Eosphaerophoria dentiscutellata (Keiser, 1958)

Mengual, Ximo, 2013, Notes on Citrogramma Vockeroth and Eosphaerophoria Frey (Diptera: Syrphidae), Zootaxa 3745 (3), pp. 388-396 : 393-394

Eosphaerophoria dentiscutellata (Keiser, 1958)

Figures 11–13

Tambavanna dentiscutellata Keiser, 1958 . Rev. Suisse Zool., 65: 202, figs. habitus, head, wing. Holotype: m, Sri Lanka: Kandy, Deiyannewela [NHMB, Basel] by original designation.

Eosphaerophoria dentiscutellata . Vockeroth, 1969: 135 (new comb., species misidentified from Vietnam); Knutson et al. 1975: 313, cat. cit.; Ghorpadé 1994: 5 (key reference, citation); Claussen & Weipert 2003: 354, key; Mengual & Ghorpadé 2010: 55, descr., key, figs.

Mengual & Ghorpadé (2010) re-describe this species based on the only known specimen, the male holotype from Sri Lanka. In the RMNH collection, a female specimen was found which is described below.

Differential diagnosis (based on Mengual & Ghorpadé 2010). Species characterized by a medial tooth in the posterior margin of the scutellum (broken in this female specimen, Fig. 12 ), like Eosphaerophoria adornata Mengual in Mengual & Ghorpadé, 2010 and E. hermosa Mengual in Mengual & Ghorpadé, 2010. Eosphaerophoria dentiscutellata differs from both in having 2nd tergum black with lateral margin yellow ( Figs 11, 12 ) and 5th tergum with two lateral yellow maculae (see Mengual & Ghorpadé 2010: 56, Figs. 32 and 34).

Material examined. 1 female, INDIA: Kerala State, Anamalai hills, Cinchona, 150 m, xi.1959, P. Susai Nathan, ex. coll. V.S.v.d. Goot [RMNH].

Description of female. Head. ( Fig. 13 ) Face straight, narrow, parallel-sided, with distinct round tubercle, yellow with medial black vitta fading below tubercle and not reaching oral margin, yellow pilose; gena yellow; lunula black; frons completely black on dorsal 1/4–1/3 (length between anterior ocellus and lunula), yellow on ventrolateral 2/3–3/4 with medial broad black vitta (about 3/5 of frons width); dichoptic; vertex and vertical triangle shiny black, black pilose; ocelli brownish; antenna yellow, basoflagellomere brown dorsally, oval; arista brown; occiput mainly black, yellow ventrally, yellow pilose ventrally, black pilose dorsally. Thorax. ( Fig. 11 ) Scutum mainly black, shiny medially, black pollinose anteriorly and posteriorly, yellow laterally with lateral broad yellow stripe from postpronotum to scutellum, narrower after transverse suture with ventral black area, pale pilose; postpronotum yellow; notopleuron yellow with distinct posterolateral obtuse protuberance; scutellum triangular, with a tooth on medial posterior margin, yellow with dorsomedial triangular black area continuing from posterior mesonotum, golden brown pilose; propleuron, anepisternum and anepimeron entirely yellow; katepisternum black with dorsal yellow macula; meron black; katepimeron yellow; katatergum mainly yellow, black posteriorly; calypter dark brown; halter yellowish. Wing. Wing membrane hyaline, stigma yellowish, bare basomedially. Legs. Pro- and mesoleg entirely yellow, except probasitarsomere slightly brownish laterodorsally, yellow pilose except tarsi with short black setulae ventrolaterally; metacoxa and trochanter yellow, yellow pilose; metafemur yellow on basal 1/2, black on distal 1/2, yellow and brown pilose, with two ventral rows (anteroventral and posteroventrally) of short strong black spine-like setulae on the apical 2/3; metatibia black, golden brown pilose; metatarsus black, golden yellow and brown pilose. Abdomen. ( Fig. 12 ) Similar to that in male; 1st tergum black with anterior and lateral yellow margin, medially reaching the anterior margin of 2nd tergum dividing the black area in two triangular maculae; 2nd tergum black dorsally, narrowly yellow laterally on basal 1/2 continuing the yellow margin of 1st tergum; 3rd and 4th terga black with basomedial very narrow black fascia not reaching margins and with sub-basal yellow fascia, about 1/4–1/3 of tergum length, yellow on anterior 3/5 of lateral margin; 5th tergum black with two lateral small rounded yellow maculae on basal 1/3; 6th tergum black; genitalia yellow.

Length (N = 1). Body, 6.5 mm; wing, 5.0 mm.

Geographical distribution. Sri Lanka, south India.

Remarks. The holotype male of E. dentiscutellata has a yellow face, while the female specimen described here has a medial black vitta not reaching oral margin ( Fig. 13 ). Due to this sexually dimorphic characteristic, the females of E. dentiscutellata do not key out properly in the identification key provided by Mengual & Ghorpadé (2010).

Figures

FIGURES 11 – 13. Eosphaerophoria dentiscutellata, female. 11. Lateral view (scale 1 mm); 12. Dorsal view, habitus (scale 1 mm); 13. Frontal view, face (scale 0.5 mm).