FLORIDA STATE HORTICULTURAL SOCIETY 
91 
of oil emulsion sprays. These are efficient 
if properly made and applied. The object 
of emulsions is to cover the body of the 
insect and kill it by asphyxiation. The 
emulsion should be thoroughly applied 
with special nozzles in order to reach the 
under sides of the leaves and so cover the 
insects entirely. Neither of these meas¬ 
ures is anything more than a partial con¬ 
trol measure and both are costly. The 
spraying must be repeated at frequent in¬ 
tervals and must be continued. 
Much has been said, in Florida, as to 
the dangers confronting the Florida pro¬ 
ducer through the presence of the black 
fly in Cuba, the Bahamas and elsewhere. 
These dangers are real and the measures 
to prevent entry of this pest should by all 
means be continued, and doubled and re¬ 
doubled. It will be readily understood 
that if the black fly gains entry into Flor¬ 
ida another heavy and continuous burden 
of expense will be imposed upon the grow¬ 
er, already carrying a heavy production 
cost. 
I am now ready to tell you how the 
black fly was combated in Cuba. During 
the year 1917, spraying operations were 
carried on using whale oil soap almost en¬ 
tirely. Inspection work in Havana Prov¬ 
ince during the year showed that the black 
fly was confined to a five-mile zone with 
the Botanical Gardens at Havana as a cen¬ 
ter. About this time the work which had 
been started at Guantanamo with good 
prospect of being successful was aban¬ 
doned and as a result the black fly is now 
firmly established in Oriente Province. 
Early in 1918, the State Plant Board of 
Florida, at the request of the Cuban Gov¬ 
ernment, detailed temporarily several of 
its experienced inspectors to assist and ad¬ 
vise the Cuban Bureau of Plant Sanita¬ 
tion. A campaign based upon the experi¬ 
ence gained in citrus canker eradication in 
Florida was inaugurated. Field inspec¬ 
tion on a large scale was begun and spray¬ 
ing operations, together with severe prun¬ 
ing, were undertaken. A nursery inspec¬ 
tion system in conjunction with the effort 
to eradicate black fly was organized. 
Plenty of money was available and con¬ 
ditions at that time were most favorable 
for eradicating the pest. Work was con¬ 
tinued vigorously for a time and progress 
was made. This effort was unfortunately 
only sporadic. The system inaugurated 
promised to accomplish the result aimed 
at—eradication—and no doubt would 
have done so, had it not been for a change 
in administration in the Department. 
From then on the work was not followed 
as suggested by the Plant Board, and now 
we find the black fly situation in Cuba 
hopeless so far as eradication is concerned. 
Illegal movement of nursery stock has 
caused the spread of the black fly to as 
many as five or six new centers in differ¬ 
ent parts of the island. When the work 
on the black fly was first started a decree 
was published prohibiting the movement 
of all plants of the genus citrus, also 
guavas, mango, coffee, sapodilla, pome¬ 
granate, star-apple and red mammee, or 
other host plants of the black fly. Later 
the black fly was found in many of the 
patios and yards and gardens of houses in 
the Vedado, a residential district of Ha- 
bana, and the decree was made to require 
the inspection and certification of all 
