1939 - Hixson, E, Science serving agriculture - insect pest studies. Report of Okla. 

 Agr. Expt. Sta., 1936-38:94-95. Jan. 



Studies on the use of high yielding varieties of cotton in combating the boll 

 weevil. 



1941 - Rainey, R. C. Relation of developing boll of susceptibility to insects. Empire 

 Cotton Growing Corp. Rpt. Expt. Stas. 1939-1940:39-46. 



Although the boll weevil is not mentioned, the author discusses biochemical 

 factors influencing the changes in susceptibility to insect attack which occur in 

 the course of boll development. It is pointed out, however, that while the results 

 obtained may suggest a relationship, they do not prove their existence. 



1951 - Painter, R. H. Insect resistance in crop plants. The MacMillan Company, N. Y., 

 1951:309-314. 



A number of cotton plant characteristics are discussed, including earliness, 

 proliferation, fruiting rate, rate of boll growth, plant color, and odors that have 

 been shown to limit the ability of the boll weevil to attack the cotton plant. 



1951 - Stephens, S. G. Sources of resistance of cotton strains to the boll weevil and 

 their possible utilization. J. Econ. Ent. 50(5):415-41 7. 



The purpose of this paper is a consideration of the possibilities of synthesiz- 

 ing genetic resistance to the boll weevil. A suggestion for an appropriate pro- 

 cedure is given. Such factors as host specificity, plant preference, plant color, 

 plant hairiness, and influence of stem glands are discussed. The following pro- 

 gram was initiated at Raleigh, North Carolina. Objectives of this study were: 



(a) To evaluate and measure preferences associated with specific plant 

 characteristics. 



(b) To study the effect of the composition of a plant population on the degree 

 of preference expressed. 



(c) To investigate the possibility of increasing resistance by combining 

 different sources of preference. 



1951 - Wannamaker, W. K., W. H. Wessling, and S. G. Stephens. Boll weevil resistant 

 cotton. Res. & Farming (N. C. Agr. Expt. Sta.) 15(1):14. 



Two years of experiments have shown that 2 different types of hairy cotton, 

 known as "Pilose" and "MU-8," are less damaged by weevils than standard 

 commercial varieties of upland cotton. The difference runs from 10% to 30%. 



These studies are only of a preliminary nature, and the resistant types pres- 

 ently available fall far short of the standard requirements of yield and fiber prop- 

 erties in an economic variety. 



1951 - Wannamaker, W. K. The effect of plant hairiness of cotton strains on boll 

 weevil attack. J. Econ. Ent. 50(4):418-423. 



A study was initiated on the possibility of using hairy types of upland cottons 

 as a source of resistance to the boll weevil. Collections were made of upland 

 cottons representative of the available hairy types. Fj hybrids were made between 

 Pilose (H2H2) and other hairy types. 



The parental types and Fj hybrids were planted in a randomized block ex- 

 periment in the spring of 1955. The experimental field was artificially infested 

 with boll weevils. The principal results of this experiment may be summarized 

 as follows: 



1. MU-8 and Pilose which carried the homozygous major factors for 

 hairiness, Hj and H2 respectively, received significantly less boll weevil 

 damage than the other types included in the experiment. 



2. Since MU-8 and Pilose carry intensifying genes for hairiness, in addition 

 to the major factor, resistance is not due entirely to the genes H^ and H2 

 but more likely to the presence of the major factor supplemented by cer- 

 tain unknown intensifier s. 



3. Differences in the positions and characteristics of hairs are discussed 

 in relation to their possible importance in boll weevil resistance. 



Ill 



