Pest control in museums: toxicity of para-dichlorobenzene, ‘Vapona’™, and naphthalene against all stages in the life-cycle of museum pests, Dermestes maculatus Degeer, and Anthrenus verbasci (L.) (Coleoptera: Dermestidae)

Museums, herbaria, libraries and archival collections have traditionally relied on chemicals for the prevention and treatment of pest infestations. While current evidence suggests that the use of chemicals is declining, however, they are still found in many collections. The efficacy of three ‘insecticides’, para-dichlorobenzene, ‘Vapona’ and naphthalene (used in some museums to treat localized infestations and for their apparent residual benefit) against two insect species (Coleoptera: Dermestidae) was evaluated. Despite considerable variation in insect susceptibility, ‘Vapona’ was found in general, to be the most effective of the three chemicals used, particularly against larvae and adults. Naphthalene was the least effective, with low mortality rates recorded in the majority of the insect stages tested. Based on this study, an exposure/mortality relationship is presented for the prevention and treatment of insect infestations in museum and archival collections.