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of this pest in a climate that is eminently suited to its development 

 signifies the probability of its distribution throughout the State within 

 a few years' time if adequate measures are not taken to cope with it. 

 While the ant has been known to injure blossoms, its chief importance 

 in citrus groves is due to the fact that mealy-bugs, scale-insects and 

 Aphids become much more abundant as a result of its presence. 

 Extensive experiments have proved conclusively the direct relation 

 of the Argentine and certain other ants to the control of the mealy-bugo 

 on citrus trees. Banding and the use of various ant-traps have been 

 tried during recent years, but the only satisfactory measure found 

 by the authors of the present paper was the use of a modified form of 

 the poison syrup known as " Barber formula." For Californian use 

 the poison s^Tup used consisted of 12 lb. granulated sugar, 10 U.S. pints 

 of distilled water and J oz. crystallised tartaric acid ; these are boiled 

 for 30 mins. and then allowed to cool, distilled water being added to 

 allow for evaporation. Sodium arsenite (C. P. only) is then dissolved 

 in hot, distilled water using f oz. to 1 U.S. pint. This when cool should 

 be added to the poison solution and stirred in well ; 2 lb. strained 

 honey is then added and mixed thoroughly. Only the purest ingredi- 

 ents will give success. The original " Barber formula " was found 

 to be so concentrated as to produce rapid crystallisation in the dry 

 Californian atmosphere, but if modified as described, it should retain 

 its hquid form for several months. 



The best containers are 2 oz. spice tins or \ lb. paraffined paper 

 sacks for orchard use, the tin being preferable because of its greater 

 resistance to weather and ease in filling. Before use a | inch hole is 

 punched near the top to hang it up by and it is then dipped completely 

 into molten paraffin to prevent leaking and rusting. About a dozen 

 long strands of excelsior are placed in each tin or sack, 1 to 1^ inches 

 of syrup added and the covers adjusted ; they are then ready for distri- 

 bution. One tin or sack should be attached to each tree, usually 

 on the trunk near the main branches or on a main branch near its base. 

 The spot is chosen with regard to the main trail of ants and on 

 exposed trunks away from direct sunlight. Each tree should be 

 inspected every month or six weeks and the container refilled where 

 necessary. 



Ant control about buildings and ornamental grounds is more difficult, 

 and requires the liberal use of containers on the buildings, plants 

 and on the ground and wherever there are heavy trails, and these 

 should be constantly moved as new trails appear. Insecticide treat- 

 ments should also be given when the infestation is bad and compost 

 or rubbish pileg likely to harbour strong colonies should be removed 

 or treated. The best seasons for ant control are during the spring, 

 when scales and other soft-bodied insects are not abundant, and 

 during autumn, when cold nights interfere with the ants' foraging 

 habits. The cost of this method is less than fumigation or spraying, 

 not exceeding 2d. per tree including materials and labour, plus 

 subsequent inspection and refills not exceeding Id. per tree. 



Particulars are given of the efficiency of this method where 150 

 acres have been treated, resulting in total eradication of the pest. 

 A further area of about 550 acres is now under treatment. 



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