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Termites and Fungi
(1975)
Termites are one of the main insects that destroy materials. Physical, Chemical, and biological factors influencing the damage to wood and other materials by termites are discussed. Within the physical factors, environmental influences of temperature, humidity, and electromagnetic field conditions and material properties of hardness, surface, and internal structure and thickness of foils and fibres should be observed. The Chemical factors involved are sensorial influences such as repellency, attraction, and Stimulation and toxic influences such as toxic efficiency, effect on symbionts, and aging of effective substances. Biological factors include termite behaviour connected with gnawing activity, influence of Substrates, and choice or compulsory tests and various other biological factors such as species and race of the termites, number and composition of groups as well as vitality and developmental stage of the colony.
Concerning termites and wood
(1976)
A brief survey is given on the treatment of wood by diffusion of salts. The compounds used for this process, mainly boron and fluorine compounds, are mentioned and the factors influencing diffusion described. The main precondition condition is a high moisture content of the wood above 40 per cent. Fields of application are fresh roundwood, remedial treatment of poles and sleepers, preservation of posts and especially of building and other sawn timber. The treatment of building timber by spraying, dipping or soaking should be followed by the diffusion process which may provide, in a simple and cheap way, deep penetration of salts into the wood including species refractory to pressure methods.
Deterioration of wood by Marine Fungi in India and its special significance for Fishing-crafts
(1958)
Fluoride compounds have gained a considerable importance in wood preservation, especially in Germany and some other countries of Europe. They are used as single compounds or in mixtures of different compounds. The International Research Group on Wood Preservation which continues the activities of a former O.E.C.D.- Group, was aslced to prepare a survey on fluorides in wood preservation together with other papers on the present state of knowledge of wood preservatives and methods of application.
Monofluorides and silicofluorides have been used in the field of wood preservation for about 60 years and special development and application of bifluorides (hydrogen fluorides) have been going on for 30 years. Much scientific work has been carried out on fluorides and much experience in practical use is available. It thus seems to be useful briefly to summarise the information on this group of compounds in wood preservation. Due to the voluminous literature, i.e. some 270 papers which are cited in the references, only an introduction into the Problems and main results but not a detailed review of the publications is possible. The subjects dealt with in the publications are indicated in the references.
With some exceptions the brief survey is limited to the compounds and mixtures without chromium, which remain leachable in the wood. Questions of toxicity to human beings, animals and plants are not discussed in this paper.
Particle boards are of increasing economic importance. Without special treatment they are destroyed by termites. Deterioration of unprotected material as well as possibilities and present knowledge of preservation against termite attack are briefly described. Recent laboratory experiments with particle board treated to make it resistant to humidity and basidiomycete fungi showed that only one organic preservative out of four protected the boards also against termite attack; one of two water-soluble preservatives gave promising results. Heterotermes indicola (Wasmann) from India proved to be more aggressive and resistant to the preservatives than Coptotermes amanii (Sjöstedt) from Kenya and Nasutitermes nigriceps (Haldemann) from Guatemala. Kalotermes flavicollis (Fabr.) from Italy was also very tolerant to the fungicidal preservatives. Further development of treatments of particle board against termites is required.