Effects of dodecyl acetate andZ-10-tridecenyl acetate on attraction ofEupoecilia ambiguella males to the main sex pheromone component,Z-9-Dodecenyl acetate.

Attraction ofE. ambiguella males toZ-9-dodecenyl acetate (Z9-12∶Ac), alone and in combination with dodecyl acetate (12∶Ac) orZ-10-tridecenyl acetate (Z10-13∶Ac) was tested in both wind-tunnel and field experiments. In the laboratory, response toZ9-12∶Ac reached a distinct dosage optimum at which attraction was nearly as good as to live females. Addition of 12∶Ac, a minor component of female glands and effluvia, had no effect at low doses ofZ9-12∶Ac and only marginally improved attraction at the optimum. However, inclusion of 12∶Ac with an overdose ofZ9-12∶ Ac fully restored activity. In the field,Z9-12∶Ac alone was not very attractive at any dose; catches markedly increased by adding 12∶Ac and climbed with increasing dose of each compound up to 10 mg. Optimum ratio ofZ9-12∶Ac to 12∶Ac was 1∶1 to 1∶5. Another compound,Z10-13∶Ac, had the same effect as 12∶Ac in the laboratory and the field but was effective at a lower dose. In the field, inclusion of the synergist permits use of high cap loads to attract more males, perhaps from greater distances.