Xylella fastidiosa detected in Coffea spp. plants imported into Switzerland
Following the detection of Xylella fastidiosa (EPPO A1 List) by the Dutch NPPO in imported Coffea plants, tracing-forward studies were conducted in Switzerland on re-exported lots. In September 2015, the presence of X. fastidiosa was confirmed in 4 Coffea plants (asymptomatic), first by a Swiss laboratory and then by the reference laboratory of an EU country:
- 1 coffee plant in a tropical plant centre in Wolhusen (canton of Lucerne) was found to be infected by X. fastidiosa subsp. sandyi.
- 3 coffee plants in a garden centre in Dürnten (canton of Zürich). X. fastidiosa subsp. sandyi was identified in one of these plants which had been delivered by the same Dutch reseller as in the case of Wolhusen. X. fastidiosa subsp. pauca was identified in the two other plants which had been delivered by another Dutch reseller.
In the canton of Lucerne, the infected plant was a solitary coffee plant held in the reception hall next to the exhibition glasshouse. All potential host plants of X. fastidiosa (as specified by the EU Decision 2015/789) grown in the exhibition glasshouse (mainly Coffea spp. and Citrus hystrix) were sampled. Coffea spp. and potential host plants were also sampled in a second glasshouse, situated 50 m away from the first one and used to grow exotic fruit and vegetables, aromatic and coffee plants to be sold to visitors,. Although some false positive results were obtained at some point of the analysis, final results confirmed that only the solitary coffee plant in the reception hall was infected.
In the canton of Zürich, the 3 infected Coffea spp. plants (1 large and 2 smaller ones) were held in the same compartment of a glasshouse dedicated to indoor plants. A botanical inventory of the whole glasshouse was carried out to identify other potential host plants (as specified by EU Decision 2015/789). Samples were taken from these potential host plants (e.g. Olea europaea and Nerium oleander) and tested. All results were negative.
On both sites, the NPPO considers that the situation is closer to an interception than to an outbreak. All infected Coffea spp. plants have been destroyed and investigations have shown that the bacterium has not been able to spread to other plants. The movement of all potential host plants has been prohibited and surveys will be conducted in 2016 in the outdoor parts of the premises concerned.
The pest status of Xylella fastidiosa in Switzerland is officially declared as: Transient, actionable, under eradication.
Sources
NPPO of Switzerland (2015-10).
EU Commission Implementing Decision 2015/789 of 18 May 2015 as regards measures to prevent the introduction into and the spread within the Union of Xylella fastidiosa (Wells et al.). http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX