Slovenian researchers have carried out the first ever systematic census of the population of wild bee species in the country. Some of the results are surprising, including the discovery of one species previously not found on Slovenian territory.

A total of 575 species of wild bees have previously been identified in the country, but the census, carried out in five areas in central Slovenia, turned up only 239 species.

"It is difficult to say whether this is a small or large number," said the head of the research project, National Institute of Biology researcher Danilo Bevk.

At the outset he thought the number would be smaller, which is why he was positively surprised. He thinks more would be found if the census had also included the coastal parts of the country.

The pilot monitoring lasted three years and was conducted in five areas: around Celje, between Mengeš and Kranj, around Lake Cerknica, in the Ljubljana Marshes, and in Ljubljana proper.

The highest number of species, 143, were found around Lake Cerknica, a large natural park centred around the famous intermittent lake.

However, there were more than 100 in each of the five areas and the one previously undetected species was found in the Ljubljana urban area.

For 43 of the identified species, there is insufficient data about the state of their populations in Europe.

"This indicates that additional research would definitely result in additional previously undetected species," Bevk said, adding that this would show how many of the previously detected 575 species are still present.

Wild bees are very important pollinators but many species are endangered as a result of man-made environmental changes such as food shortages, climate change, lack of nesting space, pesticides, and disease.

Indeed, wild pollinators account for over a half of pollination in agriculture and their declining numbers are already having an impact on farming.

Wild bees are often more effective pollinators than honey bees. Preserving biodiversity among pollinators is key for reliable pollination and stable production, according to the Agriculture Ministry.

The ministry estimates that pollination by insects is worth €130 million in Slovenia alone.

The project involved the National Institute of Biology, the Natural History Museum and the Research Centre of the Slovenian Academy of Sciences and Arts.