Damage evaluation of Rhynchites cribripennis (Col., Attelabidae) in olive fruits

Rhynchites cribripennis is a pest of olives widely distributed in the Mediterranean region. The adults drill holes in the flesh of olives, resulting in fruit drop. Although earlier studies reported high damage levels, its damage potential has not been specifically investigated. In the current study, the damage potential of this weevil was evaluated with regard to its density. Olive shoots were enclosed in muslin cages, along with two or four adult weevils, during the initial phase of the olive fruit development. In each cage, the shoots bore 357 fruits, on average. The percentage of fruits dropped and the damage level on the fruits were recorded at about 1‐month intervals. At harvest, the fruits that remained on the shoots were individually weighed to evaluate the damage as regards fruit weight. The results showed that R. cribripennis can cause a significant damage because of fruit drop (54 ± 6%, 38 ± 4% and 16 ± 2% in the cages with 4, 2 and 0 adults, respectively). The damage was more severe in fruits within the first month after their formation. A single feeding hole was shown to cause the drop of small fruits. The high percentage of dropped fruits caused a significant decrease in the weight of the olives at harvest among treatments. These results show that R. cribripennis can cause serious damage to olive production and offer useful information for quantifying its damage potential and developing a more rationale control strategy for this pest.