Tritaeniopteron obscurum David, Salini & Nikhil, 2024

David, K. J., Hancock, D. L., Salini, S., Ningthoujam, Kennedy, Khemrajji, Hatwar Nikhil, Abhishek, V., Gracy, R. G. & Sushil, S. N., 2024, New species and new records of fruit flies of tribe Acanthonevrini (Diptera: Tephritidae: Phytalmiinae) from India, Zootaxa 5506 (3), pp. 301-321 : 308-310

Tritaeniopteron obscurum David, Salini & Nikhil , sp. nov.

urn:lsid:zoobank.org:act:D2BBB96C-688A-485E-9F0F-1C37D8D3B9A9

( Figures 15–25 )

Material examined: Type: Holotype ♂, INDIA: Karnataka, Bengaluru, GKVK Botanical Garden , 23.viii.2016, Prabhu. G. ( NIM).

Paratypes: 4♀♀, same data as holotype ; 1♂, INDIA: Karnataka, Bengaluru, GKVK Botanical Garden , 16.viii.2016, Veena Kumari, K. ( NIM) .

Diagnosis: Tritaeniopteron obscurum ( Figs 15, 16 ) is similar to T. punctatipleurum (Senior-White) from Sri Lanka ( Figs 26–30 ) in having a black spot next to the black lateral vittae on scutum and presence of a facial spot near the lower facial margin, but can be differentiated by the presence of straight black lateral vittae on the thorax (not L-shaped posteriorly), an interrupted black transverse band on tergite 3 in males and tergite 2 in females, and extensive black markings on anepisterum, anepimeron and katepisternum. Apart from these external characters, postabdominal characters of male and female T. obscurum are distinct from those of T. punctatipleurum : acute apex of lateral surstylus (profile view); blunt aculeus tip without prominent constriction, spermatheca devoid of apical projection and conical shape of spicules on distal end of eversible membrane.

Description (male): Head ( Fig. 17 ) higher (1.4 mm) than long (1.00 mm); frons as wide as long, fulvous with 1 pair of frontal and 2 pairs of orbital setae, ocellar triangle black with moderately developed ocellar setae, lateral and medial vertical setae well developed, postocellar setae yellow, vertex, occiput, gena fulvous, postgena bulbous, postocular setae thin, white; scape, pedicel and first flagellomere fulvous, arista plumose; combined length of antennal segments less than half vertical length of face; face yellow with a black spot in the lower half.

Thorax (Figs 15,16,18) predominantly yellow with black prescutellar patch between postpronotal lobe and anterior notopleural seta; black, lateral postsutural vitta tapering posteriorly and a spot adjacent to it near the transverse suture, anepisternum and katepisternum with prominent black patches, anepimeron predominantly yellow with a small black patch, anatergite, katatergite, subscutellum yellow, mediotergite shining black with a medial fulvous band. Chaetotaxy (all setae yellow; in pairs): 2 scapular setae, 1 postpronotal seta, 1 anterior notopleural seta, 1 posterior notopleural seta, 1 postsutural supra-alar seta, 1 postalar seta, 1 dorsocentral seta, 1 prescutellar acrostichal seta, 1 anepisternal seta, 1 katepisternal seta. Scutellum yellow with three pairs of scutellar setae; middle pair half length of apical pair. Yellow prescutellar patch, lateral presutural and postsutural vittae prominent in freshly collected specimens, faded in preserved specimens.

Legs ( Fig. 18 ) fulvous/yellow without any markings; forefemur with 6–7 strong ventral setae.

Wing ( Figs 15, 16 ) predominantly hyaline (5.00 mm) with oblique transverse bands; humeral band, subcostal band reaching apex of cell cua, radial-medial band crossing vein M 1 to reach cell dm, subapical band extends to cell r 4+5, r 2+3, covering the apex of cell r 4+5; cell sc shorter than cell c; crossvein r-m placed near the middle of cell dm, cell cua with short acute extension.

Abdomen ( Figs 15, 16 ) predominantly fulvous, tergites 1 and 2 yellow/fulvous, tergites 3–5 with black lateral markings.

Male genitalia: Epandrium ( Figs 19, 20 ) weakly sclerotised with elongate lateral surstylus with acute apex, longer than epandrium; proctiger, hyaline higher than epandrium with well developed setae. Phallus elongate (2.02 mm) with sclerotised glans (0.43 mm) of phallus ( Fig. 21 ).

Female ( Fig. 16 ): Similar to male except for the presence of black lateral markings on tergite 2 and extensive fuscous markings on anepisternum, anepimeron and katepisternum.

Female genitalia: Oviscape ( Fig. 22 ) dark brown to black (1.16 mm), eversible membrane as long as oviscape (1.2 mm); spicules on distal end of eversible membrane with 5–6 conical projections ( Fig. 23 ), aculeus (1.10 mm) with nearly flat aculeus tip and two pairs of elongate preapical setae and two pairs of short preapical setae ( Fig. 25 ); three black, oval spermathecae ( Fig. 24 ).

Etymology: The specific name is derived from the Latin word "obscura" meaning dark; here refers to dark pleura and with a neuter ending to conform with the gender of the genus.

Biology: Adults were collected resting under the leaves of Sterculia urens Roxb. ( Malvaceae ). In Taiwan, females of the related species T. excellens (Hendel) have been collected ovipositing in the trunks of standing Acacia confusa Merr. (Leguminosae) trees ( Huang & Lo 2021) and it is likely that all members of the genus breed beneath the bark.

Figures

FIGURES 15−18. Tritaeniopteron obscurum David, Salini & Nikhil, sp. nov. 15, habitus dorsal (male); 16, habitus dorsal (female); 17, head (male); 18, lateral view excluding wings.

FIGURES 19−25. Tritaeniopteron obscurum David, Salini & Nikhil sp. nov. 19, epandrium (lateral view); 20, epandrium (posterior view); 21, glans of phallus; 22, ovipositor, 23, spicules on eversible membrane; 24, spermathecae; 25, aculeus tip.

FIGURES 26−31. Syntypes of Tritaeniopteron punctatipleurum (Senior-White). 26, syntype female (dorsal view); 27, syntype female (lateral view); 28, syntype female label data; 29, syntype male (dorsal view) Orig. Daniel Whitmore (NHM), © NHM (26,27,29,30); 30, syntype male (lateral view); 31, syntype male label data—Orig. David, K. J., © NHM (28,31)