Dilobocondyla rufida, Chen & Li & Zhou, 2019

Chen, Zhilin, Li, Wenjie & Zhou, Shanyi, 2019, Taxonomic review of the ant genus Dilobocondyla from China (Hymenoptera: Formicidae), with a revised key to the known species, Zoological Systematics 44 (2), pp. 132-139 : 135-137

Dilobocondyla rufida sp. nov. ( Figs 7–12 )

Type materials. Holotype worker, CHINA: Guangxi, Fangchenggang, Fulong , 21.82°N, 107.95°E, 510 m, 17.IV.2017, leg. Zhilin Chen, No. G 170183 . Paratype. 1 dealate gyne from the same colony with holotype worker .

Diagnosis. The new species is close to D. fouqueti Santschi , but can be distinguished from the latter by the relatively shorter petiole and more convex dorsum, distinct micro-reticulations on the gaster, and black colored mesosoma, petiole and postpetiole, and lightly colored gaster. The new species is also similar to D. gaoyureni Bharti & Kumar , but distinguishable from the latter by the relatively shorter petiole and strongly convex dorsum, weakly depressed metanotal groove, bluntly angled posterior head corners, and black colored head, mesosoma and waist segments.

Description. Holotype worker ( Figs 7–9 ). TL 5.3, HL 1.24, HW 1.23, CI 99, SL 0.81, SI 66, ED 0.30, PW 0.88, MSL 1.67, PL 0.50 PH 0.33, DPW 0.33, LPI 66, DPI 66.

In full-face view, head nearly rectangular, a little longer than width, posterior margin distinctly concaved medially, posterior corners bluntly angled, lateral margins weakly convex. Mandibles triangular, masticatory margin 6-toothed, with large apical, preapical and basal teeth, and three additional small but obvious teeth. Clypeus without longitudinal median carina, anterior margin notched in the center. Frontal carinae conspicuous, curved outward, reaching to 3/4 of head length. Antennae 12-segmented, with distinct 3-segmented club, scapes reaching to 3/4 of head length. Eyes large and convex.

In lateral view, promesonotal dome weakly convex dorsally, a little higher than propodeum, promesonotal suture absent. Metanotal groove weakly impressed. Dorsum of propodeum weakly convex, forming a broadly rounded corner with declivity. Propodeal lobes well developed, with rounded apices. Petiole relatively short, 1.7 times as long as high, with dorsal margin strongly convex, anteroventral corner largely toothed. Postpetiole roughly triangular, incrassate posteriorly, dorsum strongly convex, higher than petiole. Gaster ovate.

In dorsal view, pronotum broad and roughly trapezoidal, narrowed posteriorly, humeral corner forming a small pointed denticle. Promesonotal suture absent. Mesonotum short and narrower than pronotum. Metanotal groove indistinct. Propodeum roughly rectangular and narrower than pronotum. Petiole narrow and rectangular, weakly widened posteriorly, lateral margins straight. Postpetiole broader than petiole and widening posteriorly, with convex lateral margins. Gaster ovate.

Mandibles longitudinally striate. Clypeus and vertex of head longitudinally rugose, the rest of head rugose-reticulate. Mesosoma, petiole and postpetiole rugose-reticulate, reticulation became weaker on mesopleura and metapleura. Gaster distinctly micro-reticulate and dull, first gastral tergite with abundant basal costulae. Whole body surface with abundant erect to suberect hairs. Body black, scapes and gaster reddish brown, flagella and legs blackish brown.

Paratype gyne ( Figs 10–12 ). TL 7.88, HL 1.69, HW 1.63, CI 96, SL 0.92, SI 56, ED 0.30, PW 1.33 , MSL 2.56, PL 0.75, PH 0.44, DPW 0.44, LPI 59, DPI 59. Similar to the holotype worker with the following exceptions. Body relatively larger. Head with 3 ocelli and relatively larger eyes. Mesosoma massive and fully segmented, in lateral view mesosomal dorsum roundly convex, petiolar dorsum moderately convex; in dorsal view pronotum reversed V-shaped, scutum triangular, mesonotal suture weakly arched posteriorly, scutellum transverse and lunulate. Propodeum roughly trapezoidal and narrowed posteriorly, broader than long. Mesonotum with longitudinally ridged.

Habitat. The type series was found nesting in a small dead twig of Rhododendron henryi (Hance, 1881) .

Etymology. The specific name refers to the reddish brown gaster.

Remarks. The body color pattern of the genus seems to be relatively unstable by examining the specimens and AntWeb’s pictures. All known species can be classified roughly into “concolor” and obviously “bicolor” groups. The former group consists of 12 species and subspecies, D. bangalorica , D. borneensis , D. chapmani , D. didita , D. fulva , D. oswini , D. sebesiana , D. selebensis , D. selebensis simalurana , D. silviae , D. rufobrunnea , D. yamanei . And the latter group consists of 9 species, D. cataulacoidea , D. carinata , D. eguchii , D. fouqueti , D. gaoyureni , D. gasteroreticulata , D. karnyi , D. propotriangulata , D. rugosa . In the known bicolor species, the gaster is usually lighter than the head, or the same color as the head. D. rufida sp. nov. can be classified into the “bicolor” groups and can be distinguished from the other species of Dilobocondyla by its black colored mesosoma, petiole and postpetiole, and reddish brown graster.

Figures

Figures 7−12. Dilobocondyla rufida sp. nov. 7−9. Worker. 10−12. Female. 7, 10. Head, full-face view. 8, 11. Body, dorsal view. 9, 12. Body, lateral view.