ABSTRACT
This paper reports formally the occurrence and describes the damages by Semiaphis dauci (Fabricius, 1775) (Insecta, Hemiptera, Aphididae, Aphidinae, Macrosiphini) on arracacha (Arracacia xanthorrhiza Bancr.) (Apiaceae) in Brazil. The infestation was initially noted on April/2002 at Núcleo de Produção de Mudas, Departamento de Sementes Mudas e Matrizes, Coordenadoria de Assistência Técnica Integral, Secretaria de Agricultura e Abastecimento, São Bento do Sapucaí, State of São Paulo. Posteriorly the occurrence was detected in other parts of the municipality of São Bento do Sapucaí such as Serrano, Paiol Grande and Cantagalo, being the incidence higher in localities at lower altitudes. The colonies, with large number of individuals, were settled on both sides of the leaves and also hidden under petiole, but with lower number of specimens. The adult plants were underdeveloped and the growing of aphid colonies induced the blossoming. In the seedlings the symptoms were severer with reduction in the development and death of plants. When the colonies were placed in the dorsal side of the leaves, there was a tendency to wrinkling and rolling to upper side that was used as shelter by the aphids. Morphological characterization, illustrations and notes on biology of .. dauci and a survey of the Arthropoda related with .. xanthorrhiza are also presented.
KEY WORDS Aphidinae; Apiaceae; arracacha; Arracacia xanthorrhiza ; Macrosiphini; Semiaphis dauci