 One beetle, the wharf borer ("Nacedes melanura"), can attack untreated or damaged treated hardwoods and conifers with high moisture contents by tunneling extensively and leaving behind dark brown fecal matter that further degrades the wood.Wood decay describes wood in all stages of fungal attack, from the initial invasion of hyphae into the cell walls to the complete destruction of the wood.Wood-inhabiting fungi are most common on timber piles above the water surface since the lack of oxygen below water inhibits fungal growth.