Prioritising environmental invasive weeds of European concern for classical biological control: A reanalysis

Authors: LESIEUR, VINCENT - Csiro European Laboratory; SFORZA, RENE - European Biological Control Laboratory (EBCL); SHEPPARD, ANDY - Commonwealth Scientific And Industrial Research Organisation (CSIRO); SHAW, RICHARD - Commonwealth Agricultural Bureau International (CABI)

Submitted to: Weed Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/27/2023
Publication Date: 4/12/2023
Citation: Lesieur, V., Sforza, R.F., Sheppard, A., Shaw, R. 2023. Prioritising environmental invasive weeds of European concern for classical biological control: A reanalysis. Weed Research. 1-14. https://doi.org/10.1111/wre.12582.
DOI: https://doi.org/10.1111/wre.12582

Interpretive Summary: Many invasive alien plant species (IAPs) have been widely recognised as having major adverse existential impacts to native biodiversity ecosystems, agricultural production and human wellbeing; but also represent agents of future future threats. The numbers of alien plant species being introduced and establishing around the world continues to increase unabated, and globally around 10% of introduced and established alien plants become invasive. The impact of IAPs is not limited to natural and manmade ecosystems, but there are also significant human health impacts. A recent economic assessment indicated that invasive alien species (including plants) cause losses of €116.61 billion to the European economy every year. The aim of this study was to use an existing system to generate a prioritized table of IAPs of environmental concern drawn from those listed on Annexe 1 of the European Regulations for Invasive Species to assist future decision making on biologically-based management approaches to weeds at the European level.

Technical Abstract: Many invasive alien plant species (IAPs) have been widely recognized as having major adverse existential impacts to native biodiversity ecosystems, agricultural production and human wellbeing; but also represent agents of future threats. IAPs invade all types of natural and managed habitat and their impacts, through increased numbers and area invaded, are growing exponentially. Current control options in Europe are largely limited to manual and chemical control, which is high cost, short-term in effectiveness and, with regards to chemical control, declining in public acceptability. Globally, classical biological control (CBC) is widely and successfully used to manage many IAPs. CBC aims to redress the ecological imbalance caused by the IAPs that are generally introduced without their natural enemies. The steps are to select, and risk assess, potential specific natural enemy biocontrol agents of the IAP (from the IAP’s native range) and follow a regulatory approval protocol prior to releasing them to suppress the IAP abundance. CBC is not widely used in Europe. Only five active programmes exist. In this paper we apply an existing framework to develop a ranked list of IAPs named in the EU Regulation on Invasive Species for biocontrol. We used a scoring system based on existing knowledge on the IAPs impacts, the amount of effort needed to deliver a CBC programme targeting them and the feasibility and likelihood of success of such programmes. We identify 16 IAPs in Europe for which CBC has relatively high potential and discuss existing knowledge that can underpin any future investments in such activities against each of these IAPs. The top three species being Eichhornia crassipes, Pistia startiotes and Acacia saligna. This research should support decision making on the instigation of future CBC programmes against IAPs in Europe. We set this analysis in the context of other operational and regulatory constraints on developing CBC programmes against IAPs in Europe.