Mating disruption of Plodia interpunctella in small-scale plots: Effects of pheromone blend, emission rates, and population density

An indoor mating disruption experiment was performed on the stored-product pest Plodia interpunctella. The female of this: species emits a four-compon ent pheromone blend consisting of Z9,E12-14: OAc, Z9,E12-14: OR Z9,E12-14: Ald, and Z9-14: OAc. Mating of Plodia interpunctella was disrupted up to 93 % by using synthetic pheromone in small-scale plot experiments. The study w as performed in 2.5 m x 2.5 m x 2.5 m polythene cubicles housed in a greenh ouse, and pheromones were released by MSTRS spraying every 15 min. The disr uption effect was tested at different doses 0.075, 0.75, and 3.75 mg/spray (corresponding to 5, 50, and 250 mug/min), different pheromone formulas (on e-component (Z9,E12-14: OAc) and four-component), and at different populati on densities (10, 20, and 30 individuals, equivalent to 0.32, 0.64, and 0.9 6 individual s/m(2)). The moths were released into the cubicles and recaptu red 24 hr later. The females were checked for spermatophore presence indica ting successful mating. The mating was significantly suppressed in all trea tments compared to the control. There was, however, no difference in mating activity between the one-component and four-component disruptants. In addi tion, EAG measurements were conducted with a portable device to keep track of aerial concentrations of pheromone. The results show that the one-compon ent formula disrupts mating as efficiently as the more complete four-compon ent blend at doses applied in this study. This fact improves the prospects for mating disruption of indoor pyralids, since many pyralid species share the major component in their pheromones, and, thus, can probably be control led simultaneously by using this compound only.