Ceraturgus Wiedemann (1824)

Barnes, Jeffrey K., 2008, Review of the genus Ceraturgus Wiedemann (Diptera: Asilidae) in North America north of Mexico, Zootaxa 1766, pp. 1-45 : 5-6

Ceraturgus Wiedemann (1824)

Ceraturgus Wiedemann, 1824: 12 . Type species: Dasypogon aurulentus Fabricius , by monotypy.

Body length, excluding antennae, less than 28 mm. Head width 1.5–1.6 times eye height; face in profile produced beyond eye margin, lacking pronounced tentorial pits; mystax occupying lower half or more of face; sides of frons more or less parallel sided, not strongly converging or diverging dorsally; compound eye with anterior ommatidia greatly enlarged; ocellar tubercle low, bearing several stout setae and shorter hair-like setae; occipital pile dense. Proboscis laterally compressed, apically blunt; palpus 2-segmented. Antennae exceptionally long, much longer than head, with 5 antennomeres, including 3 elongate flagellomeres; scape and pedicel subequal; first flagellomere less than twice length of scape and pedicel combined; second flagellomere short, about half length of scape; antennal bases on raised area. Thorax with scutum typically vittate, bearing sparse or dense pile of short or long, erect or reclinate, hair-like setae shorter or longer than scape; anepisternum and katepisternum bearing many long or short setae; katatergite bearing fan of long setae; anatergite tomentose, lacking long setae; scutellem low convex, bearing band of long marginal bristles; postmetacoxal area membranous. Femora stout but not swollen, usually with apical circlet of stout setae; fore and mid femora with 0–5 stout anterior setae; hind femur usually with anterior row of 2-8 stout setae. Fore tibia with all apical bristles straight, usually with anterodorsal and posterodorsal rows of short, stout setae and posteroventral row of long, stout setae; mid tibia with apical ventral bristles directed distally, not toward body, usually with anterodorsal, anteroventral, posterodorsal, and posteroventral rows of stout setae; hind tibia with anterior, dorsal, and ventral rows of stout setae; pulvilli present. Wing hyaline to moderately infuscated; vein C continuing around posterior wing margin to wing base; R2+3 ending in C, its apex not directed sharply forward before ending in C; R4 not unusually arched and sinuate; apical portion of M3 at an angle to crossvein mm; CuA2 and A1 ending separately; cell m3 open at wing margin; cell cu p closed or narrowly open at wing margin. Prosternum not fused to proepisternum. Abdomen usually black with conspicuous white to yellow pollinose posterior fascia; segment 2 not unusually elongate; gonocoxite often bilobed, bearing tuft of long, stout setae; tergite 10 with strong bristles in female.

Discussion. Wiedemann (1824) described the genus Ceraturgus to receive the single distinctive species Dasypogon aurulentus Fabricius , known at that time from a single specimen, “Habitat in New-York Americes Dom. de Sehestedt” ( Fabricius 1805). His brief description distinguished the genus primarily on antennal characters: antennae porrect, long, 5-segmented: segments 1–3 subclavate, segment 4 cup-shaped, 5 with obtuse apex; body naked.

The Asilidae have not yet been subjected to thorough phylogenetic analysis, although work is presently underway. Higher classification within the family remains unstable. Artigas and Papavero (1991a) included the genera Ceraturgus and Myelaphus in their new tribe Ceraturgini of the subfamily Stenopogoninae . Stenopogoninae are recognized by the following combination of characters: prothoracic tibia lacking a differentiated apical spur (stouter than others, or twisted and sigmoid), vein R2+3 ending in vein C, prosternum not fused to proepisternum, ovipositor with acanthophorite spines ( Wood 1981, Artigas and Papavero 1988). These features are presumed to be plesiomorphic, so the subfamily probably is not monophyletic.

Female Ceraturgus , like many other orthorrhaphous Brachycera (e.g. Mydidae , Apioceridae , Therevidae , Scenopinidae , and Dolichopodidae , and some other Asilidae ), have tergite 10 divided into a pair of spinebearing hemitergites called ancathophorites, used for digging during oviposition ( McAlpine 1981). According to Papavero (1973), primitive asilid female terminalia have spined acanthophorites. Reduction of spines and fusion and elongation of the two acanthophorites led to the formation of several types of ovipositors found in other groups of robber flies. He found spined acanthophorites in only some genera of Stenopogoninae , Dasypogoninae , Apocleinae , and Asilinae. He found them lacking in Laphystiinae, Laphriinae , Ommatiinae , and Trigonomiminae .

Ceraturgini have the head wider than high, antennae with 3 flagellomeres (total of 5 antennomeres), third flagellomere pubescent and as wide or wider than first flagellomere ( Artigas and Papavero 1991a). Ceraturgus lacks the deep clefts at the apices of the first and second flagellomeres that are found in Myelaphus . The name Ceraturgus is derived from the Greek word Keratourgos, meaning horn-maker.