Ovipositional preferences amongst navel sweet orange types by the false codling moth, Cryptophlebia Ieucotreta

Summary Five different navel sweet orange cvs or cv. selections, planted in the Citrusdal area of the western Cape Province, South Africa, were evaluated for their susceptibility to false codling moth infestation. The proportion of yield lost by two of them, cv. Bahianinha and the ‘Buffelspoort’ cv. selection, was lower than losses from the others evaluated. Damage due to other factors causing fruit abscission was also lowest in the cv. Bahianinha. The greatest number of eggs laid throughout the season was on the ‘Addo’ cv. selection, and losses due to the false codling moth were also greatest on this orange type. Rate of oviposition was significantly (P > 0.05) lower on the cv. Bahianinha than on all the other types. Parasitism by a trichogrammatid egg parasitoid appeared to have no impact on overall egg mortality and did not account for any of the observed differences in fruit loss. The relationship between egg deposition and fruit loss was not clear and many factors require further investigation. Nevertheless, the distinct difference in rate of oviposition on the ‘Addo’ cv. selection, on the one hand, and on the cv. Bahianinha, on the other, indicates some consistent response to positive or negative stimuli.