The effect of heather beetle Lochmaea suturalis on vegetation in a wet heath in NE Scotland

摘要: An outbreak of heather beetle Lochmaea suturalis on a wet heath in north-east Scotland was monitored. In many respects, the similar to those described lowland heaths; it started at particular locus and when Calluna vulgaris depleted, spread throughout heath. Population size then decreased annually due some undetermined exogenous factor. A contributory factor may be high incidence (35%) parasitoid infestation which is density independent and, thus, not controlling. There no evidence that hairiness var. hirsuta has an effect herbivory by Lochmaea. The distribution larvae through canopy neither influenced morphology Calluna, nor associated species, appears random. This probably represents eggs since little lateral migration takes place. The response vegetation simple. Associated with cover increase Sphagnum plumulosum Hypnum jutlandicum reduction S. compactum Pleurozium schreberi. Changes seem depend initial other parameters measured (e.g. proximity propagules, microclimate). Regeneration does occur, largely layering; although seedling occurrence increases areas, especially Sphagnum, seems unlikely this will make major contribution recovery Calluna.