go 
Journal of Agricultural Research 
Vol. I, No. a 
In addition to these differences in characters, specimens of the Arizona 
form were found in hibernation in their cells until September i, while 
the eastern form is never found in its cells in cotton bolls after March 15. 
The Arizona insect seems to be confined to one, or not more than two, 
annual generations, while the cotton boll weevil has many generations. 
The former lives on Thurberia, the latter on Gossypium. The Arizona 
weevil was found at 4,000 feet altitude, while the Texas weevil has never 
been found above 2,000 feet altitude. The two forms are geographi¬ 
cally isolated by mountain divides. When the Arizona weevil was seen 
in the field, it displayed a tendency to oviposit at a different place and 
to seal its egg puncture differently; the egg itself was of a slightly 
different shape. 
The Mexican cotton boll weevil has never been known before this year 
to feed readily or breed in any other plant, although suspected of being 
capable of adapting itself to other foods if forced to it. When oppor¬ 
tunity was given the Texas boll weevil to attack Thurberia squares and 
bolls, it fed readily and eagerly, sometimes displaying a preference for 
Thurberia over cotton when both were available. The Thurberia-feeding 
weevil, on the other hand, was able to feed upon and breed in cotton 
squares. 
Mr. B. R. Coad, of the Bureau of Entomology, has succeeded in rear¬ 
ing undoubted crosses between the two varieties from females of each 
form, although these hybrid offspring were somewhat undersized. 
It will be seen from further evidence in this paper that the two forms 
must represent merely two subspecies, or varieties, or geographic races of 
a single species. The Arizona form is therefore to be known as Anthono- 
mus grandis thurberiae, new variety. Its technical description is as fol¬ 
lows : 
Anthonomus grandis thurberiae, n. var.—Stout, subovate, rufo-piceous, and 
clothed with coarse, pale-yellowish pubescence. Beak long, slender, shining, and 
sparsely pubescent at the base; striate from base to the middle, striae rather coarsely 
punctured; apical half finely and remotely punctured. Antennae slender, second 
joint of funicle longer than the third; joints 3 to 7 equal in length but becoming gradu¬ 
ally wider. Head conical, pubescent, coarsely but remotely punctured, front foveate. 
Eyes moderately convex, posterior margin not free. Prothorax one-half wider than 
long; base feebly bisinuate, posterior angles rectangular; sides almost straight from 
base to middle, strongly rounded in front; apex slightly constricted and transversely 
impressed behind the anterior margin; surface moderately convex, densely and sub- 
confluently punctured; punctures irregular in size, coarser about the sides; pubescence 
more dense along the median line and on the sides. Elytra oblong, scarcely wider 
at the base than the prothorax; sides robust to subparallel for two-thirds of their length, 
thence gradually narrowed to and separately rounded at the apex, leaving the 
pygidium moderately exposed; striae deep, punctures large and approximate; inter¬ 
stices convex, rugulose, pubescence somewhat condensed in spots. Legs rather stout, 
femora clavate, anterior strongly bidentate, inner tooth long and strong, outer one 
acutely triangular and connected with the former at the base; middle femora with 
small second tooth and posterior femora unidentate. Tibiae moderately stout, anterior 
bisinuate internally, posterior straight; tarsi moderate, claws broad, blackish, and 
