1961] 
Insect Control Programs 
93 
course, rendered unfit for human consumption. Host fruits infested 
are citrus, peach, mango and about 200 other fruits and vegetables. 
Although some true fruit fly species are found in temperate regions, 
most, including the medfly, are at home in tropical or subtropical 
climates. 
In a climate like that of Florida, the medfly can produce about 10- 
12 generations per year, since the life cycle is completed in slightly 
under one month in warm weather. The medfly is a native of Africa, 
but it has spread to most of the world’s citrus-producing areas in 
infested fruits carried by human commerce; the United States is one 
of the few such countries that have managed to exclude it. Since 1912, 
U. S. Plant Quarantine has intercepted the medfly over 1600 times 
at various ports of entry in this country, and it became established 
here twice, in 1929 and again in 1956, both times in Florida. On both 
occasions, vigorous efforts by combined Federal and state forces eradi- 
cated the fly before it could become established outside of Florida, and 
at present writing, the pest has no known breeding population in the 
continental United States. 
The 1929 Campaign 
On April 6, 1929, larvae were discovered in grapefruit at Orlando, 
Florida, and by April 10, adult flies had been found and positively 
identified as Mediterranean fruit fly. The Florida State Plant Board 
and the USDA sprang into action immediately, shifting inspectors to 
the area, and by May 1, 1929, a quarantine was invoked in connection 
with a program aimed at prevention of spread of the pest and its 
eventual eradication. Quarantine stations were set up on railways, 
roads and ports on coastal waters and inland waterways. The quaran- 
tine of automobiles moving north and south from, the infested area 
proved difficult, but was strictly enforced — when necessary, with the 
help of the National Guard. Between 410,000 and 625,000 vehicles 
were examined each month, of which 6,900 to 13,100 were found 
carrying contraband material, including fruits, vegetables, soil, nursery 
stock, compost, etc. 
Within the affected area, all actual infestations discovered and the 
area surrounding each one for one mile were designated as “infested 
zones,” while a “protective zone” extended for another nine miles 
beyond every infested zone. Within the infested zones all known 
fruits and vegetables were destroyed in order to deprive the flies of 
breeding opportunities. Removal of host fruit was continued in the 
infested zones, and no vegetables were planted there. Packing houses 
were supervised in order to prevent shipping leaks through this 
channel and to enforce sanitary measures against possibly infested 
