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

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.

A field test of a lindane/dieldrin smoke for control of the death-watch beetle, Xestobium rufovillosum (Deg.) (Coleoptera, Anobiidae)

In view of the promising results obtained with insecticidal smokes against the common furniture beetle, Anobium punctatum (Deg.), a field trial was conducted to study the effect of deposits from lindane/dieldrin smoke on adults of the death-watch beetle, Xestobium rufovillosum (Deg.), emerging from infested roof timbers of a college chapel in Cambridge, England, in 1963. Quantitative determination of the insecticidal deposits was made and methods were devised for studying the effect of the treatment on the numbers of beetles emerging subsequently in order to assess the long-term value of annual treatments for reducing the population. Beetles collected from an untreated building were used for comparison.Fewer males were found than in preceding years and it is postulated that some may have been prevented by the insecticides from emerging. The normal sequence of beetles dropping from roofing timbers—males predominating first, then females—did not occur. Both sexes dropped nearly uniformly, a fact suggesting, particularly in the case of the females, that the insecticides had caused them to drop before their normal time. Mating was considerably reduced. Examination of females showed no signs of their having laid eggs, this being attributed to the action of the insecticide deposits. Beetles obtained from an untreated building and placed on wood surfaces which had been exposed to the smoke treatment were affected but laid some eggs, of which a small proportion hatched; larval boring into such surfaces was, however, completely prevented.From these results it was inferred that the deposits from the treatment with lindane/dieldrin smoke prevented emerging adults from causing reinfestation of the roofing timbers and it is argued that, provided that this can be achieved annually by a succession of treatments, the beetle population should ultimately be eliminated or, at least, greatly reduced. Other possible effects which might result from annual smoke treatments are accumulation of the insecticide deposits with a consequent increase in toxicity of the timber surfaces and sorption of the deposits by the timber to a point where they might exert a toxic effect on larvae or pupae beneath the surface.

A NEW ANOBIID BEETLE FROM BRITISH COLUMBIA

During the summer of 1946 specimens of anobiid beetles were received from G. Stace Smith of Creston, British Columbia, for identification. Mr. Smith believed that the specimens represented a new species and requested that the species be described.This species resembles the European Xestobium rufovillosum DeGeer so closely that they can only be separated with great difficulty, but the habits of the two species are entirely different.