A further contribution to the knowledge of Uroleucon species (Hemiptera, Aphididae) living on Adesmia (Fabaceae) in southern South America, with description of a new species from Chile.

Uroleucon (Hemiptera, Aphididae, Macrosiphini) is a highly diverse and widely distributed genus. Most of its species are hosted by plants of the Asteraceae or Campanulaceae, but three species from the southern end of South America have specialized to live on plants of the genus Adesmia (Fabaceae). New morphological and chorological data are provided for U. adesmiae Mier Durante and Ortego and U. naheulhuapense Nieto Nafría von Dohlen, with a description of the alate viviparous female of the latter species. U. australe Nieto Nafría Mier Durante, sp. n. is described from apterous viviparous females, oviparous females and males from four localities in the Chilean regions of Aysén and Magallanes; it is very close to U. nahuelhuapense, both morphologically and genetically. Contrary to what is typical for aphids, the males of U. australe have a greater number of distinguishing characters than are found in viviparous females. A modification of the identification key to the apterous viviparous females of the known Uroleucon species in South America by Nieto Nafría et al. (2019) is presented.

Three new species of the genus Neuquenaphis (Hemiptera, Aphididae, Spicaphidinae) from southernmost South America.

Three new species of Neuquenaphis Blanchard are described from aphids collected in southernmost South America on several species of Nothofagus, southern beeches: Neuquenaphis blackmani Nieto Nafría and Brown, sp. n. from apterous and alate viviparous females and alatoid nymphs collected on Nothofagus dombeyi in Los Lagos and Los Ríos regions (Chile) and on Nothofagus nitida in Los Ríos region, Neuquenaphis aurata Mier Durante and von Dohlen, sp. n. from apterous and alate viviparous females collected on Nothofagus betuloides in Magallanes region (Chile) and Tierra del Fuego province (Argentina), and Neuquenaphis ramireziNieto Nafría and Ortego, sp. n. from apterous viviparous females collected on Nothofagus pumilio and N. antarctica in Tierra del Fuego province (Argentina) and La Araucanía, Aysén and Magallanes regions (Chile). Sequences of the mitochondrial COI "barcode" region and the tRNAleu-COII locus support the distinction of these new species from described Neuquenaphis species. Morphological characteristics that differentiate the new species from already described species of the genus are discussed. Partial identification keys for known apterous and alate viviparous females of Neuquenaphis species are presented on the basis of those established by Quednau (2010).

Aphis (Hemiptera, Aphididae) species living on Baccharis (Asteraceae) in southern South America, with description of three new species.

Aphid specimens belonging to the genus Aphis (Hemiptera, Aphididae, Aphidinae) collected on species of Baccharis (Asteraceae) in localities of Argentina and Chile, preserved in the Natural History Museum in London and in the Universidad de León collections, have been studied. They belong to six species: Aphis craccivora, Aphis gossypii and Aphis spiraecola, which are widely-distributed and polyphagous, and the new species: Aphis ingeborgae Nieto Nafría and Brown sp. n., Aphis conspicua Nieto Nafría and Mier Durante sp. n. and Aphis fuentesi Nieto Nafría and Ortego sp. n. which are here described from apterous and alate viviparous females, and also from oviparous females and males in the case of Aphis fuentesi. These six species plus the native and monophagous A. coridifoliae are those known in southern South America living on plants of Baccharis. Diagnostic features of new species and an identification key for apterous viviparous females of these seven species are presented.

The species of Uroleucon (Hemiptera: Aphididae) living on Adesmia (Fabaceae) in Argentina, with the description of a new species.

Uroleucon Mordvilko is the largest genus in the Macrosiphini (Hemiptera, Aphididae) and most of its species live on species of Asteraceae. Uroleucon nahuelhuapense Nieto Nafría von Dohlen sp. n. is described from apterous viviparous females collected on Adesmia boronioides (Fabaceae) in a locality of Neuquén province (Argentina). The morphological characters and the sequence of the tRNAleu-COII mitochondrial locus support the inclusion of the new species in the genus Uroleucon. Apterous viviparous females of Uroleucon adesmiae Mier Durante Ortego collected in two Argentinean localities have also been studied and ranges of several quantitative features have been modified. The identification key for the Uroleucon species known in South America by Nieto Nafría et al. (2007) has been modified to include the new species.