CONTROL OF THE CITROPHILUS MEALYBUG. 11 



Table 1. — Control of the Argentine ant in a citrus orchard at Upland, Calif., 1917. 

 Demonstration Plot, First 10 Acres, 674 Trees. 



Date of 



Poison 



dis- 

 tributed. 



Trees with ants. 



Check area. 



inspec- 

 tion. 



Clean. 



Very 

 light 

 trail. 



Light 

 trail. 



Me- 

 dium 

 trail. 



Heavy 

 trail. 



Clean. 



Very 

 light. 



Light. 



Me- 

 dium. 



Heavy. 



Sept. 23.. 





5 



99 



.SI 2 



13.S 



12.=; 















Oct. 5 



Over entire area. 













Mar. 24... 



671 1 1 3 



Only on trees w 



648 1 20 1 6 



Only on trees w 



642 17 ! l.^i 

















Apr. 9 



th ants. 

 1 













Apr. 9 













June 17... 



June 17 



th ants. 









• 





June 29... 





672 2 

























1 '1 













Demonstration Plot, Second 10 Acres, 676 Trees. 



Sept. 23... 





2 

 391 



157 



9P.R 





107 

 15 



68 

 14 





9 



5.^ 20 



24 



Mar. 20... 



Nov. 5 



On 600 trees. 



119 t 61 1 

 On 600 trees. 



Trap nest under 76 trees. 

 8 1 1 19 1 23 



26 





Apr. 1 

 Apr. 5 













On 76 trees. 





Apr. 30 . . . 







546 

 577 

 593 



39 

 18 



7 



10 



5 

 



4 

 

 



1 

 

 



57 

 75 

 76 



13 

 1 

 



5 1 1 

 

 







June 11... 









June 29... 















Burlap Banding. 



Although by winter the ants were controlled and early the follow- 

 ing spring were almost completely eradicated, the mealybugs con- 

 tinued in severe infestations and during the latter part of March were 

 noted to begin descending the tree trunks. The descent continued to 

 increase in April and no large number of natural enemies appeared 

 as was anticipated. It soon appeared that elimination of the ant was 

 not alone sufficient to bring about control of the citrophilus mealy- 

 bug, as had proved the case for the common mealybug. The citro- 

 philus mealybug species was not attacked by either numerous or 

 effective natural enemies. The necessity of artificial means of con- 

 trol to supplement ant eradication was thus at once apparent. 



A study of the habits of this mealybug showed a spring migration 

 to the trunk and rough places on the main branches where egg 

 masses for the succeeding generation are deposited. The accumula- 

 tion of insects and egg masses in cases of severe infestations, as pre- 

 viously pointed out, became so great as frequently to present the ap- 

 pearance of large tufts of cotton. This massing on the trunk and 

 lower branches presented a favorable point of attack and the spray- 

 ing of these masses with an effective insecticide promised a great re- 

 duction of the total insects present. It was noted, in the case of 

 some trees which had been banded with cotton bands by an orchardist 

 at Upland in 1915, that these acted to attract the ovipositing females 

 beneath them in great masses. Since cotton bands were scattered 

 by the winds and birds, it was decided to substitute burlap and ac- 



