These beetles take mass flight not every year, but approximately every 4–5 years, so this spring they could be seen much more in the forests.
“If this spring it seemed that a squadron of beetles was buzzing overhead, you were not mistaken,” the service writes.
According to VMT, this year was a year of “explosion” of the forest beetle population. At the end of April–May, adult beetles flew out en masse to find mates, feed, and lay eggs.
The largest populations of forest beetles gather in the eastern, especially southern part of Lithuania. Because of this, specialists from the VMT Forest Sanitary Protection Department have been observing the life and counting the abundance of these beetles for several years in the territory of the Druskininkai regional division.
860 beetles in one trap
This year, specialists counted an average of 860 forest beetles in one trap. Although the number seems impressive, the service provides good news – this population peak was smaller than in previous similar years, 2016 and 2021.
“No large-scale damage to forests has been recorded,” announces VMT.
Forest beetles feed on the leaves of downy birch, oak, and shrubs. However, deciduous trees can withstand some of the damage caused by these insects because they can grow new leaves in summer and thus compensate for the eaten foliage.
The real “work” of beetles happens underground
The service points out that this year’s beetle flight is only one episode of their life cycle. Their real development continues underground.
After mating, females lay eggs from which white, fleshy larvae hatch. In light, sandy soil, they can develop and grow for about five years.
Meanwhile, the larvae actively feed on plant roots. At first, their “menu” consists of smaller roots, but as they grow, they start feeding on larger ones.
So this spring, not only was a large generation of adult beetles visible in the forests – the life cycle of a new generation also began.
Helps plan forest work
VMT states that knowing the beetle’s life cycle allows specialists to predict when larvae will be most active and when there may be a higher risk of damage to greenery.
This knowledge helps plan forest restoration work and assess the possible impact of beetles on young greenery.
So far, according to the service, the forests have coped quite well with this year’s beetle influx. Although their flights in spring may have seemed impressive, no large-scale damage to forests has been recorded.
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