| abstract | The male and female of Amblyomma parvum Aragao, 1908 are redescribed and larva and nymph described for the first time together with the description of ail active stages of Amblyomma pseudoparvum sp. n. A. pseudoparvum was found on Dolichotis salinicola and to a lesser extent on cattle in Argentina. A. parvum was found on cattle, dogs, donkeys, goats, horses, men, mules, pigs, Cebus apella paraguayanus, Lagostomus maximum inmolis, Mazama sp. and Tolypeutes mataco. A. parvum occurs in a vast area of the Western Chaco District of the phytogeographical Chaquefio Domain, whereas A. pseudoparvum was found only in the northwest of that district. |