To optimize catches of Heliothis punctigera and H. armigera pheromone blends, dispenser and trap design have been evaluated and modified over a.7 year period. A laminated plastic lure loaded with appropriate pheromone blends was.found to give a high and prolonged attraction of males of both species. A.hollow cone (Texas) trap has given higher catches than the standard dry.funnel trap, but the latter was more robust and less expensive..A tendency has been shown for pheromone traps to over estimate the.proportion of .H. armigera in comparison to that found in light trap.catches and egg identification of the two species. GLC. analysis of.weathered lures indicated a more rapid release of aldehyde than acetate.components of pheromone blends . Departure of blends from the optimum ratio.is more likely to affect the efficiency of H. punctigera lures which.contain both components, than those of H. armigera lures which contain.only aldehydes