44 REPORT OF SEARCH FOR ENEMIES OF CITRUS WHITE FLY. 



frequently somewhat severely. The white fly was found on citrus 

 trees tliroughout this region, vnth the exception of the Central 

 Provinces and the Bombay Presidency; in these places it was seen 

 only on Jasminiun. Probably the majority of citrus trees examined 

 were entirely free of the white fly, and where tliis msect was present 

 it was entirely imder control, barring two or tliree exceptions. On 

 the Jasminum, however, it was seldom that living material was not 

 present, and frequently infestation was more or less severe. 



The Jasminum is a low, spreading bush with very dense foliage, 

 which remains on the plant throughout the year. The broods of 

 the white fly on this species are not distinct as on the citrus plants, 

 which was shown b}'' the presence of adult white flies on Jasmmum 

 at several different times between the months of May and October. 



Enough has already been stated to show the preference, m many 

 instances in India, of the v/hite fly for the Jasminum rather than 

 for citrus plants. The following additional evidence is in itself con- 

 clusive: During May, while adult flies were emerging in large num- 

 bers on a Jasminmn bush, a number of small seedling orange trees 

 of very tender foliage were placed immediately about the plant, so 

 that the leaves of the orange trees were in contact mth those of 

 the Jasminum. Very few flies settled on these orange trees, while 

 large numbers woidd be -present on leaves of the Jasminimi \NHthin 

 a few inches of the former. Even if the bush was so distui'bed 

 that the flies in theu' flight would settle on the orange trees thej^ 

 would ultimately desert these in order to go back to the original 

 food plant. - 



In addition to citrus plants and Jasminum the only other host 

 of Aleyrodes citri seen in India was a large-leaved vine — Hiptage 

 mandalohata. The citrus white fly appears to be less parasitized on 

 these two hosts than on citrus trees. 



PROBABLE NATIVE HOME OF ALEYRODES CITRI. 



Authorities on citrus fruit trees are generally agreed that the 

 native home of this group of plants is southeastern Asia. The 

 %\Titer's observations in the Orient support this conclusion in all 

 respects. By far the most common variety of citrus finiit in the 

 Oriental region is the tangerme (Mandarin) orange, including other 

 forms so closely allied as evidently to belong to the same group. 

 Tangerines are foimd everywhere that citrus plants can be gro\\Ti. 

 The \\Titer has seen them throughout the Indian Empire, where 

 tlioy form the bulk of the orange crop, in Ceylon, Java, and the 

 Pliilippines. In China they are extensively grown and are foimd 

 also in southern Japan. That oranges are not native to but have 

 been mtroduced from the mainland into the surrounding islands is 



