Pest Control - Psocids
From time to time people often find that their food cupboards have become infested with tiny grey or brown insects. These are psocids and are often found on the packaging of dry goods such as flour, powdered milk, sugar or semolina.
What do the look like?
Psocids (pronounced so-sids) are a common but harmless household insect pest, they are smaller than a pinhead (usually 1-1.5 mm) and are attracted to dry powdered food. They may live for about six months during which time the female will lay up to 100 eggs.
Where do they live?
They are not caused by poor hygiene, they are just as common in the cleanest of homes. They prefer to live in dark, warm humid places (such as the folds of packaging in food cupboards) they dislike light and disturbance. The kitchen environment is likely to provide the conditions they need and fitted cupboards provide the darkness that attracts them. Some food products such as flour naturally contain moisture that attracts them. In warm conditions psocids can rapidly increase in number. This is most likely to occur during the summer months when temperatures are higher, leading to their discovery in autumn.
Psocids are always associated with high humidity. This could be caused by new plaster drying out, it could be from condensation if you do not have enough ventilation in the house or a leaky water pipe.
What do they eat?
They feed on a wide variety of food products mainly dry goods such as flour and also the microscopic moulds that develop in humid conditions.
Harmless insect household pest, has no health implications and is regarded as a ‘nuisance’ pest.
Remove the affected food immediately and dispose of it in an outside dustbin. Check everything else in the cupboard removing anything that contains them. Food in cans and bottles will still be all right but do check them for any insects that may be hiding (including under labels). Clean out all dust and crumbs from the cupboard effectively using a vacuum cleaner dispose of contents of cleaner in an outside dustbin. Make sure the cupboard is completely dry. Any objects you suspect may contain psocids or their eggs, which you do not want to throw away can be placed in a sealed bag in a freezer for 24hrs, this will kill any psocids or their eggs.
Having done this, you should find the cause of the elevated humidity and cure it.
To prevent a problem with psocids developing in your home follow these tips –
- Packets of food that have been opened should be used up quickly and not pushed to the back of the cupboard.
- Food storage areas should be well ventilated and cool.
- If storage in cool ventilated cupboards is not possible, make sure that your cupboards are always free from condensation and damp. If you notice that condensation occurs in your kitchen, particularly during cooking or washing, open the windows. If the problem is continual, contact the Public Protection Department for more advice.
- Any potential hiding places should be sealed with paint or mastic. Many fitted kitchen cupboards are made from laminated chipboard and the surfaces, which are not on view, tend not to have a laminated finish. These unfinished edges can provide crevices for the psocids to hide in and should be sealed with a coat of paint or varnish.
- Regular cleaning of cupboards is advisable, since crevices of cupboards storing dry food can provide a food supply for psocids. Use of a vacuum cleaner is recommended, provided the contents are immediately disposed of in an outside dustbin. Do not use a very wet cloth as this may seal food into crevices and encourage humidity and the growth of mould in the chipboard.