10 FUMIGATION FOR THE CITRUS WHITE FLY. 
tunately the list of food plants" is limited, and the greater number 
of those thus far recorded is subject to infestation only when located 
near or in the midst of heavily infested citrus groves. The food plants 
which are of most importance in connection with the white fly control 
are the chinaberry trees, privets, and cape jessamine, and these — 
except for the last, in certain sections where grown for commer- 
cial purposes — can be eradicated readily, or their infestation may 
be prevented where community interests precede those of the indi- 
vidual in controlling public sentiment. These food plants favor the 
rapid dissemination of the white fly from centers of infestation and 
their successful establishment in uninfested localities. The}" seriously 
interfere with the success of fumigation, as well as of all other remedial 
measures, by furnishing a favored breeding place where the white fly 
can regain its usual abundance in a much shorter time than would be 
the case if it were entirely dependent upon citrus fruit trees for its 
food supply. The plants mentioned, together with Citrus trifoliata 
(except where used in nurseries), and all abandoned and useless citrus 
trees should be condemned as public nuisances and destroyed in all 
communities where citrus fruit growing is an important industry. 
Where the destruction of chinaberry trees is impracticable for any 
reason, they may be rendered innocuous by taking steps to prevent 
their becoming heavily infested each year. Tins may be accomplished 
by either defoliating each winter or by destroying entirely all privets 
and cape jessamines and by thoroughly fumigating each winter all 
citrus trees within a distance of 200 or 300 yards of each chinaberry 
tree. 
SEASON OF THE YEAR. 
Fumigation for the white fly should be done during December, 
January, and February, beginning not earlier than sixteen to twenty 
days after the adults have disappeared, in order that all of the eggs 
a The complete list of food plants so far as known is as follows: Citrus (all varieties), 
chinaberry (Melia azedarach and Melia azedarach umbraeuliformis), cape jessamine 
(Gardenia jasminoides), wild persimmon (Diospyros virginiana), Japan persimmon 
(D. Jcahi), privets (Ligustrum spp.), Viburnum nudum, Fieus altissima, prickly ash 
(Xanthoxylum clava-herculis) , cultivated pear (Pyrus sp.), cherry laurel (Prim us 
laurocerasus), Prunus caroliniana, lilac (Syringa sp.). Water oak (Qjiercus nigra) has 
been reported as a food plant of the citrus white fly, but there is no definite record of 
the insect reaching maturity on this plant, and the observations made in connection 
with the present white fly investigations show that for practical purposes oaks may be 
ignored as food plants of this species. Professor Gossard reports having observed 
larvae of the citrus white fly on scrub palmetto (Sabal megacarpa I. The author once 
ob erved larvae on the banana shrub (Magnolia fuscatum) but apparently none reached 
maturity on this plant. Dr. E. A. Back has observed two live larva- of the citrus 
white fly on oleander (Nerium oleander). These plants (oaks, scrub palmetto, banana 
shrub, and oleander) may be ignored absolutely as food plants unless it is proved 
beyond doubt thai ii is possible for the citrus white fly to reach maturity on them. 
The cultivated figi Ficus),and thesweel baj I \fagnolia virginiana) have been reported 
as food plants, but with little doubt these reports are erroneous. 
