Mating rhythm of the African fig fly is predominantly controlled by light-dark cycles.

Abstract

The African fig fly, Zaprionus indianus, is an invasive pest of global concern, infesting over 80 crop species - including high-value fruits such as figs, strawberries, and guavas - and driving significant economic losses. Its ecological success is closely linked to circadian-regulated mating behavior, which enhances reproductive efficiency and fosters adaptability to diverse environments. Like the popular model organism Drosophila melanogaster, Z. indianus exhibits robust locomotor rhythms. A key feature of the circadian clock is its ability to anticipate predictable events, such as light-dark transitions, by gradually increasing or decreasing activity in advance. Mating rhythm is uniquely synchronized to light cycles: mating peaks show anticipation of both lights-on and lights-off transitions, with lights-off anticipation persisting even under long photoperiods (16-h light:8-h dark), suggesting circadian control. Remarkably, Z. indianus rapidly adapts to simulated jetlag, underscoring its plasticity in shifting environments. A critical distinction from D. melanogaster is its persistently low mating activity under constant darkness, indicating an obligate light dependence for mating. This reliance on light cues, combined with circadian plasticity and rapid environmental acclimation, likely underpins its capacity to colonize ecologically diverse regions and expand its geographic range. These insights into Z. indianus's mating rhythm not only advance understanding of its invasive success but also offer actionable targets for disrupting its reproductive cycles, informing strategies to curb its spread and mitigate agricultural damage.