4.1 Glyphosate exposure and mosquito life history traits
Exposure of larvae to the two realistic concentrations of glyphosate had
no significant effect on mosquito size and other life history traits.
Although our second experiment tended to show a slight effect of
glyphosate (0.05mg/L) on larval development time, this was not observed
in the first experiment even when the concentration of glyphosate in the
rearing solution was doubled. These results are consistent with a recent
study that found no effect of glyphosate on Aedes aegyptimosquito larvae at concentrations 20 times higher than ours (Baglan et
al., 2018). In a pilot study, we even showed that a glyphosate
concentration of 1g/L did not affect larval survival rate. In other
aquatic invertebrate species, this molecule tends to have more
significant effect. Glyphosate exposure, even at low concentration (0.1
- 0.05 mg/l), induced a reduction of juvenile size in the planktonic
crustacean Daphnia magna (Cuhra et al., 2013) and negatively
impacted the survival rate in the amphipod Hyalella castroi and
the crayfish Cherax quadrinatus (Avigliano et al., 2014; Dutra et
al., 2011). This suggests that mosquito larvae are more tolerant to
glyphosate than other aquatic invertebrate species.