Comparison of pheromone-mediated mating disruption and conventional insecticides for management of tufted apple bud moth (Lepidoptera: Tortricidae)

Suppression of leopard moth (Lepidoptera: Cossidae) populations in olive trees in Egypt through mating disruption

The leopard moth, Zeuzera pyrina (L.) (Lepidoptera: Cossidae), is a damaging pest for many fruit trees (e.g., apple [Malus spp.], pear [Pyrus spp.] peach [Prunus spp.], and olive [Olea]). Recently, it caused serious yield losses in newly established olive orchards in Egypt, including the death of young trees. Chemical and biological control have shown limited efficiency against this pest. Field tests were conducted in 2005 and 2006 to evaluate mating disruption (MD) for the control of the leopard moth, on heavily infested, densely planted olive plots (336 trees per ha). The binary blend of the pheromone components (E,Z)-2,13-octadecenyl acetate and (E,Z)-3,13-octadecenyl acetate (95:5) was dispensed from polyethylene vials. Efficacy was measured considering reduction of catches in pheromone traps, reduction of active galleries of leopard moth per tree and fruit yield in the pheromone-treated plots (MD) compared with control plots (CO). Male captures in MD plots were reduced by 89.3% in 2005 and 82.9% in 2006, during a trapping period of 14 and 13 wk, respectively. Application of MD over two consecutive years progressively reduced the number of active galleries per tree in the third year where no sex pheromone was applied. In all years, larval galleries outnumbered moth captures. Fruit yield from trees where sex pheromone had been applied in 2005 and 2006 increased significantly in 2006 (98.8 +/- 2.9 kg per tree) and 2007 (23 +/- 1.3 kg per tree) compared with control ones (61.0 +/- 3.9 and 10.0 +/- 0.6 kg per tree, respectively). Mating disruption shows promising for suppressing leopard moth infestation in olives.

New pheromones and insect control strategies

A survey of the new environmentally safe strategies used for insect control is presented. The survey includes mating disruption, pheromone antagonists as chemical communication inhibitors, pheromones and plant-based volatiles, attractant-and-kill, and push-pull strategies. Important successes have been obtained, particularly in mating disruption with significant reduction in pesticide use in low to moderate pest infestations. One important factor of concern is the high cost of semiochemicals and formulations containing them in comparison to the conventional insecticide treatments, and a combined effort by scientists, producers, and farmers should be made to reduce the cost of application of these semiochemicals.

Comparison of pheromone application rates, point source densities, and dispensing methods for mating disruption of tufted apple bud moth (Lepidoptera: Tortricidae)

Small-plot (approximately 0.1 ha) studies were used to evaluate different pheromone dispensing systems, application rates, and point-source densities for mating disruption of the tufted apple bud moth, Platynota idaeusalis (Walker). Using polyvinyl chloride spirals impregnated with tufted apple bud moth pheromone (1:1 ratio of E11-tetradecenyl alcohol/E11-tetradecenyl acetate), pheromone rates of > or = 1,482 spirals per hectare (74.1 g pheromone per hectare) were superior to a rate of 988 spirals per hectare (49.4 g pheromone per hectare) in decreasing male response to pheromone traps in 1995, whereas no differences were detected among rates of 988, 1,482 and 1,975 spirals per hectare in 1996. Within a range of 370-988 pheromone dispensers per hectare, point source densities were equally effective in suppressing male response to pheromone traps. Pheromone-impregnated paraffin disks were equally effective at inhibiting male response to pheromone traps compared with polyvinyl chloride spirals. However, a paraffin emulsion formulation of pheromone applied with a hand-held grease gun provided longer residual communication disruption effects than polyvinyl chloride spirals. Dilution of paraffin emulsion pheromone formulations in water for application with a backpack sprayer and airblast sprayer rendered them ineffective in reducing male response to pheromone traps. The releases of pheromone from polyvinyl chloride spirals and paraffin disks aged in the field were described by a linear and negative logarithmic curve, respectively, indicating that dispenser life time should be longer for spirals. The ratio of acetate to alcohol components of pheromone released from spirals increased over time, whereas the release ratio remained more constant for paraffin disks. This suggests that the disruption efficacy of spirals may be prematurely reduced because of imbalance of the released components.