Woodlice

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Last revised: 6 October 2008

Description

The adult wood louse is about 15mm in length, quite flat and slate grey in colour with seven pairs of legs. Wood lice are not insects but crustaceans.

Distribution

Wood lice are usually found in damp areas and they are associated with dead and rotting vegetation and wood. They are often found beneath stones, flowerpots and other similar materials and nooks and crannies in the garden providing suitable cover.

There are about thirty-five species of wood lice and they are essentially garden creatures but will on occasions enter houses/buildings searching for protection from the onset of cold weather. These are usually the garden wood lice.

Once indoors they tend to group together mainly at the edges of carpets, floor coverings and under skirting boards. They can also be found in corners and dark places such as kitchen cupboards. If disturbed wood lice naturally curl up into a ball.

Life cycle

The mature wood lice mate and the female produces up to one hundred and fifty eggs, which she contains inside her body in a brood pouch.

Once the eggs have hatched the young are released into the environment and are white in colour and around 2mm in length with six pairs of legs.

The wood louse takes up to a year to become full size and during this time they will grow an extra pair of legs.

Wood lice do not breed indoors, they usually only come inside to protect themselves from cold weather.

Significance

There are about 35 species of wood lice in Britain, some have horticultural or agricultural significance as they eat and damage plants.

Wood lice are classed as casual intruders, posing little threat to goods or property.

Control Methods

Proofing Cracks and crevices on the outside of the building and around doors and windows should be sealed to prevent wood lice gaining access. These gaps if large should be sealed with strong cement or a mastic seal. Fitting of draught excluders on doors will help to stop wood lice getting in.

Cleaning Control of wood lice in a room may be achieved by regular cleaning including vacuuming around floor edges, which should help to remove them. They should not re-appear unless proofing is inadequate.

Outside removing accumulations of leaves, weeds, brick, wood and rubble from the outside walls and doors will help to remove their hiding places. It is preferable not to have plant pots and garden ornaments near the house. If you wish to keep them close to the house then frequent cleaning underneath and also under doormats is recommended.

Treating with insecticides, which are formulated to kill crawling insects, may be used to eradicate wood lice, but unless proofing work is carried out more woodlice will appear. The use of a residual insecticide around wall edges will quickly reduce the population.

Advice

The Council does not treat for wood lice problems and for professional treatment you can approach an independent pest control company, details of which can be found in telephone directories and local newspapers.

Safety

If you intend to carry out your own treatment read the label of the insecticide container before you buy it to ensure it is suitable for wood lice.

Always follow the manufacturer’s instructions carefully when applying insecticide so that you do not cause harm to yourself or your furnishings.