Simosyrphus grandicornis ( Macquart, 1842 )

Ramage, Thibault, Charlat, Sylvain & Mengual, Ximo, 2018, Flower flies (Diptera, Syrphidae) of French Polynesia, with the description of two new species, European Journal of Taxonomy 448, pp. 1-37 : 22-24

Simosyrphus grandicornis ( Macquart, 1842)

Figs 5F, I, 6B

Syrphus grandicornis Macquart, 1842: 96 (holotype: ♂, MNHN; type locality: Australia, Sydney, Port Jackson).

Syrphus sydneyensis Macquart, 1846: 263 .

Syrphus pusilla Macquart, 1847: 77 .

Syrphus melanurus Bigot, 1884: 97 .

Syrphus obesus Hutton, 1901: 41 .

Syrphus vitiensis Bezzi, 1928: 71 .

Ischiodon scutellaris Bryan, 1934: 412 .

Metasyrphus fasciatus Shiraki, 1963: 186 .

Syrphus australiensis Van der Goot, 1964: 220 .

Syrphus huttoni Van der Goot, 1964: 220 .

Differential diagnosis

Simosyrphus grandicornis has often been confused with species of Ischiodon , especially I. scutellaris , as they are sympatric and the males of both species have large genitalia. The morphological characteristics to distinguish S. grandicornis are the broadly rounded basoflagellomere (subacute apically in I. scutellaris ), black katepisternum ( Fig. 5F) (with a dorsal yellow marking in I. scutellaris ; Fig. 3G), simple male metatrochanter ( Fig. 6B) (with a spine-like process in I. scutellaris , Fig. 6A) and black metafemur, yellow on the apical fourth (mostly yellow, black only subapically in I. scutellaris ).

Material examined

Not collected or studied from French Polynesia, but Nishida (2008) reported it from the Society Islands. We believe that Nishida’s records might be a misidentification of I. scutellaris .

Geographical distribution

Very common Australasian species, found throughout Oceania (from New Caledonia and Fiji to Hawaii), New Zealand and Australia (all states). Simosyrphus grandicornis is absent from the island of New Guinea.

Status in French Polynesia

Unknown.

Flowers visited

No records.

References

Nishida 2008 (list).

Remarks

Among the material examined there were no individuals of this species from French Polynesia; thus, we believe that S. grandicornis is not present in the archipelago. Mengual (2015) stated that the dispersal of this species into many of the occupied Oceanic islands in its range was due to human activities, probably introduced by the early Polynesians who might have brought them in as larvae on fruits and plants they were transporting. Because it is plausible that S. grandicornis will reach the islands of French Polynesia in the near future, we have included this species in the identification key (indicated with an asterisk *).