In newly built and reconditioned houses and other buildings, small, black or brown insects may appear in appreciable numbers. These are known collectively as ‘Plaster Beetles’ and belong to at least two beetle families.
Under favourable conditions the life cycle from egg to adult may be completed in one to three months but can take longer indoors.
The Beetles and their larvae feed on mould and mildews and can only exist in damp conditions. They occur in the warm, moist foundations of straw and hayricks, in damp cellars where packing materials are stored, or any material which has become mildewed. They are common on tree foliage, especially late in the year and can occur in birds’ nests from which they may stray into buildings. The conditions found in new buildings which have not completely dried out are ideal, as the beetles can live on microscopic moulds which grow on new plaster behind skirtings, picture rails and other fixtures.
These insects can be eliminated by ensuring that the premises are dried out. With the increased use of central heating, their occurrence in houses, etc, will be reduced. Insecticide aerosols for the control of crawling insects may be used as necessary.