Hypothesized direct and indirect effects of picaridin on aquatic predators of mosquito larvae indicating a human-environment positive feedback loop. Image: Leslie Tumblety
Widely used mosquito repellent is lethal to their predators - life short science news

Insect repellents containing picaridin can be lethal to salamander larvae, the natural predators of mosquito larvae. A toxicity study in the laboratory with realistic concentrations of repellent in the water showed that about half of the larval salamanders in the study died within 25 days of exposure, while the mosquito larvae were unaffected. This suggests that using the picaridin-containing repellent, which enters aquatic ecosystems through sewage effluent, might in fact increase the survival of mosquito larvae, and consequently also the numbers of adult mosquitos that people want to combat with the repellent. This might constitute a feedback loop that leads to fewer salamanders and more mosquitos over time.

Read the full story: Cary Institute of Ecosystem Studies
Scientific publication: Biology Letters