Eosphaerophoria symmetrica Mengual, 2010

Mengual, Ximo & Ghorpadé, Kumar, 2010, The flower fly genus Eosphaerophoria Frey (Diptera, Syrphidae), ZooKeys 33 (33), pp. 39-80 : 71-73

Eosphaerophoria symmetrica Mengual , sp. n.

urn:lsid:zoobank.org:act:62588E50-7113-4DE3-83F9-6BA7827EC755

Figs 31, 49; MorphBank [http://www.morphbank.net/?id=478083]

Vockeroth 1969: 135, in part as E. dentiscutellata (citation).

Male. Head. Face straight, narrow becoming broader ventrally, with distinct round tubercle, yellow, yellow pilose; gena yellow, yellow pilose; lunula yellow; frons completely black on dorsal 1/3 (length between anterior ocellus and lunula), yellow on ventral 2/3, yellow pilose on yellow areas and dark pilose on black areas; dichoptic; vertex and vertical triangle black, black pilose; ocelli brownish; antenna yellow, basoflagellomere orange, brown dorsally, oval; arista brown; occiput mainly black, yellow ventrally, yellow pilose an silvery pollinose ventrally, black pilose and golden pollinose dorsally.

Thorax. Scutum mainly black, shiny medially, black pollinose anterior and laterally, yellow laterally with lateral broad yellow stripe from postpronotum to scutellum, slightly narrower after transverse suture with ventral black area, golden brown pilose except lateral yellow stripe with yellow hairs; postpronotum yellow; notopleuron yellow without posterolateral protuberance; scutellum subtriangular, more round than in other species, yellow with dorsomedial small subtriangular black area, golden brown pilose; pleura yellow 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 yellow. Wing. Wing bare basomedially.

Legs. Pro- and mesoleg entirely yellow, except distal part of mesofemur and basal part of mesotibia slightly darker, yellow pilose except tarsi with short black setulae ventrolaterally; both metalegs are broken on basal part of the femur, but metacoxa, metatrochanter and basal section of metafemur yellow, yellow pilose.

Abdomen. Fig. 31. Dorsum mainly black, black pilose except 1st, 2nd and 3rd terga yellow pilose laterally; 1st tergum black with anterior and lateral yellow margin, medially reaching anterior margin of 2nd tergum dividing black area in 2 triangular maculae; 2nd tergum black dorsally with dorsomedial elongated yellow macula, narrowly yellow laterally on basal 3/4 continuing the yellow margin of 1st tergum; 3rd tergum black with basomedial very narrow black fascia and with basal yellow fascia, about 1/4 of tergum length, becoming broader medially and produced posteriorly in a medial triangular emargination reaching half length of tergum, yellow on anterior 2/3 of lateral margin; 4th tergum black with basomedial narrow black fascia and with basal yellow fascia slightly broader, about 1/3 of tergum length, produced posteriorly in a medial triangular emargination reaching half length of tergum, yellow on anterior 1/2 of lateral margin; 5th tergum black with basal narrow black fascia and with anterobasal yellow fascia narrowing medially, yellow on anterior 1/2 of lateral margin; sterna yellow, yellow pilose; male genitalia as figured ( Fig. 49 ).

Female. Unknown.

Type locality. VIETNAM: Lam Dong, Dà Lat. 11°56'43.51"N 108°26'31.59"E.

Type. Holotype: “ VIET NAM // Dalat , 1500 m // 11.IX. 1960 ” “ J.L. Gressitt // Collector // BISHOP MUSEUM” “ HOLOTYPE // Eosphaerophoria // symmetrica // det. X. Mengual 20 09 ” [red, second and third lines handwritten] USNM ENT00036554 [1♁, BPBM].

Length (1): body, 6.3 mm; wing, 4.5 mm.

Distribution: Vietnam.

Etymology. The specific epithet is derived from Greek symmetros meaning corresponding part for part, proportional, symmetrical ( Brown 1956: 306), and it refers to the symmetrical superior lobes of the male genitalia. Species epithet to be treated as adjective.

Differential diagnosis. Species with notopleuron not produced posteroalterally and a yellow macula on 2nd abdominal tergum. Similar to E. punctata , but differs in having the frons yellow on ventral 4/5 and 1st abdominal tergum yellow with 2 posterior subtriangular black maculae.

Remarks. This species is very similar to E. punctata . Both species share a unique morphological character with E. bifida : a medial yellow macula on 2nd abdominal tergum. Eosphaerophoria symmetrica could be the male of E. punctata because they also have in common the absence of the posterolateral obtuse protuberance of notopleuron, but they differ in the abdominal pattern of the 1st tergum and the frons. Nonetheless, due to the low number of records/specimens of this genus and the morphological differences, we consider E. symmetrica as a species different from E. punctata . Eosphaerophoria symmetrica and E. vietnamensis are described from the same locality, but they present several differences that make them easy to distinguish: E. symmetrica has a yellow macula on 1st abdominal tergum, and a yellow fascia on 5th tergum (Fig. 31). Eosphaerophoria vietnamesis has 2nd tergum black with yellow lateral margin and two yellow maculae on 5th tergum (Fig. 42). Moreover, the superior lobes of the male genitalia in E. vietnamensis are asymmetrical ( Fig. 50 ), unlike E. symmetrica which has them symmetrical ( Fig. 49 ).

Figures

Figure 49. Eosphaerophoria symmetrica, male genitalia a left lateral view b right superior lobe, dorsal view c tergite 9, cerci and surstyli, dorsal view.

Figure 50. Eosphaerophoria vietnamensis, male genitalia a left lateral view b right superior lobe, lateral view c right superior lobe, dorsal view d left superior lobe, dorsal view e tergite 9, cerci and surstyli, dorsal view.