Adachia 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 : 44-45

Genus Adachia Evenhuis , gen. n.

( Figs. 4, 13, 21)

Type species: Eurynogaster apicenigra Parent, 1940 , by present designation.

Diagnosis: Species in this genus are readily recognized by generally strong bristling on the head, thorax, and abdomen as well as the lack of strong ventral bristles of femur I and III (if present, basoventral bristles on femur II are always much weaker or much shorter than ventral bristles on tibia II). Further generic features are the dense microtrichia in the wing giving it a darkened or smoky appearance; and the hypopygial characters comprising the bare surstylus and extremely enlarged postgonite ( Fig. 21). Adachia is most similar to E urynogaster but can be separated from it by the long hairs on the posterior margins of the abdominal tergites and the extremely well developed postgonite of the hypopygium.

Description: Male. Body length: 2.4–3.4 mm. Wing length: 3.0–4.2 mm. Head. Generally shining metallic; face narrower than distance between lateral edges of antennal sockets (cf. Fig. 3), narrowing below antennae, then parallel to clypeus; clypeus small, ventral margin well above lower margin of eyes; palpi not extending below eyes. Antennae with first flagellomere subconical, rounded apically, length about 2 x width; arista dorsal, with micropubescence along entire length. Ocellars large, 3/4 head height; verticals strong, erect to proclinate. Thorax. Generally shining metallic dorsally, pleura subpollinose. Chaetotaxy as follows: 5 dc; 2 np; 1 ph; 1 pa; 1 sc; 2 sa; ac absent. Legs. Coxa I with numerous fine setae along anterior surface, apically with strong bristles; CII and CIII with strong lateral bristle. All femora with numerous 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. 4, 13). With dense brown microtrichia giving wing a smoky brown appearance (in hispida and williamsi , apical margin of cell m with sparser microtrichia giving a more subhyaline appearance). CuAx ratio about 1. Abdomen. Shining metallic dorsally, pollinose on sternites. Segments I–V subequal in length; posterior margins of tergites I–VI with long bristles, dense, fine hairs elsewhere. Sternite IV extending outward to accommodate terminalia. Tergite IV normal in size laterally, not extended as in Arciellia . Hypopygium ( Fig. 21). Subtriangular; extending forward to posterior margin of fourth abdominal segment. cercus small, rounded, clothed with fine hairs of different lengths, longest hairs usually apical; surstylus usually unilobed (sometimes with very small second lobe), subtriangular, without strong apical setation, fine short hairs apically; basiventral epandrial lobe long, thin, straight or slightly sinuous; apicoventral epandrial lobe extremely reduced or absent; hypandrium well developed, broad, bladelike, with small recurved hook apically; postgonite extremely well developed, broad, larger than hypandrium, with serrate to ciliate margins.

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

Discussion: The macrochaetae (bristles, strong hairs) of species in this genus are generally stronger and longer than in related Hawaiian genera, and is especially manifested in the long ocellars (length ca. 3/4 head height), the dc, and tibial setae.

Included Species: Adachia apicenigra (Parent) , comb. n., A. hispida (Hardy & Kohn) *, comb. n., A. nigripedis (Hardy & Kohn) *, comb. n., A. nudata (Hardy & Kohn) *, comb. n., A. obscurifacies (Parent) *, comb. n., A. williamsi (Hardy & Kohn) *, comb. n.

Etymology: The genus­group name honors Marian Kohn (née Adachi), in recognition of her many years of work on Hawaiian dolichopodids. Gender is feminine.