Female sex pheromone of brinjal fruit and shoot borer, Leucinodes orbonalis blend optimization

The brinjal fruit and shoot borer, Leucinodes orbonalis is the major pest o f eggplant in South Asia. Analysis of female pheromone gland extracts prepa red from insects of Indian and Taiwanese origin confirmed (E)-11-hexadeceny l acetate (E11-16:Ac) as the major pheromone component with 0.8 to 2.8% of the related (E)-11-hexadecen-1-ol (E11-16:OH), as previously reported from Sri Lanka. The average quantity of E11-16:Ac extracted per female was estim ated to be 33 ng. with a range of 18.9 to 46.4 ng when collected 2 to 3 hr into the scotophase. In field trials conducted in India, blends containing between 1 and 10% E11-16:OH caught more male L orbonalis than E11-16:Ac alo ne. At the 1000 mug dose. on white rubber septa. addition of 1% E11-16:OH t o E11-16:Ac was found to be more attractive to male L. orbonalis than eithe r 0.1 or 10% E11-16:OH. Trap catch was found to be positively correlated wi th pheromone release rate, with the highest dose tested. 3000 mug, on white rubber septa catching more male moths than lower doses. Field and wind tun nel release rate studies confirmed that E11-16:OH released from white rubbe r septa and polyethylene vials at approximately twice the rate of E11-16:Ac and that the release rate of both compounds was doubled in polyethylene vi als compared to white rubber septa. This difference in release rate was ref lected in field trials conducted in Bangladesh where polyethylene vial disp ensers caught more male moths than either black or white rubber septa, each loaded with the same 100:1 blend of E11-16:Ac and E11-16:OH in a 3000 mug loading.