Some 25,000 species of arthropods live in Panamanian forest

By Susan Milius

Web edition: December 13, 2012

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BUG CENSUS

The scarab beetle Megasoma elephas was one of the residents tallied in a heroic effort to determine how many arthropod species live in Panama’s San Lorenzo forest.

Credit: courtesy of Thomas Martin, Jean-Philippe Sobczak and Hendrik Dietz, TU Munich

An international effort has put together the first tally of all the species of butterflies, beetles, ants, bees, roaches and their fellow arthropods that live in a tropical forest. And the count: 25,000.

Arthropods represent a big chunk of the diversity of species on Earth, but biologists analyzing such basic questions as how forest ecosystems will respond to climate change haven’t had much solid data on what’s really scurrying, flying and buzzing through those forests. To get a better sense, a team of 102 researchers from 21 countries sampled arthropods in the San Lorenzo forest, a 60-square-kilometer tropical forest in Panama.

Researchers collected samples from the soil on up to the treetops using professional tree climbers, a crane, even a helium-filled balloon to extend their reach. Then came eight years of determining the species for 129,000 individual specimens.

Analyzing the count suggested possible short-cuts for estimating diversity, Yves Basset of the Smithsonian Tropical Research Institute in Panama and his colleagues report in the Dec. 14 Science. The best predictor of total arthropod species was the total plant species in the forest. Of course, then scientists have to count the plants.