: DESCRIPTIONS AND FIRST RECORDS FROM COLOMBIA ( DIPTERA , MUSCIDAE , COENOSIINAE )

Bithoracochaeta Stein is a Neotropical genus of Muscidae, Coenosiinae, known from ten species recorded from Argentina, Brazil, Costa Rica, Cuba, Ecuador, Guyana, Jamaica, Mexico, Panama, Paraguay, Peru, Puerto Rico, Surinam, Uruguay and Venezuela. The genus is recorded for the first time from Colombia, with the occurrence of the following species: B. annulata Stein, 1911; B. calopus (Bigot, 1885); B. flavicoxa Malloch, 1934; B. leucoprocta (Wiedemann, 1830); B. maricaensis Couri & Motta, 1995 and B. varicornis (Coquilett, 1900). B. nigricoxa, spec. nov. is described from Mexico and Brazil. A brief diagnosis of the known species and a complete description of the new species are given.

The genus is easily distinguished from the other Coenosiinae, Coenosiini, by the presence of only two dorsocentral postsutural setae, basal scutellar pair of setae shorter than the apical one and by the presence of three long median setae on hind tibia, on anteroventral, anterodorsal, and posterodorsal surfaces and in most of the species a fourth long median posteroventral one.
In the identification key to the Neotropical genera of the Muscidae , Bithoracochaeta is close to Schoenomyzina Malloch, which also has only two dorsocentral postsutural setae and from which it can be distinguished by the other characters mentioned above.
Bithoracochaeta is placed in the tribe Coenosiini and, according to Couri & Pont (2000), forms a monophyletic clade together with Insulamyia Couri, as the loss of the postsutural intralar seta is a synapomorphy for them. This paper aims to describe a new one from Mexico and Brazil and to record the presence of the genus Bithoracochaeta from Colombia for the first time, on the basis of five known species. A brief diagnosis of the known species and a full description of the new one are given.

MATERIAL AND METHODS
The majority of the material studied in this paper was collected in Colombia in 1955 by E.I. Schlinger and E.S. Ross and is deposited at California Academy of Sciences (CAS, San Francisco, California) collection. Most of the specimens are not in good conditions.
The dissected terminalia were clarified in a solution of 10% potassium hydroxide for 24 hours. They were then dissected in glycerol, drawn, stored in a microtube with glycerol, and attached to the pin bearing the specimen.
All studied material is deposited at CAS, unless otherwise indicated in the examined material.

RESULTS AND DISCUSSION
New records of Bithoracochaeta from Colombia are: B. annulata; B. calopus; B. flavicoxa; B. leucoprocta; B. maricaensis and B. varicornis, which can be easily segregated in the keys given by Malloch (1934) and .

B. annulata Stein
Bithoracochaeta annulata Stein, 1911:178. Diagnosis: General color brown, with grey pollinosity; flagellomere yellow; arista with longer cilia on basal two-thirds; katepisternum with many ground cilia; fore coxa brown with yellow apex; mid and hind femora mainly yellow, except for the extreme brown apices; hind tibia with four median long setae on anteroventral, anterodorsal, posteroventral and posterodorsal surfaces; hypandrium with spines.
Previously recorded from Brazil, Guyana, Peru and Surinam.

B. calopus (Bigot)
? Hydrophoria calopus Bigot, 1885:275. Diagnosis: General color brown, with grey pollinosity; antenna and palpus entirely dark brown; arista with very short hairs; mesonotum with five vittae, the median one not reaching the disk of scutellum; katepisternum with 1-3 extra setae besides the usual ones; fore femur more or less extensively brown; mid and hind femora brown at least in middle and extreme apices; hind tibia with four long median setae on anteroventral, anterodorsal, posteroventral and posterodorsal surfaces; tubular hypandrium short.

B. flavicoxa Malloch
Bithoracochaeta flavicoxa Malloch, 1934:228. Diagnosis: Parafacial hardly visible in lateral view; mesonotum with no traces of vitta; fore coxa entirely yellow in male and female; male with all femora and tibia yellow, female with mid and hind femora with apices somewhat brown; hind tibia with three long median setae on anteroventral, anterodorsal and posterodorsal surfaces, the posteroventral lacking; abdomen glossy black, tergites 3-5 with a transverse mark of grey dust on each side near base.
Diagnosis: Flagellomere fuscous; mid and hind femora mainly yellow, brown at extreme apices at least on dorsal surface; inferior calypter slightly widened from base to near middle; hind tibia with four long median setae on anteroventral, anterodorsal, posteroventral and posterodorsal surfaces; hypandrium long, without spines.
According to Malloch (1934); in some males the fore femur is swollen at base and has a long and strong posterior seta near the base in the central series, below which there is another series of much shorter, stout upcurved setae that decreases in length and strength as they approach middle.
Previously recorded from Argentina, Brazil, Costa Rica, Cuba, Guyana, Jamaica, Mexico, Panama, Paraguay, Peru, Puerto Rico, Uruguay and Venezuela Thorax: Dorsocentrals 1:2; acrostichals short, in two series; 1 postpronotal; 1 presutural; 1 intralar; 2 supralars; 2 postsupralars. Notopleuron with two setae, similar in size. Scutellum with one short pair of basal setae and one strong apical. Anepisternum with 2 long setae, each one of them preceeded by a fine one. Katepisternals 1:1:1, with an extra anteroinferior seta. Anepimeron bare. Lower calypter about 1.8 the length of the upper. Wing veins R 4+5 and M 1+2 parallel at apex. Legs with fore femur with a posterior, posterodorsal and posteroventral row of sparse setae, the last one longer; fore tibia with a long median posterior seta and another one preapical; dorsal surface with two preapical setae; claws and pulvilli well developed; mid femur with three long and sparse anteroventral setae on middle third; posterior surface with two preapical setae; hind femur with an anteroventral and an anterodorsal row of setae on basal two thirds followed by a preapical one; hind tibia with the four characteristic median setae, on anterodorsal, anteroventral, posterodorsal and posteroventral surfaces; preapical dorsal and anterodorsal setae and one long anteroventral apical.
Abdomen: Lateral pair of setae on tergites 1+2 and 3; tergites 4-5 with four sparse setae on disc and tergite 5 also on apex. Sternite 5 a little longer than wider, with two long setae on posterior margin (Fig. 1).
Other examined material: Paratypes labeled as holotype, 1 male and 1 female (MNRJ). some peculiar characters as surstylus with short and fine setae in its all extension and gonopod with short spines at apex (holotype and paratype male dissected). In  key, the new species approaches couplet 3, where it can be distinguished by the totally yellow mid and hind femora.

B. varicornis (Coquillet)
Coenosia varicornis Coquilett, 1900:256. Diagnosis: Antenna with escape, pedicel and base of flagellomere dark brown, rest of flagellomere yellow; mesonotum with a broad dark brown median vitta, almost reaching apex of scutellum; femora almost all brown; fore femur more extensively brown; mid and hind femora brown at least on dorsal surface; hind tibia with fourth long median setae on anteroventral, anterodorsal, posteroventral and posterodorsal surfaces; hypandrium with spines.