| Popis: |
Possibilities for the use of sex pheromones to control the summerfruit tortrix moth, Adoxophyes orana, in dutch orchards. The sex pheromone of Adoxophyes orana has been identified as a two-component system consisting of cis-9- and cis-11-tetradecenyl acetate (tda). Optimum attraction in the field is obtained with a ratio cis-9-tda: cis-11-tda = 9:1. Research on the problem how to make use of pheromones for control in practice is less spectacular and very laborious. Even if we restrict ourselves to the simplest possibility, namely the detection of the presence and the observation of the flight activity of the moths, we shall quickly encounter problems like the interpretation of the numbers of moths caught in the traps. Several examples indicate that the course of the sex trap data can differ very much from the course of the population density as determined by other sampling methods. There is the extra difficulty that we are observing the activity of the adult moths, but that we are primarily interested in the control of the larvae. During the past 2 years we achieved a very satisfactory control of A. orana by the use of a combination of daily sex trap observations and the so-called temperaturesum method. The relation between sex trap catches and population density will be further analyzed. |
