October, '16] DE ONG: ARGENTINE ANT CONTROL 469 



In the fall of 1908 the University established a laboratory in East 

 Oakland for the studj^ of this pest, part of the results of which were 

 published in October 1910, including the formula for a weak arsenical 

 solution that has proven so effective as a control measure. To L. 

 H. Day, an assistant in the laboratory, is due the first proof of the 

 greater efficiency of this strength of poison. 



About this time the City of Berkeley appropriated five hundred 

 ($500.00) dollars for a campaign against the pest; this work was carried 

 on by L. J. Nickels^ under the plan outlined by Professor WoodwOrth. 

 At this time there were but two small colonies in Berkeley, one cover- 

 ing about two blocks, the other parts of four blocks. Considering the 

 seriousness of the pest and the smallness of the infestation, it was con- 

 sidered advisable to attempt eradicating the ants. A careful survey 

 was made and every effort used to secure the cooperation of all resi- 

 dents in the affected areas, to the end that all supplies of food except 

 the poisoned bait might be ^hut off from the ants as far as possible, 

 ant syrup in small perforated containers was placed in every lot. To 

 supplement the poisoned bait a solution of cyanide (2 oz. sodium 

 cyanide to 1 gallon of water) was used on the nests wherever found, 

 the entire expense of labor and material being borne by the city. The 

 manufacture and distribution of the ant syrup was done entirely by Mr. 

 Nickels or an assistant. This plan was tried for several months and 

 although the ants were not exterminated they were controlled, and 

 to the extent that invasions of houses in the infested areas immediately 

 ceased or were rare and of short duration and. after a time were un- 

 known; even at a time of the year when they are most annoying and 

 though the ants were present in the yard. Control, that is freedom 

 from ants as a house pest, was attained although the desired result, 

 eradication, was not achieved. This immunity was attained by thus 

 reducing their numbers. When the ants can be controlled so that 

 they are not a serious pest and the territory is not increasing the work 

 justifies the effort. 



Because some of the Berkeley colonies crossed the line into Oakland 

 it was very evident that eradication would be impossible without joint 

 action with that city, therefore a successful effort was made to extend 

 the work to the Northern section of Oakland. 



It was soon seen, however, that eradication was going to be an im- 

 possibility, at least with the funds that could be made available, and the 

 whole attempt was dropped. 



In 1915 the City of Piedmont took official recognition of this pest 

 and asked the University for assistance in carrying on control work. 

 At this time only four or five blocks of the town were known to be 



1 Jour. Econ. Ent. IV, 4, Aug. 1911. 



2 



