Among the aphids associated with wheat and other winter cereals, Rhopalosiphum padi (L.) is currently the predominant species in the wheat growing region of southern Brazil. The damage caused by this aphid occurs by direct feeding and/or by the transmission of pathogenic viruses, such as the Barley/Cereal yellow dwarf virus. In order to estimate the direct damage caused by R. padi on wheat, we evaluated the population growth of this aphid during the tillering and elongation stages and its effects on grain yield components. The experiment was conducted in a screenhouse with three wheat cultivars (BRS Guabiju, BRS Timbaúva, and Embrapa 16). The effect of a period of 16 days, starting from an infestation of 40 aviruliferous aphids/plant, was evaluated and compared to non-infested plants. In both stages, the population growth of R. padi was lower on the BRS Timbaúva. Although infestation caused a reduction in the grain yield of the three cultivars, this effect was lower for BRS Timbaúva. The cultivar Embrapa 16 supported higher infestations and was more tolerant to damage than the BRS Guabiju.

A B S T R A C T Twenty species of Tephritidae (Diptera) are recorded in association with capitula of plants in the family Asteraceae. The Tephritidae genus Tetreuaresta is registered for Rio Grande do Sul for the first time. Five species of Tephritidae are newly recorded for Rio Grande do Sul, and new hosts are recorded for the following fly species: Dioxyna chilensis (Macquart), Plaumannimyia dolores (Hering), Plaumannimyia imitatrix (Hering), Plaumannimyia miseta (Hering), Plaumannimyia pallens Hering, Tomoplagia incompleta (Williston), Tomoplagia matzenbacheri Prado, Norrbom & Lewinsohn, Tomoplagia reimoseri Hendel, Xanthaciura biocellata (Thomson) and Xanthaciura chrysura (Thomson).

Seventeen new species of Anastrepha, primarily from Suriname, French Guiana and Pará, Brazil, are described and illustrated: A. aithogaster Norrbom from Brazil (Pará), French Guiana, and Suriname; A. aliesae Norrbom from Suriname; A. brownsbergiensis Norrbom from Suriname; A. crassaculeus Norrbom & Rodriguez Clavijo from Colombia (Magdalena, Norte de Santander) and Suriname; A. curvivenis Norrbom from Brazil (Amazonas), Ecuador (Zamora-Chinchipe), Peru (San Martín), and Suriname; A. fuscoalata Norrbom from Brazil (Pará), French Guiana, and Suriname; A. gangadini Norrbom from Suriname; A. juxtalanceola Norrbom from Brazil (Pará) and Suriname; A. microstrepha Norrbom from Brazil (Bahia) and Suriname; A. mitaraka Norrbom from French Guiana; A. neptis Norrbom from Brazil (Pará), Ecuador (Orellana), Peru (Loreto) and Suriname; A. sobrina Norrbom from Brazil (Pará), French Guiana, and Suriname; A. surinamensis Norrbom from Suriname; A. tenebrosa Norrbom from Brazil (Pará) and Peru (Loreto); A. triangularis Norrbom from Suriname; A. wachiperi Norrbom from French Guiana and Peru (Cusco); and A. wittiensis Norrbom from Suriname. The following host plant records are reported: A. aithogaster from fruit of Parahancornia fasciculata (Poir.) Benoist (Apocynaceae); A. aliesae from fruit of Passiflora coccinea Aubl. and P. glandulosa Cav. (Passifloraceae); A. crassaculeus from fruit of an undetermined species of Pouteria (Sapotaceae); A. fuscoalata from fruit of Trymatococcus oligandrus (Benoist) Lanj. (Moraceae); A. sobrina from fruit of Eugenia lambertiana DC. (Myrtaceae); and A. wittiensis from fruit of Manilkara bidentata (A. DC.) A. Chev. (Sapotaceae).

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