The Venus Flytrap-Dionaea muscipula closing trap animation,

A new study finds that pollution turns carnivorous plants into vegetarians, according to Dr. Jonathan Millet from Loughborough University. Plants, such as the Venus flytrap, are changing their behavior and become vegetarian.   The Venus Flytrap-Dionaea muscipula closing trap animation, image credit Wikimedia Commons

An increase in acid rain has caused there to be more nitrogen in the soil than usual, and as a result the plants are opting to eat fewer insects.
“Nitrogen pollution is giving carnivorous plants on Swedish bogs so many nutrients that they don’t need to catch as many flies, new research by Loughborough University shows.”
“In the sites with more nitrogen deposition, these plants now get much more of their nitrogen from their roots, but they still have to bear the residual costs of being carnivorous, and other plants without these will be better able to survive,” Millett comments.  “So it’s quite likely we’ll see less abundance and perhaps local extinctions from carnivorous species.  The individual plants get bigger and fitter, but the species as a whole is less well adapted to high-nitrogen environments and will lose out over time.”

The Venus Flytrap-Dionaea muscipula

Carnivorous plants are plants that derive some or most of their nutrients (but not energy) from trapping and consuming animals or protozoans, typically insects and other arthropods. Carnivorous plants have adapted to grow in places where the soil is thin or poor in nutrients, especially nitrogen, such as acidic bogs and rock outcroppings. Charles Darwin wrote Insectivorous Plants, the first well-known treatise on carnivorous plants, in 1875.

source Loughborough University