Research project Newly emerging risks of pests for plants and plant products in Belgium

General introduction

The EMPHYPEST project evaluated the phytosanitary status in Belgium of six regulated plant pathogenic fungi and five insect pests, each for specific host plants and/or sectors (fruit growing, ornamental horticulture, forests, nature) in which they could potentially occur. The question was whether the fungi and insects were present or absent in our territory. The answer was generally no, except in two relatively manageable cases. Among the fungi and oomycetes, the target pathogens were not detected, except for Phytophthora pluvialis (on Pseudotsuga, a conifer) in Wallonia. Among the insects, most species, except for Pochazia shantungensis, were not found during an interception (a check of imported host plants from Southern Europe).
EMPHYPEST is part of EU quarantine legislation, and in particular Directive EU/2019/2072. This lists regulated plant pests and then draws up a plan to monitor the phytosanitary risks for Europe and determine whether strict control actions are required.

Research approach

Specifically, the following fungi (and oomycetes) and insects had to be checked for presence: Colletotrichum fructicola and C. siamense in apples, pears, and strawberries; Phytophthora pluvialis in Douglas fir; Phytophthora nemorosa and Phytophthora hibernalis in the ornamental horticulture sector; and Phytophthora austrocedri in wild juniper. In the entomological part, the researchers searched for Chionaspis pinifoliae (a scale insect), Crisicoccus pini (a mealybug), and Toumeyella parvicornis (a scale insect) on pines, the moth Garella musculana on walnuts, and the polyphagous winged leafhopper Pochazia shantungensis. The status of all these pathogens was determined through targeted surveys, specifically for the host plants and at-risk sectors. In some cases, detection or analysis methods were first validated or developed. Samples were collected over two years during relevant periods. Whether or not they were stored, the samples were analyzed using the most appropriate method for detecting and identifying the organisms in question.

Relevance/Valorization

Among the fungi and oomycetes, of all the target pathogens, only Phytophthora pluvialis was found, in Wallonia, on Pseudotsuga (a conifer). This was the first observation for continental Europe. The pathogen is likely latently present on a larger scale than originally thought, but difficult to detect. The damage caused by Phytophthora pluvialis appears limited, possibly because the most susceptible host plant for this pathogen (Tsuga) is only present in limited numbers in Belgium. Although the target was not found in other surveys of, for example, Phytophthora nemorosa, this survey did provide a valuable overview of other Phytophthora species present: 22 species were detected, five of which were the first observations for Belgium.
Among the insects, most species were also not found, except for Pochazia shantungensis. These observations were classified as interceptions: they occurred following the recent import of host plants from Southern Europe, but no further observations were made during intensive environmental monitoring.
The risk assessment and status determination of regulated organisms under EU quarantine legislation are based on scientifically sound methods. The legislation now also places a greater emphasis on prevention. The project also contributed to this by raising awareness of these organisms among scientists, operators, and the public.

Financing

FOD Volksgezondheid, Veiligheid van de voedselketen en Leefmilieu