1912 - Hunter, W. D., and W. D. Pierce. The Mexican boll weevil: A summary of the 



investigations of this insect up to December 31, 1911. U.S. Sen. Doc. 305, 188 p. 



Description of the various stages, a detailed review of its life history, food 

 habits, mating habits, oviposition, and seasonal abundance. 



1914 - Worsham, E. L. The Mexican cotton boll weevil. Ga. State Bd. Ent. B 39, 



24 p., 1 fig., 7 pi. Feb. 



The weevil is restricted to the cotton plant, and passes the winter in the 

 adult stage, with old cotton stalks, dead leaves, timber, and such affording 

 shelter. A temperature below 12°F. is fatal to hibernating individuals. The 

 date of emergence varies from February to July. The first weevils to emerge 

 feed upon young seedlings, puncturing the stem at or just below the attachment 

 of the cotyledons. One of the first effects of oviposition is the opening of the 

 bracts and the exposure of the bud. The larva hatches in about 4 days and feeds 

 first on the immature pollen in the center of the square, then on the pistil and 

 other tissues of the bud. Many eggs are laid in bolls, and the larvae from these 

 feed on the seeds and occasionally on the immature fibers. During the summer 

 the average length cf the larval stage is 8 days. The pupal period varies from 

 2 to 14 days. Ten generations may occur in one season. Adults of any genera- 

 tion may hibernate on the approach of cold weather. 



During spring and summer there is a continual flight of weevils from plant 

 to plant. In autumn, large numbers make flights of considerable length seeking 

 new feeding grounds, the yearly increase in distribution taking place at this time. 

 The weevil may be prematurely carried into uninfested territory in cottonseed 

 products, in wagons, railways, or on clothing. 



Numbers of eggs of larvae are killed by the rapid proliferation of the tissues 

 in which the eggs are laid. The only effective methods of control are cultural 

 ones: the destruction of cotton stalks in autumn, clean cultivation, crop rotation, 

 early planting, fertilizing, and working are all important factors. Hand picking 

 of fallen squares proves a satisfactory means of control in some localities; 

 squares should be burned, preferably in wire cages so that parasites may es- 

 cape. Early varieties of cotton should be selected; those which do not form a top 

 crop late in autumn, which tend to retain infested squares, and which have heavy 

 stems are the best kinds to plant. 



1915 - Coad, B. R. Recent studies of the Mexican cotton boll weevil. U„ S. D. A. 



B. 231:1-34. 



Includes a report of investigations on the biology of Anthonomus grandis 

 thurberiae at Victoria, Tex., in 1913. 



1916 - Coad, B. R. Studies on the biology of the Arizona wild cotton weevil. U. S. D, A. 



B. 344, 23 p. Jan. 18. 



Discusses occurrence, distribution, and biology of Anthonomus grandis 

 thurberiae (Pierce) in wild cotton, and Thurberia thespesioides , in the moun- 

 tains of southeastern Arizona. 



1916 - Howe, R. W. Studies of the Mexican cotton boll weevil in the Mississippi Valley. 

 U. S. D. A. B. 358, 32 p. April 12. 



Numerous observations have shown that the complete data secured shortly 

 after 1892 on the biology of A. grandis need revision. Under new climatic and 

 other environmental conditions to which the weevil has been subjected in the 

 course of its spread, changes have been taking place in its life history. A new 

 variety, A. grandis thurberiae Pierce, has also been recorded since that date. 

 Many studies of this pest have, therefore, been repeated under both old and new 

 conditions. 



The information given is presented chiefly in a series of 25 tables. In 

 northern Louisiana the average longevity of A. grandis adults on cotton squares 

 was 54.56 days, on bolls 34.41 days, on cotton leaves 8.17, and on okra fruit 5.4. 

 The longevity of the variety thurberiae is greater in every instance, the cor- 

 responding figures being 61.4, 48.6, 62.04, and 18.3. In A. grandis the females 



125 



