A rare beetle lives by Glomsinjoki river

10.12.2025 6.02Updated: 10.12.2025 6.42

An autumn forest landscape with a small rapid flowing between the rocks. The ground is covered with plenty of yellow and orange leaves. In the background, there is a dense forest with both deciduous and coniferous trees. — The Bemböle mill ruins are located between Ring Road III and Turuntie. You can get there by buses going to Oittaa or on foot from Espoon keskus, for example. There are no parking spaces in the area.Photo: Tero Ikäheimonen.

There is a rare beetle species whose only population in Finland lives in the ruins of an old mill by the Glomsinjoki river.

Bembidion monticola is a small ground beetle that can be found in Finland only in the Glomsinjoki area in Espoo. This very rare beetle was discovered in 1991.

“Bembidion monticola lives at the water’s edge, hiding under rocks. It feeds on small insects and larvae,” says Miina Heinonen, limnologist at the City of Espoo.

For the winter, the beetles climb above the flooding line into the forest to find a place to overwinter under leaf litter.

“In order to protect the Bembidion monticola, it is very important to keep the river bank in its natural state, meaning that the vegetation and microclimate should remain unchanged. This ensures favourable living conditions for this species.”

The ruins of the old Bemböle mill are located by the Glomsinjoki rapids. The mill site has probably been used for grinding grain as early as in the 16th century. The ruins of the last mill, which was in operation until 1929, include distinguishable dam and mill structures that provide a good habitat for Bembidion monticola.

Last summer, the ruins were renovated. There is a hiking trail in the area that connects to the ski track network in the winter.

“The old Glomsinjoki pedestrian bridge was in poor condition and had to be demolished as part of the renovation, so there is no more access across the river. Now, the branch of the trail leading to Glomsinjoki ends at the bank of the river,” says Katrin Aia, Environmental Planner at the City of Espoo.

“Bemböle is an interesting destination for adventurous hikers who are interested in historical sites and don’t need proper trails.”

Did you know that...?

Bembidion monticola is an endangered species.
Bembidion monticola is found in rocky waterside areas in Estonia, Latvia and Lithuania – and at the Glomsinjoki river in Espoo.
The Bemböle mill ruins are of national value and protected by the Antiquities Act.

Text: Minna Saano

This article was originally published in the Espoo-lehti magazine 3/2025. Read other Espoo-lehti articles.