A new Syllimnophora with a key to the species from Ecuador ( Diptera : Muscidae )

Syllimnophora Speiser belongs to the Limnophorini tribe of the Coenosiinae subfamily. The genus can be distinguished from the others by the presence of cilia on the apical half of the dorsal surface of vein R1, combined with a strongly projected gena. In he Neotropical Region 28 species are known, three of them recorded from Ecuador - S. atrovittata (Stein), S. browni (Snyder) and S. suavis (Stein). The study of material from South America deposited at Museum national d'Histoire naturelle (Paris) enabled the description of one species new to science - S. argentifrontata sp. nov. from San Miguel de Ibarra (Ecuador). A key to the identification of the four species is given.

Adults of Syllimnophora Speiser, 1923 can be distinguished from the other Limnophorini (Coenosiinae) genera by the presence of cilia on the apical half of the dorsal surface of vein R 1 , combined with a strongly projected gena.In addition, the prosternum bears lateral cilia; the palpus is long, enlarged and flat at the apex; the ocellar triangle is long; the dorsocentral setae are 2+3; and the anepimeron is bare.The genus is known in the Neotropical Region from 28 species (CARVALHO et al. 2005) recorded from Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Juan Fernández Island, Mexico and Peru.Three species have been recorded from Ecuador -S.atrovittata (Stein), S. browni (Snyder) and S. suavis (Stein).
Syllimnophora atrovittata was described by STEIN (1904) in Limnophora Robineau-Desvoidy, 1830 based on one female from Calanga, Peru.Later, the geographical distribution of the species was extended to Chile and Bolivia (STEIN 1911) and Colombia (STEIN 1918).PONT (1972) transferred the species to Syllimnophora.LOPES & BAPTISTA (1992), studying material from Ecuador, described and illustrated the male and female terminalia.STEIN (1911) presented a very short description of S. suavis (also in Limnophora), comparing it to L. compressifrons, as both species, according to him, are very similar morphologically, differing only in the color pattern of the scutum and abdomen and by the dark brown longitudinal cloud on the anterior margin of wing of S. suavis.The author also differentiated S. suavis from S. atrovittata, as both species have a similar cloud on the wing.SÉGUY (1937) transferred the species to Syllimnophora and PONT (1972) made notes on the type.The species was originally described from Peru and CAMPOS (1960) recorded it from Ecuador.SNYDER (1957) described S. browni from one male and one female, both from Ecuador.The species was keyed and considered morphologically close to S. latimana Malloch, 1934, from which it can be distinguished by the golden yellow sternite 5.The species is known only from the original material and remains endemic to Ecuador.COURI & CARVALHO (2002) presented the available keys to identification of the species.
This paper describes a new species and presents a key to the identification of the Syllimnophora recorded from Ecuador.

MATERIAL AND METHODS
The material belongs to the collection of the Muséum national d'Histoire naturelle, Paris (MNHN).The holotype of the new species and two paratypes are deposited at MNHN and one paratype is at the Museu Nacional, Rio de Janeiro (MNRJ).
For the dissection of the terminalia, the apex of the abdomen was macerated in a solution of 10% potassium hydroxide for 24 hours.After the dissection in glycerol, the structures were stored in a microtube attached to the pin bearing the specimen.The terminology of the descriptions followed MCALPINE (1981).

TAXONOMY
The following key segregates the four species and is followed by the description of the new species.One female of S. atrovittata from Quito (R. Benoist leg., I/1930) was also identified in the examined material and is deposited at the MNHN.

M. S. Couri
ZOOLOGIA 27 (4): 643-645, August, 2010  with six long setae.Fore femur with a complete row of setae on dorsal, anterodorsal and anteroventral surfaces.Tibia with a ventral and a dorsal apical seta, the latter longer.Mid femur with a complete row of setae on anterodorsal surface; ventral surface with a row of fine setae on basal half; posterior surface with two pre-apical setae.Mid tibia with five setae on posterior surface; anterior, ventral, posterodorsal and posteroventral surfaces each with apical seta.Hind with a complete row of setae on anterodorsal and anteroventral surfaces.Hind tibia with four anterodorsal setae on middle third, one anteroventral submedian, one dorsal preapical and one ventral apical.Abdomen: margin of tergite 4 and disc of tergite 5 with a series of fine setae.Sternite 5 higher than wider as in figure 1. Terminalia: Cercal plate and surstyli as in figures 2-3.Aedeagus as in figure 4.
Female.Similar to male but series of anteroventral setae on hind femur restricted to 4-6 fine and spaced setae on basal half.Ovipositor as in figure 5.
Remarks.The silver frons contrasting with the dark brown head, combined with a clear wing, yellow halteres and hind tibia with four anterodorsal setae on middle third segregate this species from its congeners.
Etymology.The specific epithet refers to the strongly silver frons in both sexes.