CONTROL OF ARGENTINE ANT IN CALIFORNIA. 



31 



Fig. 13.— Types of ground traps: a, A small baking-powder 

 tin with the edge bent to permit passage of ants ; b, a special 

 ground trap used in California for control about residences. 



the main runways of the ants. A small baking-powder can with 



friction cover indented in two or three places immediately beneath 



the cover to allow passage of ants would prove satisfactory. Such a 



can is being used in Louisiana. A very successful lawn trap used 



in California consists of a 



pimiento can protected by 



a special cover attached to 



a 6-inch stake. (Fig. 13.) 



A hole is made in the grass 



large enougli for the can. 



The stick is then set into 



the ground until the cover 



fits firmly over the can. 



When these covers are 



painted foliage-green and 



sunk even with the grass 



they are inconspicuous. 



The lawn can be mowed or watered without destroying the sirup or 



container. 



KILLING AND DISTRIBUTING CONTAINERS 



It has been found most practical to fill the containers in the field. 

 The cans or bags are prepared beforehand and taken into the orchard. 



These are arranged on 

 trays as showji in figure 

 14. A gallon can with 

 a long spout is handy 

 for filling. In each con- 

 tainer three-fourths to 

 one inch of sirup is used 

 and this in reality aver- 

 ages about 1^ ounces. 

 At first small cubes of 

 sponge were used in each 

 can or bag to increase 

 the feeding surface. It 

 was soon discovered that 

 the sponge§ liastcned 

 evaporation and thick- 

 ening of the sirup and were thus a disadvantage rather than an asset. 

 A very satisfactory substitute for t lie sponge was found in excelsior and 

 four or five clean strands about a foot long were folded very loosely in 

 the can or preferably suspended from the top, as shown in figure 15. 

 Under no circumstances sliould a large, heavy, compact wad of excel- 

 sior be used. The advantage of the loose strands is that they furnish 

 an attractive runway for the ants, reduce tiie likelihood of their 



Fi(i. 14.— A convenient type of tray for field distribution of poison 

 containers, and a 1-gallon can for holding poisoned sirup. 



