Capture of wild and marked Agriotes obscurus in pheromone traps according to distance, wind direction and date of trapping

Abstract A study was conducted to determine rates of recapture marked Agriotes obscurus (AO) males released in a grassy field on four occasions the centre pheromone trap squares with traps spaced 2.5, 5.0, 7.5 and 10.0 m apart. Concurrent catches naturally occurring dispersed (wild) AO were also recorded. Catch highest during peak emergence when maximum weekly temperatures ranged from 15.7 17 °C, rainfall light. Mean catch 2.5–10.0 was, respectively, 82.0, 79.0, 77.0 65.0%, which occurred within one week release. lower (range squares: 74.5–50.5%) early activity period, due higher rainfall, protracted over 3 weeks. two releases under favourable weather late period reduced (range: 25–58%), likely loss vigour and/or efficacy. wild or apart, suggesting independence these traps, between-trap competition at 2.5 5.0 spacings. From data, we estimated that an effective spacing for mass trapping arrays would be approximately 6 m. Significantly upwind all squares, indicating wind direction should considered structuring placement programs non-farmed headland areas.