Olive orchards from Argentina affected by Xylella fastidiosa

PACCIORETTI PATRICIA; DEFEA, BÁRBARA; PARADELL SUSANA; CALAHORRA, ANDREA; OTERO M.; PEREYRA MORA; HAELTERMAN RAQUEL; TOLOCKA PATRICIA; FOIERI ALVARO; ROCA MONICA

Córcega

Simposio; Second European Conference on Xylella fastidiosa; 2019

European Food Safety Authority

Decline symptoms in olive trees caused by Xylella fastidiosa (Xf) infection have emerged as a potential disease threat to one of the most important olive production area in Argentina. In La Rioja province, the local cultivar Arauco is the most affected by the bacterium but was also detected in the cvs. "Manzanilla", "Arbequina and "Picual". Since 2013, a marked decline of the traditional cultivar is observed being affected both, old and young orchards. Total samples were collected from infected trees, in seven commercial lots of Arauco, some of them were randomly selected around the tree and others, sectorized from branches with a marked dried symptom advance. Xf was best detected from the sectorized samples (92%) than from the samples taken around the tree (65.8%) and until now, only the pauca subspecies (ST69) was detected in olive plants. This type sequence has only been found in Argentina where was also detected in orange trees from the northeastern region. To identify the potential vectors of Xf sampling was conducted in olive orchards positive to the bacterium located in La Rioja province (Chilecito). Since 2016, insects are collected from olives trees with sticky yellow traps and from the surrounding vegetation with entomological sweep nets. The collected specimens were identified by Auchenorrhyncha specialists (CEPAVE, CONICET-UNLP and IMYZA INTA Castelar). Until know, the subfamily Cicadellinae (Cicadellidae) was the second most represented and species of the genera Macugonalia Young, Scopogonalia Young and Molomea China were the most abundant. The sharpshooters Bucephalogonia xanthophis (Berg), a vector of Xf in Brazil (Redak et al., 2004) along with other species tested positive for the bacteria in northeastern Argentina were also recorded. Specimens of Notozulia entreriana (Berg) (Cercopidae) were collected in the spontaneous vegetation associated with the crop.