Aphis adesmiae Delfino sp. n. is described from South Patagonia (Argentina). This new aphid species is associated with a native shrub Adesmia boronioides (Fabaceae). Morphological characters of the apterous viviparous female are described and illustrated and biological remarks are given.

Aphis adesmiae Delfino sp. n. se describe del sur de la Patagonia (Argentina). Esta nueva especie de áfido está asociada con el arbusto nativo Adesmia boronioides (Fabaceae). Los caracteres morfológicos de la hembra vivípara áptera y aspectos de su biología son descriptos e ilustrados.

The quality of the ornamental plants is closely related to their phytosanitary state, that, in turn, is affected by the activity of some insect groups. Aphids are common pests of nearly all kinds of plants, ornamental plants among them. The fauna associated with aphids that colonize ornamental plants includes honey ants (Hymenoptera: Formicidae) that establish mutualistic relations, and some parasitoids (Hymenoptera: Braconidae, Aphidiinae) that contribute to the control of the aphid population. Very little is known about the aphids and their associated fauna living on ornamental plants of Cordoba, Argentina. The goal of this work was to identify the aphids that colonize ornamental plants, as well as their associated honey ants and parasitoids. Samples of sprouts, leaves and/or flowers of aphid-colonized ornamental plants of the Jardín Botánico Municipal of Cordoba city were collected weekly, from October 2003 to November 2004. Whenever found, the associated honey ants and "mummies" of aphids atacked by parasitoids were also collected. One hundred and thirty two aphid-plant associations were registered, 64.4% of which were unknown in the country. In 33.3% of these associations, the aphids were tended by honey ants whereas the presence of aphid parasitoids was registered in 16.7%. Ninety five species of ornamental plants were colonized by 41 aphid species, whereas six ant species tended 10 aphid species. Aphid parasitoids were represented by four species related to 11 aphid species.

La calidad de las plantas ornamentales se relaciona estrechamente con su estado fitosanitario, que se ve afectado por la actividad de los insectos. Entre los principales insectos plagas se destacan los pulgones o áfidos. La fauna asociada con los áfidos que colonizan plantas ornamentales, incluye hormigas melívoras (Hymenoptera: Formicidae) que establecen relaciones de mutualismo; además, los microhimenópteros parasitoides de áfidos (Hymenoptera: Braconidae, Aphidiinae) contribuyen al control de estos insectos plaga. Se conoce muy poco sobre estos grupos de insectos en plantas ornamentales de Córdoba, Argentina. El objetivo de este trabajo es dar a conocer los áfidos que colonizan plantas ornamentales, como así también las hormigas melívoras y parasitoides asociados. Para ello, brotes, hojas y/o flores de las plantas ornamentales colonizadas por áfidos fueron colectadas semanalmente en el Jardín Botánico Municipal de la ciudad de Córdoba, desde Octubre 2003 a Noviembre 2004. También se colectaron las hormigas melívoras asociadas y las "momias" de áfidos parasitados. Se registraron 132 asociaciones áfido-planta ornamental, de las cuales el 64,4% no se conocían en el país. Los áfidos fueron atendidos por hormigas melívoras en el 33,3% de las asociaciones, mientras que en el 16,7% se registró la presencia de parasitoides. Las especies involucradas incluyen 95 de plantas ornamentales colonizadas por 41 de áfidos, mientras que seis de hormigas melívoras atendieron a 10 de áfidos. Los parasitoides estuvieron representados por cuatro especies que estuvieron relacionadas con 11 de áfidos.

Uroleucon é um dos poucos gêneros de afídeos com espécies nativas da América do Sul. Neste trabalho, é descrita e ilustrada uma nova espécie do Chile, Uroleucon eumadiae sp. nov., coletada em duas espécies sul-americanas do gênero Madia (Asteraceae): M. sativa Mol. e M. chilensis (Nutt.) Reiche. São discutidos os caracteres morfológicos e aqueles utilizados para distinguir U. eumadiae de outras espécies relacionadas. O ultimo segmento rostral piloso desta espécie sugere uma adaptação alimentar, paralela a uma outra espécie que ocorre na América do Norte e que também se alimenta de plantas de do gênero Madia, mas que não é filogeneticamente próxima.

Uroleucon is one of very few aphid genera that have species indigenous to South America. A new species of aphid from Chile is described and illustrated, Uroleucon eumadiae sp. nov., living on the two South American species of the genus Madia (Asteraceae): M. sativa Mol. and M. chilensis (Nutt.) Reiche. Morphological characters are discussed and the characters by which this aphid species may be distinguished from related ones are given. The long, hairy last rostral segment of the new species suggests strongly a feeding adaptation, and parallels that of a North American Madia-feeding species in the same genus which is not, however, closely related.

Indivíduos de Uroleucon bereticum (E.E. Blanchard) foram coletados sobre plantas de Conyza bonariensis (L.) Cronquist (Ateraceae), no Parque Nacional "Quebrada del Condorito" na localidade de 'Pampa de Achala', Provincia de Córdoba, Argentina. Esa espécie de afídeo havia sido descrita como Macrosiphoniella beretica por Blanchard (1922), a partir de fêmeas ápteras vivíparas, sendo que desconheciam-se fêmeas vivíparas aladas. Neste trabalho redescreve-se U. bereticum, através das características morfológicas de fêmeas vivíparas ápteras e aladas. Muito pouco se conhece, até o momento, sobre os parasitóides de afídeos na Argentina e exemplares de espécies de afídeos nativos endêmicos não têm sido investigados. Binodoxys achalensis Starý, sp.n. é descrita como um novo parasitóide endêmico associado a U. bereticum. Há indicações, nesta localidade, da ocorrência de novos e numerosos parasitóides oligófagos.

Collections of Uroleucon bereticum (E.E. Blanchard) on Conyza bonariensis (L.) Cronquist were made throughout the National Park "Quebrada del Condorito" at Pampa de Achala, province of Córdoba, Argentina. This aphid species was described as Macrosiphoniella beretica by Blanchard (1922) from apterous viviparous female and the alate viviparous female were unknown. Morphological characteristics of U. bereticum presented in this paper include the re-description of the apterous viviparous female as well as a new description of the alate viviparous female. Very little is known about the aphid parasitoids in Argentina and material of the indigenous endemic aphid species has not been collected up to now. Binodoxys achalensis Starý, sp.n. is described as a new endemic parasitoid species associated with U. bereticum and its seems to indicate the occurrence of new and more numerous oligophagous parasitoid guild in the target area.

Enchenopa sericea Walk. (Membracidae), a gregarious, sap-feeding treehopper, is tended by the ant Camponotus rufipes (Fabricius) (Formicidae) on Caesalpinea gilliesii (Wall. et Hook.) Dietr. (Fabaceae) shrubs in La Quebrada, Río Ceballos, province of Córdoba. We investigated the effects of ant-attendance on eggs, nymphs and adults of the membracid. Local populations of the membracid and their associated ants were counted nondestructively at weekly intervals during 21 weeks from October 1997 to March 1998. Seventy-four ant-present aggregations (control) and 25 ant-excluded aggregations (unattended) were studied. The results of field censuses revealed a positive correlation between ants and membracids. Attendance greatly increases the mean number of surviving nymphs, reaching them higher numbers in ant-present aggregations than in ant-excluded aggregations. The mean number of females and males, and the sexual ratio, were greater when attended by the ants than where ants were excluded. Eggs were not attractive to Camponotus rufipes and no correlation was found with them. Enchenopa sericea females apparently remain longer with the egg masses in the absence of ants to attract them to the future group of nymphs, and this behaviour is interpreted as a form of parental care. Proportionally, ants attended adults in larger numbers than nymphs, suggesting that ant attendance can be related to the quantity of honeydew available.

Las agregaciones del membrácido Enchenopa sericea Walk. son atendidas por hormigas Camponotus rufipes (Fabricius) sobre brotes de Caesalpinia gilliesii (Wall. et Hook.) Dietr. en La Quebrada, Río Ceballos, provincia de Córdoba. Para conocer los efectos de esta atención sobre las oviposturas, ninfas y adultos del membrácido, se impidió la atención de hormigas a 25 agregaciones y otras 74 se utilizaron como controles; en ambos casos fueron censadas desde octubre de 1997 hasta marzo de 1998. Se registró una correlación entre el número total de hormigas y de membrácidos. El número promedio de ninfas aumentó en las agregaciones atendidas, como así también el de machos, hembras y la proporción de sexos. Las oviposturas no fueron atractivas para Camponotus rufipes. Las hembras de Enchenopa sericea aparentemente permanecieron más tiempo junto a las ovisposturas en las agregaciones no atendidas, lo que es interpretado como una forma de cuidado parental. Proporcionalmente, las hormigas atendieron un mayor número de adultos, lo que estaría relacionado con la cantidad de melado disponible.