Please find the issue of July 2021 of the Ragweed observatory Letter on our new website, espece-risque-santé.info : click here to consult it

This newsletter aims to provide general and scientific information on the latest news concerning ragweed species.

As well as the Ragweed Observatory missions, it will evolve to the newsletter of the Observatory of hight-stake species for human health. Thus, it will provide general and scientific information on others species, like for exemples the processionnary oak and pine caterpillars.

In this issue :
– French international ragweed days 2021 & ragweed observatory’s 10 years old event
– Creation of the “Observatory of high-stake species for human health”
– Bird seed food in Belgium
–International ragweed society conference, Budapest 2022

If you know anyone who might be interested in this newsletter, please share them the link ! They also can contact us (observatoire.ambroisie@fredon-france.org ) and we will send them the next issue (just a few issues are in English: one or two newsletters will be translated each year).



The president and members of the IRS committee are pleased to announce that the next IRS CONFERENCE will take place in Budapest in September 8 & 9, 2022.

« What’s new in the world with Ambrosia ? »

Please make sure to save the date on your agenda and kindly forward this message to anyone in your network who you feel might be interested in attending. You will receive all important information concerning dates, registration, booking, fees, etc. in the course of the year 2021.

Looking forward to meeting you in Hungary,
Michel Thibaudon, President of the International Ragweed Society
The local organizing committee: László Makra, Donát Magyar and Tamás Szigeti (National Public Health Center, Hungary)

IRS Symposium – relive

IRS Symposium – relive

The International Ragweed Symposium was held on Monday, September 14th 2020 by video. You can see it again on Youtube!

Speakers :

2”35- Chantal Déchamp -Henriette Méon -Patrick Chevrolat -Yves Auda-2020: update on common ragweed remote-sensing data in France

19”55- Heinz Müller-Schärer – How to better predict long-term benefits and risks in weed biocontrol: an evolutionary perspective

42”00- Yan Sun and Heinz Müller-Schärer – Rapid evolution of a plant invader in response to biological control and global warming

58”40 – Michel Thibaudon–Jordina Belmonte –Samuel Monnier –Fanny Vasseur – Can photoperiod parameter limit the northward expansion of Ragweed?

1’31’30 – Arnaud Monty – Sylvain Mahieu – Adrien Delforge – Is it really there or not? Updating the common ragweed (Ambrosia artemisiifolia L.) distribution in Southern Belgium

1’29”25- Marilou Mottet –Quentin Mettray -Ambrosia – birdseeds

1’46”30 – Gerhard Karrer -Mladen Zadravec-Benno Augustinus -Heinz Müller-Schärer-Yan Sun-Barbara Horvatić – Paula Prpić – Dejan Kulijer – Eastward spread of the ragweed leaf beetle Ophraella communa towards the Pannonian plain and the Balkans

2’09″02 – Jordina Belmonte – Chantal Dechamp –Henriette Méon – AFEDA database on airborne Ambrosia pollen concentrations, 1982-2019 (France)

2’26″02 – Diana Deleanu -Corina Bocsan-Ragweed pollen allergy in Transylvania

IRS Symposium – September 14th

IRS Symposium – September 14th

Dear colleagues,

The International Ragweed Symposium, which should have been taken place in Vodice before the Neobiota congress, will be held on Monday, September 14th only by video.

Our French colleagues from the Ambrosia Observatory have accepted to host the organization of this virtual symposium. It will take place from 2.30 pm.

To follow the symposium, please click on the Youtube Live’s link.

Please find the agenda of the symposium here.

We  hope that many of you will take part in our event, sign of your interest in ambrosia.