Eosphaerophoria bifida Mengual, 2010

Mengual, Ximo & Ghorpadé, Kumar, 2010, The flower fly genus Eosphaerophoria Frey (Diptera, Syrphidae), ZooKeys 33 (33), pp. 39-80 : 51-53

Eosphaerophoria bifida Mengual , sp. n.

urn:lsid:zoobank.org:act:CC72B15F-EB91-49C0-8B29-100D2E5D39E1

Figs 24, 37, 44; MorphBank [http://www.morphbank.net/?id=478062]

Vockeroth 1969: 135 as Eosphaerophoria sp. (citation).

Male. Head. Face straight, with distinct round tubercle, yellow, yellow pilose; gena yellow, yellow pilose; lunula black; frons completely black on dorsal 2/3 (length between anterior ocellus and lunula), yellow on basolateral 1/3 with medial broad black vitta, about 1/2 of the facial width, yellow pilose on yellow areas with some dark pile on black areas, with distinct round tubercle at medial section between anterior ocellus and lunula; dichoptic; vertex and vertical triangle black, dark pilose; ocelli brownish; antenna light brown to dark yellow, darker than face, basoflagellomere brown, darker dorsally, oval; arista dark brown; occiput mainly black, yellow ventrally, yellow pilose and silvery pollinose ventrally, and dark pilose and golden pollinose dorsally, no pile seen at medial section.

Thorax. Scutum black, shiny medially, black pollinose laterally, golden brown pilose, yellow laterally with lateral yellow vitta from postpronotum to scutellum, narrow- er between transverse suture and postalar callus with ventral black area; postpronotum yellow; notopleuron yellow with distinct posterolateral obtuse protuberance; scutellum triangular, yellow with dorsomedial triangular black area continuing from posterior mesonotum, brownish 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 darker, mesocoxa darker, and pro- and mesotarsus slightly darker, yellow pilose except tarsi with short black setulae ventrolaterally; metacoxa and trochanter yellow; metafemur yellow on basal 1/3, black on distal 2/3, brownish pilose; metatibia black, black pilose; metatarsus black, golden pilose ventrolaterally.

Abdomen. Fig. 37. Dorsum mainly black, dorsally black pilose except 1st tergum and anteriorly 2nd tergum yellow pilose laterally; 1st tergum black with anterior and lateral yellow margin, medially reaching anterior margin of 2nd tergum dividing the black area in 2 triangular maculae; 2nd tergum black dorsally with medial elongat- ed yellow macula, yellow laterally on basal 3/4 continuing the yellow margin of 1st tergum; 3rd tergum black with basoanterior very narrow black fascia not reaching margins and with basal yellow fascia, about 1/5–1/4 of tergum length, produced posteriorly in a long triangular emargination reaching 2/3 length of tergum, with lateral margin yellow on anterior 4/5; 4th tergum similar to 3rd but posteromedial yellow emargination looks shorter because the tergum is shorter; 5th tergum black with anterior narrow black fascia not reaching lateral margin, with 2 lateral narrow triangular yellow maculae joining medially forming very narrow yellow fascia, laterally yellow on basal 1/3; sterna yellowish, yellow pilose except 4th sternum with posterior margin black pilose medially; male genitalia as figured ( Fig. 44 ).

Figure 2Ι. World distribution of Eosphaerophoria Frey, 1946 , an estimate. The dotted line indicates that insufficient information is available and that the limit shown is only an approximation defined by collecting points. Adapted from Vockeroth (1969).

Female. Unknown.

Type locality. PAPUA NEW GUINEA: Morobe, Bulolo, Wau. 7°20'30.51"S 146°42'15.98"E.

Type. Holotype: “ New Guinea // Wau, 1250 m // 20.VIII.1965 ” “ Malaise Trap // J&M. Sedlacek // BISHOP” “ HOLOTYPE // Eosphaerophoria // bifida // det. X. Mengual 20 09 ” [red, second and third lines handwritten] USNM ENT00036558 [1♁, BPBM].

Length (1): body, 5.7 mm; wing, 4.2 mm.

Distribution: Papua New Guinea.

Etymology. The specific epithet refers to the shape of surstylus in male genitalia, which presents the distal margin divided in two lobules posteriorly (see Fig. 44c ), and it is from the Latin bifidus meaning split into two parts, bifurcated ( Brown 1956: 345). Species epithet to be treated as adjective.

Differential diagnosis. Species easy to identify by an elongated yellow macula on 2nd abdominal tergum and the face entirely yellow. It has the male genitalia similar to E. luteofasciata , especially the bifurcated surstylus. The surstylus of E. bifida has two lobes of different sizes ( Figs 44a, 44c ) but E. luteofasciata has the surstylus divided in two similar lobes in lateral view ( Figs 47a, 47d ). Moreover, E. bifida has superior lobes with conical shape and E. luteofasciata has them expanded anteroventrally.

Remarks. Eosphaerophoria bifida is described based on a single male from Wau ( Papua New Guinea). Eosphaerophoria bifida could be the male of E. nigrovittata that is described from two females, holotype also from Wau. There are differences between both species. E. bifida has an all yellow face, but E. nigrovittata has a medial broad black facial vitta. However, this character does show dimorphic variation (for example see E. marginata ), but in this case is much more divergent. Eosphaerophoria bifida has a yellow macula on 2nd tergum and E. nigrovittata does not or it is not clear (see comments about variation of E. nigrovittata ). In species with both sexes known, such as E. marginata and E. vietnamensis , the abdominal pattern does not display significant differences. The fact that both species, E. bifida and E. nigrovittata , were collected in the same region but in different years is not an argument to consider them the same taxon, because there is an example of different species collected from the same place and the same date, E. vietnamensis and E. symmetrica . Based on this, we consider E. bifida and E. nigrovittata as being different species.

Figures

Figure 44. Eosphaerophoria bifida, male genitalia: a left lateral view b right superior lobe, dorsal view c tergite 9, cerci and surstyli, dorsal view.

Figure 47. Eosphaerophoria luteofasciata, male genitalia a left lateral view b right basal appendix of aedeagus c right superior lobe, dorsal view d tergite 9, cerci and surstyli, dorsal view.