International Ragweed Society

The IRS Committee is pleased to invite everyone interested in Ambrosia research and management to join our upcoming “Let’s Talk About Ambrosia” online conference! The session will be presented by Zoé Rousset, a PhD researcher at INRAe, who will discuss the spread of Ophraella communa in France since its detection in October 2023. This insect, a natural predator of common ragweed (Ambrosia artemisiifolia), is currently under monitoring to better understand its expansion and potential impact.

The event will feature a 15-minute presentation followed by a 15-minute Q&A session and is scheduled for February 19 at 9:00 AM CET.
For those who are unable to attend, the conference will be recorded and made available afterward.

Join the conference via Microsoft Teams using the following link:

Teams link

Please feel free to share this invitation with your colleagues and networks.
We look forward to your participation!

February 3, 2025 – The International Ragweed Society (IRS) committee met online to discuss recent developments, ongoing projects, and future plans for 2025. The meeting, attended by all Committee members, focused on the outcomes of the
2024 World Aerobiology Conference, upcoming leadership elections, and the latest research on Ambrosia pollen.

Looking Back: 2024 in Review
IRS President, Prof. László Makra, noted that the World Aerobiology Conference 2024 in Vilnius, Lithuania, saw strong participation, although some IRS members were unable to attend. A major highlight was the ragweed-focused scientific session, featuring cutting-edge research on Ambrosia pollen monitoring and transports, meteorological modeling, invasion dynamics and real-time detection technologies, showcasing research from Lithuania, Italy, Turkey, France, and Poland. Among the notable studies presented were:

• Ragweed Pollen and Atmospheric Circulation in Lithuania
• Aerotape: Real-Time Optical Detection of Ragweed Pollen
• Hotspots of Ragweed Pollen in Türkiye and Meteorological Impacts

IRS also provided scholarships to three new members, reinforcing its commitment to supporting emerging researchers in the field. The organization maintains a strong financial position, with membership fees remaining stable for 2025.

Plans for 2025: Strengthening Research and Leadership
With the committee’s mandate officially ending in 2024, current IRS President László Makra has agreed to continue his role through 2026. However, a formal election process will be announced at the next General Assembly, potentially scheduled after the upcoming “Let’s Talk About Ambrosia” lecture.
Also, Tristan Grausi joining the committee to replace Marilou Mottet.
A key priority for IRS in 2025 will be the proposed special journal issue on Ambrosia-related studies, which has received strong support from committee members. The society also plans to expand its online lecture series, with the next talk focusing on Ophraella-Ambrosia interactions, led by the research team of Nicolas Desneux.

Expanding the Scientific Frontier
IRS committee members demonstrated remarkable research productivity in 2024, with 25 scientific publications on ragweed and its pollen. Leading contributors included Yan Sun & Heinz Müller-Schärer (8 papers) and Victoria Rodinkova (6 papers). These publications cover a broad spectrum of topics, from pollen exposure modeling to Bayesian analysis of sensitization patterns.

New Research and Global Collaboration
Discussions also highlighted ongoing and planned ragweed-related research projects. These research projects span global pollen monitoring, machine learning applications, plant-soil evolutionary feedbacks, and human health impacts.

• Yan Sun & Heinz Müller-Schärer are leading multiple projects, including studies on plant-soil interactions and genetic drivers of male/female flower production.
• László Makra is working on machine learning models to predict pollen exposure under future climate scenarios.
• Victoria Rodinkova is spearheading new research on sensitization to Ambrosia pollen in Ukraine.

Additionally, IRS members expressed interest in developing a large-scale European research initiative, possibly under the COST framework.

Enhancing Public Awareness
Recognizing the need for effective science communication, the committee proposed creating informational materials on ragweed invasion and its impacts. These resources, created for both scientists and the general public, could be integrated into press releases and awareness campaigns, including Ragweed Day initiatives.

Looking Ahead
The next IRS committee meeting is expected in April or May 2025, providing an opportunity to finalize research plans and solidify organizational goals for the year ahead. As IRS continues its mission, 2025 promises to be a year of scientific collaboration, strategic expansion, and impactful outreach in the fight against ragweed-related health challenges. The IRS continues to play a crucial role in coordinating international research efforts on ragweed, a plant species of significant environmental and public health concern.

Ragweed section, initiated by IRS was carried out within the World Aerobiology Congress. It was held in Vilnius, Lithuania from July 1-5, 2024. Ragweed-devoted section gathered 6 outstanding works which discussed ragweed ecology and health impact including those caused by pollen migration.

The study “Association of Ragweed Pollen Episodes in Lithuania with Atmospheric Circulation Patterns” by Ingrida Šaulienė, Gintautas Stankūnavičius, and Laura Šukienė found that Vilnius recorded higher frequencies and concentrations of ragweed pollen compared to other Lithuanian cities over 15 years. Utilizing volumetric Hirst pollen traps and the Hess and Brezowsky atmospheric circulation classification, they identified specific weather patterns, such as Central European Troughs, as conducive to high pollen levels. Understanding these patterns helps predict high-risk pollen episodes.

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The IRS General Assembly took place during the World Aerobiology Congress presenting an extensive agenda to its members. The World Aerobiology was held at the Radisson Blu Hotel Lietuva in Vilnius, Lithuania, from July 1-5, 2024.

The IRS meeting was chaired by its President Prof László Makra.

The IRS assembly’s agenda included the approval of the minutes from the previous General Assembly, reports on IRS activities, a comprehensive membership overview, and the financial report for 2022, 2023, and 2024 presented by Roberto Albertini. Additionally, Franziska Zemmer delivered the IRS Auditor’s report.

Both reports confirmed no financial problems with a positive financial balance on the IRS Bank account.

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