Insects and fungi infect the forest: New vermin spreading in the forest

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Careful forest visitors have discovered the largest ever Asian longhorn beetle infestation at Zell LU in 2022, as the Forest Conservation Competence Center of the Swiss Federal Forest, Snow and Landscape Research Institute (WSL) announced Tuesday.

This insect is considered the biggest pest of deciduous trees because it infests many deciduous tree species. WSL accompanies the fight. Most recently, the Asian longhorn beetle was successfully eradicated in Switzerland in 2019.

In 2022, forest experts also discovered five notifiable invasive canary grass and fenugreek beetle species in Ticino. All four are new in Switzerland. So far, the WSL Forest Conservation Center knows little about the occupants’ preference to feed the trees.

Maple stem crab from North America is still on the rise. The fungus first appeared on six trees in 2021. In 2022, the qualification center has already confirmed 39 infested trees.

Heat and drought continued to be a major problem in the forest in 2022. They reduced tree growth by 10 to 50 percent compared to the average of the last decade. Especially in Valais, the leaves turned brown earlier in the year.

The warmer climate encourages harmful organisms from the south. Their large numbers threaten the forest ecosystem. Native plants have little or no defense mechanisms against new species and diseases such as Dutch elm canker, ash dieback, or boxwood moth.

Forest experts are increasingly confronted with various pathogens on weakened trees. It is often unclear how the various factors interact.

(SDA)

Source : Blick