Determination of Spraying Dates for Adoxophyes orana by Sex Pheromone Traps and Temperature Recordings13

Abstract

Successful spraying against Adoxophyes orana (Fischer von Röslerstamm), the main leafroller pest in Dutch orchards, depends on correct timing. Sprays are most effective against newly hatched larvae before they reach young leaves where they spin their webs. Prediction of hatching of larvae is based on sex pheromone trap observations of the preceding moth flight and temperature recordings during embryonic development of the eggs. A model has been designed for quick calculation of stage of egg development as a percentage of total development. As soon as the cumulative percentages exceed 100, hatching can be expected.