Reduction of olive fruit fly damage by early harvesting and impact on oil quality parameters

Abstract

Olive fly population was monitored weekly on two olive cultivars (Buža and Istarska bjelica), from June until mid October, in Rovinj and Livade (Istria, Croatia). The number of eggs, larvae, and pupae was established and the total and active infestation was calculated. The fruit infestations for early and for late harvesting were obtained based on the calculated regression equation. For the prediction of the changes in the oil quality parameters linear regression slopes, obtained by Koprivnjak et al., were used. We established a strong positive correlation between DD accumulation and cumulative capture of flies, as well as with the total and active fruit infestations. According to obtained results it can be stated that I. bjelica is less sensitive to decrease in total phenols amount, to increase in free fatty acids mass ratio and to increase in peroxide values comparing to Buža. Moreover, the differences in investigated parameters between earlier and late harvesting dates in I. bjelica are lower due to lower infestation predicted for both harvesting dates and due to lower sensitivity to the changes in quality parameters. Therefore, early harvesting date as a model for preventing fruit damage and as a model for preventing negative change in oil quality parameters is a valid tool. However, the effectiveness of this model could also depend on the characteristics of olive cultivar. Practical applications: Understanding the factors that affect the olive fly attack is the basis of scientific and practical interest in the production of olives and olive oil. Research of monitoring methods allows reliable forecasting and determining protection measures. Knowledge about this topic could contribute to the reduction of insecticides use and to the improvement of quality and food safety concept in olive oil production. Damaged olive fruits are proved to directly affect the quantitative and qualitative properties of olive oils. The most important fruit damage is caused by the olive fly (Bactrocera oleae Gmelin).

Influence of enzymes and technology on virgin olive oil composition

“…Many enzymes of this group are involved in a variety of physiological functions such as plant defence, signalling, metabolism of cell wall and lignification (Minic, 2008). Olive fruits can be seriously deteriorated by pre and postharvest damage due to the attack of insects, such as the olive fruit fly, which strongly alters the quality of olives (Rojni c et al, 2015). Olive fruits susceptible to fly infestation could be related to the ability of the oleuropein-degrading-[beta]-glycosidase to produce the highly reactive molecules in the damaged tissues.…”

The Impact of Beehive Proximity, Human Activity and Agricultural Intensity on Diptera Diversity in a Mediterranean Mosaic of Agroecosystems, with a Focus on Pest Species

“…Accordingly, this study found it in all locations with high anthropic disturbance and intensity. This pest occurs every year, and its success is mainly controlled by climate conditions (temperature, rainfall, and relative humidity) [ 116 ]. For example, in addition to causing significant losses to nature, the infection of the olive fly contributes a lot to the decline in oil quality [ 117 ].…”

A review of plant protection against the olive fly (Bactrocera oleae (Rossi, 1790) Gmelin) and molecular methods to monitor the insecticide resistance alleles

“…In Slovenia, the olive fly is monitored with yellow sticky traps with an added pheromone (Dacotrap®, Isagro S.p.a., Milan, Italy) (Knap and Bandelj, 2016). Rojnić et al (2015) observed that McPhail traps with hydrolyzed protein were more attractive to olive flies than yellow sticky traps baited with a pheromone. However, the correlation coefficients that were calculated using the cumulative capture of olive flies were high, which proved the comparability of these two trap types.…”