insects Article Do Grapholita funebrana Infestation Rely on Specific Plum Fruit Features? Roberto Rizzo 1 , Vittorio Farina 2 , Filippo Saiano 2 , Alberto Lombardo 3, Ernesto Ragusa 2 and Gabriella Lo Verde 2,* 1 CREA-Research Centre for Plant Protection and Certification, SS.113, Km 245,5, 90011 Bagheria, PA, Italy;
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[email protected]; Tel.: +39-09123896021 Received: 25 September 2019; Accepted: 9 December 2019; Published: 11 December 2019 Abstract: The effective control of the plum fruit moth, Grapholita funebrana (Lepidoptera: Tortricidae) still represents a difficult challenge for organic plum farming. Little information is available on the susceptibility of plum cultivars to this moth pest. We investigated the roles of several fruit parameters (i.e., shape, volume, hardness, fruit colour, and physiochemical properties) on the susceptibility of four different plum cultivars (Angeleno, Friar, President and Stanley) to G. funebrana attack. Field data demonstrated the importance of some fruit parameters (i.e., elongation index, sugar degree, titratable acidity, cover colour percentage) on susceptibility to G. funebrana infestation. Under laboratory conditions, colour and shape had a significant role in determining the time spent on false fruits, i.e., female moths preferred yellow and rounded fruits over elongated red or green fruits. Angeleno (yellow and rounded fruits) and Stanley (green and elongated fruits) were the most and least susceptible cultivars, respectively.