Fresh, damp plaster in a new build property can be an invitation to plaster beetles to come in and feast. If you or your clients experience an infestation, it could be due to the house not being dried out properly prior to habitation.

Although not considered to be harmful, plaster beetles are a pest in a new build property. Even after fumigating, a re-infestation can quickly occur if the root of the problem is not treated.

New properties are often a host to plaster beetles where damp plaster provides the perfect environmental conditions for them to thrive. Plaster beetles can also be known as scavenger beetles and are part of the lathridiidae family (with over 1050 species in the family). A plaster beetle infestation can be unpleasant as well as a real nuisance and can be present in in swarms of thousands attacking electrical appliances such as microwaves, televisions and toasters.

Contrary to advice, turning the heating up and opening windows does not help the problem, neither does insect spray. Instead, trickle vents should be left open and heating should be turned down to 14-16C. Dehumidifiers also help to speed up the drying out process.

Plaster beetles thrive in damp conditions which makes them more prevalent in Autumn and Winter although if there are damp conditions in a new property, this could lead to a case of mould colonisation which may cause an infestation of plaster beetles. Damp conditions in a new home are common and can be caused by either the property not having been dried out properly, flooding by careless plumbers or just temporary residual construction moisture. Even if the fabric of the building is relatively dry, humidity levels may be high enough to support fungal growth. Hidden voids may also contain interstitial condensation and can be home and a food source to plaster beetles.

Plaster beetles can range in size from 0.8mm to 3mm in length and live up to between 13 and 28 days. The life cycle is relatively short compared to the pupation cycle which can take up to five months. After adult beetles have deposited their eggs near a mouldy food source the larvae which emerges feeds on the mould spores before pupating into adults. Some varieties of plaster beetle can also fly and can often be seen congregating around a source of light such as a window or light bulb.

How to treat an infestation

Chemical treatments only offer a temporary solution and also involves spraying harmful chemicals into the home. It makes sense to treat the cause of the problem which are the damp conditions and mould colonisation which provide a food source for the beetles.

Heat treatment is also another way of treating the infestation by heating up the property to 45 degrees C which should kill of the infestation but again, this does not treat the underlying cause which is the damp.

Five factors need to be considered to treat the underlying cause and to manage the beetles:

Identifying the source of the damp and eliminating it

Carry out rapid drying of the property

Eliminate the food source (mould colonisation)

Manage the humidity of the house

Regular cleaning protocol

Identification of the moisture source is key to dealing with the beetle infestation and keeping on top of humidity will ensure that you are controlling mould colonisations.

If you identify mould colonisations, then you can treat this with a fungicidal spray to help eliminate the beetles’ food source. If underlying cause cannot be identified, then you may need to call in a chartered building professional. Pest control companies should not be considered, and money would be better spent on treating the underlying cause of moisture.


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