Two new species of the genus Aphis (Hemiptera, Aphididae) from Chile on host species of Alstroemeriaceae and Ericaceae.

Specimens from Southern Chile belonging to two undescribed aphid species held at the Natural History Museum in London have been studied. Aphis luzuriagaesp. n. collected on Luzuriaga radicans and on other unidentified Luzuriaga species (Alstroemeriaceae) is described from apterous and alate viviparous females. Aphis gaultheriaesp. n. collected on Gaultheria mucronata (Ericaceae) is described from apterous viviparous females. Taxonomic peculiarities of both species are discussed.

Delfinoia, a new South American aphid genus (Hemiptera, Aphididae, Macrosiphini) on Cayaponia (Cucurbitaceae).

The genus Delfinoia Nieto Nafría & Mier Durante gen. n. is established, and Utamphorophora peruviana (Essig), originally Amphorophora peruviana and currently Delfinoia peruvianacomb. n., is designated species type of the genus. The synonymy between this species and Wahlgreniella australis Delfino syn. n. is established. Apterous and alate viviparous females of D. peruviana are redescribed; the male is also described. The species is currently known from Peru and Argentina; a plant of the genus Cayaponia (Cucurbitaceae) is the only identified host.

Aphis species (Hemiptera, Aphididae) living on Mulinum (Apiaceae) in South America, with a description of a new species.

Aphis species living on the South American native genus Mulinum are studied. Aphis vurilocensis Nieto Nafría, Brown and López Ciruelos, sp. n. is described from apterous viviparous females. Alate viviparous females, oviparous females and winged males of Aphis roberti are described. Knowledge of intraspecific variability of apterous viviparous females of A. martinezi, A. paravanoi and A. roberti is developed. An identification key of apterous viviparous females of Aphis species living on Mulinum is presented.

Three new South American species of genus Aphis (Hemiptera: Aphididae) living on species of Euphorbia (Euphorbiaceae).

Three species of Aphis living on species of Euphorbia in Argentina and Chile are described: Aphis tehuelchis Nieto Nafría & López Ciruelos, sp. n., from viviparous females collected in the Argentinean provinces of Santa Cruz and Neuquén, Aphis maulensis Mier Durante & García-Tejero, sp. n., from viviparous females collected in the Chilean Region VII, and Aphis eucollinae López Ciruelos & Ortego, sp. n., from viviparous females, oviparous females and males collected in the Argentinean province of Mendoza. These new species may be distinguished from each other, besides other features, by the abdominal marginal tubercles: in A. tehuelchis these are present on segments 1 and 7 and on several of segments 2 to 6, in A. maulensis they are on segment 1 and on several segments 2 to 6, but lacking on segment 7, and in A. eucollinae they are only on segments 1 and 7. Differences between the new species and those currently known living on Euphorbia around the world are presented.

Three new Asiatic species of Hyadaphis (Hemiptera, Aphididae).

Three new species of Hyadaphis Kirkaldy, 1904 (Hemiptera, Aphididae, Macrosiphini) are established: Hyadaphis levantina sp. n. from specimens caught on Lonicera nummulariifolia from Lebanon and Israel, and Hyadaphis anethi sp. n. plus Hyadaphis parva sp. n. from specimens respectively caught on Anethum sp. and Andrachne (?) cordifolia from Pakistan. Apterous viviparous females of all three species, alate viviparae of the first two and males of H. anethi are described. Known and new species of Hyadaphis are grouped for two relevant characters: (1) size and shape of siphunculi, and (2) host plant and life cycle; and the discriminant features of apterous viviparous females of the new species are compared with the already described species of the same group and a key for the Hyadaphis species is provided.

The histo structure of galls induced by aphids as a useful taxonomic character: the case of Rectinasus (Hemiptera, Aphididae, Eriosomatinae).

Morphological differentiation of gall tissues induced on plants may play a role to characterize the real taxonomic position of the gall inducer. We verified this hypothesis with galls induced by Rectinasus buxtoni on Pistacia palaestina. There is controversy about the taxonomic localization of genus Rectinasus: in one classification it is situated with the genera Forda and Paracletus while in another it is linked to the genera Geoica and Baizongia. Histological examination of the walls of the galls reveals the presence of two opposed vascular bundles and an inner surface of the gall with cavities. These features place Rectinasus in the same group as Geoica and Baizongia, and not with Paracletus and Forda, whose galls have a different histological structure, as generally admitted.

A new species of Rhopalosiphum (Hemiptera, Aphididae) on Chusquea tomentosa (Poaceae, Bambusoideae) from Costa Rica.

The new species Rhopalosiphum chusqueae Pérez Hidalgo & Villalobos Muller, is described from apterous viviparous females caught on Chusquea tomentosa in Cerro de la Muerte (Costa Rica). The identity of the species is supported both by the morphological features and by a molecular phylogenetic analysis based on a fragment of the mitochondrial DNA containing the 5' region of the cytochrome c oxidase 1 (COI) and on the nuclear gene coding for the Elongation factor-1 alpha (EF1α). The taxonomic position of the new species is discussed. An identification key to the Aphidinae species living on plants of Bambusoideae (Poaceae) is presented.