70% of butterfly species have been reduced in Catalonia in the last thirty years

In Catalonia there are fewer and fewer butterflies. The data collected by the Catalan Butterfly Monitoring Scheme (CBMS), a project to monitor the population of butterflies in Catalonia, leaves no room for doubt. In the last thirty years there has been a 70% reduction in the species of this insect and 5% of the studied populations have suffered local extinctions.

The report, which began in 1994, estimates that there are 45 threatened species of butterflies, twelve of which are threatened with extinction. More than thirty are in a “vulnerable” situation and one has already become extinct as a breeder in Catalonia.

Lepidoptera that have their habitat in meadows and grasslands are the ones that have registered the greatest decline. Much more than those who live in forest environments, according to data collected in the report ‘Els pol·linitzadors silvestre a Catalunya’, published today by the Generalitat.

Other pollinating insects have also reduced their presence. Bees, especially those of a larger size, those with a long tongue or those with a high degree of specialization, in their habitat or diet, are the most affected.

Of the more than 2,000 species of bees that exist in Europe, 9% are considered threatened and 37% are in decline. In the case of daytime butterflies, the European Red List estimates that 9% are threatened and 31% are in decline.

The report also indicates a reduction of other pollinating insects, although to a lesser degree, such as hoverflies, flower flies or kestrel flies.

Among the main causes of this decrease, the report points out the loss and fragmentation of natural habitats, the intensification of agriculture with greater use of pesticides, the urbanization of the territory, the closure of clearings in forest areas and climate change, which also negatively affects flower production and nectar secretion.

The solution to expand the presence of these insects is to recover the grasslands and multifunctional margins in the cultivated fields. The authors of this analysis point out that agricultural intensification implies a loss of crop diversity and habitats in general and a greater use of pesticides, which harm pollinators.

With this report, the Generalitat wants to promote a strategic plan to fight against the decline of pollinators in Catalonia. “The study is the prelude to a plan that should have gone further in the analysis of the situation and that should show us the way to promote concrete actions and measures agreed with all the sectors involved to reverse the situation,” says Marc Vilahur, General Director of Environmental Policies and Medi Natural.