46 REPORT OF SEARCH FOR ENEMIES OF CITRUS WHITE FLY. 
westward throughout northwestern and north-central India. He has 
also seen this insect at Macau, in southern China, while in the collec- 
tion of this bureau in Washington is material on orange leaves col- 
lected at Canton, southern China. These records are sufficient to lead 
to the belief that the white fly occurs on citrus plants throughout 
southern Asia. If citrus is the original food plant of this insect (but 
we have no conclusive evidence that it is) it would then appear quite 
probable that its original home was in that part of southeastern 
Asia in which citrus plants originated and that it followed the dis- 
tribution of the citrus through other parts of that continent. 
In India the white fly prefers Jasminum as a host plant over citrus 
trees. On this plant the insect was of much greater occurrence and 
capable of withstanding climatic conditions better than on any other 
host. Viewing the problem entirely from the standpoint as seen by 
the writer in India, it would appear that Jasminum was the original 
host rather than citrus. The most commonly cultivated species of 
Jasminum, called sambac, is considered a native of India, but other 
allied species are native to China. Various species are cultivated 
throughout subtropical Asia. Hence it is quite probable that the 
white fly infests this plant in China as well as in India. 
The lightest infestation of the white fly occurs in the eastern part of 
India while the most severe infestation is in the northwest. Consider- 
ing climatic conditions one would expect the contrary, as the weather 
of Assam is of greater humidity and less extreme temperature than 
the upper country. Trees in the Khasia Hills at between 1,000 and 
1,500 feet elevation and surrounded by forest trees so as to be abun- 
dantly protected by shade were so lightly infested that only an occa- 
sional insect could be found and most of these were parasitized. 
Although the infestation in the northwest was so light that the insect 
was in a satisfactory condition of control it could be generally stated 
to be much more severe than in eastern India. This condition, 
together with the fact that the only known reports of injury from the 
white fly received in the Indian Museum came from the northwest 
during the early nineties, leads the writer to believe that this insect is 
of recent introduction into that region. 
After all has been said and we know that citrus and Jasminum 
are the present preferred food plants of Aleyrodes citri in southern 
Asia, nobody is able to state definitely that either is the original host, 
even though indications would tend to point that way. Nevertheless, 
it is sufficiently certain as to be considered a fact that the citrus white 
fly is a native of the semi tropical part of continental Asia, and the 
strongest indications point toward the Indo-Chinese region as its 
original home. 
