Endemic to New Caledonia, Nepenthes vieillardii has leaves ending in an urn more or less closed by a cover and containing a digestive liquid which attracts and traps insects. Inside these traps, however, there is a profusion of larvae of Tripteroides caledonicus mosquitoes which have made a specialty of laying in the urns of Nepenthes vieillardii. Their larvae survive there despite the enzymes supposed to digest them.