Oviposition Preference and larval performance of Ceratitis capitata (Diptera: Tephritidae) on apple and pear fruits: influence of female age and oviposition periodicity

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), is a major pest affecting fruit-producing regions in Portugal, with particularly severe impacts in the Oeste region, Algarve, and island territories. The Oeste region is one of the largest apple and pear production areas in the country. These two economically important fruits are often cultivated in adjacent orchards and suffer significant economic losses due to this pest. This study investigated the effects of female age on oviposition preference, larval development, and oviposition periodicity of C. capitata. The first experiment consisted of a laboratory free-choice test to evaluate oviposition preference throughout the adult lifespan between Royal Gala apple (Malus domestica) and Rocha pear (Pyrus communis). The number of oviposition attempts and the number of larvae per fruit were recorded and correlated with key fruit parameters, including colour (ripeness), penetration resistance, and soluble solids content. Fresh fruits were provided daily. The second experiment focused on determining the daily oviposition periodicity under controlled photoperiod conditions (14h light : 10h dark). During the day, mated females (7–9 days old) were exposed to fruits at different intervals: every 3.5 hours during the light phase and one fruit during the dark phase. The number of emerging larvae was recorded at each interval to identify peak oviposition activity. Although data analysis is still in progress, we anticipate that our findings will provide novel insights into C. capitata's reproductive behaviour, with direct implications for pest management strategies in fruit orchards. By the time of the congress, complete results will be available for discussion, offering valuable information for improving monitoring and control techniques in affected regions.