European earwig phenology and effect of understorey management on population estimation

摘要

European earwigs (Forficula auricularia L.) were sampled in a Canterbury apple orchard over two growing seasons using shelter traps comprised of corrugated cardboard rolls. Adult activity peaked during December and January in both seasons, while activity of nymphs peaked two weeks earlier. Earwig counts were consistently higher in a block receiving herbicide treatments, compared with an adjacent block receiving pea straw mulch. Competition between the sampling unit and the surrounding pea-straw habitat probably explains this effect. Factors affecting the sampling method used are discussed, and the need for an alternative sampling system that better reflects absolute abundance is concluded.