Eothalassius sp.

Brooks, Scott E. & Cumming, Jeffrey M., 2022, New Australasian Parathalassiinae (Diptera: Dolichopodidae sensu lato), Zootaxa 5188 (6), pp. 521-543 : 534

Eothalassius sp.

( Figs 8, 11 , 34–38 )

Material Examined. NEW CALEDONIA: Plage de Poé [ca 21°36ʹ48ʺS 165°24ʹ02ʺE], 15.5 km W Bourail, 15.vii.1995, beach/shrubs, B.J. Sinclair (1♀, CNC) .

Diagnosis. Body length: 1.51 mm. This New Caledonian species of Eothalassius , known only from a single female specimen, has wing cell dm and crossvein dm-m present ( Fig. 36 ), unlike E. platypalpus and E. merzi , but not E. borkenti and E. gracilis , and lacks spiny setae on the basal portion of the costa ( Fig. 36 ) that are present in E. borkenti . The New Caledonian female is very similar to the relatively widespread E. gracilis , which is known from Thailand, Indonesia and Papua New Guinea, but has a dark brown postpedicel (yellow in E. gracilis ) and dark brown palpus (brownish-yellow in E. gracilis ) ( Fig. 35 ).

Distribution. This potentially undescribed species is currently known only from the coast of the Bourail Commune in the South Province of New Caledonia ( Figs 8, 11 ).

Remarks. The unique female specimen of this apparently undescribed species represents the first record of the genus in New Caledonia. It was collected from a sandy coastal beach ( Fig. 11 ), similar to the habitat of other Eothalassius species, except E. borkenti , which inhabits rocky seashores. Shamshev & Grootaert (2003) noted some colour variation among the type series of E. gracilis (with some paler specimens), so the discovery of a male of the New Caledonian Eothalassius is required to confirm its status as a separate species and not a darker form of E. gracilis .

Figures

FIGURES 8–11. Known geographical distribution and collection localities of Chimerothalassius and Eothalassius from New Caledonia. 8. Distribution of C. riparius sp. nov., C. sinclairi sp. nov. and Eothalassius sp. 9–10. Rivère Bleue, type locality of C. riparius sp. nov. and C. sinclairi sp. nov. (photos by Brad Sinclair). 11. Plage de Poé, collection locality of Eothalassius sp. (photo by Brad Sinclair).

FIGURES 34–38. Female of Eothalassius sp. from Plage de Poé, New Caledonia. 34. Habitus. 35. Head, oblique view. 36. Head and left wing. 37. Abdomen and terminalia, lateral view. 38. Abdomen and terminalia, dorsal view. Abbreviations: dm— discal medial cell; dm-m—discal medial crossvein; plp—palpus.