Eothalassius Shamshev & Grootaert, 2005

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

Eothalassius Shamshev & Grootaert

Eothalassius Shamshev & Grootaert, 2005: 108 .

Type species: Eothalassius platypalpus Shamshev & Grootaert , by original designation.

Diagnosis. The genus Eothalassius is distinguished from other parathalassiine genera by the following characters: head with face narrow (less than or about width of anterior ocellus, Fig. 35 ), gena scarcely projected below eye, antenna with arista-like stylus lengthened (at least 5X length of postpedicel, Fig. 35 ), mouthparts directed ventrally with fleshy labellum, palpus broad and flattened (particularly in males) with apex slightly pointed to widely rounded apically ( Fig. 35 ); thorax with prosternum fused to proepisternum forming precoxal bridge, scutellum with 1 pair of strong setae near apex; wing with R 1 short reaching costa before middle of wing (or before base of M 2), crossvein bm-m incomplete, cell dm present ( Fig. 36 ) or if absent without vein dm-m, CuA rounded, cell cua convex apically, anal lobe not developed; male terminalia with right epandrial lamella lacking ventral process, hypoproct projected as pair of non-setose asymmetrical lobes, cerci broad and asymmetrical; female abdomen with apical segments retracted into segment 6 ( Fig. 34 ), terminalia ( Figs 37, 38 ) with syntergite 9+10 divided and bearing acanthophorous setae, cercus slender and terminating with long seta.

Remarks. Species of Eothalassius are known from the Mediterranean coast of Turkey, Cyprus and Malta ( E. merzi (Gatt)) , the Pacific coast of Costa Rica ( E. borkenti Cumming & Brooks ), the coasts of Southeast Asia and Papua New Guinea ( E. gracilis Shamshev & Grootaert and E. platypalpus Shamshev & Grootaert ) and now the coast of New Caledonia ( Eothalassius sp. ) ( Cumming & Brooks 2019). Shamshev & Grootaert (2005) indicate that the type series of Eothalassius gracilis was collected from littoral and supralittoral zones of sandy coastal beaches, and E. platypalpus was collected along creeks exiting onto sandy coastal beaches. Eothalassius merzi was also collected on sandy coastal beaches ( Gatt 2003), whereas E. borkenti was found on rocky seashores ( Brooks & Cumming 2011).

Figures

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.