am D a 
SOUTHERN FIRELD-CROP TNSECT INVESTIGATIONS 
J. L. Webb, Associate Eniomologist, Acting in Charge 
As a result of the finding by Department inspectors of the Thurberia 
weevil in all the cotton area aiong the Santa Cruz River in Arizona, from 
a point 15 miles north of Nogeles as far as what is known as the Postvale 
Tract, the State of Texas has placed a quarantine against the infested 
area. This action followed a conference held recently at Tucson, Ariz., 
between B. R. Coad and officials of Arizona and Texas. The counties 
involved in the area quarantined include Pima, Santa Cruz, Graham, Cochise, 
and part of Pinal, all in southeastern Arizona. On a recent trip of in- 
vestigation Mr. Coad confirmed the reports that the infestation of the 
. Thurberia weevil in cultiveted cotton grown near Continental, Sahuarita, 
Tubac, and Cartaro was greater than ever before. Biological investigetions 
conducted near Tucson during the past year by 7. P. Cassidy indicate the 
probability that, if established in the western cotton areas, this pest 
will be even more injurious than the ordinary boll weevil or pink bollworm. 
For further protection against. the possible spread of this insect into the 
western part of Texas, where the. Mexican cotton boll weevil can not thrive, 
but where the Thurberia weevil can exist and do great damage, the State 
Department of Agriculture of Texas has asked the Federal Horticultural 
Board also to plece a quarantine against the infested district. 
Mr. Coad, on the same western trip, visited Yuma, Ariz., Calexico 
and El Centro, Calif., and Mexicali, Mexico, to investigate reports received 
that the cotton leaf perforator, Bucculatrix thurberiella, was becoming a 
serious pest of cotton, particularly in the Imperial Valley. This insect 
has been known to occur on cotton practically since its earliest planting 
in that vicinity, but opinions as to damage have varied considerably, and 
it is only in the last few years that fairly consistent injury seems to have 
developed. Investigation shows that in 1924 this pest apparently caused a 
loss of something in excess of 15 per cent in the cotton production of the 
Imperial Valley. It is estimated that one firm at Mexicali lost in a single 
season at least one and a half million dollars. Only fragmentery investi- 
gations have been made on this species, and comparatively little is knom 
of its activities. For this reason it is planned to open a laboratory, 
probably at Calexico, in the very near future and undertake an intensive 
study of the pest. 
W. A. Stevenson, who has been located for some time at the Florence, 
S, C., Boll Weevil Laboratory, has been transferred to the Arizona weevil 
investigations, with headquarters at Tucson. H.C. Young and A. J. Chapman, 
of the Tallulah laboratory, have been transferred to the same investigations. 
_ A. C. Johnson, of the Tallulah laboratory force, has-resigned, his 
resignation taking effect March 31, 
