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Field trials were carried out from 2002 to 2004 in an olive grove near Cairo, Egypt, to evaluate the efficacy of mating disruption to control the olive moth, Prays oleae (Lepidoptera: Yponomeutidae), during the first and second generations. Adding the stabilizer butylhydroxytoluene (BHT) to the β -cyclodextrin ( β -CD)–pheromone complex and using polypropylene tubes as new dispensers maintained an adequate level of pheromone release for >60 days in 2004 vs. ≈10 days in 2002. With this improved application technique and applying the mating disruption at a dose of 40 g active ingredient per ha a few days before the onset of the first flight (“the flower” generation), the inhibition of successful orientation was almost complete (>96%). Moreover, in 2004, significant reductions in fruit fall early in the season ( F = 133.2; df = 2, 12; P = 0.01) and fruit damage late in the season ( F = 34.03; df = 2, 12; P = 0.01) were observed. Also yield/tree was significantly higher ( F = 54.98; df = 2, 12; P = 0.01) in treated trees (105.5 ± 2.4 kg/tree) compared with untreated ones (66.6 ± 3.5 kg/tree). Mating disruption applied on the same olive trees over three years progressively reduced the olive moth population from year to year. The results of 2003–2004 confirm that the principal mechanism of the mating disruption treatment - interference with mate location and reproduction - worked successfully with the pheromone formulation, dose, dispensers and early application of the pheromone. Integration of MD with other biological control methods may also improve the efficacy of this technique. |
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