BUREAU OF ENTOMOLOGY AND PLANT QUARANTLNE 15 
were found to be of value in detecting pink bollworm infestations in 
the outlying lightly infested and in identifying noninfested areas of 
Texas. Pink bollworm moths were collected in traps in Fannin and 
Lamar Counties, which were not previously known to be infested. 
This work was in cooperation with the Division of Farm Electrifica- 
tion, Bureau of Plant Industry, Soils, and Agricultural Engineering 
and the Texas Agricultural Experiment Station. 
Synthetic media developed for laboratory rearing of pink boll- 
worms and boll weevils 
For the first time the pink bollworm has been reared from egg to 
adult on a medium in which all components are known and are chem- 
ically pure. This medium is composed of dried egg albumin, dextrose, 
cottonseed oil, and crystalline vitamins. Physical conditions neces- 
sary for the development of the insect were also determined. The 
shortest period for development from egg to adult was 41 days. The 
average development period in the field is about 31 days. 
Starting with half-grown larvae, normal adult boll weevils were 
also produced in a synthetic medium. Crystalline vitamins, purified 
dried-egg albumin, dextrose, fats, salts, and water were combined to 
produce a homogenous, solid, soft medium suitable for their develop- 
ment. Larvae were observed to feed and prepare a hollowed-out space 
in the medium for pupation, similar to that in a square or boll. Nor- 
mal pupation and emergence occurred. 
Boll Weevil Damage Relatively Light 
Weather conditions during the critical fruiting period of the 1952 
cotton crop were not conducive to heavy boll weevil buildup. Ac- 
cordingly, the damage caused by this insect was relatively light, ex- 
cept in the Lower Rio Grande Valley of Texas, where severe losses 
occurred. Despite the relatively low damage caused by the boll weevil 
in comparison with previous years, experimental data at Tallulah, La., 
showed an average increase in yield of 18.4 percent where insecticides 
were used for boll weevil control. At San Benito and Brownsville, 
Tex., the increases in yield from a combination of boll weevil and pink 
bollworm control averaged 97.3 and 288 percent, respectively; while 
at Florence, S. C, the average increase from cotton-insect control 
where the boll weevil was the principal pest was 30 percent. 
Stalk Destruction Important in Boll Weevil Control 
Just how essential cotton-stalk destruction is in boll weevil control 
was amply demonstrated in the Lower Rio Grande Valley of Texas 
during 1952. For several years practically all cotton stalks in that 
area had been destroyed by August 31, the deadline imposed by the 
pink bollworm quarantine regulations. During the years when this 
stalk destruction was accomplished by the deadline date, the boll 
weevil problem was minimized during the following year and compar- 
atively light damage resulted. In the fall of 1951, however, owing to 
unfavorable weather conditions, the deadline date for stalk destruc- 
tion was extended and a thorough job of destroying the stalks was 
never accomplished. As a result, many boll weevils survived the 
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