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Brazil Bug Study May Aid Farmland Preservation

John Roach
for National Geographic News
October 3, 2002
 
Overturn a wet rock or poke into a pile of damp leaf litter, and you may send a mass of tiny creatures known as Collembola jumping for cover.

The world's most abundant insect (although taxonomists debate if they are true insects), Collembola have been around for at least 400 million years and exist in as many as 100,000 varieties.

They have segmented bodies, antennae, eyes, and legs that enable them to feel, see, and move about in nearly every kind of terrestrial environment, from high mountain peaks to sandy shores of tropical beaches.

Many species of Collembola live in soil and are an important component of agricultural ecosystems. They feed on soil microorganisms and organic material, thereby helping to regulate the mineralization of nutrients and make them available to plants.


Despite this critical function, however, very little is known about Collembola in biologically rich tropical environments.

Mark Culik, an entomologist from West Virginia University, is scouring the soils of Espírito Santo, Brazil, to find out more about the Collembola that dwell there—knowledge that he hopes will benefit agriculture in one of the world's most threatened ecosystems.

"In general, Collembola are seldom noticed in agricultural or other environments," said Culik, who has been collaborating since 1999 with scientists at INCAPER, the Espírito Santo state rural research and extension organization.

"Almost nothing is known of the Collembola of Espírito Santo, and relatively little is known about the Collembola of Brazil and other tropical areas," he added. Ken Christensen, a biologist at Grinnell College in Iowa who specializes in the study of Collembola, said the work by Culik and his colleagues "will help remedy this."

The research, which is funded in part by a grant from the National Geographic Society's Committee for Research and Exploration, has led to the discovery of several new species of Collembola and the documentation of their abundance in Brazil.

Espírito Santo

Espírito Santo is a 28,583-square-mile (46,000-square-kilometer) slice of land located at the center of Brazil where temperate mountains rise from the hot and humid Brazilian coast.

Agriculture is the main source of income for about 12 percent of the 3 million people who call Espírito Santo home. The state is the second largest coffee producer in Brazil. Papaya, avocado, banana, oranges, cocoa, and mango are among the other abundant crops.

"Espírito Santo also contains about 400,000 hectares (988,422 acres) of Atlantic forest, which is one of the most biologically diverse types of environments in the world," said Culik, who added that the state is as equally endowed in national park and reserve areas as it is with productive agricultural lands.

Culik hopes that by learning more about the Collembola that inhabit tropical regions such as Espírito Santo, researchers will be able to use the wingless bugs to better manage, utilize, and preserve agricultural land "making it less necessary to destroy natural areas for food production in the future."

Collecting basic information about the abundance and diversity of Collembola in areas such as Espírito Santo is the first step to reach this goal, says Culik.

For example, he says that in order to efficiently and effectively use organic materials as fertilizer in sustainable agricultural systems, knowledge of organisms such as Collembola that influence decomposition of organic matter is important.

Likewise, he said, learning the effects of Collembola on microorganisms located in the soil that cause plant diseases may lead to better methods for avoiding and managing plant pathogens.

"Only by understanding fully the impact of agricultural practices upon the health of the living soil can we develop a truly sustainable agriculture," said Christiansen. "The study of Collembola is important in this."

Discovery

To date, Culik and his colleagues have collected 38 species of Collembola, of which 35 are newly documented in Espírito Santo and 17 in Brazil. At least one, and perhaps three, of the newly identified species is new to science.

The research builds on the scant knowledge of Collembola of the region. Previously, just 11 other species of the bugs were known from Espírito Santo and about 200 in all of Brazil. This compares to about 800 in North America and 7,500 known worldwide.

Scientists believe that upwards of 100,000 varieties of Collembola may exist throughout the world, making the study of Collembola an almost completely unknown and explored field.

Culik says the soil beneath his feet is "like another world, as interesting and amazing as the ocean depths and outer space, inhabited by Collembola and other creatures with shapes and structures as spectacular as those one might expect to be found on alien beings from other planets."
 

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