Year of Soils column by Matty P. Berg

Woodlice: everyone knows them but they’re not exactly held in great esteem, even though they deserve better. In the Netherlands they’re known as ‘pissabeds’, because according to popular mythology, eating them was supposed to cure bed-wetting.
There are more than 11,000 species of woodlice and other isopods worldwide, 39 of which are found in the Netherlands. The smallest of these live underground and are just a few millimetres long while the biggest, a littoral woodlouse known as the ‘sea roach’, may reach up to 4.5 centimetres in length.

Woodlice thrive in a temperate climate and in damp to wet surroundings, where you may find hundreds of them in a single square metre. In loose sandy soils, on the other hand, they dry out so quickly that you’ll only find a few or none at all.

Garbage collectors
Woodlice feed on dead organic matter: fallen leaves, soft bark, dead roots, mushrooms and potatoes that have been left in the ground, as well as cadavers. In fact they will even eat the bodies of other, dead woodlice if it comes to that.
Acting as ‘garbage collectors’ to the soil, they serve an important purpose. Without them, plants would have less access to nutrients in spring, slowing down their growth. And we would have to go to the bother of getting rid of all the dead leaves from our garden ourselves.

Kangaroos of the soil
Being a marine species originally, woodlice are actually crustaceans, not insects. The females carry their babies between their legs in a brood pouch. When the babies are ready to leave after 4-6 weeks, they wriggle until the pouch is torn open and they all fall out.
The young woodlice can already look after themselves at this stage, although they have to eat the faeces of adult woodlice to boost microbial activity in their gut. Without microbial enzymes, woodlice can eat leaves but not digest them.
Some species of woodlice appear to be female-only: their daughters are born through parthenogenesis from unfertilized eggs.

Photograph woodlouce: Theodoor Heijerman.

Keywords: year of soil columns