The Common Deathwatch Beetle Xestobium rufovillosum (DeGeer, 1774) as a Pest for Paper in Books

Abstract A small repository in a cathedral in Poland, storing severely damaged books, was investigated with regard to insects and fungi. Entomological and microbiological surveys were performed to estimate the extent of the infestation and the microbial deterioration of the books. Most of the books were attacked by insects although to varying degrees. They were damaged by tunnels bored by the larvae and filled with larval faeces. Some living larvae and many dead adult beetles were found in the books or in the frass. The larvae and most of the beetles were identified as the common deathwatch beetle Xestobium rufovillosum (DeGeer, 1774). The development of Xestobium rufovillosum in books is an unusual case and has rarely been mentioned in the literature. Several books in the repository were also covered by microfungi, especially by Chaetomium murorum, Ch. elatum, Myxotrichum chartarum, Stachybotrys atra and Epicoccum nigrum. The temperature in the repository varied, depending on the season of the year (2.6 °C – 26.2 °C), while the relative humidity was high (constantly above 65 %). The concentration of the fungal bioaerosol was very high (4,120 cfu/m3). The article includes a list of recommendations pertaining to the elimination of the microorganisms and insects.