Xestobium rufovillosum is a species of insects that causes significant both in the historical monuments and in the old book collections. Identifying the species is easy when biological material is preserved (adults, larvae or excrement in a specific shape). Even in the absence of these elements, the degradations produced by X. rufovillosum are easily recognizable. The attack of this species occurs in the presence of moisture and fungi that emit substances attractive to insects in the atmosphere. The galleries produced by the larvae go through the covers and the pages, producing gaps in the content (text, graphics), fracturing the sheets or the whole book. The attack of this pest in monuments and collections of cellulosic fiber objects could be prevented if atmospheric humidity and object humidity were controlled. The appearance of the X. rufovillosum attack in the collections of old books and documents in libraries requires curative treatments for their disinfection and that of the storage spaces. For the restoration of the objects with galleries caused by X. rufovillosum, an important step is filling these galleries, in order to ensure the physical integrity of the books. The paper presents these stages in the case of the 19th century Irmologhion manuscript.