Survey of leafhopper (hemiptera: cicadellidae) vectors of Xylella fastidiosa in citrus groves of the north coast of Bahia state. / Levantamento de cigarrinhas (Hemiptera: Cicadellidae) vetoras de Xylella fastidiosa em pomares cítricos do litoral norte da Bahia.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

This study was carried out to identify vectors or potential vectors of Xylella fastidiosa Wells et al. in citrus groves of the north coast of Bahia State, Brazil, based on a faunistic survey and determination of predominant sharpshooter leafhoppers (subfamily Cicadellinae). The survey was carried out from March/2002 to February/2003 in five old sweet orange [Citrus sinensis (L.) Osbeck, cv. Pêra, grafted on rangpur lime (Citrus limonia Osbeck); 7-9 years old] groves of northeastern Bahia State, located in Alagoinhas, Inhambupe and Rio Real. Fifteen yellow sticky cards (8,5 X 11,5 cm) were installed 40x40 m apart in each grove, hanged at the height of 1.5 m on the upper north side of citrus canopies. Cards were replaced monthly or fortnightly. A sweep net was periodically used to sample leafhoppers in the herbaceous weeds inside the groves, by selecting five points at random and performing 30 sweeps in each point (sample unit). Data was uses to calculate indices of constancy, frequency, abundance, dominance, diversity, equitability and similarity. A total of 1860 specimens of 54 species belonging to 7 families of suborder Auchenorrhyncha were collected, most of them in the families Cicadellidae (84,3%) and Membracidae (14,2%). A larger number of species was observed in a grove located nearby a non-degraded native wood. The subfamily Cicadellinae, which includes the sharphooter vectors of X. fastidiosa, showed the largest number of species (15) and specimens (63,92%). There was a variation in Cicadellinae species composition depending upon the sampling method, which indicates that two distinct groups of potential sharpshooter vectors are inhabiting the citrus canopy and the weedy vegetation. Acrogonia flagellata Young, A. citrina Marucci &Cavichioli, Homalodica sp. e Cicadellini sp.1 predominate in the yellow sticky cards hanged on the citrus canopy, whereas Hortensia similis (Walker) e Erythrogonia dubia (Medler) were dominant species on weeds. Among the Cicadellinae species already known as vectors of X. fastidiosa in citrus, only A. citrina, Bucephalogonia xanthophis (Berg) e Ferrariana trivittata (Signoret) were found; the two latter species were accidentally trapped by sweep net in the weedy vegetation. Among the new potential vectors, A. flagellata, Homalodisca sp. e Cicadellini sp.1 are predominant species in citrus groves of the north coast of Bahia and should be tested with respect to their ability to transmit X. fastidiosa to citrus.

ASSUNTO(S)

orchards bactéria fitopatogênica citrus variegated chlorosis citric fruits frutas cítricas insetos vetores phytopathogenic bacterium clorose variegada dos citros pomares insect vectors

ACESSO AO ARTIGO

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