42 BULLETIN 647, U. S. DEPARTMENT OF AGRICULTURE. 
the tree from which ants were excluded and 10.4 per cent on the tree 
to which they had access. 
On July 17 the banded tree still led in white-fly infestation, there 
being 3,711 living young on this tree to 1,497 on the ant-patrolled 
tree, and by the 13th of August white-fly eggs, larvse, and pupae were 
too numerous on both plants to count. This final heawy infestation of 
both trees was expected, as it was improbable that complete white- 
fly control in the height of its breeding period could be accomplished 
by the ant. 
The relations of the ants to emerging white flies brought out in 
the foregoing experiment led to similar observations on other trees 
On June 12, at the height of a white-fly emergence period, two more 
trees from which ants were excluded and two on which they were 
present were inspected. On the first two trees there were 431 empty 
pupa cases from which white flies had emerged, and 369 adult white 
flies, or 85.6 per cent of all which had emerged, still remained upon 
the trees. On the ant-invaded trees there were 600 empty pupa cases 
with emergence slits, but only 36 of the white flies, or 6 per cent of 
the emergence, remained upon the trees. 
These observations indicate that the principal direct effect of the 
Argentine ant upon the citrus white fly in Louisiana is to destroy a 
varying proportion of them, thus entitling this ant to be called a 
white-fly enemy. 
RELATIONS WITH APHIDS. 
The relation of the Argentine ant to aphicls has been observed 
principally on the orange-infesting species, chief of which is Aphis 
qossypii Glov. In Louisiana, however, certain observations have 
been made upon the relations of this ant with aphids on loquat, 
elder, privet, oak. cypress, and certain weeds. 
The Axt as a Protector of Aphids. 
The orange aphid appears in considerable numbers, sometimes 
very large numbers, on the newer growth early in the spring, often 
increases throughout April and May, causing some of the leaves to 
curl, and thereafter rapidly disappears, while a heavy parasitization 
is indicated by numerous dried skins punctured by the exit holes of 
the parasites. This condition, which has long existed both in Cali- 
fornia and in Louisiana, has not been altered materially even in 
groves and trees overrun by the Argentine ant. In Louisiana it 
occurs in scattered groups in January and February, often greatly 
increases in March, and becomes numerous on tender leaves and some 
of the blossoms in certain orchards during April and May. Even 
where heavily attended by the ant, however, its natural enemies. 
