Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Pest survey card on Thekopsora minima.

Abstract

This pest survey card was prepared in the context of the EFSA mandate on plant pest surveillance (M-2017-0137) at the request of the European Commission. Its purpose is to guide the Member States in preparing data and information for Thekopsora minima surveys. These are required to design statistically sound and risk-based pest surveys, in line with current international standards.Thekopsoraminima is not regulated in the EUbut is included in theEPPO A2 list of pests recommended for regulationas a quarantine pest. It is the causal agent of blueberry leaf rust on the American highbush blueberry (Vacciniumcorymbosum). In the EU, the pathogen has been reported in Belgium, Germany, the Netherlands, Portugal and Spain. Host availability seems to be the only limit to the spread of the pest due to its broad climatic tolerance. Surveys should be performed mainly in spring or autumn (in regions with a Mediterranean climate) or late summer and the beginning of autumn (in temperate climates). Detection surveys should mainly target Vaccinium corymbosum in nurseries, plantations and naturalised plants, whereas for delimiting surveys Tsuga and Rhododendron spp.should also be monitored. Surveillance of Thekopsora minima in the EU should focus onthe visible symptoms on Vaccinium plants caused bythe uredinialstage of the fungus that can be identified morphologically by experts. However, reliable identification of T. minima requires molecular methods and DNA sequence analysis.