MATING DISRUPTION OF PEA MOTH CYDIA-NIGRICANA F (LEPIDOPTERA, TORTRICIDAE) BY A REPELLENT BLEND OF SEX-PHEROMONE AND ATTRACTION INHIBITORS

Synthetic sex pheromone of the pea moth Cydia nigricana, (E,E)-8,10-dodecadien-1-yl acetate (E8,E10-12:Ac), was applied in polyethylene dispensers at a rate of 30 g/ha and 600 dispensers/ha in a 0.6-ha pea field. The release rate of E8,E10-12:Ac was 140 mg/ha/day after six days, and 82 mg/ha/day after 20 days. Aerial concentrations of E8,E10-12:Ac, as measured by a portable EAG apparatus, ranged from 2 +/- 2 to 7 +/- 3 ng/m3. The antennal signal was high and rather constant within pea canopy, but was lower and fluctuated strongly above canopy. Initially, >99% isomerically pure E8,E10-12:Ac was released, and male moths were attracted to dispensers. After nine days, isomeric blend composition had equilibrated to approx. 92% E8,E10-12:Ac and 8% of the inhibitory isomers E,Z-, Z,E-, and Z8,Z10-12: Ac. Males were then repelled from the pheromone-permeated field. Traps baited with 100 mug E8,E10-12:Ac caught 258 +/- 133 C. nigricana males/trap in the control, but no males at all in the disruption field.