Figure 3.

Classical toxicology of chlorantraniliprole and locomotor deficits induced at a sublethal dose. (A) Bees exposed according to current mandatory classical mortality tests experienced a severe decrease in survival for doses >100 ng/bee during a long-lasting period of observation (6 days). In this survival test, all control bees (grey line) were alive after 6 days (120 h). (B) Seven days after exposure, the dose 100 ng induced a level of mortality not more elevated than the control exposure and is thus retained as a sublethal dose at 144 h (SLD_144h), whereas 250 ng was highly toxic (p < 0.01, mean ± SEM). Different letters indicate a significant difference. (C) A daily locomotor test revealed that a dose characterized as sublethal at 7 days (SLD_144h) increased periods of prostration 6 hours and 7 days after exposure (p < 0.001) with a transient attenuation of symptoms at day 2 and day 3. In box and whiskers graphs, individual data are presented as circles (open and filled for control and exposed bees, respectively), boxes show quantiles and whiskers the minimum and the maximum values. (D) Periods of prostration were not compensated by periods of intense phases of activity, since the distances covered by bees during active walking was decreased, not only at 6 h and 7 days after exposure, but at 24 h as well (p < 0.001, p < 0.05 and p < 0.001 respectively). An apparent but transient recovery was thus observed at day 2 (48 h).