CABI has undertaken groundbreaking research that underscores the value of harnessing citizen science to monitor the propagation and dispersion of a natural predator aimed at combatting the invasive shrub known as Chromolaena odorata, or Siam weed, across South and South-East Asia.
Dr. Matthew Cock, an esteemed CABI Emeritus Fellow, utilized the iNaturalist.org platform to evaluate the establishment and proliferation of the moth Pareuchaetes pseudoinsulata. This moth was released across six countries in South and South-East Asia with the intention of controlling the spread of C. odorata.
In collaboration with peers from Australia’s Department of Agriculture and Fisheries and MIA Consulting based in Utah, U.S., Dr. Cock’s research significantly supplements existing knowledge. The study has revealed that P. pseudoinsulata is successfully established in Thailand and Vietnam, and its range extends to China, Cambodia, and West Malaysia.
This novel research, featured as a concise communication in the CABI Agriculture and Bioscience journal, also attests to the widespread presence of P. pseudoinsulata in southern India and Sri Lanka, based on observations contributed by citizen scientists via iNaturalist.
The researchers assert that iNaturalist serves as an invaluable supplementary source of information regarding the prevalence and migration of introduced species, including those employed for biological control. However, its effectiveness hinges on the subjects’ recognizability from photographic documentation.
Citizen science, a collaborative approach where the general public, often referred to as amateur or non-professional scientists, participate in scientific research, assumes a pivotal role. A 2013 “Green Paper on Citizen Science,” issued by the European Commission’s Digital Science Unit and Socientize.eu, highlights the role of participants in furnishing experimental data, posing novel inquiries, and collectively cultivating a fresh scientific ethos.
Chromolaena odorata, a pioneering shrub indigenous to the Americas, spanning from the southern United States to Argentina, has evolved into one of the most formidable invasive species in the humid tropics and subtropics of the Old World.
Pareuchaetes pseudoinsulata was meticulously introduced across select nations in Africa, South and South-East Asia, as well as portions of the Pacific, eventually establishing a presence in these regions.
The efficacy of several releases of P. pseudoinsulata was inconclusive, with instances where the agent failed to establish (e.g., Thailand and Vietnam) or lacked subsequent published assessments of its success.
Dr. Cock elucidated, “This paper delves into the veracity of certain reports while also underscoring the benefits of utilizing citizen science to monitor the introduction and progression of weed biological control agents.”
The visual records shared by citizen scientists via iNaturalist validate the existence of P. pseudoinsulata in multiple locales, even in regions where its presence had not been hitherto documented.
In cases where the moth’s establishment had been reported but lacked supporting imagery, the study indicates avenues for focused citizen science initiatives or alternative forms of on-site validation involving researchers specializing in biological control.
Overall, this study by CABI underscores the invaluable role of citizen science in tracking the expansion of introduced species and contributes to a more comprehensive understanding of the efficacy of biological control agents.