Small Scale Trials of Mating Disruption of Epiphyas postvittana (Lepidoptera: Tortricidae)

Disruption of Epiphyas postvittana mating behavior using synthetic pheromone was investigated in field cages and in replicated small-plot trials in a pine Pinus radiata (D. Don) plantation. Polyethylene tubing dispensers releasing two formulations were tested: 70% ( E )-11-tetradecenyl acetate and 30% ( Z )-11-tetradecenyl acetate (monoene) or 92.6% ( E )-11-tetradecenyl acetate, 2.8% ( Z )-11-tetradecenyl acetate, and 4.6% ( E,E )-(9,11)-tetradecadien-1yl acetate (monoene/diene). Field cage tests suggested that the second blend was the more effective disruptant, probably because of the presence of the diene. The concentration–response of males to the monoene/diene blend showed greater disruption of their normal response to caged females than the monoene alone ( P 500/ha of monoene in 100-m2 plots ( P < 0.01). The percentage of tethered virgin females that were mated also was significantly reduced in all monoene treatments ( P < 0.01) compared with untreated controls. In larger plots (900 m2), the highest rate of monoene (1,000 dispensers/ha) resulted in 17% mating of tethered females ( n = 64) compared with 93% mating in controls ( n = 57). However, the second blend containing monoene/diene applied at 1,000 dispensers/ha reduced the percentage of mated females to 0 ( n = 35), at an average pheromone release rate of 9.8 mg/ha per h. In a similar trial of the monoene/diene blend (900 m2 plots), 73% of females mated in control plots ( n = 80), compared with 1% ( n = 90) in plot treated with 1,000 dispensers/ha (9.5 mg/ha per h).