Estimating the economic benefits of the biocontrol agent Ophraella communa for Ambrosia artemisiifolia
Ambrosia artemisiifolia (Asteraceae: EPPO List of Invasive Alien Plants) is native to North America and is a widespread invasive alien plant in the EPPO region. A. artemisiifolia is an annual weed which competes strongly with crop plants for water and nutrients. It is a very prolific seed producer (a plant typically produces 30,000 - 40,000 seeds per year and can be up to 100,000) and seeds can remain viable for 5-14 years. It can have negative impacts on agricultural production by reducing yields of cereals and other field crops (e.g. sunflower). Its presence can reduce fodder quality of meadows and pastures (A. artemisiifolia is not palatable to livestock), and taints diary products if cattle do feed on it. In addition, its pollen is strongly allergenic to humans (hay fever) and can cause contact dermatitis. In China, a North America beetle (Ophraella communa: Coleoptera, Chrysomelidae) has been utilised against A. artemisiifolia as a classical biological control agent. In 2013, the same beetle species was found to have accidently established in Northern Italy and Southern Switzerland where it has been shown to inflict significant damage on A. artemisiifolia populations, and in particular, ragweed pollen concentrations in Northern Italy have been shown to decrease with the presence of the biocontrol agent. In the current study, the authors set out to estimate the potential economic benefits of the establishment of O. communa in the Rhône-Alpes region in south-eastern France, where detailed data on the economic impact of A. artemisiifolia are available. By extrapolating the change in airborne ragweed pollen concentrations in Italy to that in the South of France, the authors estimated that establishment of O. communa in the Rhône-Alpes region could reduce the number of days with ragweed pollen concentrations at which sensitive people express symptoms by 50% thus reducing medical costs by 5.2–6.8 million Euros annually.
Sources
Mouttet R, Augustinus B, Bonini M, Chauvel B, Desneux N, Gachet E, le Bourgeois T, Müller-Schärer H, Thibaudon M, Schaffner U (2018) Estimating economic benefits of biological control of Ambrosia artemisiifolia by Ophraella communa in southeastern France. Basic and Applied Ecology https://doi.org/10.1016/j.baae.2018.08.002