392 



use of this trap Involves complex variables related to environmental, physio- 

 logical, chemical, and physical factors, reliable quantitative estimates of 

 trapping efficiency (the percent of a population caught by a trap or a group 

 of traps) are essential to their successful use for either survey or suppres- 

 sion. Results of limited studies to date are inconclusive and indicate ef- 

 ficiencies ranging from 12 to 93 percent, but the available information in- 

 dicated that the density of the natural boll weevil population is probably 

 the most critical factor affecting trap efficiency and that trap efficiency 

 is highest when densities are lowest. Thus, the present pheromone traps 

 show promise of suppressing populations when native populations are low, 

 probably 10 or less per acre. 



i / 



767. ; Jones, S. L.; Coppedge, J. R. ; and Lindquist, D. Ai 1968. Systemic 



activity of 2-niethyl-2-(methylthio)propionaldehyde 0-(met:hyl-carbamoyl)oxime 

 (UC-21149) in the cotton plant with special reference to the boll weevil. 

 J. Econ. Entrmol. 61: 1703-1712. 

 Bioassay of parts of cotton plants that had been sidedressed with 2-methyl- 

 2-(methylthio)?ropionaldehyde 0-(methylcarbamoyl)oxime (Union Carbide UC- 

 21149) showed that the greatest amount of toxicant accumulated in older 

 leaves and the least in debracted squares (floral buds). One sidedress 

 application of A lb toxicant per acre or 2 sidedress applications of 2 lb 

 per acre effectively controlled Anthonotnus grandis Boheman, in field cages; 

 however, 2 applications were more effective. When the same total amounts of 

 UC-21149 were applied as multiple and single sidedressings, the multiple 

 applications resulted in greatest uptake in new plant growth. Both deep 

 placement in the soil close to the cotton plant and irrigation increased the 

 uptake of sidedressed UC-21149, but placement did not affect uptake when the 

 soil was irrigated. Foliar applications of a cottonseed oil feeding stimulant 

 Increased the effectiveness of a sidedressing of UC-21149. After soil appli- 



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