oviposition, while growing leaves appear not only to sustain life, but also to 

 stimulate egg-laying by supplying the necessary food concentration. The 

 question of oviposition is important from the point of view of poisoning 

 the weevils when they emerge from hibernation. If it is realized that the weevils 

 feeding on the cotton buds prior to the appearance of squares will lay their eggs 

 on the latter as soon as they appear, early poisoning should be rigorously 

 followed; but if it is believed that they must first feed on squares, poisoning may 

 be delayed long enough for the hibernated weevils to establish the next genera- 

 tion. 



1928 - Isely, Dwight. Ark. Agr. Expt. Sta. 40th Ann. Rpt.--B. 231:48. Dec. 



Larvae of boll weevil feed and develop either in squares or in bolls. They 

 prefer squares as food. While they deposit eggs in bolls, they must have squares 

 or very young bolls as food if reproduction is to continue. Weevils feeding on 

 large bolls exclusively would not produce eggs. Those feeding on small bolls 

 reproduced at a lower rate than those fed on squares. There was a definite 

 relationship between abundance of squares in fields late in season and the 

 presence of overwintered weevils in the field the following spring. 



1928 - Isely, Dwight. Oviposition of the boll weevil in relation to food. J. Econ. Ent. 



21(1):152-155. 



Studies carried out in 1926 and 1927 showed that while larvae of A_. grandis 

 feed and develop either in squares or bolls of cotton, adult weevils show a 

 preference for squares. Experiments based upon daily oviposition records of 

 110 mated pairs, the food of which was controlled from the date of emergence 

 until death, indicated that not only are the longevity and period of oviposition of 

 weevils fed upon squares greater than that of those fed exclusively on bolls, but 

 squares and small bolls are essential for reproduction. Weevils fed exclusively 

 on squares deposited an average of 110 eggs, the average oviposition period 

 being 21.18 days and the average longevity 26.27. The figures for females fed 

 solely on small bolls were 17.7, 13.8, and 25.5. Most of the weevils fed ex- 

 clusively on large bolls deposited no eggs, while the longevity period was 23.17 

 days. None of the weevils that were fed upon large bolls for the first 10 days 

 after emergence and then changed to squares began oviposition until after the 

 change was made. Eighty percent began depositing eggs after an average interval 

 of 3.72 days from the change of food, the number of eggs deposited being 34.9, and 

 the oviposition period 10.3 days. Weevils which fed on squares for 10 days and 

 then changed to large bolls stopped oviposition on an average of 3 days after the 

 change of food. 



In the latter part of the season if the formation of squares stops, oviposi- 

 tion soon ceases. The requirement of squares for reproduction limits the 

 number of weevils that go into hibernation. This was also a factor in the local 

 distribution of overwintering weevils, as field observations indicated a tendency 

 for them to migrate to fields where squares were most abundant at the end of the 

 season. 



(In a discussion that followed the presentation of this paper, the author stated 

 that as the weevil is largely a feeder on pollen in the squares, nitrogen content is 

 probably the factor controlling oviposition and longevity.) 



1929 - Dunnam, E. W. Experiments on the relation between the location of cotton fields 



and the intensity of boll weevil infestation the succeeding season. J. Econ. Ent. 

 22(5):750-756. 



Experiments on the migratory habits of the cotton boll weevil were carried 

 out in Louisiana in 1928 by means of screen traps under conditions that were 

 peculiarly favorable, as floods in 1927 had destroyed large areas of cotton. 

 Observations were carried out both in fields where cotton had been grown in 1927 

 and also in cotton situated at varying distances up to 3 miles from the site of an 

 isolated extensive cotton planting of that year. Additional tests were made in 

 woods and in an unplanted field a mile away from the site of this planting. 



129 



