Plant Perspicacity

Plant Perspicacity

A species of pitcher plant growing in Borneo has been found to strategize its prey catching capabilities in order to maximize the windfall. This pitcher plant, Nepenthes spp.,  is able to  adjust the slipperiness of its characteristic pitfall trap in response to changing weather conditions so as to dine on large number of ants at once, rather than individual ants. Pitcher plants have cup-shaped leaves which get slippery at the rim causing insects to slip into the cup where it is digested and provides the plant with needed nutrients which they cannot derive from the nutrient-poor soils they inhabit.

When the weather is hot and dry the pitcher’s surface is dry and hospitable for ants, allowing them to visit and leave unharmed. These scout ants return to the nest with sweet nectar easily begotten at the beautiful pitcher plant, this encourages more ants to accompany the scouts back to the plant for more. The ants march en masse to the pitcher plant which has now made its rims slippery and thus inescapable, the plant now gets a large meal for very little effort.

The plant secretes sugary nectar which primes the surface and allows it to collect condensation at lower humidity levels than other plant surfaces. This activates the trap during hot afternoons when day insects are still foraging. This makes the Nepenthes pitcher plant appear intelligent, to which the lead researcher on this project, biologist Ulrike Bauer of the University of Bristol in the U.K. responded, “Of course a plant is not clever in the human sense – it cannot plot. However, natural selection is very relentless and will only reward the most successful strategies.” Results from this study were published in the Proceeding of the Royal Society B, earlier this week.

There are approximately 600 known species of carnivorous plants living around the planet, they are usually found in nutrient-poor environments making it necessary for them to obtain them by other means. Some plants attract insects, while others will trap birds and small mammals. And while this has long been thought of as a classic predator/prey relationship, this current research indicates it may be mutualistic, Bauer explains; “As long as the energy gain (eating the nectar) outweighs the loss of worker ants, the ant colony benefits from the relationship just as much as the plant does.”