BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 67 
Solutions of dichloroethyl ether have given encouraging results as a 
soil insecticide against the sugar-beet wireworm and the Pacific coast 
wireworm as well as the raspberry root borer. 
Sprays of phenothiazine were fairly effective against the tomato 
fruitworm, Mexican bean beetle, and southern armyworm, and slightly 
useful against the tomato and tobacco worms. This material was 
also highly toxic to the raspberry fruitworm but caused such serious 
injury to the raspberry plants as to preclude its further use for the 
purpose. 
In limited experiments metaldehyde proved very effective against 
slugs and snails in Maryland and California. 
SWEETPOTATO WEEVIL CONTROL AND ERADICATION 
The program which was begun in July 1937 to eradicate the sweet- 
potato weevil from areas of commercial production where wild host 
plants do not persist through the year was continued, and inspection 
was extended to areas not previously scouted for the pest. Surveys 
were conducted during the year in 62 counties in Alabama, Georgia, 
Mississippi, and Texas, 24 of which were found to have infestation in 
seedbeds, fields, or stored potatoes. 
Eradication activities included the destruction of infested seedbeds, 
clean-up of infested fields and storage places, and the destruction of 
volunteer sweetpotato plants on infested and adjacent properties. In 
Alabama native host plants were eradicated from extensive areas 
along the coast by relief labor under a State-sponsored W. P. A. 
project. 
The regulations of the standardized State quarantine were strictly 
enforced in cooperation with the States. 
COTTON INSECT INVESTIGATIONS 
In March 1939 the laboratory for the investigation of the cotton 
flea hopper at Port Lavaca, Tex., and in June the laboratory for 
investigation of the cotton bollworm at College Station, Tex., were 
closed and the work was consolidated with headquarters at Waco, Tex. 
Both insects are normally serious pests of cotton in the Blacklands 
section, and large areas of cotton on both river-bottom and prairie 
land, typical of central Texas, are available for conducting experi- 
ments in the vicinity of the new station. In addition, investiga- 
tions will be undertaken in cooperation with the Soil Conservation 
Service on their Blacklands Experimental Watershed (Brushy Creek 
project) to determine the relation of conservation measures to the 
abundance of cotton insects, and for developing cultural practices 
for their control. 
In June 1939 an employee of the Division was transferred to the 
lower Rio Grande Valley of Texas to secure information on the life 
history and habits of the pink bollworm in the new environment for 
immediate use in the eradication program to be undertaken by the 
Division of Pink Bollworm and Thurberia Weevil Control. 
BOLL WEEVIL 
Although the damage caused by the boll weevil in L938 was almost 
double that of 1937, it was about 2 percent less than the average 
