22 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE, 1934 
conducted over some 4,000 acres. This is the acreage from which plants were 
actually removed, and not the total acreage covered, as a very large area had to 
be scouted to locate the plants. Approximately 375,000 mature and 150,000 
seedling plants were removed from the area cleaned for the first time. From the 
area recleaned approximately 9,500 mature, 1,280,000 seedling, and 110,000 
sprout plants were removed. The greater portion of these plants during both the 
first and second clean-ups was removed from the Cape Sable area. The cotton 
at Cape Sable is not very accessible, and while the work was being carried on this 
past season it was necessary for the men to cut some 25 miles of trails so that the 
laborers could be transported directly to the cotton. It was also necessary to 
construct a number of bridges over canals. These bridges were made of drift 
lumber and logs without any expense to the Department, and considerable 
ingenuity was exhibited by the inspectors in constructing them. Many of the 
keys in Florida Bay were cleaned for the first time. Most of the cotton remaining 
to be cleaned is in the Cape Sable area, and some is on keys in Florida Bay. 
Toward the close of the fiscal year a second recleaning this season was made 
along the west coast from Naples northward and on the mainland keys over which 
the highway passes so as to prevent any seedlings from producing fruit before the 
work can be resumed next fall. Since the clean-up was begun in June 1932 
approximately 1,000,000 mature, 250,000,000 seedling, and 130,000 sprout plants 
have been removed from some 9,500 acres. As an example of the progress being 
made, it is of interest to note that the first clean-up on Lower Matecumbe Key 
in 1932 required 114 man-days. Naturally part of this time was devoted to 
cutting trails through the dense growth to reach the cotton. This key was 
recleaned in April of this year and required only 26 man-days. A second reclean- 
ing was made in June, and this required only 4 man-days. Each time an area is 
recleaned considerably less time is required, as there is less cotton to be removed 
and the inspectors know just where it occurs. On the west coast several places 
where colonies were cleaned last season were found to be entirely free of cotton 
this season. 
Last year some experiments were begun to determine the practicability of 
destroying wild cotton with poison. It has now been determined that this can be 
done, but the poisoning treatment alone is rather expensive. Therefore, a com- 
bination method has been worked out whereby the poison is applied only to plants 
growing in rocky places where they cannot easu'y be grubbed. The most effective 
method of applying the poison is to cut the plant off, leaving a stump from 3 to 
6 inches high. The stump is then lacerated and about half a pint of sodium arse- 
nate solution, in the proportion of 2 pounds of sodium arsenite to a gallon of 
water, is poured on it. Excellent results are now being obtained with this treat- 
ment. 
As noted in last year's report, several small experimental plantings of culti- 
vated and wild cotton were left at Chapman Field to avoid any possibility of 
driving the pink bollworm to some other malvaceous plant. In cooperation with 
the Bureau of Plant Indust^, all fruit from this cotton was removed and inspected. 
Incidental inspections of Hibiscus and okra blooms were also made from time to 
time. On August 23, 1933, 2 pink bollworm larvae were found in Hibiscus blooms, 
the plant having been identified as Hibiscus rosa-sinensis, a hybrid. Immediately 
after this finding an intensive examination of Hibiscus blooms, particularly in 
the vicinity of Chapman Field, was made, and the examinations were continued 
from time to time until the close of the year without any more specimens being 
found. It therefore appears that the above infestation was casual, and that no 
general infestation exists in Hibiscus. The results of the inspection of cotton 
blooms continued negative until June 19, 1934, when 1 larva was found, followed 
by 2 on June 21, and 4 additional ones the last week of June. The last finding 
before this was in March 1933, at which time it was attributed to overwintering 
larvae in the soil. These later findings, however, indicate that the infestation is 
now coming from some outside source, and efforts are being made to locate it. 
CLEAN-UP IN BIG BEND AREA OF TEXAS CONTINUED 
The special control program begun in the Big Bend area last season to reduce 
the heavy infestation and thereby lessen the danger of spread of the pink bollworm 
to the main Cotton Belt has been continued. The measures consist of the 
clean-up of fields and premises after picking is completed, delayed planting the 
following spring, and the use of trap plots of cotton. As stated in the last annual 
report, infestation had been found by June 30, 1933, in 47 of the 67 plots and 
in only 14 of the adjacent fields. These trap plots were continued until the middle 
of July, at which time the field cotton had reached the same size and fruiting stage 
