Study finds market forces influence the value of bat-provided services

February 3, 2014
This photo shows bats returning to Frio Cave near Conan, Texas, in the early morning. Credit: Amy Russell of Grand Valley State University

Services provided by Mother Nature, such as pest control from insect-eating bats, are affected by market forces like most anything else in the economy, a University of Tennessee, Knoxville, study finds.

The study's results have implications for biodiversity conservation efforts.

Researchers from UT and the University of Arizona, Tucson, studied how forces such as volatile market conditions and technological substitutes affect the value of pest control services provided by Mexican free-tailed bats on in the U.S. They found the services are impacted by the forces to the tune of millions of dollars.

The study, conducted by Gary McCracken, professor in the Department of Ecology and Evolutionary Biology, and led by UA's Laura López-Hoffman, is the first to examine how bat ecosystem services change over time. It is published in this week's edition of the journal PLOS ONE.

There are more than 1,200 bat species and two-thirds of them are insectivorous, which means they help farmers by preying on pests and reducing the need for insecticides. The researchers calculated the value of the bat pest control service each year from 1990 through 2008 by estimating the value of avoided crop damage and the reduced social and private costs of insecticide use in the presence of bats.

Taking into account a drop in cotton commodity price, the resulting decrease in cotton production and the adoption of transgenic Bt (Bacillus thuringiensis) cotton, which is modified to express its own pesticide, the researchers found that the value of the pest control services dropped 79 percent, from a high of $23.96 million in 1990 to a low of $4.88 million in 2008.

"The results of this study document that volatile market conditions and technological substitutes such as Bt cotton can affect the value of an ecosystem service even when ecosystem function, in this case bat population numbers, may remain constant," said McCracken.

The findings fuel a discussion as to whether or not it is economically worthwhile to conserve biodiversity.

"There is a worry that technological substitutes such as cloning and pesticides that replace nature's services such as pollination and natural pest control diminish the importance of protecting ecosystems," said López-Hoffman. "While our research shows a diminished value of pest control due to fluctuations in market conditions, our larger analyses show that conservation is still economically beneficial."

The researchers point to mounting evidence of the evolution of pest resistance to Bt cotton, suggesting that the value of bat pest control services may increase again.

"This evidence of resistance evolution suggests that Bt may not be a long-term solution to pest-related losses," said McCracken. "In fact, by preying on the individual insects that survive the Bt toxin, bats may provide the additional service of slowing the evolution of resistance to Bt and other insecticides. Bats are also free of charge and, as generalist predators, are providing a broad spectrum of ."

Explore further: New bacteria toxins against resistant insect pests

More information: To view the article, visit http://dx.plos.org/10.1371/journal.pone.0087912.

Related Stories

New bacteria toxins against resistant insect pests

October 19, 2011

Toxins from Bacillus thuringiensis bacteria (Bt toxins) are used in organic and conventional farming to manage pest insects. Sprayed as pesticides or produced in genetically modified plants, Bt toxins, used in pest control ...

Bt sweet corn can reduce insecticide use

October 7, 2013

Since 1996, corn containing a gene that allows it to create a protein that is toxic to certain insects, yet safe for human consumption, has been grown in the United States. However, most of this "Bt corn" has been used for ...

Recommended for you

Hairs, feathers and scales have a lot in common

June 24, 2016

The potential evolutionary link between hairs in mammals, feathers in birds and scales in reptiles has been debated for decades. Today, researchers of the University of Geneva (UNIGE) and the SIB Swiss Institute of Bioinformatics, ...

Insects were already using camouflage 100 million years ago

June 24, 2016

Those who go to a masked ball consciously slip into a different role, in order to avoid being recognized so quickly. Insects were already doing something very similar in the Cretaceous: They cloaked themselves in pieces of ...

Molecular scissors help evolutionary investigation

June 24, 2016

Scientists at KIT (Karlsruhe Institute of Technology) detected an important mechanism in the evolution of plant genomes: Using Arabidopsis thaliana as a model organism, they studied the formation of tandem repeat DNA sequences ...

Decoding the rubber tree genome

June 24, 2016

Researchers at the RIKEN Center for Sustainable Resource Science (CSRS) in Japan along with collaborators at Universiti Sains Malaysia (USM) have succeeded in decoding the genome sequence for Hevea brasiliensis, the natural ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.