Nov. io, 1913 
A Cotton Boll Weevil in Arizona 
9i 
rather widely separate; tooth almost as long as claw. Length, 5 to 5.5 mm. (0.20 to 
0.22 inch). 
This variety differs from Anthonomus grandis on cotton by its greater robustness 
(PI. VI); the more golden appearance of the scales; the slighter constriction of the 
prothorax (figs. 1 and 2); its stouter and more coarsely sculptured beak (figs. 3 and 4); 
its slightly more compact antennae (figs. 5 and 6), with funicle of a lighter color than 
the club; its stouter legs, with a distinct second tooth on the middle femora (figs. 
7 and 8); the wing (fig. 9), which shows a slightly more distinct spot. It also differs in its 
food plant (Thurberia thespesioides), its altitude (4,000 feet upward), its breeding 
season (August 15 to November), and in certain physiological and biological char¬ 
acters. The most obvious diagnostic characters are as follows: 
Anthonomus grandis thurberiae 
Antennal funicle of a distinctly lighter color than 
the club; punctation of elytral striae strongly and 
clearly defined; prothorax usually very feebly con¬ 
stricted and not emarginate or but very slightly so; 
elytra often robust; vestiture of ochreous scales 
intermixed with black hairs; breeds in Thurberia 
thespesioides; range, above altitude of 4,000 feet. 
Fig. r.— Anthonomus grandis , var. thur¬ 
beriae: Prothorax. Much enlarged. 
(Original.) 
Anthonomus grandis 
Antennal funicle and club concolorous; puncta¬ 
tion of elytral striae not clearly defined from the 
striae; prothorax strongly constricted at apex and 
usually emarginate in front; sides of elytra usually 
parallel; vestiture of grayish to ochreous scales in¬ 
termixed with very inconspicuous grayish to very 
dark-brown hairs; breeds in Gossypium spp.; range, 
below altitude of 2,000 feet. 
Fig. 2.— Anthonomus grandis Boh.: Pro¬ 
thorax. Much enlarged. (Original.) 
Hibernation. —It is not known whether Anthonomus grandis thurberiae hibernates 
as an adult outside of its cell, but it is known positively that many individuals pass 
the winter and even the summer in the cells formed during the preceding fall. In 
May, 1913, from the material sent by Mr. McCleary, the 'writer found 18 live adults in 
their cells in an examination of 743 bolls, 220 of which were infested. On August 27 
Dr. Morrill found six live boll weevils still in their last year’s cells at about 4,500 feet 
altitude in Sawmill Canyon, Santa Rita Mountains, and on August 30 the writer 
found another live weevil in its cell in Ventana Canyon, Santa Catalina Mountains. 
As further evidence of the prolonged rest of this variety, no immature stages were 
found, beyond a one-fifth grown larva in squares. The extreme lateness of the plants 
in the canyons where the boll weevil was found indicated that the weevils could not 
have had buds on which to feed for much more than two weeks in August. Plants 
grown from seed at Victoria, Tex., and Tallulah, La., did not begin to pioduce buds 
until well along in August. The natural dormant period of the Arizona boll weevil 
therefore lasts about nine months. 
It is interesting to note that the Thurberia weevils extracted from their cells in May 
and sent to Victoria, Tex., immediately began to feed and breed upon cotton and pro¬ 
duced several generations. 
