Sangabasis dentifer ( Needham and Gyger, 1939 )

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 : 13-15

Sangabasis dentifer ( Needham and Gyger, 1939)

( Figs. 3 , 12 , 17, 18 , 23, 24 , 33, 34 , 47 , 59 , 68 )

Teinobasis dentifer Needham & Gyger, 1939: 300 –301, Figs. 278, 299 (original description ♀, Philippines, Mindanao Island).

Amphicnemis dentifer (Needham & Gyger) ;— Lieftinck (1940: 362: footnote);— Hämäläinen & Müller (1997: 259, 276: note 1);— Villanueva (2005: 80, comparison with S. braulitae ).

Amphicnemis cf dentifer (Needham & Gyger) ;— Villanueva (2009: 30, Dinagat Island).

Sangabasis dentifer (Needham & Gyger) ;—Villanueva (2012: 582, 595, Fig. 6 , transferred to Sangabasis).

Material (all Philippines, in coll. RJTV unless otherwise noted). Mindanao Island: 5 ♂, ♀, no specific location, 2004, leg. RJTV; 6 ♂, ♀, Davao Oriental, Mati, Mt. Hamiguitan, Lake Gamay, 26 iii 2007, leg. HC; 8 ♂, 2 ♀, same location, 27 viii 2008, leg. HC; 2 ♂, same location, 18 iii 2007, leg. RJTV; 3 ♂, Davao Oriental, San Isidro, La Union, Lake Gamay, 26 iii 2009, leg. HC; 7 ♂, ♀, same location, 4 ix 2009, leg. HC; 2 ♂, ♀, Davao Oriental, Mt Agtuuganon, Boston, Camp 55, 29 v – 7 vi 1996, in RMNH, leg. R.A.Müller, A. Buenafe & Gorostiza; 7 ♂, 2 ♀, Davao Oriental, Governor Generoso, 1 ix 2009, leg. HC; 7 ♂, Davao Oriental, San Isidro, Bitaogan, Tibanga, 25 iv 2010, leg. HC; 3 ♂ RJTV, Davao Oriental, Bagangga, Panjugan, 2 vii 2010, leg. HC; ♂, Davao Oriental, Bagangga, Kinablangan, 10 vi 2012, in RMNH, leg. HC; ♀, Davao Oriental, Bagangga, Kinablangan, 10 vi 2012, in colll. RAD, leg. HC; 2 ♂, Davao Oriental, Bagangga, Panhugan, 10 vi 2012, in RMNH, leg. HC; ♂, Davao Oriental, Bagangga, Panhugan, 10 vi 2012, in coll RAD, leg. HC; ♂, Davao Oriental, Bagangga, Panhugan, 10 vi 2012, in coll RAD, leg. RAD; 4 ♂, ♀, Davao Oriental, Cateel, Aliwagwag, Purok 5, Dispatcheng, 11 vi 2012, in coll. RAD, leg. HC; ♂, Davao Oriental, Cateel, Aliwagwag, Purok 5, Dispatcheng, 11 vi 2012, in RMNH, leg. RAD; 5 ♂, 2 ♀ (one pair in tandem), Davao Oriental, Cateel, Aliwagwag, Purok 5, Dispatcheng, 11 vi 2012, in coll. RAD, leg. RAD; ♂, Davao Oriental, Cateel, Aliwagwag, Purok 5, Dispatcheng, 12 vi 2012, in coll. RAD, leg. HC; 3 ♂, Davao Oriental, Cateel, Aliwagwag, Purok 5, Dispatcheng, 12 vi 2012, in coll. RAD, leg. RAD; 4 ♂, 2 ♀, Davao City, Datu Salumay, 25 xi 2004, leg. RJTV; ♂, Surigao, 16 viii 1916, in SMF, leg. G. Boettcher; 2 ♂ Surigao, 7 viii 1916, in SMF, leg. G. Boettcher”; ♂, Surigao, 22 viii 1916, in SMF, leg. G. Boettcher; ♂, Surigao, 23 viii 1916, in SMF, leg. G. Boettcher; 3 ♂, ♀, Surigao, 1 xi 1915, in SMF, leg. G. Boettcher; 3 ♂, Surigao del Sur, Carmen, km 11, Lanang Line, 2 Equipment Shop, 21–24 iv 1995, in RMNH, leg. R.A.Müller, A. Buenafe & Gorostiza; ♂, Surigao del Sur, Meme River, Tago, 10–18 vi 1996, in RMNH, leg. R.A. Müller, A. Buenafe & Gorostiza; ♀, Surigao del Sur, Hitaub Creek, Tandag, 16–19 iv 1995, in RMNH, leg. R.A. Müller & A. Buenafe & Gorostiza; 2 ♂, Surigao del Sur, swamp near Managoy, 27 iii 2013, in RMNH, leg. HC; 5 ♂, 2 ♀, Surigao del Sur, swamp near Managoy, 27 iii 2013, in coll. RAD, leg. HC; 6 ♂, ♀ (in tandem), Surigao del Sur, swamp near Managoy, 27 iii 2013, in coll. RAD, leg. RAD. Dinagat Island: ♂, Loreto, Ferdinand, Danao Daku, 25 viii 2008, leg. RJTV; 16 ♂, ♀, Libjo, Paragua Forest, 16 xii 2007, leg. RJTV; 3 ♀, same location, 23 iii 2008, leg. RJTV; 3 ♂, 2 ♀, same location, 30 viii 2008, leg. RJTV; ♂, same location, 20 viii 2009, leg. RJTV; 2 ♂, Loreto, Layonggan, mangrove, 5 iii 2008, leg. RJTV; 3 ♂, 3 ♀, same location, 15 iii 2008, leg. RJTV; 3 ♂, 2 ♀, same location, 19.iii.2008, leg. RJTV; ♂ ♀, same location, 16 xii 2008, leg. RJTV; ♂, pond and swamp by San Hose – Loreto road, 22 iii 2013, in RMNH, leg. HC; 8 ♂, ♀, pond and swamp by San Hose – Loreto road, 22 iii 2013, in coll. RAD, leg. HC; 2 ♂, pond and swamp by San Hose – Loreto road, 22 iii 2013, in RMNH, leg. RAD; 2 ♂, pond and swamp by San Hose – Loreto road, 22 iii 2013, in coll. RAD, leg. RAD. Siargao Island: ♂, Dapa, 11 xi 1916, in SMF, leg. G. Boettcher.

First description of male (from Mt. Hamiguitan population). Head: Labium pale, and mandibles pale adjacent to genae, becoming darker near labrum. Labrum shiny black except for yellow anterior quarter. Genae pale, pale colour continued to eye margin and narrowly along eye margin from ridge of frons to level of antennal sockets. Anteclypeus pale blue with broad dark central band beneath postclypeus. Postclypeus black. Frons black, with distinct ridge, anterior face with paired transverse yellow streaks separated centrally. Vertex black with metallic reflection. Pale vertical streaks on antennal socket and scape. Rest of antennae brown. Remainder of head dark metallic green. A distinct rounded tubercle situated anteriorly beside eye margin in postocular area.

Thorax: Prothorax dark metallic green except for pale transverse streak on crest of anterior lobe, lower part of propleuron. Shelf of posterior pronotal lobe ( Fig. 12 ) short, very weakly bi-lobed. Horns of posterior lobe moderately long, rearward and slightly outward and downward directed ( Fig. 3 ), with tip at level of centre of mesinfraepisternum. Synthorax ( Fig. 33 ) with dorsal carina equipped with short, blunt process arising at anterior 1/ 4 of its length. Mesinfraepisternum metallic green with irregular pale borders. Mesepisternum metallic green except for pale streak along mesepleural suture near antealar carina, mesepimeron mostly metallic green with pale streak along interpleural suture ( Fig. 33 ). Metepisternum pale, large metallic green marking adjacent to antealar carina. Metepimeron pale except for black marking at metapleural suture near antealar carina. Legs with coxa and trochanter yellowish, femur and tibia pale with dark spines, blackish streaks on extensor surfaces and dark markings around joint. Tarsi without denticle. Wings hyaline with dark brown veins; arc at level of or a little distal Ax2, Ac near Ax2, petiolation ceases before level of Arc; R4 arising at subnodus; IR3 distal to subnodus. 13–14 Px in both wings. Pt dark brown, ca square, costal side shorter than subcostal side.

Abdomen: S1 with shiny black patch on dorsum. S2 dorsum black, becoming pale lower on sides; S3–7 dark brown, becoming darker apically, paler laterally with narrow, faint pale basal ring; S8–10 black with pale streak along lower margin. Cerci whitish yellow, more than twice length of S10. Fork of upper branch at ca 1/3 length of upper branch ( Fig. 59 ). In lateral view upper branch shaped as in Fig. 47 , with small black tooth at tip; groove present on inner surface of this branch over much of its length ( Fig. 59 ). Spur in dorsal view clearly shorter than distance from S10 to fork of upper branch but broad, with rounded upper border, dense setae on upper inner surface, well visible in lateral view. Lower branch absent. Paraprocts typical for genus.

Measurements (mm): abdomen including cerci 38–46, Hw 23–25.

Variation in males. Anteclypeus brownish in some individuals, pale vertical streaks on antennal socket and scape sometimes absent. In Dinagat population posterior pronotal lobe with shorter horns, process on dorsal carina of synthorax shorter ( Fig. 33 ) and groove in upper branch of cercus extends less basally.

Female. Similar to male except: yellow anterior area of labrum broader; shelf of posterior pronotal lobe shallowly bilobed ( Fig. 24 ); horns of posterior pronotal lobe moderately long, directed upward and rearward ( Fig. 18 ); S8 pale laterally; S9 with black restricted to dorsal line, toward apex extended laterally.

Measurements (mm): abdomen 38–41, Hw 21–27.

Diagnosis. Readily distinguished from all species except S. bukid and S. hamis by the absence of the lower branch of the cerci. Differing from S. hamis in having a distinct tubercle on the dorsal carina of the synthorax and in the position of the fork of the upper branch of the cerci. Distinguished from S. bukid by the less strongly downward-directed horns of the posterior pronotal lobe with tips always at or above level of centre of mesinfraepisternum, and by the larger spur of the upper branch of the cerci in dorsal view and the less slender apical part of the upper branch in lateral view.

Remarks. This species was described from a single female specimen collected in Davao Province, Mindanao, and originally placed in Teinobasis ( Needham & Gyger 1939) . Later Lieftinck (1940) suggested the species be transferred to Amphicnemis . Lieftinck (1974), when describing Amphicnemis circularis , commented on dentifer : “unquestionably also a true Amphicnemis but probably more remotely allied.”

The material of this species currently available for study is very variable. The female specimens all agree broadly with the description and illustration provided by Needham and Gyger (1939). However, there is some variation on the form of the horns of the posterior pronotal lobe. Of the populations on Mindanao Island, females from the Mount Hamiguitan population are the closest to the description of the type.

Populations from Dinagat Island and Siargao Island are rather distinct from the Mindanao populations, with a longer tubercle on the dorsum of the synthorax ( Fig. 33 ), and differences in the female posterior pronotal lobe. In Mindanao females the horns are longer than the shelf ( Figs. 18 , 24 ) but in the Dinagat and Siargao populations the horns are shorter than the shelf ( Figs. 17 , 23 ). There are also small differences in the male cerci. However, we feel that the differences in the males are insufficient to warrant separating the Dinagat and Siargao populations at this time and will review their status when supporting molecular evidence becomes available.

Figures

FIGURE 68. Distribution of S. bukid (black circle), S. dentifer (black triangle) and S. hamis (black square).

FIGURES 1 – 5. Lateral views of male posterior pronotal lobe: (1) S. braulitae holotype; (2) S. bukid paratype; (3) S. dentifer Minadano; (4) S. hamis holotype; (5) S. janvantoli holotype.

FIGURES 8 – 15. Male posterior pronotal lobe, dorsal views: (8) S. braulitae Camiguin; (9) S. braulitae Homonhan; (10) S. bulba holotype; (11) S. circularis Tawi-Tawi; (12) S. dentifer Mindanao, Davao Oriental; (13) S. feliculoi paratype; (14) S. furcata; (15) S. zamboanga holotype.

FIGURES 16 – 18. Female posterior pronotal lobe, lateral views: (16) S. bukid paratype; (17) S. dentifer Dinagat; (18) S. dentifer Mindanao.

FIGURES 19 – 26. Female posterior pronotal lobe, dorsal views: (19) S. bukid paratype; (20) S. bulba paratype; (21) S. carmelae paratype; (22) S. circularis Tawi-Tawi; (23) S. dentifer Dinagat; (24) S. dentifer Mindanao; (25) S. feliculoi paratype; (26) S. furcata.

FIGURES 33 – 34. Lateral view of male synthorax of S. dentifer: (33) Dinagat; (34) Mindanao.

FIGURES 47 – 52. Lateral view of male anal appendages: (47) S. dentifer Mindanao; (48) S. feliculoi holotype; (49) S. furcata; (50) S. hamis holotype; (51) S. janvantoli paratype; (52) S. zamboanga paratype.

FIGURES 59 – 64. Dorsal view of male anal appendages: (59) S. dentifer Mindanao; (60) S. feliculoi holotype; (61) S. furcata; (62) S. hamis holotype; (63) S. janvantoli holotype; (64) S. zamboanga paratype.

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.