Sy) 
‘The period of time prior to the date of normal maximum emer- 
gence during which the accumulated temperature must be ascertained 
in order to determine the total amount of accumulated temperature 
A | | | 
ial 
NEES88 
Sh 
A NS 
i 
cH 
a 
Bees a a Ba 
PREEEEEE 
NORMAL MEAN MONTHLY TEMPERATURE CURVE 
-—-----— —— 1904 MEAN MONTHLY TEMPERATURE CURVE 
Fia. i. —Diagram showing normal mean monthly temperature and the mean monthly bemipera: 
ture during 1904 at Victoria, Tex. (original). 
necessary for maximum emergence, and the average temperature of © 
the date on which this accumulation must begin both for the normal 
and any individual year, must be determined and will doubtless 
estimated, for in the spring the latter half of the month will be warmer and 
in the fall cooler than the first half. An examination of the daily temperature 
curves for any year corroborates this view. 
Considering that the weevils first commence to emerge normally at 68° F., 
and that the maximum emergence is normally at 78° F., then the amount of 
temperature necessary to accumulate after the first emergence before the 
maximum emergence will be represented by the area ABC, and the maximum 
emergence will be at the point B, where the normal mean temperature line 
crosses 78° F., or, approximately, May 15. In 1904 the first emergence would 
theoretically have taken place at A’, where the mean temperature crosses 68° F 
or about March 12. After that for about a month there was an excess of 
temperature and then a deficiency until July. The mean temperature line 
did not cross 78° F. until about June 3 ; 
But if we ascertain the date of maximum emergence in 1904 by the hypoth- 
esis proposed we would proceed as follows: The point of departure of the 
