Biological warfare between Drosophila species hints for sustainable crop protection

Species that share the same ecological niche often avoid costly competition with contextdependent behaviors. This is the case of the invasive insect pest that can develop in ripe fruit where it encounters . Previous research showed prevents costly larval competition by not ovipositing in substrates with eggs. We discovered females respond to cues produced by bacteria in the gut microbiome of . This behavior of varied over time and among populations, revealing subtle condition-dependence. In particular, females that bore bacteria stopped avoiding sites with cues. The adaptive significance of the behavior was investigated by reproducing experimentally in-fruit larval competition. larvae only suffered from competition with if the competitor was associated to its microbiota, suggesting has evolved a solution to avoid offspring develops in challenging environments. We argue that competition avoidance behavior has features enabling the design of an evolution-proof repellent to protect crops.