Arciellia Evenhuis, 2005

Evenhuis, Neal L., 2005, A review of the genera comprising species of the genus Eurynogaster sensu Hardy & Kohn, 1964 in Hawai‘i (Diptera: Dolichopodidae), Zootaxa 1017, pp. 39-60 : 45-48

Genus Arciellia Evenhuis , gen. n.

( Figs. 2, 5, 14, 22)

Type species: Eurynogaster dolichostoma Hardy & Kohn, 1964 , by present designation.

Diagnosis: Closest in appearance to Adachia and Eurynogaster but easily separated by the disproportionately large mouthparts ( Fig. 2) (mouthparts small and less conspicuous in Adachia and Eurynogaster ); and the hypopygium with a shovel­shaped cercus, and the hypandrium with a sharp, tricornate lateral process ( Fig. 22).

Description: Male. Body length: 2.8–3.7 mm. Wing length: 3.5–4.2 mm. Head. Generally subpollinose; face slightly narrower than distance between lateral edges of antennal sockets ( Fig. 2), parallel to clypeus; clypeus small, ventral margin well above lower mar­ gin of eyes; palpi large, extending below eye; mouthparts very large, extending below eye about 1/3–1/2 head height, sometimes flared outward. Antennae with first flagellomere short, rounded apically, length subequal to width; arista dorsal, with micropubescence along entire length. Ocellars large, 1/2 head height; verticals absent or hair­like. Thorax. Subshining to subpollinose anteriorly and dorsally, pleura subpollinose. Chaetotaxy as follows: 5 dc; 2 np; 1 ph; 1 pa; 1 sc; 2 sa; ac absent. Legs. Coxa I with sparse fine setae along anterior surface, with long apical bristles; CII and CIII with strong lateral bristle. All femora with fine setae. Anterior preapicals only on FII and FIII. Tibia II and TIII with strong bristles. Claws normal in size (cf. Fig. 12b). Wing ( Figs. 5, 14). With microtrichia giving wing a faint brownish appearance (apical margin of cell m of some species with sparser microtrichia giving a more subhyaline appearance). CuAx ratio about 1. Abdomen. Subpollinose to subshining dorsally, shining laterally, pollinose on sternites. Segments I–V subequal in length; posterior margins of tergites I–VI with longer setation than elsewhere on abdomen, but not as long as in Adachia ; fine hairs elsewhere. Tergite IV extending well below level of ventral margin of tergite III. Hypopygium ( Fig. 22). Extending forward to middle of 4th segment. In lateral view: hypopygium subtriangular; cercus hemitrulliform, pointed apically; surstylus deeply bilobed, with delicate setation apically; hypandrium long, length subequal to surstylar lobes, with tricornate lateral process; apicoventral and basoventral epandrial lobes absent; phallus slightly sinuous toward apex; postgonite, long, thin, bicornate.

Female. As in male except for genitalic features; legs normal, without modifications.

Included species: Arciellia dolichostoma (Hardy & Kohn) *, comb. n., A. flaviventer (Hardy & Kohn) *, comb. n., A. xanthopleura (Hardy & Kohn) *, comb. n.

Etymology: The genus­group name honors Robert Cyril Layton Perkins, whose pioneering work on the insect fauna of the Hawaiian Islands during his sojourn there from 1892–1901, working for the Sandwich Islands Committee in England, are legendary and will never be equaled. The name incorporates the phonetic sounds of his initials “R.C.L.” Gender is feminine.