The effect of trap heights above soil surface was determined when traps of different heights were competing to attract released boll weevils,Anthonomus grandisBoheman, and where the heights were separate and not competing for capture of the same weevils. Other factors compared in the same way were trap color, trap design, grandlure concentration, and ratio of the 4 grandlure components. These tests were conducted to determine the degree of bias that may result when trap factors compete for a natural field population of boll weevils. The importance of trap height, color, design and grandlure concentration was less in noncompetitive tests; however, 30:40:30 and 50:33:17 ratios of grandlure compounds I:II:III&IV were equally effective in both comparisons.