"Fool me once, but rarely fool me twice": recapture rates and the effect of lure-ageing in pheromone traps for the burnet moth Zygaena filipendulae

Pheromone lures are a powerful tool in monitoring and recording moths. An important part of accurately interpreting the data obtained is determining the recapture rate of pheromone traps and the longevity of pheromone lures. This study investigates the recapture rate and longevity of Zygaena filipendulae (Linnaeus, 1758) pheromone lures. 175 Z. filipendulae were trapped using a pheromone, individually marked and then released within a 1 metre radius of a pheromone trap. The recapture rate of the pheromone traps and the number of times individuals were caught was studied over 5 consecutive days. The recapture rate dropped from 52% on the first day to 9% on the fifth day. 45% of marked moths were not recaptured, 36% were recaptured once, 14% were recaptured twice, 2% were recaptured 3 times and 3% were recaptured 4 times. In the lure longevity experiment lures were exposed to field conditions for 0, 1, 3, 5, 7, 14, 28, 42, 56, 70 and 84 days. The lures of different ages were tested for attractiveness in the field. Lures that had been exposed for 0, 1 and 3 days attracted significantly more moths, but all lures still attracted moths and an endpoint in the lure's longevity was not reached. The implications of these findings are discussed.