October 2018. The Vaia storm fells 42 million trees across the eastern Italian Alps—Veneto, Trentino, Friuli—in just three days. It's the largest forest catastrophe in recent Italian history. The Alpine landscape is transformed—stretches of shattered trunks, entire mountainsides stripped bare. Then comes the second disaster, invisible: the bark beetle. An insect just 5 millimeters long that finds in millions of felled logs a paradise of fresh wood to colonize—and then, its populations exploding exponentially, it spreads to the living trees still standing. And kills them.

What is the bark beetle?

The bark beetle (Ips typographus) is a small scolytid beetle measuring 4–5.5 mm, with an almost anonymous appearance—dark brown, cylindrical. It lives beneath the bark of conifers (mainly Norway spruce, Picea abies) where it tunnels to lay eggs. The name "typographus" comes from the characteristic ladder-like pattern of larval galleries that resemble the page of a typographic book, with the maternal gallery running vertically and larval galleries running perpendicular. The bark beetle is an indigenous species of Alpine forests—it has always existed, in balance with its host plants. Under normal conditions, healthy firs resist attack by producing resin in abundance, which traps and kills the boring larvae. But when trees are stressed—by drought, mechanical injury, or storms—resin production decreases and the bark beetle can penetrate. In a weakened tree, the beetle tunnels, deposits eggs, and larvae consume the phloem (the tissue that transports sugars) in a circular pattern—interrupting nutrient flow between leaves and roots and causing the tree's death within months.

From the Vaia storm to the bark beetle epidemic

After Vaia (October 2018), the 42 million felled logs became an enormous reserve of fresh wood—the ideal substrate for bark beetle reproduction. Populations exploded exponentially during the warm seasons of 2019–2022. The Norway spruce forests of the eastern Alps, already weakened by increasingly intense summer droughts, couldn't resist attacks from such massive populations. In 2019–2023, an estimated 150,000–200,000 hectares of Alpine forest were affected by the bark beetle epidemic following Vaia, with millions of Norway spruces dead across Veneto, Trentino, and Friuli. Forest management faced a dramatic dilemma: rapidly harvest infested wood (to reduce bark beetle populations) or leave it standing as deadwood (which has enormous ecological value but fuels the epidemic). There is no simple answer.

The role of climate change: drought as a trigger

The relationship between the bark beetle and climate change is direct and well-documented. Alpine Norway spruce forests increasingly suffer from prolonged summer droughts