Factors Affecting Water Deprivation Resistance in Bactrocera oleae (Olive Fruit Fly)

The olive fruit fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae), causes significant damage to olive crops worldwide. However, the factors affecting its survival under water deprivation have not been studied yet. In this study, the water deprivation resistance of male and female olive fruit flies was measured at three ages in virgin and mated adults fed either a full or a restricted diet. The experiments (24 treatments) were conducted under constant laboratory conditions, using insects collected in the wild and reared on olives. Additionally, a baseline experiment was conducted to provide data on the insects’ life expectancy under no-stress conditions. Our findings revealed that males showed much less resistance under water deprivation compared to females. Younger adults endured for longer than older ones, and adults fed a restricted diet endured water deprivation longer than those fed a full diet. Our results suggest that during periods of water scarcity, releasing sterile males is most effective, because the wild male population decreases. Since females of reproductive age are more resistant, this should ensure a higher number of matings with sterile males. These findings can be used to formulate improved pest control strategies that enhance olive product quality while relying less on insecticides.