Education

Going on Assignment in Prague July 2025 – July 12, 2025

Beating Back the Beetles

By Emilia Wisniewski

Things are looking up since an insect infestation ravaged Czech forests a few years ago, but the country isn’t out of the woods yet.

A tiny insect called the bark beetle has infested and killed hundreds of thousands of trees across the Czech Republic, affecting forest owners like Jaroslav Chalupa.

He owns more than 32 acres of wooded land that has been in his family for generations and said many of his trees have been damaged by the beetles. Because they were not cut down fast enough, he said, dozens of trees were killed.

Chalupa said some other small forest owners do not have the proper knowledge, tools, or “relationship” with their forests to stop the damage and end up selling their land.

“But in a majority of cases, the owners are rebuilding the forests and they are taking care of them to make the best possible result from it,” Chalupa said.

Bark beetles may be small in size but their numbers in the Czech Republic have grown considerably, causing foresters to cut down trees en masse and prompting researchers and advocates to find ways to reduce the amount of wood infected by the bugs. Researchers have pegged the countrywide outbreak back to 2003, but the intensity “reached an unprecedented intensity” in 2017-2019.

The Czech Republic is not alone: the beetles have infiltrated wooded areas in several other Central and Eastern European countries, including Slovakia, Poland, and Germany. Green and luscious trees that spanned miles of hills have now turned brown and dry, with deep, small holes burrowed in trunks.

One tree is the favored home for many kinds of bark beetle: the Norway spruce, which makes up around half of the country’s forested area after three centuries of intensive planting of this quick-growing, commercially valuable tree.

Between 3.1% to 5.4% of Norway spruce trees were damaged by bark beetles each year from 2017 to 2019, completely eradicating the tree in some areas, according to a 2021 study.

“The situation in the first year [2017] of the bark beetle calamity was worse in Czechia compared to surrounding states,” said Jan Lubojacky, a researcher at the Forestry and Game Management Research Institute (FGMRI). The extensive drought periods in 2015 and 2018 was a significant factor, creating favorable conditions for the beetles to multiply rapidly across the extensive tracts of spruce forest.

The bugs – attracted to weakened host trees or areas affected by harsh climate changes – burrow tunnels deep enough to lay around 30 to 50 eggs, producing up to three generations. The insects and their larvae grow in numbers and damage the tree, eventually resulting in its death. Both Lubojacky and Chalupa stressed the need to quickly harvest severely infested trees to prevent the beetle from spreading to nearby trees.

There are 100 different species of bark beetles identified in Czechia alone, with 40 of those living in spruce trees, said Roman Modlinger, an entomologist at the Czech University of Life Sciences.

“These species is able to exponentially grow in population,” Modlinger said. “Several of them are aggressive, and the whole forestry sector is trying to manage it.”

Modlinger said the fate of the forests along the country’s most traveled motorway from Prague to Brno have shown many Czechs firsthand the severity of the destruction.

“I think the most influenced [by the damage] were small forest owners or villages, and also the people who living in the affected areas, because their environment was dramatically changed,” he said.

On the Rebound

Over the last three years, there has, however, been a gradual decrease in damaged wood. According to FGMRI, 5.8 million cubic meters of wood were damaged by bark beetles in 2022, much less than the 9.7 million destroyed in 2021 and the 15.4 million in 2020.

Lubojacky said even less was damaged in 2023, noting that his institute found only around 3 million cubic meters had been damaged.

“In general, the forestry sector has recovered from the initial shock, and the harvesting, operating, and marketing capacities have gradually increased,” Lubojacky said. “I think that this situation will definitely improve in the future.”

More rainfall and increased predator activity have all helped to slow down the rate of bark beetle reproduction. Lubojacky and other researchers have been looking into alternative ways to make sure the bark beetle population doesn’t explode again.

The team is halfway through a three-year project to evaluate different methods to control the bugs, including placement of “tree traps” – which entails cutting a wide ring around a healthy spruce tree to monitor beetle presence. 

Environmental activists have also crafted plans that they believe the Czech government should take into account when handling bark beetles. Hnuti Duha (Friends of the Earth Czech Republic), a leading NGO, has advised that loggers concentrate their efforts on less attacked areas if they want to slow down the infestation, and to stop logging in national parks and protected areas, where natural processes should be given priority over timber production, they argue.

“The amount of bark beetle-infested trees was much greater than the capacity of the logging companies,” Jaromir Blaha, a forest protection expert at Hnuti Duha, wrote in an email. “Most of the trees were cleaned only after the bark beetle had [departed], which did not make sense from the point of view of trying to prevent its further spread.”

Five years ago, the Ministry of Agriculture identified the areas most affected by the bark beetle outbreak and financially aided foresters to harvest newly affected trees to slow down the population growth.

Chalupa said he has taken the necessary measures to save his trees, but believes mixed forests – those with multiple, prominent tree species rather than spruce monoculture – could prevent the bark beetle from spreading as much as it already has in the country.

“If the forests were mixed, the bug would not have wreaked such havoc,” said Chalupa. “There is a bigger effort to make the forests mixed to prevent these catastrophes from happening, which is a good message.”

“Difficult and harsh times are [still] coming, and then it will get better,” he added.

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Emilia Wisniewski, a senior at Boston University studying journalism and business administration.
She reported and wrote this story while on Transitions’ Going on Assignment international reporting summer course in July 2024.