BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 51 
Effective, large-scale pink bollworm control, for example, revolve- 
around the fact that the insect goes into winter hibernation in cotton 
bolls left in the field where the insect developed or in untreated cotton- 
seed from that field. These two facts render this species especially 
vulnerable to field cultural practices or to a relatively simple cotton- 
seed heat treatment at the gin. These are relatively inexpensive 
operations. The object of Held cultural practices is to check develop- 
ment of pink bollworms in the fall and to destroy all bolls left in 
the field after harvest. Such practices include early shredding, cut- 
ting, and plowing under of all crop residue before the pink bollworms. 
can go into hibernation. Cottonseed heat treatment consists of the 
application of moist or dry heat to cottonseed at a temperature of 
150° F. for a period of BO seconds. 
A combination of such cultural control and cottonseed heat treat- 
ment, effectively enforced through State and Federal cooperation, has 
for many years confined the pink bollworm to parts of five States,, 
with commercial damage limited to a few border counties in Texas. 
It is estimated that the pink bollworm has never until 1951 accounted 
for the destruction of more than one bale in each thousand produced 
in the United States. Other cotton insects have occasionally destroyed 
one bale out of each seven. 
A further estimate shows that during the 35 years these control 
measures have been practiced, the gin and oil mill industry and the 
farmers have invested no more than $15 million in equipment for 
pink bollworm control. Farmers in a pink bollworm infested area 
pay about 25 cents an acre for cottonseed treatment. Furthermore, 
State and Federal combined control and research activities on the 
pest have cost less than $30 million. On the other hand control of 
other cotton insects is estimated to have cost the farmer more than 
1 billion dollars in equipment and insecticides during the same span 
of years, with several billion dollars* worth of cotton destroyed by 
these insects. 
Were it necessary similarly to apply insecticides to the entire cotton 
crop for pink bollworm control, following current research recom- 
mendations and attaining only partial kill, it is estimated that the 
annual cost would be a half billion dollars. 
Although infestation in many south Texas counties was fairly light 
at the beginning of the 1951 crop, it later built up to the heaviest ever 
recorded in that section. Commercial damage occurred in many 
fields. A light infestation persisted in counties found infested in the 
1950 crop in north-central Texas and in the Oklahoma regulated area. 
Infestation in 1951 was generally lighter in the western part of Texas, 
New Mexico, and in the Torreon and Delicias areas of Mexico. Only 
one pink bollworm was found in the regulated area of Arizona. A 
light infestation recurred in Vermilion Parish, La., but none was 
found in the other parishes under regulation. Area-wide inspection 
activities in 1951 showed further spread of this insect to 17 counties 
in Texas and two counties in Oklahoma, east of the previously in- 
fested counties. It was also necessary to reclassify, from lightly to 
heavily infested. :\:\ Texas counties. 
Build-up and dispersion of pink bollworm infestation in the past 
two years has resulted because known control measures were not ap- 
plied in a number of important cotton growing counties. This per- 
