BIOLOGY OF THE MEXICAN COTTON BOLL WEEVIL. 2 
In 1914 the life history and habits of the Arizona weevil were 
studied under natural conditions in the mountains near Tucson, Ariz. 
These studies are discussed in two papers.” 
Thus it is seen that these studies embrace a wide range of time and 
conditions. In fact, the conditions of humidity, rainfall, tempera- 
ture, altitude, soil, etc., include practically all extremes found in the 
cotten belt. 
SCOPE OF THE PRESENT LIFE-HISTORY STUDIES. 
The biological studies of the boll weevil at Madison, Fla., during 
the year 1918, included a thorough study of the boll weevil under 
outdoor insectary conditions on both upland and sea-island cottons. 
The main object of this study was to determine the difference, if any, 
in the weevil’s biology on the two kinds of cotton. During the month 
of August, 1918, a small series of experiments was made to deter- 
mine the length of the developmental period of the weevil from egg 
to adult under actual field conditions. The results of the field studies 
indicated conclusively that a wide variation existed in the length of 
time required for the developmental period of the weevil under 
insectary conditions compared with the true developmental period 
under normal field conditions. Consequently the studies in the 
biology of the weevil during the year 1919 were arranged to include 
a thorough study of the field biology of the boll weevil. Insectary 
studies in the biology of the weevil were conducted at the same time 
the field tests were under observation, to serve as a check. 
METHODS USED IN THE STUDY OF THE BOLL WEEVIL UNDER 
OUTDOOR INSECTARY CONDITIONS. 
The numerous experiments of 1918 were conducted in a specially 
constructed outdoor insectary at the Madison, Fla., laboratory (fig. 
8). The sides of. the insectary building were constructed entirely 
of 16-mesh galvanized wire screen from the floor to the ceiling, 
which permitted free air circulation at all times. The roof of the 
insectary building extended 2 feet over the sides of the building, 
preventing the direct rays of the sun from touching any of the breed- 
ing jars. All the insectary breeding work was conducted in glass 
tumblers half filled with white sand. The sand was kept constantly 
moist. Lantern globes with cheesecloth covers were used for the 
longevity experiments. 
7Coad, B. R. Relation of the Arizona Wild Cotton Weevil to Cotton Planting in the 
Arid West. U. S. Dept. Agr. Bul. 233, 12 p., 4 pl. 1915. 
Coad, B. R. Studies on the Biology of the Arizona Wild Cotton Weevil. U. S. Dept. 
Agr. Bul. 344, 23 p., 2 pl., 1 fig. 1916. 
