Navigation Links
Amphibians living close to farm fields are more resistant to common insecticides
Date:5/1/2013

PITTSBURGHAmphibian populations living close to agricultural fields have become more resistant to a common insecticide and are actually resistant to multiple common insecticides, according to two recent studies conducted at the University of Pittsburgh.

In a study published today in Evolutionary Applications, the Pitt researchers demonstrate, for the first time, that tadpoles from populations close to farm fields are more resistant to chlorpyrifosone of the most commonly applied insecticides in the world, often sold as "Dursban" or "Lorsban." In addition, a related study published in February shows that tadpoles resistant to chlorpyrifos are also resistant to other insecticides.

"While we've made a lot of progress in understanding the ecological consequences to animals that are unintentionally exposed to insecticides, the evolutionary consequences are poorly understood," said study principal investigator Rick Relyea, Pitt professor of biological sciences and director of the University's Pymatuning Laboratory of Ecology. "Our study is the first to explore how amphibian populations might evolve to be resistant to insecticides when they live in places that have been sprayed for many years."

The Pitt researchers used newly hatched tadpoles collected from nine populations of wood frogs living at different distances from agricultural fields. They tested the frogs' resistance when exposed to chlorpyrifos, which is used against insects, and Roundup Original MAX, which is a common herbicide used against weeds.

Relyea and his Pitt collaborators exposed the tadpoles from each of the nine populations to environments containing either no pesticides, chlorpyrifos, or Roundup. After 48 hours, they measured how well the populations survived.

"Wood frogs living close to agricultural land were more likely to have been exposed to pesticides for many generations compared to those living far from agriculture; the latter frog populations likely experienced little or no exposure to pesticides," said Rickey Cothran, the lead author of the study and a postdoctoral researcher in Relyea's lab. "Although populations differed in their resistance to Roundup, populations closer to fields were not more resistant to the herbicide."

"Because chlorpyrifos kills in a way that is similar to many other insecticides, higher resistance may have been favored each time any insecticide was sprayed," said Pitt alumnus Jenise Brown (A&S '09), a coauthor of the study and a former undergraduate researcher in Relyea's lab. "In contrast, herbicides have a variety of ways that they kill organisms, which may make it harder for animals to be resistant when exposed to different herbicides over many years."

In a related study, published online Feb. 21 in Environmental Toxicology and Chemistry, Relyea's Pitt research team examined whether wood frog populations that were resistant to chlorpyrifos might also be resistant to other insecticides. This phenomenon, said Relyea, happens commonly in pest species when farmers switch pesticides from year to year, but little is known about how this switching of pesticides affects amphibians.

Using three commonly applied pesticides that have similar chemical properties chlorpyrifos, carbaryl, and malathionthe Pitt researchers exposed 15 populations of wood frog tadpoles to high concentrations of each insecticide. They found that wood frog populations with resistance to one insecticide also had resistance to the other insecticides.

"This has a beneficial outcome," said Jessica Hua, the lead author of the second study and a graduate student in Relyea's lab. "While it doesn't mean that pesticides are beneficial to amphibians, our work does suggest that amphibians can evolve to resist a variety of pesticides and therefore improve their survival."

As they hypothesized in the study published today, the researchers suspect that the reason for this cross-resistance is that chlorpyrifos kills in a way that is similar to many other insecticides. Thus, evolving higher resistance to one insecticide may provide higher resistance to others.

"This finding may buffer an amphibian population from suffering the consequences of exposures to new, but similar-acting chemicals," said Aaron Stoler, a coauthor of the second paper and a graduate student in Relyea's lab.

In the future, Relyea and his team plan to study the genetic mechanisms that underlie increased resistance in amphibians and determine whether increased resistance occurs in additional animal species that are not the targets of pesticides.

The article published today in Evolutionary Applications is titled "Proximity to agriculture is correlated with pesticide tolerance: Evidence for the evolution of amphibian resistance to modern pesticides." The article published Feb. 21 in Environmental Toxicology and Chemistry is titled "Cross-tolerance in amphibians: Wood frog mortality when exposed to three insecticides with a common mode of action."


'/>"/>

Contact: B. Rose Huber
rhuber@pitt.edu
412-624-4356
University of Pittsburgh
Source:Eurekalert

Related biology news :

1. International collaboration to investigate disappearing reptiles and amphibians
2. The amazing amphibians and reptiles of the Philippine island Luzon
3. Environmental concerns increasing infectious disease in amphibians, other animals
4. 100+ million mapped (and growing) records of nearly every living US species
5. Genome sequencing of the living coelacanth sheds light on the evolution of land vertebrate
6. Living in a sunny climate does not improve vitamin D levels in hip fracture patients
7. Not just cars, but living organisms need antifreeze to survive
8. ArcticNet recommends practical solutions to improve standard of living in Canadas north
9. Malnutrition -- Living hungrily ever after
10. NIH grant funds Boston College research into illnesses afflicting people living with HIV
11. Peering into living cells -- without dye nor fluophore
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/16/2016)... June 16, 2016 The ... expected to reach USD 1.83 billion by 2024, ... Research, Inc. Technological proliferation and increasing demand in ... expected to drive the market growth. ... The development of advanced multimodal techniques for ...
(Date:6/3/2016)... LONDON , June 3, 2016 /PRNewswire/ ... Transport Management) von Nepal ... ,Angebot und Lieferung hochsicherer geprägter Kennzeichen, einschließlich ... weltweit führend in der Produktion und Implementierung ... an der Ausschreibung im Januar teilgenommen, aber ...
(Date:5/24/2016)... Ampronix facilitates superior patient care by providing unparalleled technology to leaders of the medical ... premium product recently added to the range of products distributed by Ampronix. ... ... ... Ampronix News ...
Breaking Biology News(10 mins):
(Date:6/22/2016)... Research and Markets has announced the addition of the ... The global biomarkers market has ... The market is expected to grow at a five-year compound annual ... $50.6 billion in 2015 to $96.6 billion in 2020. ... to 2020) are discussed. As well, new products approved in 2013 ...
(Date:6/22/2016)... LOS ANGELES , June 22, 2016   ... an SNNLive Video Interview with Dr. Nader Pourhassan ... a biotechnology company focused on the clinical development and ... and prevention of HIV infection, according to the company,s ... was recorded on Tuesday, June 7 th , 2016, ...
(Date:6/22/2016)... DIEGO , June 22, 2016   ViaCyte, ... first pluripotent stem cell-derived islet replacement therapy for the ... presentations at ISSCR 2016 Annual Meeting.  ISSCR 2016, the ... to 25th at Moscone West in San Francisco.  ... of the presentations are as follows:Event: , Focus Session: ...
(Date:6/22/2016)... (PRWEB) , ... June 22, 2016 , ... ... at placing a spotlight on immigrant achievements and contributions to North Texas and ... most important contributors from the immigrant community to the civic and economic vitality ...
Breaking Biology Technology: