Sangabasis cahilogi, Villanueva, R. J. T. & Dow, R. A., 2014

Villanueva, R. J. T. & Dow, R. A., 2014, Review of the Philippine taxa formerly assigned to the genus Amphicnemis Selys, II. Genus Sangabasis with descriptions of eight new species (Odonata: Coenagrionidae), Zootaxa 3815 (1), pp. 1-28 : 7-8

Sangabasis cahilogi sp. nov.

( Figs. 6 , 30 , 44 , 56 , 67 )

Type material. Holotype: ♂, Philippines, Negros Id, Murcia, Minoyan, Sitio Gayas, Oroplata, 3 v 2010, in RMNH, leg. HC. Paratypes: 2 ♂, data as holotype, in coll. RJTV.

Etymology. A noun in genitive case, after Hilario Cahilog, field assistant of the first and sometimes the second author, for collecting the present species and several other new species in collection RJTV.

Description of male holotype. Head: Labium pale, mandible bases pale except for small dark mark. Labrum shiny black with slightly less than anterior half yellow. Genae pale, pale colour continued to eye margin and narrowly along eye margin from ridge of frons to level of antennal sockets. Anteclypeus mostly pale with dark central marking beneath postclypeus. Postclypeus black. Frons black, with distinct ridge, anterior face almost entirely occupied by broad transverse yellow streak. Vertex black, broad pale streak on antennal socket, top of scape pale, pale streak along anterior face of pedicel, rest of antennae brown. Remainder of head black except for pale rear margin of occiput.

Thorax: Prothorax dark metallic green except for pale transverse streak on crest of anterior lobe, and lower part of propleuron. Rear of posterior pronotal lobe simple, subrectangular with two slight peaks along rear margin interior to corners ( Fig. 6 ). Synthorax ( Fig. 30 ) with dorsal carina without distinct tubercle and almost entirely smooth along anterior 1/4. Mesinfraepisternum mostly metallic green with intermittent and irregular pale border. Mesepisternum dark metallic green, mesepimeron dark metallic green and pale as shown in Fig. 30 . Metepisternum largely pale, large metallic green marking adjacent to antealar carina, separated from tiny dark mark on metapleural suture, metepimeron pale. Legs with coxa and trochanter pale, femur and tibia pale with dark spines, blackish streaks on extensor surfaces, and dark markings around joint. Tarsi with very small denticle. Wings hyaline with black veins; Arc just off Ax2, Ac near Ax2, petiolation ceases well before level of Arc. R4 arising at subnodus, IR3 a little distal to that. 12 Px in all wings. Pt with brownish center, approximately square with costal side a little shorter than subcostal side.

Abdomen: S1–2 black dorsally, yellowish lower on sides. S3–10 reddish brown, basal part of S3–5 and dorsum of S8 darker. Cerci pale basally, darkening towards tips, more than twice length of S10. Fork of upper branch at slightly more than 1/4 length of upper branch ( Fig. 56 ). In lateral view upper branch shaped as in Fig. 44 , in dorsal view ( Fig. 56 ) expanding apically, somewhat hollowed before rounded tip. In dorsal view spur of upper branch narrowly triangular, slightly shorter than the distance from S10 to base of fork, spur well visible in lateral view. Lower branch of cercus visible in lateral view, short but robust, pointed tip not reaching level of fork of upper branch. Paraprocts typical for genus.

Measurements (mm): abdomen including cerci 44, Hw 26.

Female. Unknown.

Diagnosis. Distinguished from all species apart from S. bulba by the absence of a postocular tubercle and simple structure of the posterior pronotal lobe. Separated from S. bulba by the shape of the posterior pronotal lobe and of the upper branch of the cercus.

Remarks. This species is encountered perching at or guarding water-filled tree holes in lowland dipterocarp forest with no nearby running water. This species, and perhaps also its close congener S. bulba , appear to be obligate phytothelmata breeders, like the genus Pandanabasis in the eastern Philippines that breeds in water-filled leaf axils (Villanueva 2012).

Figures

FIGURE 67. Distribution of S. cahilogi (black circle) and S. janvantoli (black triangle).

FIGURES 6 – 7. (6) S. cahilogi holotype posterior pronotal lobe in dorsal-lateral view. (7) S. carmelae holotype posterior pronotal lobe and part of synthorax in dorsal view, tubercles on mesinfraepisternum visible.

FIGURES 27 – 32. Lateral views of male synthorax: (27) S. braulitae holotype; (28) S. bukid holotype; (29) S. bulba holotype; (30) S. cahilogi holotype; (31) S. carmelae holotype; (32) S. circularis Tawi-Tawi Island.

FIGURES 41 – 46. Lateral view of male anal appendages: (41) S. braulitae holotype; (42) S. bukid holotype; (43) S. bulba holotype; (44) S. cahilogi holotype; (45) S. carmelae holotype; (46) S. circularis Tawi-Tawi.

FIGURES 53 – 58. Dorsal view of male anal appendages: (53) S. braulitae holotype; (54) S. bukid holotype; (55) S. bulba holotype; (56) S. cahilogi holotype; (57) S. carmelae holotype; (58) S. circularis Sibutu.