H.—34.

Australian termites introduced into New Zealand, and the report, together with the comments of interested bodies, is being considered by the Timber Protection Research Committee with a view to making recommendations as to the steps that should be taken to implement Mr. Ratcliffe's recommendations. The following is an account of the work that has been carried out during the year :— Dominion Laboratory. (1) The analysis of all samples of timber-treating liquids submitted by the State Advances Corporation for examination. (2) Work on the development of a field test to differentiate between treated and untreated wood. A test involving the incorporation of a fluorescent material in the treating liquid and the subsequent examination of small particles of the wood, under ultra-violet light, has been proposed and investigated. (3) Miscellaneous work, such as solubility tests on the ingredients used in the timber-treating liquids and the indexing of articles on wood preservation appearing in Journals received by the Laboratory. Entomology Division, Plant Research Bureau. The problems selected for study are concerned with (1) Anobium domesticum (common house-borer). (2) Anobiid sp. (large native borer). (3) Lyctus brunneus (powder-post beetles). (4) Ambeodontus Iristis (two-tooth long horn). (5) Termites (white ants). At the present time attention is being given particularly to A. tristis and the termites, and to a less extent Anobiid sp. The others —i.e., A. domesticum and L. brunneus —have been studied in detail in other countries, though a great deal needs to be done regarding them in relation to New Zealand timbers and timber structures, and their control. In the case of termites the avenues of study are as follow (certain phases, marked with an asterisk, are being studied in co-operation with officers of the Australian Council of Scientific and Industrial Research) : — (1) Survey of range and relative economic importance of species in New Zealand : (2) Influence of climate on the geographic range of different species, with the object of ascertaining zones that are likely to remain termite-free : * (3) The inroads of different species on different kinds, qualities, and conditions of timbers : (4) Biology of the species, involving : * (a) Systematica ; (b) seasonal history ; (c) rato of growth ; (d) season and time of swarming ; (e) location of reservoir colonies ; (/) time required to cause major structural damage ; (g) characteristic appearance of wood infested by species of termites, and specific characters of frass; (h) relation to fungi, moisture, temperature, and general environment, such as types and regions of structures favoured (in co-operation with State Advances Corporation and Plant Diseases Division). (5) Control: * (a) Prevention of introduction of alien species and the check to spread of species already in the country ; * (b) modification of building technique ; * (c) treatment of timber ; * (d) destruction of colonies detached from buildings, &c. In regard to A. tristis, the main points being elucidated follow largely those of termites. Recommendations were made to the Department of Housing Construction covering modifications of building technique as soon as it became apparent that the Australian termite problem was of importance. These recommendations have since been confirmed by Mr. Ratcliffe. Plant Diseases Division, Plant Research Bureau. (a) Field Survey. Studies have been made of decay of house timbers and eucalypt power-poles in the vicinity of Auckland City, caused by the common fungi and insects. Particulars are being collected covering the conditions under which each operates. Examinations have been made of timbers treated with various therapeutants in the field, and the efficiency of such as preservatives noted. A brief survey of the position of housing-timber diseases was made in Wellington and Christchurch. (b) Laboratory Investigations. Numerous isolations have been made of wood-destroying fungi common in New Zealand in house timbers and power-poles. These organisms, together with twelve wood-destroying test fungi supplied from the laboratory at Princes Risborough, England, have been grown in cultures in the presence of matai and rimu blocks to compare their wood-destroying properties. The purpose of this work is to ascertain the behaviour of our organisms as compared with those introduced from overseas, so that results can be compared with these standard test fungi. Attempts have also been made to isolate the fungi responsible for sap-staining in timber, but so far with small success. Cultures of all fungi collected in this manner are being propagated for testing of therapeutants as soon as a standardized technique has been evolved.

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