BUREAU OF PLANT QUARANTINE 27 
Cooperation with Mexico. — A considerable amount of cotton is produced in the 
Conchos and Juarez Valleys of Mexico, these areas being immediately adjacent 
to the Big Bend and the El Paso Valley of Texas, respectively. This cotton is 
also infested with the pink bolhvorm, and the Mexican officials are endeavoring 
to control the pest with measures similar to those enforced in this country, such 
as field clean-up, seed sterilization, and safeguarding of products at the oil mills. 
There is naturally frequent interchange of visits between the inspectors of this 
project and the Mexican officials in coordinating and carrying out the various 
measures. An excellent spirit of cooperation has always been maintained. 
THURBERIA WEEVIL 
During the year only about 400 acres were planted to cotton in the Thurberia 
weevil area of Arizona, necessitating the operation of only one gin. AH of the 
trash produced at this gin was inspected with one of the small machines. As 
there was not sufficient cotton for the gin to operate steadily, field inspections 
were made from time to time. After the ginning season closed a general inspection 
was made of all fields in the area. A supply of bollies was collected, and this 
material is now being inspected. No specimens of either the Thurberia weevil 
or pink bolhvorm were found in the area during the entire season. 
The same safeguards used in controlling the pink bolhvorm are also employed 
in controlling the Thurberia weevil. These consist of the disposal of gin trash, 
sterilization of the seed, compression and vacuum fumigation of lint, and a 
clean-up of gins, oil mills, etc., at the close of the season's operations. The 
results of each of these activities are included in the figures given for the pink 
bolhvorm. 
Effective October 2, 1933, the Thurberia weevil regulations were revised. 
Under this revision the use of various improved treatments and other safeguards 
that have been developed by the Department in recent years was authorized. 
The changes in every case provide for the issuance of permits for interstate ship- 
ments, on conditions with which it will be simpler and less expensive to comply 
than it was with those previously required, or under which a wider market for 
cotton products is authorized. Changes include a provision under which cotton- 
seed given special heat treatment of 145° F. for 1 hour may move to any desti- 
nation; baled cotton lint may be either fumigated under vacuum, or compressed 
or roller-treated instead of having to be both compressed and fumigated as here- 
tofore; and cottonseed hulls may be shipped to nonregulated territory after such 
special treatment as may be required by the inspector. The regulated area 
includes Cochise, Santa Cruz, and parts of Graham, Pima, and Pinal Counties, 
in the southeastern part of Arizona. 
MEXICAN FRUIT FLY 
INFESTATIONS IN TEXAS 
The extensive use of glass flytraps during the fiscal year resulted in taking 
specimens of Mexican fruit flies (Anastrepfm ludens Loew) from approximately 
three times as many groves in the lower Rio Grande Valley of Texas as were 
found infested in any previous year. Despite intensive inspections of the fruit 
in the 176 groves in which adult flies were taken, no larvae were found until the 
latter part of April after the end of the harvesting and shipping period, when 
fruit gleaned from four groves in the tree-to-tree inspections in the Mission district 
was found infested. Adults had previously been taken in three of these groves. 
Of interest in the larval findings was the fact that several green " October-bloom "' 
fruit were found infested with full-grown larvae, indicating that the eggs had been 
laid while the fruit was decidedly immature. 
The inability to locate larval infestations, even in view of a 35-day extension of 
the harvesting period, indicates thai the number of Hies present in the \alle\ was 
considerably less than during some previous years, even though the number of 
groves involved shows a rather general scattered infestation. Traps were oper- 
ated during the year in 1,-110 groves throughout the valley. Adult Mexican 
fruit Hies were taken in 176 groves, or approximately 12 percent of those trapped. 
This seemingly high rate of infestation may be accounted for by the tact that the 
most susceptible groves were chosen for trapping, and also by the efficiency oi t he 
glass traps. Data accumulated in the trapping work indicated that the adult 
flies did considerable drifting about. A.S further evidence of the effectives 
the traps it is interesting to note that of the 1 . "> I females taken, only Hi) had 
in the ovaries, the remaining 124 presumably having been trapped before their 
