1961] 
Insect Control Programs 
IOI 
scale production in July, 1958. By early spring of 1959, it was pro- 
ducing for release at the phenomenal rate of 50-60 million flies per 
week. The flies were placed in special cardboard cartons that could 
be opened as dropped from the plane. About 20 light planes were used 
at the peak of operations, each flying five to six hours a day over 
prearranged flight patterns based on a few strategic release centers 
spaced over Florida. Three long trap lines covering the state from 
north to south provided information on the effectiveness of the opera- 
tion, and a field force of about 50 livestock inspectors worked on 
quarantine patrol duty. Stringent quarantine regulations were set up 
to prevent infested livestock from entering the Southeast from across 
the Mississippi. 
The program had a swift and dramatic effect on the Florida screw- 
worm population. By the middle of March, 1959, all attempts to 
find egg masses or active screwworm infestations in Florida proved 
negative. On June 13 of that year the USDA and the Florida Live- 
stock Board could announce, “Southeast free of screwworms for 16th 
consecutive week.” This record was marred in the following week by 
the discovery of a single case of screwworm infestation in Highlands 
County, Florida. The releases continued at a rate of about 42 million 
flies a week, blanketing the area from southern Alabama and Georgia 
south to Key West. After some weeks during which no signs of a 
wild fly population were found, the rate of releases was dropped to 
30 million flies per week and lower, and finally, on November 14, 
1959, by releases were terminated. The total eradication of the south- 
eastern screwworm population had been achieved. 
In the months since the release ended, an infested dog has been 
found in Florida — evidently brought in from the outside — and dur- 
ing the spring and summer of 1961, infestations have appeared at 
points along the Gulf Coast from the west, apparently originating 
from infested livestock shipped from the Southwest. It seems that 
these new threats to the Southeast can be handled with the available 
weapons, and the long-range problem now is centered on rolling the 
screwworm menace back across a defensible line in southern Mexico 
or Central America, and holding it there by quarantine and possibly 
by a constantly maintained belt of sterile flies. 
COMPARISONS OF THE FOUR PROGRAMS 
In comparing operations against the four pests we have just con- 
sidered, it is well to recall once again that each insect is a separate 
and distinct problem in control. Some insects have characteristics 
