30 
By platting the temperature curves for different points it will be 
seen that the mean daily temperature falls below 60 about December 1 
at Victoria, Tex. (which agrees with the observations of Hunter and 
Hinds), at College Station about November 10 to 15, at Dallas several 
days earlier, and for the northeastern part of Texas about November 5. 
From a brief study of the available data, which we are having tabu- 
lated and expressed graphically, we believe that these dates will be 
found to coincide very closely with those of the first killing frosts 
for these sections, although the frost dates will fluctuate much more 
widely from year to year than does the mean daily temperature. 
In carefully observing the numbers and activity of the weevils 
every day during the fall, it was interesting to note that the activity 
was immediately arrested whenever the mean daily temperature 
dropped below 60°, and a comparison of this daily record with the 
temperature curve platted for College Station shows this strikingly. 
The number of weevils entering hibernation will depend almost 
entirely upon the food supply during the fall. Whether there are 
one or two more broods in one part of the State than another matters 
not, for after the third brood the weevils become so abundant that 
their numbers are limited only by the available food supply. There- 
fore, with a normal or excessive rainfall during September and early 
October, which would cause the plants to square freely, there would 
be an abundant food supply and many more weevils entering hiberna- 
tion than. in a dry year when but few squares are formed. The 
weather of the fall, then, has a considerable influence on the number 
of weevils which commence reproduction the next spring. 
At present one of the most important natural factors in reducing 
the food supply of the weevils in the fall is the leaf worm, or so-called 
“army worm ” (Alabama argillacea,Hiibn.). It is a most interesting 
entomological phenomenon that this insect. which formerly did so 
many million dollars’ worth of damage to the cotton of the South and 
which was the subject of much investigation, has now become one of 
the Texas cotton planter’s most valued alles and is welcomed by him 
wherever the weevil occurs. That the defoliation of the plant by 
these caterpillars has an important influence on the number of weevils 
hibernating is certain. 
Of course, the same results are accomplished by thoroughly grazing 
the cotton, or better, by cutting and pulling the stalks, and the 
latter forms the most important feature in the fight against the pest, 
as discussed hereafter. As far as we can ascertain, the number of 
weevils entering hibernation will average about one per stalk; in 
badly infested fields it will often be two per stalk, and it may be as low 
as one to two stalks, with cotton planted an average distance apart. 
Where the stalks are allowed to stand, many of the injured bolls 
remain on them unopened during the winter, and in these the imma- 
