The Association Between Scab 1 and Some Insect Pests 2 of Apple Fruit 34

Abstract

There was no association between lesions of apple scab incited by Venturia inaequalis (Cke.) and damage done to unsprayed harvested mature fruit of ‘Jonathan’, ‘Golden Delicious’, and ‘Gallia Beauty’ apples (Malus domestica Borkh) by codling moth, Laspyeresia pomonella (L.), apple maggot, Rhagoletis pomonella (Walsh), plum curculio, Conotrachelus nenuphar (Herbst), or redbanded leafroller, Argyrotaenia velutinana (Walker). However, there was a negative association of apple scab and damage by rosy apple aphid, Dysaphis plantaginea (Passerini) with ‘Jonathan’. When scab infestation was prevented by weekly spraying of half of each tree with dodine, the insect species tended to damage more sprayed than unsprayed fruit. Plum curculio showed a significant ovipositional preference for scabfree (sprayed) ‘Golden Delicious’ and ‘Rome Beauty’. In unsprayed, detached ‘Jonathan’ apples in trays, fruit with scab lesions had significantly more redbanded leafroller feeding scars than fruit without scab lesions.