Woodlice

Porcellio scaber

The woodlouse is a gray to brown-gray colored animal up to 20 mm long with a primitive shape. It has an oval, flat body, a dorsal carapace and 14 legs. Although it looks like an insect, it belongs to the crustaceans.

Woodlice live under stones, plant pots, wooden slats, and all kinds of containers - preferably where there is a foul, musty smell.
They need a damp, shady or dark environment to live. They always stay in the direct catchment area of their food sources.

Apart from Antarctica, woodlice live on all continents of the world. They may not be particularly attractive, but they are very useful because they keep the natural cycle of matter going. In droves, these primitive-looking little crustaceans burrow through the uppermost layers of soil and process dead plant residues. In cellars, greenhouses and on terraces, however, they tend to be uninvited guests. There they are unpleasant and annoying, like to gnaw on stored supplies or eat young plants.

Woodlice come out of their hiding places at night and go in search of food. During the day, the small creepy-crawlies stay in a suitable shelter that provides protection, moisture and darkness. Before winter, they look for a frost-proof hiding place where they fall into hibernation.

Life cycle of the woodlouse

The fertilized eggs are carried by the female in a fluid-filled breast pocket for 40-50 days, after which the young larvae hatch. The young are fully grown after three months and after numerous molts are sexually mature. A woodlouse lives a maximum of two years.

Damage caused by woodlice

Damage is caused by adult woodlice in the storage cellar, in the greenhouse, in cold frames and on the terrace. When they appear in masses, the uninvited guests are often perceived as a nuisance and unpleasant near the house.

In cold frames and greenhouses, they leave behind unsightly feeding damage to seedlings and young plant parts. Young cucumber plants in particular are at the top of the menu for woodlice. In the cellar, they also gnaw on stored supplies such as potatoes and apples.

Control woodlice with nematodes

Nematodes are natural enemies of woodlice. The nematode species Steinernema carpocapsae specializes, among other things, on woodlice and can use them for its own feeding and reproduction. The nematodes are contained in a bait that is placed in a trap. The woodlice are lured into the trap by the bait, where they become infected with the nematodes and die after a few days. The trap can be used indoors all year round.