Ceratomerus Philippi, 1865

Bradley J Sinclair, 2003, Taxonomy, Phylogeny and Zoogeography of the Subfamily Ceratomerinae of Australia (Diptera: Empidoidea), Records of the Australian Museum 55, pp. 1-44 : 5-6

Ceratomerus Philippi

Ceratomerus Philippi, 1865: 765 . Type-species Ceratomerus paradoxus Philippi (monotypy).

Tomia Paramonov, 1961: 100 nec Martynov (1936: 1262). Typespecies Tomia campbelli Paramonov (original designation) (Colless & D.K. McAlpine, 1991: 760).

Notes on synonymy. Tomia Paramonov was erected for the highly autapomorphic species C. campbelli , but the extreme morphological features are not unusual for the genus Ceratomerus , and Colless & D.K. McAlpine (1991) were justified in this synonymy. In addition, Tomia Paramonov is a junior homonym of Tomia Martynov (1936) , a fossil Paraplecopteran of the family Tomiidae ( Rohdendorf, 1991) .

Diagnosis. This genus is distinguished from other Ceratomerinae by the following combination of characters: posterior ocelli usually widely separated with ocellar bristles inserted anteriorly, postpedicel lengthened and tapered apically, acrostichal setulae present, 3–5 dorsocentral bristles present, Sc complete, R 4+5 branched, cell dm emitting 2 veins (M 1+2 and CuA 1), cell cu p absent, presence of distinct bristles on tibiae,scutum not highly polished,and abdominal sclerites not heavily sclerotized and punctate.

Description. Male. Head. Dichoptic, bare; face parallelsided; frons slightly narrowed above antennae; posterior ocelli usually widely separated with ocellar bristles inserted anteriorly. Antenna with scape at least 2 times length of pedicel; pedicel normally ovate, sometimes slightly to greatly lengthened; postpedicel with quadrate base, attenuated and strongly prolonged apically; occasionally apical segments (8–10) fused to postpedicel. Proboscis long, slender; labrum long, stout, with pair of apical epipharyngeal blades; lacinia free, blade-like; pseudotracheae absent.

Thorax. Antepronotum usually with stout pair of setae; scutum generally completely clothed in fine, pale pruinescence; acrostichal setulae uniserial or biserial, rarely absent; 3–5 dc; 1–2 npl, 1–2 pairs sctl; laterotergite bare.

Wing long and narrow; stigma absent or present at apex of R 1 or apex of cell r 1; Sc complete; C circumambient; R 4+5 branched; cell dm emitting 2 veins (M 1+2 and CuA 1); cell cu p absent.

Abdomen. Sclerites usually not heavily sclerotized; lacking punctate appearance.

Terminalia . Hypandrium narrow with pair of divergent postgonites, gonocoxal apodemes short and slender, somewhat projected beyond hypandrium. Phallus short with plate-like ejaculatory apodeme fused to base of phallus. Epandrial lamellae separated, lacking dorsal bridge ventral to cercus; surstylus weakly to strongly articulated. Cercus membranous to strongly sclerotized, often with long apical setae and long setae surrounding anus.

Female. Terminalia . Posterior margin of T7 with row of setae. T8 articulated anterolaterally with S8; anterior margin with pair of flattened plates, single, rounded median plate, or margin straight (plates absent); posterior margin with median membranous cleft; medially with transverse row of setae. S8 with slender ventral setae, membranous posteriorly. T10 with 1 or more posterior rows of acanthophorite spines of various sizes. Cercus held upright, slightly arched, bearing apically numerous spine-like bristles similar to acanthophorite spines on T10, posterior margin with long, slender setae. Spermathecal receptacle spherical, darkly pigmented on long, unpigmented duct.

Remarks. This genus is recorded from Australia, New Zealand and South America. There are 19, nearly 40, and five species known from Australia, New Zealand and South America, respectively. The above generic concept of Ceratomerus is based on the examination of all known species of Ceratomerinae , which is the preliminary result of an on going phylogenetic analysis reported by Sinclair (1998).