Infestation by Calliphora vicina and Tineola Bisselliella inside the halls of a museum

One of the main causes of museum heritage losses, is related to insect pests, especially those attacking directly wood, paper, leather and fabrics. However, issues related to pests that may affect indirectly the museum works are not to be neglected either. In this paper we describe the experience carried out at a major art museum in the province of Bologna (Northern Italy), where we were called upon to manage a heavy infestation by Calliphora vicina and Tineola bisselliella,which threatened to damage the paintings on display and put in serious crisis the preciousness of the exhibition. The exhibition season of the museum was undermined to the point of requiring its closure and moving to temporary headquarters until the completion of the host structure disinfestation. Usually, the answer to this type of biological attacks was a massive use of insecticides, with the well-known and documented negative consequences both for the works of art and the people attending the museums. Currently, procedures and strategies aimed at prevention and integrated pest management are to be preferred even in these type of structures and the best practices available include the implementation of monitoring/maintenance programs, associated with the use of physical means (eg. capture and exclusion systems), biotechnical devices (pheromones and growth regulators), treatments with heat, cold and non-toxic gases. Thanks to a thorough inspection, the origin of the infestation was tracked back to structural factors related to the building that housed the museum, which is a thirteenth century castle, whose exhibition halls had a coffered ceiling of great artistic value. Above the wooden structure, however, there was an attic in a state of neglect, with conditions especially favourable to the development of insect pests. The presence of C. vicina was linked to some carcasses of Rattus rattus detected inside the attic, as a consequence of a service of rodent control. T. bisselliella was thriving in the footboards woolly material, used as insulators for the coffered ceiling. In both cases, the adult insects entered in the underlying museum halls through the wood cracks and the holes for spotlights. In these case, control techniques based on insecticides must be avoided. The strategy adopted was the use of light traps to catch all newly emerged adults for the whole duration of the flights, awaiting the restoration works of the museum.