Cultivar Susceptibility of Grape Berry Clusters to Larvae of Lobesia botrana (Lepidoptera: Tortricidae)

A 3-yr study was conducted in 2 experimental vineyards near Bordeaux by using Artificial infestations of berry clusters with eggs of Lobesia botrana (Denis & Schiffermûller). Settling of neonates and subsequent larval survival were used to measure host susceptibility. Infestation by 2nd generation larvae was influenced significantly by the cultivar every year. The cultivars in Increasing order of susceptibility were as follows: ‘Merlot’, ‘Cabernet sauvignon’, ‘Cabernet franc’, and ‘Semillon’. The 3rd-generation infestations tended to confirm the same order of susceptibility, particularly in 1993.The susceptibility of Sauvignon was variable and not significantly different from either Cabernet sauvignon or Cabernet franc. In 1994 and 1995, there was a high positive correlation betweenberry-clustertightnessandinfestationby2nd-generationlarvae.The involvement of cluster compactness in susceptibility of grape cultivars to L. botrana is discussed.