An insect-trapping pitcher plant in Venezuela uses its downward pointing hairs to create a ‘water slide’ on which insects slip to their death, new research reveals. The research was published today, 19 December, in the journal Proceedings of the Royal Society B.
They found that wetting strongly enhanced the slipperiness of the
trap and increased the capture rate for ants almost three-fold – from 29
per cent when dry to 88 per cent when wet. Upon further examination,
they found that the wetting affected the insects’ adhesive pads while
the directional arrangement of the hairs was effective against the
Dr Ulrike Bauer, lead author of the paper from the University of
Cambridge, said: “When the hairs of the plant are wet, the ants’
adhesive pads essentially aquaplane on the surface, making the insects
lose grip and slip into the bowl of the pitcher. This is the first time
that we have observed hairs being used by plants in this way, as they
are typically used to make leaves water repellent.”
They also found that the plant used a wicking method during dryer
times to pull moisture from the bowl of the pitcher up to the hairy
trapping surface, enabling them to capitalise on this aquaplaning effect
even when there is no rain.
Dr Bauer added: “This very neat adaptation might help the plants to maximise their nutrient acquisition.”
The Heliamphora nutans pitcher plant lives on the spectacular
table mountains of the Guyana Highlands in Southern Venezuela, between
altitudes of 2000-2700m. The pitchers can grow up to 18 cm tall and 7 cm
wide and trap mainly ants.