BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 77 
Surveys Show Louisiana and Texas Still Free of Citrus Canker 
Completion of the second phase of a 3-year cooperative Federal- 
State citrus canker survey in Louisiana disclosed no evidence of the 
disease. This year's activities consisted of a survey of abandoned and 
escaped citrus trees along the bayous and in swamp areas in parishes 
where canker infection had been found at any time since 1935. One 
State and two Federal inspectors were engaged in this survey from 
October 9 until December 2, 1950. More than 20,000 citrus trees were 
examined on 2,300 properties in 8 parishes. Most of the trees were 
so seriously infected with scale and red fungus that inspection for 
canker was difficult. Two previously infected properties far out in 
the marshes of Terrebonne Parish, where citrus canker was found 
in 1936 and 1939, were reached by boat for thorough reinspections and 
no canker was found. 
Areas in Texas where citrus-canker infections were found between 
1935 and 1943 were reexamined with no canker being found. Most 
of the work was in the vicinity of Alvin in Brazoria County, Alta 
Loma in Galveston County, and Navasota in Grimes County. Canker 
infection was last found in Texas in 1913 at Navasota on a small Pon- 
cirus trifoliata seedling on a property which was originally found 
infected in 1911. Two previously infected properties in Corpus 
Christi and six near Hamshire in Jefferson County were also given 
close inspection. A number of old P. trifoliata hedges in Washington 
and Montgomery Counties were inspected. Approximately 208,000 
citrus trees on nearly 700 properties in 10 counties were inspected. 
Dutch Elm Disease Reported From Three More States 
Out of a total of 5,124 elm specimens submitted to the Dutch elm 
disease service laboratory for culturing, the disease was identified in 
3,868 sets of specimens. The identifications confirmed the presence 
of the disease in 15 States and the District of Columbia. Specimens 
for culturing were submitted by 16 Federal, 37 State, and 49 local 
Government agencies, 63 arborists, and 102 institutions and property 
owners, in 21 States and the District of Columbia. 
The Dutch elm disease fungus was found for the first time, in 
August 1950, in Illinois, Michigan, and New Hampshire. The disease 
reappeared in Rhode Island, where it had not been found since 1946. 
A heavy outbreak was discovered in the Pittsburgh, Pa., area. In the 
District of Columbia and adjoining area, 1950 confirmations tripled 
those of the previous year. When control work was discontinued in 
Indianapolis in 1943, only two diseased trees could be found there. 
Elms died there by the hundreds in 1950. There was no reported 
recurrence of the disease in Colorado in 1950. 
Technical assistance was furnished the Michigan Department of 
Agriculture in initiating a Dutch elm disease scouting and control 
program in the Detroit area. 
Directions for detecting diseased trees, containers for forwarding 
specimens, and educational displays were furnished various agencies 
in 15 States. 
