In southern Italy, a plant pathogen called Xylella fastidiosa has been ushering in an agricultural, environmental, and political crisis. The infection is affecting olive trees, which are a critical part of Italian culture and heritage. Containment of this epidemic would require cutting down trees to prevent the spread of the disease. But that recommendation has been met with resistance by the locals, who have produced various conspiracy theories to explain why people are trying to get rid of their trees.

If this crisis is not resolved soon, the infection could spread throughout the region and cause serious plant losses in Europe and the Mediterranean, according to a new perspective in Science Magazine.

X. fastidiosa is a bacterial species that feeds on the xylem of plants and is spread by insects. In the past, the most severe economic effects of the X. fastidiosa were felt in the US and Brazil. These countries now have control plans that are deployed to reduce the spread of this disease, including reducing the insect population that spreads the disease and removing infected plants from areas with outbreaks. Currently, France has implemented similar procedures in response to the presence of the disease in Italy, but no such actions have been taken in southern Italy.

Preventing the spread of X. fastidiosa requires early detection to ensure that the infected area remains small. Unfortunately, it can take 12 to 14 months for trees to show symptoms of infection, which makes it tricky to contain a potential epidemic. As a result, containing the infection generally requires the removal of asymptomatic infected plants. However, the prospect of killing trees that don’t appear to be sick is particularly tricky in Italy due to the cultural significance of olive trees.

In southern Italy, olive trees are planted to mark major life events, including births of family members. This tradition goes back for generations, and the local olive groves serve as a reminder of families’ historical roots in the area. Cutting down olive trees means destroying physical manifestations of the local history and culture. Not surprisingly, the people who live there have responded with distrust of scientists, environmentalists, and lawmakers.

The European Commission has made efforts to manage the epidemic and reduce the spread of disease, but these actions have been challenged by local environmentalists and politicians, who are responding in part to public distrust of science. This distrust of science has led to local conspiracy theories regarding the plant epidemic, including one unsubstantiated claim made by anti-GMO activists that the bacteria was inadvertently released in the area by scientists.

In June, the European Court of Justice ruled that the European Commission’s recommended X. fastidiosa control measures were legal and should be implemented despite local politicians' objections. However, it's unclear if this measure will move forward. Political leaders are reluctant to force through any control schemes that include killing trees due to the public resistance.

The mistrust of scientists has a complicated history in Italy. The certainty of DNA evidence was a major issue at a prominent murder trial, and some seismologists were convicted of manslaughter after underplaying the risk prior to a deadly earthquake. There was also a recent GMO research scandal, where an Italian researcher likely fabricated data showing that GMOs are harmful to mammals. Italy is also consistently among the European countries with the highest frequency of measles, a vaccine-preventable disease.

Regardless of the country, mistrust of science is an issue with no easy solution, and it continues to influence lawmakers’ ability to implement data-backed best practices and policy recommendations.

If X. fastidiosa control measures are not implemented due to the public mistrust of science, the consequences for European plant life could be dire. The severe loss of food crops can permanently reshape a region’s social and political landscape. A rapid resolution of the conflict between local culture and the European Commission’s suggested best practices for containing the epidemic is clearly needed.

Science, 2016. DOI: 10.1126/science.aaf9710 (About DOIs).