Optimizing decision-making potential, cost, and environmental impact of traps for monitoring olive fruit fly Bactrocera oleae (Rossi) (Diptera: Tephritidae)

Abstract

This work aimed to optimize olive fruit fly (OFF) Bactrocera oleae (Rossi) (Diptera: Tephritidae) monitoring and integrated management, thereby ensuring optimal and less-costly decision-making and timely intervention. Field trials in Andalusia (Spain) were undertaken over 2 years to optimize trap model, color, size, and density for the accurate determination of pest spatial distribution and damage as a function of olive cultivar. McPhail traps and yellow sticky panels outperformed the other 4 models with respect to the number of OFF captured. However, McPhail traps caught more natural enemies than yellow sticky panels and so sticky panels were selected to unravel the effect of color on the number of both OFF and natural enemies [hymenopteran parasitoids (Psyttalia concolor) and lacewings (Chrysopidae)] captured. Yellow sticky panels outperformed white, green, and blue ones for the number of OFF captured and captured the fewest natural enemies. When comparing the surface area of yellow sticky panels, 20 × 25 and 10 × 25 cm double-sided panels were equally effective at catching OFF. However, large double-sided yellow sticky panels caught significantly more natural enemies than the small double-sided panels, a key result for developing a less costly and environmentally friendly monitoring system. Furthermore, it was shown that the damage curve had a cultivar-based shape, i.e., for the same population size of OFF the damage caused varied depending on cultivar. Finally, 15 sticky panels per hectare were the optimal number for estimation of OFF spatial distribution. The present research provides key information for new trap design, OFF forecasting, and IPM development.