92 NORTHERN TERRITORY TBRMlTIDjE^ i., 



CoPTOTERMES ACiNACiFORMis Froggatt. (Plates xiv.-xviii.) 



Termes acinaciformis Froggatt, op. cit., 1897, p. 740. 



This is, probably, the commonest species in the northern part 

 of the Territory, where they are responsible for most of the 

 damage to growing forest-trees. Hollow Iron wood-trees (Pithe- 

 colohium moniliferum) and Eucalypts are almost invariably in- 

 fested with them, but they are rarely found in fence-posts or in 

 buildings constructed of indigenous or imported timbers. 



The large, dome-shaped termitaria (Plate xiv.), typical of the 

 species, are usually found on well-drained, open forest country at 

 the base of a tree, or enveloping a stump (Plate xv.). They are 

 rarely found on wet lands or on hill-sides. Few attain a height 

 of more than four or five feet, but occasionally one sees a straight 

 column, six to eight feet high, surmounting one of these dome- 

 shaped mounds. These columns are formed as the tree-trunks 

 are gradually converted into food, and finally replaced by a 

 column of earth and triturated wood. In most cases, trees appear 

 to be attacked from below ground, and hollowed out to a con- 

 siderable height before any external evidence of the presence of 

 termites can be detected. Sometimes destruction is not carried 

 beyond this stage, and excellent fencing timber is obtained from 

 such trees, especially from Eucalyptus ininiata, a timber that 

 possesses considerable termite-resisting properties when used for 

 fences, stock-yards, etc. More often, however, destruction con- 

 tinues, and the characteristic termitaria are built, and gradually 

 extended, until the weakened trunk is blown over or consumed. 

 Isolated mounds are common, and, if opened, will be found to 

 contain, as a rule, some portion of a tree or stump (Plate xvi.). 

 What occurs, when this portion is consumed, is not known, but 

 there is evidence, in the shrivelled condition of the queens' abdo- 

 mina, in the small number of soldiers and workers often observed, 

 and in the number of abandoned and ruined termitaria, to suggest 

 that the community dies out gradually as the food-supply 

 diminishes. 



The walls of the termitaria are constructed of fine particles of 

 earth and sand, gathered on the surface of the ground, and 

 firmly cemented together into an intensely hard mass. The 



