Benefits of biological control of invasive alien plants
Ambrosia artemisiifolia (Asteraceae - EPPO List of Invasive Alien Plants) is native to North America and was accidentally introduced into the EPPO region in the 19th century. It is a major problem in spring-grown crops and causes allergic rhinitis and asthma in sufferers due to its allergenic pollen. In China, Ophraella communa (Coleoptera, Chrysomelidae) has been utilised against A. artemisiifolia as a classical biological control agent. In 2013, it was found to have accidentally established in Northern Italy and Southern Switzerland where it has been shown to inflict significant damage on A. artemisiifolia populations. In particular, ragweed pollen concentrations in Northern Italy have been shown to decrease with the presence of the biocontrol agent. Using data on Ambrosia pollen exposure from across Europe, data on Ambrosia sensitisation among the population, and data on the impact of O. communa on pollen production, projections are made of positive benefits of the biocontrol agent. Prior to the establishment of O. communa in Europe it is estimated that some 13.5 million people suffered from Ambrosia induced allergies causing costs of approximately 7.4 billion Euros annually. Once O. communa has colonised its environmental niche, the number of patients is expected to reduce by approximately 2.3 million with a saving in economic terms of 1.1 billion Euros a year.
Sources
Schaffner U, Steinbach S, Sun Y, Skjøth CA, Weger LA, Lommen STE, Augustinus BA, Bonini M, Karrer G, Sikoparija B, Thibaudon M, Müller-Schärer H (2020) Biological weed control to relieve millions from Ambrosia allergies in Europe. Nature Communications, DOI: 10.1038/s41467-020-15586-1