Pest Management Professional, March 2011

New Construction the unwelcomed guest Lets take a look at some situations that can lead to pest problems in newly built homes Dr Gerald S Wegner BCE Contributor F amilies and couples who watch with anticipation as their new home is taking shape expect that everything will be in top notch condition and most certainly pest free when the time arrives for moving in Unfortunately this is often not the case What we do not see is what goes on in and around the construction site when the contractors leave the sun goes down or the weather conditions are less than perfect The phases of home construction typically require one to several months depending on the size of the home financing availability and coordination of the various subcontractors and of course weather conditions During this time the wooden structural components that have been delivered and stacked or even the exposed wood framing may be wetted by rain or snowfall Wood absorbs and retains moisture and dries slowly in dry air and sunlight Likewise any gypsum board and fiberglass insulation exposed to moisture will retain some for a period of time By the time the new house is entirely finished chances are there is a higher than ideal level of humidity retention in the structural components With adequate air conditioning and dehumidification during the next year or so a beneficial balance of humidity and dryness will be achieved However the first year or two and sometimes longer moisture conditions may attract a variety of pests that thrive in such an environment Meet the beetles Tiny foreign grain beetles Ahasverus advena plaster beetles Family Lathridiidae and other fungus beetles 1 16 in or less in length lay their eggs on the damp wood gypsum board and paper backing of insulation where fungus has begun to grow The beetle immature stages feed on the fungus and give rise to new adult beetles which mate and repeat the cycle until fungi can no longer thrive in the drying structural voids In the meantime the small beetles will enter the living spaces sometimes in great numbers and be a nuisance to the homeowners Occupants of homes finished inside with milled wood paneling may be surprised to discover medium to large multi colored beetles with long antennae crawling about or congregating at windows and lights These longhorned beetles Cerambycidae develop as larvae known as round headed borers inside trees that may be milled for paneling These beetles have a two or three year and sometimes longer life cycle and if the wood is not heat cured before use in construction the newly emerged beetles may emerge from oval exit holes they chew through the surface of the paneling Fortunately most long horned beetles do not re infest the wood from which they emerged Free to a damp home Besides fungus beetles other pests that enter damp areas of homes under construction include Springtails mostly Entomobrya spp in Collembola are 1 8 in long or smaller gray colored and jump when touched They can breed in the damp conditions that persist behind brick veneer stone facing and wood siding of outside walls and may be found indoors on floors near outside walls and doorways 50 March 2011 Pest Management Professional mypmp net