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Subterranean-grass Caterpillars. This problem, which concerns the depredations of certain species of Porina upon pastures, is one of major agricultural importance, and a special study of the problem has been inaugurated. This activity embraces a survey of the extent of infestation and of the species concerned, together with a detailed study of the insects and their environment, with a view to formulating some practical means of control. Sheep Maggot-ply Problem. This activity embraces (1) a taxonomic study of the blow-flies in New Zealand, (2) a survey of the flies responsible for strike throughout the country, and (3) a study of the seasonal sequence of blow-flies. The taxonomic aspect has been completed and the results issued as a monograph by the Cawthron Institute ; this publication deals with the taxonomy of both the adult flies and their larvae. The survey of " strike " shows that Collvphora laemica and Lucilla sericata are the dominant and primary maggot-flies, and that under New Zealand conditions by far the most outstanding cause of " strike " is dirty wool, pointing to management as being the main factor in control as regards sheep. There are definite indications that the incidence of C. laemica and L. sericata is correlated with climatic zones, since as one proceeds from the Auckland Province in the North to Otago in the South C. laemica, as the dominant species, gives place to L. sericata. The seasonal sequence study has been based on trapping the flies over a period of twelve months. For this purpose thirty West Australian traps were used on an area of 300 acres of sheep country, the flies from each trap being collected at fortnightly intervals. The examination of this trapped material has yet to be made. Timber-borers. In collaboration with the other activities of the Timber Protection Research Committee established during the year, this Division has undertaken the biological study of the major species of boring insects that infest constructional timbers. These insects are the common house borer (Anobium domesticum) and the native two-toothed longhorn beetle (Ambeodontus tristis). Of these, special attention is to be given to the latter owing to the fact that insufficient data are available concerning it. Since this project was commenced a very outstanding timber problem has been discovered in the presence of certain species of earth-dwelling Australian white-ants or termites in New Zealand. There are probably more than one of these species present in the country, but it is definitely known that Coptotermes lacteus and possibly C. acinaciformis are established. During last summer a survey was made in the north, and these termites were found to be established in Auckland and New Plymouth, where they were seriously damaging wooden buildings, fences, and power-poles. The survey also revealed that the native termites (Stolotermes ruficeps and Calotermes brouni), which are not earth-dwelling forms, are fairly wide-spread in houses, &c., in the Auckland Province, especially where puriri (Vitex lucens) has been used for foundations. GRASSLANDS DIVISION. Director: Mr. E. Bbtjob Lev?. The activities of the Grasslands Division have multiplied and increased during the year under review and, while there has been an increase in personnel the Division is much understaffed to carry out essential research work. On the one hand we are faced with land-deterioration problems where certain hill country, particularly, is going out of production, and, on the other hand, problems related to animal thrift on the sown and improved pastures are looming largely to the fore. In the former, loss of virginsoil fertility, increase of erosion, and spread of secondary growths are among the more important aspects of deterioration, and associated with these are economic considerations based largely on the maintenancecosts for the efficient farming of that country. In connection with the sown and improved pastures the dietetic balance, or imbalance, associated with growth condition changes from wilted to lush, rapidlygrowing pastures, calls for serious consideration. Between the lush pasture and the deteriorated pasture are hosts of problems bearing on pasture improvement, pasture management, and pasture supplementation better strains of seed, more efficient seed-mixtures, mineral balance in fertilizers, more efficient management, grazing utilization, or conservation. Weeds that reduce production in grassland should have more detailed ecological study, and in regard to pasture species themselves their inter-relation with soil, climate, and their reaction to the grazing animal calls for particular study, and in this connection work on the tussock grasslands is long overdue. Herbage-seed production and problems related to seed storage need closer examination. Collaborative work on the entomological and mycological aspects of grasslands is important, especially so in regard to some reduction or alleviation of the menace of grass-grub and subterranean-grass caterpillar. The Division throughout the year has endeavoured to work collaboratively with other Departments and organizations whose functions also connect up with grasslands, and in this regard has done all in its power to assist those organizations on the more technical aspects of the grasslands themselves. Strain Ecology. It is becoming more and more apparent that strain and the concept of strain adaption to various ecological conditions ranks equally important with the species themselves; in fact, it would appear as though there is more likelihood of securing plants of special agronomic value working with the strains of the standard grassland species than in searching for new species that might fill, or contribute towards, a specific role in a grassland structure or a grassland use. Actually agriculture itself, by instituting a specific ecological condition over a period of time, has done much to segregate strains peculiarly suited for the style of agriculture employed. What has been lacking, however, in the past has been scientific

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