SB 
818 
C578 
ENT 
1Oselilitte Issued September 29, 1909. 
United States Department of Agriculture, 
-BUREAU OF ENTOMOLOGY, 
L. O. HOWARD, Entomologist and Chief of Bureau. 
PREPARATIONS FOR WINTER FUMIGATION FOR THE: 
CITRUS WHITE FLY. 
By A. W. Morritt and W. W. Yoruers. 
INTRODUCTION. 
As a result of investigations conducted by the Bureau of Ento- 
mology during the past three years, fumigation for the citrus white 
fly has been placed upon a practical basis, and the process has been 
so simplified that any citrus grower can undertake the treatment of 
his grove without depending upon experienced fumigators to con- 
duct the operations. Under present conditions fumigation is the 
most satisfactory and profitable method of controlling the white fly 
in hundreds of infested groves in the Gulf coast citrus-growing regions, 
and its usefulness will be extended to nearly all infested groves 
when the practical recommendations in a forthcoming bulletin on 
the white fly have been put into effect. The superior quality of 
Florida citrus fruits when grown in groves free from injury from 
insect pests and the awakening of progressive growers to the neces- 
sity for organizations for combating insect pests and for marketing 
the fruit point to the general adoption of the control measures to 
be recommended in the publication referred to. 
At the present time the authors would recommend fumigation for 
the white fly under the following circumstances: In groves isolated 
by a distance of at least 200 yards % from all other infested groves, 
in citrus groves or in citrus-growing sections where the white fly has 
recently appeared and is still of limited distribution, and in sections 
where cooperation can be secured among growers in naturally isolated 
groups. In many cases the owner of an extensive and valuable 
grove which is isolated except for a small grove of a few acres from 
other infested groves can well afford to loan his equipment, or, if 
necessary, fumigate the neighboring grove entirely at his own expense, 
a Experience so far has shown that as a rule in cases of isolation of much less extent 
fumigation can be practiced without its being rendered unprofitable through the 
migration of adults. 
5937—Cir. 111—09 : 
408390 
