FILIPA BURUL1*, MARIJANA POPOVIĆ1, MAJA JUKIĆ ŠPIKA1, RENATA BAŽOK2, ELDA VITANOVIĆ1
1 Department of Applied Science, Institute for Adriatic Crops and Karst Reclamation, Put Duilova 11, 21000 Split, Croatia;
2 University of Zagreb Faculty of Agriculture, Svetošimunska 25, 10000 Zagreb, Croatia;
* Filipa.Burul@krs.hr
Abstract
The olive moth (Prays oleae Bern.) is one of the most important pests in olive cultivation. In line with the objective of the European Green Plan to reduce the use of chemical pesticides, there is an urgent need for effective non-chemical pest control methods. According to current knowledge, insects find their plant hosts through volatile organic compounds (VOCs) emitted by the plants, but the interaction between olive trees and olive moth has not yet been studied. The most damaging olive moth generations are those that attack and feed on flowers (antophagus) and fruits 4 to 6 mm in size (carpophagus).
Therefore, this study aims to identify the VOCs in olive flowers and fruits of two cultivars susceptible to P. oleae infestation to select those that could attract said pest and test their attractiveness in an olive grove. The composition of VOCs in the flowers and fruits of Lastovka and Oblica cultivars was determined by headspace gas chromatography-mass spectrometry with solid- phase microextraction (HS-SPME-GC-MS). Four different volatile blends were prepared, composed of the most abundant VOCs: two from flower volatiles (one from Lastovka and Oblica) and two from fruit volatiles (one from Lastovka and Oblica). These blends were tested in an olive grove with delta RAG traps, both with and without the addition of olive moth pheromone. The experiment consisted of ten treatments with two control variants (one with an empty trap and one with pheromone only), each repeated three times. From June to August 2023, the number of male and female moths was recorded weekly, and the trap bases and volatile dispensers were replaced. The pheromones were replaced every four weeks following the manufacturer’s recommendations. The results showed that two blends containing Lastovka and Oblica floral volatiles in combination with pheromones were statistically the most attractive to olive moths.
These results indicate that flower volatiles were significantly more attractive than fruit volatiles, suggesting that flower volatiles can significantly increase the attractiveness of pheromone traps and provide an effective non-chemical method of olive moth control. This is the first study of interaction between olive tree VOCs and olive moth so it offers an innovative and promising approach for integrated pest management in olive cultivation that is compatible with environmental sustainability goals. Future research will optimise these volatile mixtures, understand their long-term effectiveness, and evaluate their impact on non-target species.
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