Raindrops help pitcher plants trap dinner

pitcher plant Nepenthes gracilis

The lower lid of the pitcher plant Nepenthes gracilis secretes nectar that attracts unsuspecting insects. In the rain, the lid becomes a spring-loaded death trap. 

Ulrike Bauer/Univ. of Bristol

Ants crawling on the underside of a pitcher plant are flicked to their death when raindrops hit the lid. Ulrike Bauer/Univ. of Bristol
The pitcher plant Nepenthes gracilis gets a little help from raindrops in snagging a meal. When falling rain strikes the lid that hangs over N. gracilis ’ fluid-filled trap, the lid acts like a spring-loaded plate, flinging insects crawling on its underside to their death .

N. gracilis, which is native to Asia, is specially equipped to trap its prey this way. Its lid is lined with slippery wax crystals and vibrates much more quickly than that of a related species of pitcher plant. Both features seem to be crucial to the plant’s prey-trapping strategy. When the researchers removed the slippery wax or attached a slick N. gracilis lid beneath that of another species of pitcher plant, few to no ants fell to their death during simulated rainfall, researchers report October 5 in the Proceedings of the National Academy of Sciences.  

More Stories from Science News on Plants

From the Nature Index

Paid Content