Philornis seguyi Garcia, 1952 Mydaea anomala: Nielsen (1913: 251). Misidentification, not Mesembrina anomala Jaennicke, 1867. Philornis seguyi Garcia, 1952: 286. Holotype male, lost (formerly in MSPBA?) Type-locality: Argentina, Misiones. Philornis nielseni Dodge, 1968: 157 (new name for anomala Jaennicke sensu Nielsen 1913). Holotype male (ZMUC). Type-locality: Argentina. Syn. nov. The species can be recognised as follows: body length 7–9mm; frons yellowish, eye with a faint golden reflection; width of frons at level of anterior ocellus 0.07–0.09 of head width in male and 0.13–0.14 in female; antenna and palpus yellow; cheek yellow-haired; scutum brown with greyish pollinosity, with the quadrivitatte pattern typical of the genus; wing clear, some specimens with a faint brown spot on r-m cross vein; legs yellow in male and somewhat brown in female; hind tibia on anterodorsal surface with 2–4 setae on middle third, anteroventral surface with 3–4 fine bristles on middle third. Abdomen brown with greyish pollinosity. Larva intradermal. Puparium brown, cylindrical, posterior end deep with rugose margins; spiracular slits “U or “V shaped. (Figures in Couri et al. 2005). Couri et al. (2005) described the larva, puparium, adult male and the terminalia of both sexes, based on material collected in Buenos Aires province and identified using the original description of Garcia (1952). The slight differences in size and colour of the legs described in P. nielseni by Dodge (1968) are here considered as intraspecific variation, as in other Philornis species. The synonymy of P. nielseni with P. seguyi is herein proposed as there is no justification to consider them as separate species. The species was found among the material recently collected in Argentina as below. Material examined: (MQ): Argentina, Santa Fe, Santa Fe, 3138'S 6091'W. Ex nest of Troglodytes aedon: 27 males and 44 females reared from larvae. (LRA): 4 adults reared from larvae. Host: Certhiaxis cinnamomea (Furnaridae); location: Puente de Hierro, Arroyo Culul, Santa Fe (3121'S 6056'W); collection date: November 2003; accession # SF00027b.

Published as part of Couri, Márcia S., Antoniazzi, Leandro R., Beldomenico, Pablo & Quiroga, Martin, 2009, Argentine Philornis Meinert species (Diptera: Muscidae) with synonymic notes, pp. 52-62 in Zootaxa 2261 on page 58, DOI: 10.5281/zenodo.190768