U.S. biologists led by Dr Lee Dyer from the University of Nevada Reno have described a new plant species from the Andes Mountains of Ecuador.
Left: Piper kelleyi. Right upper: close-up of leaves showing characteristic red color of younger leaves; Right middle: close-up of inflorescence; Right bottom: close-up of infructescence. Image credit: Tepe EJ et al.
The chemical compounds produced by plants are source of plants’ unique flavors, aromas, and colors. What’s less appreciated is that these compounds often have important medicinal or toxic properties, and are the plant’s natural way to resist pesky herbivores.
Black pepper and its wild relatives produce a wide diversity of chemical compounds, many of which are known to be biologically active. In fact, several compounds from the new species are currently under evaluation, and show promise as possible anti-cancer drugs.
These compounds are known to deter most herbivores, but a certain group of caterpillars has been able to overcome their toxicity and, as a result, most species of the genus feed only on a single species of wild black pepper.
To make matters more complex, each of these caterpillars typically has one to several predatory wasp and/or fly species that attack only that caterpillar species.
The newly discovered wild pepper species, named Piper kelleyi, is the sole home for about 40-50 species of insects, most of which are entirely dependent on this plant for survival.
“Our team of scientists has made nearly 30,000 observations of over 100 black pepper relatives over 20+ years, and the new plant species supports the largest number of specialized caterpillar and predator species recorded for species in the black pepper family to date,” said Dr Dyer and his colleagues, who reported the discovery in the journal PhytoKeys.
“Many of these insects were discovered as a result of our investigations and are new to science – many remain unnamed.”
Evidence suggests that the unique compounds produced by a plant species, or the unique combination of these compounds, help drive the evolution of biological diversity, not only among the herbivores that feed directly on the plants, but among higher trophic levels as well.
“The discovery of our new species, along with its large cohort of dependent insects, lends considerable support to the hypothesis that a suite of new species of herbivores and predators of those herbivores evolves in response to the evolution of novel plant-produced chemical compounds,” the biologists said.
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Tepe EJ et al. 2014. Piper kelleyi, a hotspot of ecological interactions and a new species from Ecuador and Peru. PhytoKeys 34: 19–32; doi: 10.3897/phytokeys.34.6376
