of 
mined by the amount of accumulated temperature during their 
development, and, according to a recent report of the Fish Commis- 
sion, the time of hatching can be predicted or controlled to a con- 
siderable extent in this way. There can be no doubt that the time 
of emergence of insects from hibernation and the date upon which 
they begin oviposition or normal activity 1s dependent upon certain 
well-defined physical laws which can be determined only by many | 
careful observations and a judicious interpretation of the data col- 
lected. It seems to the writer that this offers a promising field for 
entomological investigation and one which may very possibly be of 
much practical importance in our warfare against insect pests. 
Though a much larger number of weevils survive the winter in 
southern Texas, the hot dry summers lall the larve in the fallen 
squares so that the rate of increase is slower, and often a good crop 
is made in spite of them. This shows that the rate of increase and 
the factors governing the mortality of the summer broods are of 
importance. 
In the study of an insect pest we must first secure as accurate and 
elaborate a knowledge as possible of its fe and habits under labora- 
tory or insectary conditions. Then, it seems to me, we must go into 
the field and ascertain what are the conditions; whether or not our 
artificial environment has changed the life history, rate of reproduc- 
tion, etc., and what factors influence these phenomena in the open. 
This is what we have essayed to do in as ‘far as our Lmited means 
would permit, assuming, for the most part, the correctness of the 
most excellent and careful laboratory studies of Messrs. Hunter and 
Hinds at Victoria. Our method in field work has been to make fre- 
quent counts of large numbers of plants in the same fields through 
the season, making note of the number of weevils on each plant and 
the numbers of squares, boils, and blooms, and the percentage of these 
which are perfect, or injured by the weevil, and the number of squares 
fallen as a result of weevil injury. Counts were also made of thou- 
sands of fallen squares at different times to determine the percentage 
injured by the weevil and the stage of the insects contained. Of 
course, as the season advanced we were compelled to examine a 
smaller number of stalks owing to the size of the plants, but always 
a sufficient number to give several thousand squares from each plot. 
in this way hundreds of thousands of plants have been carefully 
counted and the results tabulated, during the last two years. 
The first three summer broods seem to be fairly well defined, the 
first occurring during the last half of June, the second about the mid- 
dle of July, and the third about the second week in August in central 
Texas. There is an interesting relation between the normal rate of 
formation of squares on the cotton plant and the increase of the 
weevil. The rate of formation of squares is so exceedingly variable 
