What plant utilizes assassins?
By Chelsie Vandaveer
October 17, 2001
killerPlants Tendrils: ~~1~~2~~3~~4~~5~~
Suggested Reading: Click here.
Not far from the cool coastline of South Africa, there are two sticky plants, Roridula gorgonias [row rid' u la gor gon' ee as] and R. dentata [den ta' ta]. Charles Darwin declared Roridula to be carnivorous for the plants were covered with the carcasses of insects. But Roridula does not digest insects, it simply traps the unwary.
Roridula feed vicariously; they provide the home for two Hemipterans, assassin bugs. When an unwary insect lands on Roridula, it is immediately and irreversibly trapped in the mucilage exuded from the tips of the glandular trichomes. As the trapped insect struggles to free itself, it attracts the attention of the assassins.
The assassin bugs, Pamerida roridulae and P. marlothii, cross the sticky hairs with impunity and attack the defenseless insect. There they feed, emptying the exoskeleton of all its contents. The assassin bugs excrete urea onto the surface of the Roridula. The urea is a fertilizer and is absorbed through the surface of the plant.
The Roridula and Pamerida symbiosis is an obligate relationship. In nature, neither the plants nor the assassin bugs are found outside of each other's company. And they have another strange relationship. The stamens of Roridula flowers are touch-sensitive. The stamens are set like triggers when the pollen is ready to be shed. As an assassin bug crawls over the flower, the stamens slap the anthers against the insect covering it with pollen. The bug carries the pollen to every flower it visits, ensuring cross-pollination.
The Martin Reiner has an excellent series of photographs of Roridula gorgonias and the assassin bugs Pamerida roridulae and P. marlothii. (Photographs are below text.) To view the photographs, click on the link:
http://www.drosophyllum.com/english/e-roridula.htm
killerPlants Tendrils: ~~1~~2~~3~~4~~5~~
Suggested Reading:
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Could a carnivorous plant be a cure for smallpox? Herbal Foklore - July 30, 2001
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