Bilan de sept années d'essais de lutte contre la Tordeuse orientale du pêcher Cydia molesta Busck (Lep., Tortricidae) par confusion sexuelle des mâles

Evaluation of a seven year control experimentation on the Oriental fruit moth Cydia molesta Busck (Lep., Tortricidae) by the mating disruption technique The control of the Oriental fruit moth Cydia molesta Busck by the mating disruption technique was experimented in France from 1982 to 1988. Trials were carried out in the low Rhône valley in 2 peach orchards, ca 16 ha total surface, composed of about 20 plots. The synthetic sex attractant used is a blend of Z₈–12: Ac and E₈–12: Ac. The effective rate which should be released through the season is at least 20mg/ha/h. Loss rates of the dispensers were established gravimetrically and by GC analysis. The 3 ratios of the binary attractant blend 93/7, 96/4, 88/9.9 + impurity, provide equal results. Several types of dispensers and dispositions of attractant sources were compared: 200–300/ha polymeric laminated strips, 1000/ha SHIN ETSU polyethylene tubes, 500/ha polyethylene bulbs. The effect and the efficacy of the treatment were examined by male catches in attractant traps, which are not reliable, tethered females method, monitoring shoot and fruit damage. The SHIN ETSU and BASF dispensers were the most effective and simple to use. Two applications should be made per season with SHIN ETSU and 1 for BASF dispensers. The amount of Z₈–12: Ac + E₈–12: Ac required per ha/season is ranging from 200 to 250g. The results are very good and as effective as a full seasonal schedule of insecticide applications in agreement with important conditions. The limitations of the technique were defined: size, shape and isolation of orchard, density of the Oriental fruit moth population, involving sometimes 1 spray, disposition of attractant sources. The control of the Oriental fruit moth by the mating disruption technique was granted provisional registration in France which concerns at the present time a type of dispenser. Consequences of this specific technique of control on the peach orchard biocenosis and the organization of integrated pest management programme were discussed.