Stemonocera cervicornis (Brunetti)

Singh, Shakti Kumar, Hancock, David L. & Ramamurthy, V. V., 2013, On the species of Stemonocera Rondani (Diptera: Tephritidae) from the Indian subcontinent, Journal of Natural History (J. Nat. Hist.) 48 (15 - 16), pp. 945-957 : 946-952

publication ID	https://doi.org/ 10.1080/00222933.2013.830789
persistent identifier	https://treatment.plazi.org/id/038087C7-FFF4-6629-58B7-E330DF0AFA13
treatment provided by	Felipe
scientific name	Stemonocera cervicornis (Brunetti)
status

Treatment

Stemonocera cervicornis (Brunetti) View in CoL

( Figures 1A View Figure 1 – 3D View Figure 3 )

Vidalia cervicornis Brunetti, 1917 ; Norrbom et al. 1999: 210.

Body elongate, predominantly yellow, length 5.49 ± 0.93 mm. Mesonotum length 2.52 ± 0.55 mm. Wing length 5.04 ± 1.21 mm, breadth 1.90 ± 0.40 mm.

Male. head modified, much broader, 1.79 – 2.04 mm (n = 10) in width; frons each side modified into horns and only the upper pair of fronto-orbital setae arise on the frons ( Figures 1B View Figure 1 , 2A, B View Figure 2 and 3A, B View Figure 3 ), the rest located on the horn-like appendages, one horn bearing three to five, the other three or four, with tip of each bearing two such setae. orbital setae 1; ocellar setae minute, postocellar setae black; vertical setae positioned along with both inner and outer vertical setae; outer vertical, postvertical and postocellar setae all acuminate; postocular setae normal and acuminate; genal setae present, frontofacial angle obtuse, eyes elongate and 1.5× higher than long. Proboscis 1.3× as long as face and capitate ( Figures 1C View Figure 1 , 2A View Figure 2 and 3B, D View Figure 3 ). Face concave, receding, without transverse sulcus, with a dark mark and antennal grooves or carina; 1.06× as long as frons; and parafacial spot absent. Frons and parafacial region without any markings ( Figures 1A View Figure 1 and 3A View Figure 3 ). Antennae 0.67× as long as face; scape, pedicel and first flagellomere 0.09×, 0.27× and 0.5× relatively shorter than face height, respectively; first flagellomere 0.3 ± 0.09 mm long and rounded apically; and arista 0.56× as long as first flagellomere, pilose or with hairs distinctly shorter than greatest aristal width, both dorsally and ventrally placed ( Figures 1A, B View Figure 1 , 2B View Figure 2 and 3A, D View Figure 3 ).

Thorax: brownish yellow with a white-pollinose, central stripe that broadens basally, comparatively more prominent in female, inner scapular setae pale and indistinguishable from surrounding vestiture; outer scapular setae dark and distinguishable; postpronotal, dorsocentral, presutural supra-alar, acrostichal, postsutural dorsocentral and postsutural supra-alar setae present; postsutural dorsocentral setae aligned with postsutural supra-alar setae on or slightly behind transverse suture; intra-alar setae present and similar to postalar; scutellar setae 2; one apical and other basal; apical scutellar seta longer than basal; anterior notopleural setae present; and posterior notopleural setae acuminate ( Figures 1G View Figure 1 and 2C View Figure 2 ). Anapisternal seta 1, katepisternal seta 1; laterotergite without any setulae. Scutal setulae acuminate and dark; and scutellum non-setulose. Transverse suture with the lateral branches wide apart; and postcoxal metathoracic bridge absent or utmost semi-membranous; postpronotal lobe entirely pale whitish or yellowish, markedly paler than ground colour; compared with lateral postsutural stripe concolorous; posterior half of notopleuron same as ground colour. Scutum dorsad of notopleuron with a pale stripe that extends from postpronotal lobe dorsad of the darker anterior notopleuron and over posterior part of posterior notopleuron; area bordering scutoscutellar suture medially without any dark brown spot, more or less uniformly pale coloured; upper anepisternum without any or indistinct horizontal or vertical stripes; and katepisternite and transverse suture without any spots. Anatergite with a distinct pale yellow spot; subscutellum uniformly yellowish to pale brown; mediotergite uniformly black; and microtrichia of scutum evenly distributed or with a median bare area. Scutellum with its dorsum normal, flat or slightly convex, not swollen, without a dark and pale pattern, utmost with a narrow dark basal line and without any isolated dark spots and black marks.

Legs with femora swollen, unicolorous, fore femora with five or six strong black ventral setae, with one to three posterodorsal and one posteroventral row of setae; middle and hind femora with anteroventral and posteroventral row of small, stout setae; and middle tibia having feathering in male ( Figures 1F View Figure 1 and 2B View Figure 2 ).

Wings evenly covered with microtrichia, dominant wing pattern cross-banded, at least one dark band crossing most of wing, and dark, with longitudinal streaks through basal cells; cross vein r-m covered by a major cross band; cross vein dm-cu also covered by a major cross band reaching posterior margin; cross veins r-m and dm-cu not covered by a cross band; cell R 2+3 apical to r-m with a large hyaline area; cell R 4+5 subapical, its hyaline area narrowed, not extending to vein R 2+3 anal band absent, or not reaching margin; cells R 1 and R 2+3 without any darker spots within the pattern; intercalary accessory costal band absent; sub-basal cross band present and joined to discal; marginal hyaline area in cell R 1 distinct; ratio of width of apical band in cell R 4+5, 2× as long as r-m; anterior apical cross band contiguous with costa over entire length, without any marginal hyaline band or spots apically in cells R 1 and R 2+3; anterior apical band or costal band extended to vein M; and posterior apical cross band absent. Costal and discal bands joined on vein R 4+5; discal band transverse or oblique in anterobasal-posteroapical direction or absent; discal not directly joined with apical and subapical cross bands but connected along vein R 4+5; subapical and anterior apical cross bands joined; costal seta at subcostal break; ratio of marginal length of cell sc to r 1 0.25; ratio of pterostigmal length to width 2.8; vein R 1 with dorsal setation having a bare section opposite end of vein Sc; vein Rs with dorsal setation non-setulose; vein R 2+3 generally straight; accessory vein that is anteriorly directed and emerging from R 2+3 absent; vein R 4+5 without any dorsal and ventral setation or only present on node or close thereafter; cross vein r-m 0.62× shorter than costa; r-m cross vein on cell dm on or near middle of cell dm; cell bm narrow, triangular, ratio of length to width 3.4, and its width as long as cell cup width. Vein M distally straight; cell dm widened gradually towards apex; posterodistal corner of cell dm approximately a right angle; cell cup extension or lobe present, 0.35× shorter than vein A 1 + CuA 2; vein CuA 1 abruptly bent; and cell cup extension with margins parallel ( Figures 1H View Figure 1 and 2I View Figure 2 ).

Abdomen predominantly black, ovate or parallel sided, without any medial dark stripe, isolated dark areas throughout lateral margins, and in lateral view arched, dome-like and rigid. Setulae dark, pale and acuminate; microtomentum with bandlike pattern; tergites separate, at least three to five separate; tergite 1 broader at apex than at base and without a lateral prominent hump; in male tergite 5 normal and without any tergal gland; pecten on tergite 3; sternite 5 of male less than 2× as wide as long, its posterior margin with a shallow, posterior concavity; and sternite 6 of female exposed and longer than sternite 5 ( Figures 1E View Figure 1 and 2D View Figure 2 ).

Male genitalia: with epandrium and lateral surstylus dark brown; lateral surstylus 0.5× as long as medial surstylus; lateral prensiseta slightly larger than medial prensiseta; aedeagus 0.54× as long as mesonotum; aedeagal apodeme narrow, fanshaped; aedeagal glans with distinct, trumpet-shaped, subapical lobe; dorsal sclerite of glans more or less smooth; and medial sclerite of glans internally sculptured with rounded granules ( Figures 1D View Figure 1 and 2G View Figure 2 ).

Female. description as for male except for the following differences.

Head yellowish brown to dark brown, not modified, 1.79 – 1.89 mm (n = 2) in width; 1.3× higher than long with frontal setae 4 ( Figure 3A View Figure 3 ); orbital setae 1, ocellar setae weakly developed; and postocellar setae all black.

Female genitalia: with syntergosternite 7 flattened, straight and 0.24× shorter than pre-abdomen; 0.85× as long as abdominal tergite 5 and 0.43× as that of mesonotum; somewhat enlarged, dorsobasal scales present on eversible membrane; aculeus 0.67 mm long and its tip gradually tapering, needle-like, flat in cross-section, fused, not movable and with fine to medium size serration; and with three sclerotized ovoid spermathecae ( Figures 2E and H View Figure 2 ).

Material examined

PAKISTAN: Punjab (Muree hills), 2286 m, 16 ♂,. May 1918 (no date), 1♂, 19 May 1920 ; 3 ♂ and 2 ♀♀,. May 1920 (no date), Coll. Dutt. ( NPC) ; INDIA: Uttarakhand, Chakrata, Kanasar , 2♀♀, 19 May 1934, Coll. J.C.M. Gardner, on Juglans regia (FRI) .

Remarks

Brunetti (1917) described the male of S. cervicornis but the description was brief and without details of the female; only the male head and the setal arrangement on the frontal plate were included, with their arrangement, which is quite variable, being overlooked. This was observed to be 3-5: 3-4 on the left versus right aspect respectively, and an extreme variation of 1: 2 in one of the specimens was noted. Munro (1938) added a few more morphological details of the female along with those of the male and deliberated on the variations in the wing cross vein and banding pattern. Our observations agree with those of Munro (1938), especially on the wing banding pattern and morphology of thorax. Other details observed now, such as variation in the frontal plate of male, and its genitalia characters, support its placement in Stemonocera . Han (1999) advocated the importance of these characters in their diagnosis and in determining their relationship to other groups of Trypetini . He added that the numerous, oppositely directed spines on the eversible membrane in the female genitalia, although a characteristic of the Vidalia group, are also shared by the members of the Trypeta group.