'Grandlure' bait stick is the commercial version of pheromone
produced by male boll weevils. The pheromone traps when baited with 'Grandlure' are extremely attractive to any boll weevil (Fernandes; de Carvalho; Habib, 2001).
The male boll weevil produces a pheromone in his frass
that is attractive to both sexes. This pheromone helps both locate one another for mating and attracts other weevils to the food source as far as 500 feet (Layton, 2002).