First report of Fingeriana dubia cavichioli transmitting Xylella fastidiosa to citrus

Primeiro relato de Fingeriana dubia cavichioli transmitindo Xylella fastidiosa para citros

NOTAS FITOPATOLÓGICAS PHYTOPATHOLOGICAL NOTES

First report of Fingeriana dubia cavichioli transmitting Xylella fastidiosa to citrus

Primeiro relato de Fingeriana dubia cavichioli transmitindo Xylella fastidiosa para citros

Pedro T. Yamamoto^I; Marcos R. Felippe^I; Antonio C. Caetano^I; André L. Sanches^I; João R. S. Lopes^II

^IDepartamento Científico, Fundo de Defesa da Citricultura - Fundecitrus, Cx. Postal 391, CEP 14.807-070, Araraquara, SP, Brazil, e-mail: [e-mail]

^IIDepartamento de Entomologia, Fitopatologia e Zoologia Agrícola, ESALQ – Universidade de São Paulo, Cx. Postal 9, CEP 13418-900, Piracicaba, SP, Brazil

RESUMO

Este trabalho relata, pela primeira vez, a transmissão da bactéria Xylella fastidiosa, agente causal da clorose variegada dos citros, por Fingeriana dubia Cavichioli (Hemiptera: Cicadellidae: Cicadellinae). Uma planta de três testadas mostrou-se infectada e apresentou sintomas típicos da CVC aproximadamente 9 meses após a inoculação por esta espécie de cigarrinha.

Citrus Variegated Chlorosis (CVC) was first reported in Brazil in 1987, in sweet orange [Citrus sinensis (L.) Osbeck] orchards of North and Northeast regions of São Paulo State (Rossetti & de Negri, Laranja, 11:1, 1990). Later, the disease was found in other regions and today is present in most Brazilian citrus areas. In São Paulo State and Southwest of Minas Gerais State ('Triângulo Mineiro' region), 43.3 % of the sweet orange trees show CVC symptoms (www.fundecitrus.com.br). The main vectors of Xylella fastidiosa are leafhoppers (Hemiptera: Cicadellidae) from the subfamily Cicadellinae, commonly known as sharpshooters. This taxon of leafhoppers is diverse and several species have been recorded in citrus orchards of São Paulo State (Yamamoto & Gravena, An. Soc. Entomol. Brasil, 29:169. 2000; Marucci et al., Rev. Bras. Entomol. 46:149. 2002), and shown experimentally to transmit Xylella fastidiosa to citrus (Roberto et al., Fitopatol. Bras. 21:517. 1996; Lopes, Laranja 20:329. 1999; Yamamoto et al., Summa Phytopathol. 28:178. 2002). Because Fingeriana dubia Cavichioli (Figure 1) is a new Cicadellinae species found in coffee and citrus orchards in Paraná, São Paulo and Minas Gerais States (Cavichioli, Rev. Bras. Zool., 20:247. 2003), we conducted this experiment to verify its ability to transmit X. fastidiosa to citrus. The specimens of F. dubia used in the transmission experiment were captured in a citrus farm and caged on a CVC diseased plant for a 48-h acquisition access period (AAP). After AAP, groups of adults were confined on healthy seedlings of 'Caipira' sweet orange variety for a 48-h inoculation access period (IAP). Because of the low D. dubia abundance in the field, we inoculated only three test plants (10 insects per plant). After IAP, the specimens were killed and the test plants transferred to 12-liter pots, which were maintained inside an insect proof greenhouse under periodical treatments with insecticides. One of the three inoculated plants showed typical CVC disease symptoms after approximately 9 months. The presence of X. fastidiosa was confirmed by PCR using specific primers (Pooler & Hartung, Curr. Microbiol. 31:377. 1995). None of the 30 non-inoculated test plants (negative controls) showed symptoms or infection by X. fastidiosa. This result demonstrates experimentally that F. dubia transmits the CVC pathogen. Further studies on host plants and population dynamics of this sharpshooter are necessary to determine its epidemiological importance as a vector of X. fastidiosa in citrus and other possibly affected crops.

Received 19 April 2007 - Accepted 18 June 2007 - FB 7044

Autor para correspondência: Pedro T. Yamamoto

Publication Dates

• Publication in this collection
  14 Aug 2007
• Date of issue
  June 2007