctures separated by ca. 2 diameters. Pronotum transverse, anterolateral and posterolateral angles right angled, lateral carinae almost straight, punctation sparse, similar to that on head. Angle between pronotum and elytra not marked in dorsal view. Scutellar shield subtriangular, impunctate. Elytra elongate, widest in anterior half, punctation stronger than on pronotum, punctures separated by ca. 1.0 diameter.

Penis (L 0.58 mm, W 0.12 mm) elongate, with short, oval pala and long parameroids, parameroids and trigonium of similar lengths, apex of trigonium subtriangular; tegmen (L 0.24 mm, W 0.19 mm) u-shaped, with very narrow parameres and pointed apices; sternite IX (L 0.25 mm, W 0.11 mm) u-shaped, with very narrow lateral portions; tergite VIII (L 0.40 mm, W 0.38 mm) with apodemes as long as apical plate, margin of apical plate with sparse, long setae and dense, much shorter ones; tergite IX (L 0.33 mm, W 0.32 mm) with membranous, subtriangular apical plate.

Female. Size similar to that in males, TL 2.11–2.23 (2.17) mm, TL/EW ~ 1.4–1.6 (1.5). Elytra without excitators. Ventrite 4 with small, oval microreticulate area in central portion ( Fig. 7C ). Ovipositor long (L 1.7 mm), bursal sclerite relatively big (L 0.40 mm), subrectangular, plate-like, covered with subtle microsculpture.

Distribution. Known from two localities on Mindanao Is.

Etymology. Named after Dr Masahiro Sakai, who is a coleopterist and was the collector of the holotype of this species.

Figures

FIGURE 1. Calvariomorphus gen. nov., dorsal view (with the exception of H). A) C. malayanus sp. nov., male, B) same, fe- male, C) C. palauensis sp. nov., male, D) same, female, E) C. sakaii sp. nov., male, F) same, female, G) C. sp. (Nicobar Islands), H) same, semilateral view. Scale bars = 0.5 mm.

FIGURE 7. Calvariomorphus gen. nov., abdomen. A) C. malayanus sp. nov., male, B) C. sakaii sp. nov., female, C) same, close-up of ventrite 4.

FIGURE 13. Calvariomorphus sakaii sp. nov., male genitalia. A) penis, B) tegmen, C) sternite IX and tergite IX, D) tergite VIII. Scale bar = 0.25 mm.

FIGURE 14. Calvariomorphus sakaii sp. nov., female genitalia. A) genital tract, B) coxites, C) bursal sclerite. Scale bar = 0.5 mm (A, C), 0.25 mm (B).