FOOD PLANTS OF CITRUS WHITE FLT. 43 



of the white-fly situation in the Gulf States agree that the China 

 and umbrella trees (Melia sp. and var.) are the greatest breeders of 

 the white fly of all known food plants including the citrus. In 

 speaking of the umbrella China tree Morrill and Back state: 



First this insect shows in one respect a greater degree of adaptation to this food 

 plant than to citrus plants, as shown by the very low rate of mortality in immature 

 stages. The second important point is that adult citrus white flies are so strongly 

 attracted by growing leaves of umbrella trees that under certain conditions with 

 umbrella and citrus trees growing side by side more adults collect on three or four 

 umbrella leaves than are present on entire citrus trees of medium size. 



From the preference shown in the white-fly region of this country 

 for the different China trees some entomologists have even ventured 

 to state that they believed these trees to be the original host plants. 

 It is known that China trees are native to Asia, and that certain 

 species occur ^vild in India. The writer found these trees common 

 in northern India, and many were examined. In no instance, how- 

 ever, was the white fly found on China trees in that country, although 

 in some cases the foliage of these trees came in contact with aleyrodid- 

 infested orange plants.. 



Jasminum same AC. 



Some of the most common bushes throughout India belong to the 

 genus Jasmmum, and of these probably Jasminwn samhac is the 

 most common species. This plant is used for ornamental purposes 

 in yards and gardens, but is of especial importance through culti- 

 vation for its very fragrant flowers, which are used in making scented 

 oil as v/ell as in connection with various religious performances of 

 certain native sects. Patches of one-fourth, one-half, or even an 

 acre in size are common throughout northern India, and the v/riter 

 has seen the plant in every other part of this country in which he 

 has traveled. The special point of interest is that these bushes are 

 invariably mfested with the white fly, and ustiaUy more or less 

 severely. The writer has seen patches of this plant in which almost 

 every leaf of each plant contained some living white flies. Bushes 

 were sometimes found to be very black mth sooty mold, a condition 

 never seen in citrus trees. Not infrequently has the writer exam- 

 ined as many as a score of orange trees with the result of finding 

 li\dng material on only one or two, whereas every Jasmmum bush 

 in the immediate vicinity would contain much living material. In 

 the Central Provinces no white flies were seen on citrus trees, yet 

 m numerous instances Jasminum bushes planted between the trees, 

 in some cases even touching their trunks, contained many active 

 insects. 



In conclusion, it might be stated that in all localities in wJiicli 

 Jasminum bushes were examined, which included northern and 

 central India, these were found mfested with Aleyrodes citri, and 



