Diagnoses and discussion of the group 1 and 2 Brazilian species of Heteragrion, with descriptions of four new species (Odonata: Megapodagrionidae).

　Heteragrion is the most speciose and complex genus of neotropical Megapodagrionidae, with 47 species and one subspecies, and many of them are poorly defined. To improve the knowledge of the Brazilian species of the genus, 179 specimens of 13 of the 17 described species were examined. Four new species are described in tribute to the 40 thanniversary of the rock band Queen: Heteragrion freddiemercuryi (Holotype: Peruíbe (24º 22' 48" S & 47º 04' 40" W—10 m), São Paulo State—09-III-2000); H. brianmayi (Holotype and allotype: Parque Estadual da Serra do Mar—Núcleo Caraguatatuba, Caraguatatuba (23º 35' 36" S & 45º 25' 07" W—61 m), São Paulo State—05-II-2000 and 10-III-2002); H. rogertaylori (Holotype and allotype: Fazenda Trabiju, Pindamonhangaba (22º 50' 40" S & 45º 31' 01" W—651 m), São Paulo State—26-III-1999); and H. johndeaconi (Holotype and allotype: Alto Paraíso de Goiás (14º 10’ 55" S & 47º 38’ 36" W—1198 m), Goiás State—18-VI-2008 and 17-VI-2008), holotypes, allotypes and most paratypes deposited in FAAL.Diagnostic illustrations of all species studied are provided. Color photographs of live individuals of H. brianmayi, H. aurantiacum, H. consors, H. mantiqueirae, H. tiradentense and H. triangulare are also presented.