THE ARGENTINE ANT IN RELATION TO CITRUS GROVES. 21 



The black scale {Saissetia oleae Bern.) apparently was first noted 

 in Louisiana in 1910, when it was taken upon certain plants in 

 Audubon Park, New Orleans, by Barber. 1 It occurs commonly on 

 oleander in many places about the city, but not a single specimen 

 has been found in the orange groves. 



The fluted scale (I eery a purchasi Mask.), according to Mr. Ed. 

 Foster, who for many years has been an enthusiastic and discerning 

 observer of insect life about New Orleans, occurred in places near 

 present spots of infestation in and near that city as early as 1891, 

 and this is confirmed by the statements of certain nurserymen and 

 growers. It now occurs in many yards in the uptown districts of the 

 city and in several nurseries, but has not been discovered in the 

 orange groves. 



The Ant as a Protector of Soft Scales, 

 influence of the ant on abundance of mealybugs on citrus in louisiana. 



It was not possible to find sufficiently heavy infestations of mealy- 

 bugs in the orange orchards of Louisiana during the years 1913 to 

 1915 to make experiments to determine the relative increase on ant- 

 infested as compared with ant-free trees. Even in orchards overrun 

 with ants the mealybug infestations were scattering and did not per- 

 sist long enough to permit the desired experiments and observations 

 to be made. The nonimportance of the mealybug as a pest in the 

 orange groves of the State, however, seemed to make it unnecessary 

 to conduct special experiments on them. Nevertheless, mealybugs 

 were fairly abundant on fig trees in the laboratory grounds in New 

 Orleans, and experiments of this nature were conducted on these 

 trees and also on vigorous young orange trees, which were especially 

 colonized with mealybugs for this purpose. The ants first began 

 to frequent the fig trees in large numbers early in April, at which 

 time mealybugs were rare and could be found only in small numbers 

 in the most hidden places, such as old wounds, under dead bark, etc. 



On April 27 several groups of mealybugs which still occurred only 

 in hidden places on the trunks and larger branches of the fig were 

 transferred to each of two orange trees. By May 7 they had settled 

 themselves permanently on the trees. Thereafter ants were excluded 

 from one of the trees; in the case of the other, in addition to the 

 ants patrolling it from the ground, a large colony, including 25 

 queens and many eggs and young, was transferred to the soil in 

 the pot, where the ants took up their abode near the base of the tree. 

 Observations were made at frequent intervals. The number of sound 

 and parasitized mealybugs was counted and notes made on the 



'Barber, T. C. The Coccidae of Audubon Park, New Orleans, La. In Jour. Econ. Ent.. 

 v. 3, p. 424. 1910. 



