Knowledge and perceptions of invasive plant biocontrol in Europe versus the rest of the world

Abstract

Biological control (BC) of invasive alien plants (IAP) can be an effective environmental management approach. It has only very recently been adopted in Europe and is underutilized compared to other continents where this method has been successfully implemented for over a century. This is in sharp contrast to the BC of invertebrate pests, which has been taken up widely within Europe. It has been suggested that this is related to the risk-adverse attitude of Europeans towards weed BC. Scientific and public perception have a major influence on environmental policy actions. Public perception and knowledge regarding BC is an understudied subject despite its relevance for the application of this management alternative. We aimed to assess the knowledge and perception of BC of IAP among European professionals compared with their peers from other continents. To this end we conducted an online survey including multiple choice and open questions among over 700 people professionally engaged with managing the natural environment, of which approximately half were from Europe (EU) and the others from outside (non-EU). We assessed relationships between the geographical location of the respondents and their knowledge, and perceptions of BC of weeds versus BC of invertebrate pests. We found that respondents' location influenced both perceptions and knowledge of BC for weeds. Compared to non-EU respondents, EU professionals showed less appreciation for BC (e.g., regarding safety, sustainability, and cost-effectiveness), and perceived it as a riskier method, particularly in the case of practitioners and researchers. More profoundly insect pest BC tended to be considered less safe than weed BC for non-EU respondents. Confidence in weed BC as a method, as well as in the validity of the associated pre-release risk assessments, strongly increased with the level of expertise in weed BC. While a much higher proportion of non-EU respondents were correctly aware of the presence/absence of BC in their own countries and identified successful examples of BC accurately, both groups of respondents were similarly aware of unsuccessful BC examples, including BC agents against animals, stressing the bias of EU respondents towards examples of BC failure. The appreciation of weed BC in Europe could be elevated by a combination of increasing knowledge of the technique and pre-release risk assessment and promoting successful examples of weed BC, which may bring major benefits for the management of IAP across the region.