When cars drive on a road with ponding water, a layer of water can form between the tires and the road. The car loses traction in a phenomenon known as aquaplaning. Drivers dislike aquaplaning because they lose control of their vehicle. Insects can also aquaplane in some situations. Insects use an array of spines, pads and other leg features for gripping surfaces. However, if a layer of water forms between the leg and the surface, the insect will aquaplane uncontrollably.
Pitcher plants in the genus Heliamphora live in nutrient poor soils. They attract insects and capture them in the liquid at the bottom of a pitcher-shaped leaf. The insects are digested and nutrients are available to the plant. The pitcher plant attracts naive insects with a nectar secretion. However, the inside surface of a pitcher leaf is super-hydrophilic.* This creates a film of liquid that coats the pads of insects such as ants. The insects find themselves aquaplaning down the sides of the pitcher leaf on a film of water where they are trapped and digested by the plant.
Heliamorpha Pitcher Plant
* ‘Insect aquaplaning’ on a superhydrophilic hairy surface: How Heliamphora nutans pitcher plants capture prey. Ulrike Bauer, Mathias Scharmann, Jeremy Skepper and Walter Federle. Proc. R. Soc. B 22 February 2013 vol. 280 no. 1753 20122569
Published online December 19, 2012 doi: 10.1098/rspb.2012.2569
Living With Insects Blog 
Is the pitcher plant hydrophilic on the outside skin? If this is the case, how is it possible for insects to crawl its surface to climb to the inside? While it is noted that insects get trapped and slide down the walls of the pitcher plant, how well do flying insects hold up if they simply land on the liquid surface? I suppose since it mentions insects getting trapped I assume that the liquid at the bottom prevents them from flying out safely.
No only the inside surface.
It’s amazing how plants can evolve to live off of insects!
I think it’s so cool how everything is adapted like that. The plants main way of getting the proper nutrients needed is by the naiveness of the insects. Let’s say, if they figured out that those plants do that, then the insects would be too smart and the plant wouldn’t survive. Also, I think it’s fascinating that an activity like aquaplaning is used for the feeding of a species. Who would’ve known that a plant uses what a car does when the tires are wet, as a source of food.