Recommendations from Euphresco projects
The following research project has recently been carried out in the framework of Euphresco (network for phytosanitary research coordination - hosted by EPPO). A report presenting the main objectives and results of this project, as well as recommendations made, can be viewed on the Euphresco website.
Epitrix species, life cycles and detection methods (Epitrix II)
Epitrix Foudras 1860, is a genus of flea beetles that has a worldwide distribution and consists of nearly 180 species. Most species occur in South and Central America and only 12 and 10 species are known from North America and Europe, respectively. In the European Union (EU) emergency measures have been introduced to prevent the introduction of the EPPO A1 listed species Epitrix tuberis and E. subcrinita and the spread of the EPPO A2 species E. cucumeris and E. papa, present in Portugal and Spain. This project built on the expertise of a network of scientists developed during the Euphresco project Epitrix I to increase knowledge and preparedness for potential new outbreaks of Epitrix spp. affecting potato crops.
Many Epitrix spp. were collected on solanaceous plants during a field expedition to Peru in 2020. This material will be used to fill knowledge gaps on poorly-known Epitrix species and identify potential pests.
Several diagnostic tests were validated during the project and during this validation, it was noted that the quality and concentration of DNA from the non-destructive extraction method were similar to those from the destructive method, with the additional benefit that the non-destructive extraction enables the specimen to be kept as reference material. It was also noted that specimens caught on sticky traps and stored in 70% ethanol produce DNA of lower quality and caused greater cross reaction in the TaqMan real-time PCR tests. It is therefore advised that specimens are caught using insect aspirators and then stored either by freezing or in ≥95% ethanol.
The use of plant volatile organic compounds (VOCs) as attractants for monitoring Epitrix spp. was investigated. Studies on pheromone trapping showed that traps baited with Z3-6:Ac/Linalool (1:1) attracting significantly more E. papa and E. cucumeris adults than the control. Adding (E)-β-ocimene to Z3-6:Ac/Linalool (1:3) increased the attractiveness of the mixture. However, the substances tested were insufficiently attractive for reliable Epitrix detection and monitoring in the field. Further research using insect pheromones as lures for Epitrix spp. need to be carried out in the future.
Available insecticides and cultural management practices were reviewed and it was concluded that cultural practices (such as crop rotation, modifying dates of planting, use of a trap crop, destruction of crop residues, and control of solanaceous weeds) may be used with promising results to control Epitrix spp.
Duration of the project: 2017-10-01 to 2020-12-31.
Authors: Kenyon, David; Highet, Fiona MBE; Caims, Fiona; Nicolaisen, Mogens; Mouttet, Raphaëlle; Loomans, Anton; Boavida, Conceiçao; de Andrade, Eugenia; Douglas, Hume; Deczynski, Anthony.
Link: https://zenodo.org/record/5668350#.YY6EI2DMKUl
Sources
Euphresco (2021-11).