Emerging aquatic insects, after metamorphosis, have the potential to retain aquatic pollutants in their bodies and potentially transfer these aquatic contaminants into adjacent terrestrial food webs. But scientists don’t know yet whether pesticides used in aquatic ecosystems will also be transferred to terrestrial ecosystems.
Recently, a new research team from the University of Koblenzlandau in Germany showed that pesticides used in aquatic systems are transferred to terrestrial ecosystems with the help of vectors such as aquatic insects, and the results were published online in Environmental Science and Technology on April 20.
In this study, the team sprayed nine medium-polar fungicides and herbicides in the field and exposed non-biting mosquito larvae to these environments. The team then assessed pesticide bioaccumulation and biomagnification throughout the water-land life cycle.
The study found that all types of pesticides were detectable in the larvae of the mosquitoes; in the case of low-dose pesticide spraying, five pesticides could be detected in adult mosquitoes, and in the environment of higher doses of pesticide spraying, eight pesticides could be detected in adult mosquitoes.
Further studies found that there were significant sex differences in the biocouple of insecticides in adult mosquitoes, with four pesticides in higher concentrations in females. During adulthood, the concentration of pesticides in female mosquitoes generally decreased, while in male mosquitoes continued to decline.
It has been observed that terrestrial organisms such as swallows and insectivorous bats are an important part of shaking mosquitoes in their diets every day, so it is very likely that terrestrial organisms accumulate these pesticides in the body.
Pesticides are transferred by aquatic insects. Image from the paper
The team said the study confirmed that pesticides used in aquatic ecosystems can be transferred to terrestrial ecosystems. (Source: China Science Daily Zheng Jinwu)
Related paper information:https://doi.org/10.1021/acs.est.1c08079