Flea beetles -- risk to plant health
Report no: 2019:17
The flea beetles in the genus Epitrix present a low risk to Norwegian potato production. However, this risk can increase if potatoes are imported from countries where Epitrix is present, or if climate change causes increased temperatures in Norway.
This is the conclusion from the Norwegian Scientific Committee for Food and Environment in the recent pest risk assessment of selected Epitrix species. The Norwegian Food Safety Authority commissioned the risk assessment.
Epitrix is a genus of small beetles often called flea beetles, which belong to the family of leaf beetles (Chrysomelidae). There are 162 described species of Epitrix, and probably many more undescribed species. At least 10 of the Epitrix species are known to damage potato tubers. At present no Epitrix species are known to have damaged potatoes in Norway.
Import of potatoes is the most important path of entry
VKM identified three Epitrix species of potential phytosanitary concern for Norway. These three species, probably native to the Americas, have established themselves in southern Europe in countries that export potato tubers to Norway. “Unwashed potatoes is considered to be the source with the highest probability of conveying Epitrix species to Norway,” tells Johan Stenberg, chair of the Epitrix project group.
Reducing the risk by washing potatoes
VKM has also assessed risk reduction options that can reduce the probability of entry, establishment and spread of Epitrix. As consignments are closed, and the beetles have limited capabilities to spread naturally, there is low risk of Epitrix spreading to Norwegian habitats having cultivated or wild host plants.
“Washing potatoes before they are imported into Norway is probably the most efficient risk reduction option,” says Stenberg.
The Norwegian climate could also limit the establishment of Epitrix species in Norway. VKM has modelled the potential distribution of the three species, based on their known occurrence in the Americas and different climate variables.
“The results indicate a low probability of establishment in Norway, but this conclusion has a high degree of uncertainty,” says Stenberg.
VKMs panel on plant health is responsible for the risk assessment.