On 2 April 1986, while removing an accumulation of mosses from the roof of a covered picnic table near a home on Brookfield Road, St. John's (Fig. 1), several hundred larvae (leatherjackets) of the European crane fly, Tipula paludosa Meigen, were found overwintering in the moss between the slots of the asphalt shingles (Fig. 2). During the period 1971–1985 a heavy growth of mosses had become established in the slots between the shingles. Sufficient organic matter, together with particles of soil and sand, had accumulated in these slots to support the mosses, which gradually spread outward to the flat surfaces of the shingles (Fig. 1).