354 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 4 



About this time the residents of both districts appealed to the Uni- 

 versity and also the city authorities for help in controlling the pest 

 which was not only proving a great annoyance but depreciating prop- 

 erty values. 



The work was started with an appropriation of five hundred dol- 

 lars by the municipality. 



In the description of the actual field work I shall limit myself to the 

 minor territory, which I personally handled. 



As in any control work, such as this, the extent of the district affected 

 must first be determinex:!. To do this a canvass was made from house 

 to house, one block in all directions beyond the known limits of the 

 foragerfe. In order to keep an accurate record, cards three inches by 

 four inches were used, one for each city lot, one side being occupied 

 by the street on which the house is situated with the number, also a 

 plan of the lot, including the position of the house on the premises, 

 considering the outer edge as the boundary. Ant nests, trails, trees, 

 shrubs and bushes were indicated by suitable symbols. The reverse 

 side was used for notes and a record of the treatment, each jar being 

 allotted a number. The cards for each block were placed in a small 

 paper folder to faciUtate the handling as a unit. 



The result of the preliminary examination showed the ants extremely 

 abundant. Three fourths of the block were occupied by Iriclomyrmex 

 Jiumilis, the remainder by Prenolepsis imparis Say., — the honey ant. 



Practically every square yard of ground was visited by scouts or 

 covered by trails. This was due in part to the fact that many small 

 nests existed and secondly, since many of the houses are flats, there 

 were at least four regular sources of food; in most cases carelessness 

 with garbage furnished an intermittent source and this, together with 

 a large number of scale-bearing trees, furnished ample subsistence for 

 prosperity and rapid increase. Notwithstanding the presence of 

 supplies upon the ground, the ants visited the upper stories of all the 

 buildings. Trays brought to rooms on the fourth story of the hotel 

 within a very short time would be literally covered with ants. On 

 each floor refuse barrels were situated, which were visited constantly; 

 the scraps about these gave sufficient incentive for the ants to come 

 in a small but endless stream and so be on the lookout for all possible 

 sources of food. 



The baker, due to the invasion, at one time found it necessary to 

 suspend business for a short period. The butcher found it exceedingly 

 difficult to keep ants from his ice chest and the like. 



Conversation with the residents brought out the fact that they 

 had spent a good deal of time and money in driving the ants away 

 only to bring on fresh visits. The ground in this locality is adobe, 



