A scientist at the University of Worcester was involved in a major new study which has revealed that a beetle could be the key to reducing pollen from one of Europe’s most prolific plants, providing relief to more than 2 million hayfever sufferers.
Professor Carsten Skjøth was part of a team of scientists from across Europe working on the study, which has been published in the prestigious journal, Nature Communications, this week.
The study reveals that the leaf beetle, Ophraella communa, can significantly reduce pollen – which causes a range of symptoms from sneezing to itchy eyes and aggravates conditions such as asthma and eczema – from common ragweed by munching its way through the plant and its pollen producing flowers.
Professor Skjøth said: “Common ragweed arguably produces the most noxious pollen in Europe and is considered invasive in more than 30 European countries. Its spread and impact is likely to increase with rising temperatures caused by climate change. All traditional approaches to eradicate the plant have previously failed, including cutting, uprooting, and the use of pesticides. Seeds may survive for decades in the soil and plants may produce both pollen and seeds after cutting and application of pesticides. Add to this that it is expanding Northwards where climate change will increase its chance to establish in new locations.
“But what we have found is that using a leaf beetle as a biological control can have significant effects in reducing pollen produced from the plant.”
Field studies in Italy have proved that the leaf beetle can reduce ragweed pollen by 82 percent. In the Milan area, where the beetle was first detected, up to 100 percent of ragweed plants were attacked and the damage caused was enough to prevent flowering that causes pollen to be released.
The team of scientists from institutions including the University of Fribourg and ETH Zurich, Switzerland, and Leiden University, as well as Worcester, suggest countries in the Balkan Peninsula – such as Bulgaria, Romania and Serbia – will benefit most from the leaf beetle as a biological control.
Dr Urs Schaffner, lead author of the study, said, "Our study provides evidence that the impacts of common ragweed on human health and the economy are so far highly underestimated, but that biological control by Ophraella communa might mitigate these impacts in parts of Europe.
"We propose that future assessments of the economic impacts of Invasive Alien Species (IAS) should more thoroughly consider costs related to human health.”
The interdisciplinary study also quantified the economic benefits of biological control of ragweed in Europe, arguing that the costs inflicted by invasive species in Europe are ‘most probably seriously underestimated'.
Prior to the accidental arrival of the leaf beetle in 2013, some 13.5 million people suffered from ragweed-induced allergies in Europe, causing economic costs of approximately Euro 7.4 billion annually.