Three-year field trials for a sustainable approach in the control of olive fruit fly, Bactrocera oleae

Abstract: Treatments against olive fruit fly – Bactrocera oleae (Rossi) – populations can be preventive or curative; the first are the most used in organic production and their target are the adults. Some substances can physically mask the foliage of the plant, dusting it, making the fruits less attractive for the egg laying, and inhibiting the bacterial populations on the leaves’ surface. During the years 2018-2020, inorganic solids, with high specific surface area and ion-exchange capacity, were prepared starting from mineral bentonite, with high montmorillonite content, and zeolite, clinoptilolite of natural origin, both subjected to a cation exchange treatment with copper (II) salts or, for the bentonite only, after deposition of a bioactive principle based on organic compounds: aliphatic aldehydes, namely, n-hexanal and n-heptanal. Clinoptilolite exchanged with Cu (II) showed excellent efficacy against B. oleae, with a drastic reduction of the percentage of total infestation on olive trees which reaches 1.1 % for olive trees treated with the new formulation, compared to over 20%, for the untreated plants. This result is significantly better than the one obtained with other commercial products currently in use.