The sublethal effects of endosulfan on the circadian rhythms and locomotor activity of two sympatric parasitoid species.

•Endosulfan (organochlorine insecticide) largely contributes to environmental pollution.•Parasitoids are important species in ecosystems, as they control insect populations.•Endosulfan at LC 0.1 modified the rhythm of locomotor activity of two parasitoid species.•Endosulfan synchronized the diurnal activity of the two parasitoid species.•By increasing competition between these species, this could impact the whole ecosystem.