Glyphosate in a warming world: Effects on lifespan, feeding, and food conversion efficiency in a field cricket, Gryllus lineaticeps

Lead Author Major

Jacob Whitlock

Lead Author Status

Sophomore

Second Author Major

Cindy Vo

Second Author Status

Junior

Format

Poster Presentation

Faculty Mentor Name

Zachary Stahlschmidt

Faculty Mentor Department

Biological Sciences

Abstract/Artist Statement

The use of the herbicide glyphosate (GLY, the active ingredient in Roundup®) in the U.S. has increased over 200-fold since its introduction in the 1970s. U.S. farmers currently spray enough GLY to apply 1 kilogram onto every hectare of cropland. Historically, GLY was marketed as non-toxic to animals, but recent research suggests acute and chronic toxicological effects of GLY to many animal taxa— from insects to humans. Along with increased GLY exposure, animals are expected to experience warmer temperatures due to climate change. Therefore, we studied the independent and interactive effects of GLY, Roundup® (GLY + other chemicals designed to increase absorption of GLY by plants), and warming on lifespan, food intake, and food conversion efficiency during adulthood in the variable field cricket, Gryllus lineaticeps. The crickets used in this study were assigned to one of three treatment groups: (1) GLY in drinking water (5 mg / l H2O as in other insect studies), (2) Roundup® in drinking water (equivalent to 5 mg GLY / l H2O), and (3) GLY-free drinking water. The crickets’ thermal environments were also subjected to varying environmental temperatures—that is, crickets underwent a 2 × 2 factorial manipulation of GLY and temperature treatments. Half of the crickets experienced a control temperature cycle (19°C - 38°C each day), which averaged rearing temperature and fluctuated similarly to microhabitats used by adult G. lineaticeps in the field. The remaining half of the cricket cohorts were subjected to a warming temperature cycle (23°C - 42°C each day), which had the same thermal variation as the control temperature treatment but with a 4°C higher mean temperature to reflect projected warming. Our study is the first to examine interactions between GLY, Roundup®, and warming in an insect population, thereby providing critical insight into the complex dynamics between herbicides, plants, and herbivores in the context of climate change.

Location

Virtual

Start Date

25-4-2020 1:00 PM

End Date

25-4-2020 3:00 PM

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Apr 25th, 1:00 PM Apr 25th, 3:00 PM

Glyphosate in a warming world: Effects on lifespan, feeding, and food conversion efficiency in a field cricket, Gryllus lineaticeps

Virtual

The use of the herbicide glyphosate (GLY, the active ingredient in Roundup®) in the U.S. has increased over 200-fold since its introduction in the 1970s. U.S. farmers currently spray enough GLY to apply 1 kilogram onto every hectare of cropland. Historically, GLY was marketed as non-toxic to animals, but recent research suggests acute and chronic toxicological effects of GLY to many animal taxa— from insects to humans. Along with increased GLY exposure, animals are expected to experience warmer temperatures due to climate change. Therefore, we studied the independent and interactive effects of GLY, Roundup® (GLY + other chemicals designed to increase absorption of GLY by plants), and warming on lifespan, food intake, and food conversion efficiency during adulthood in the variable field cricket, Gryllus lineaticeps. The crickets used in this study were assigned to one of three treatment groups: (1) GLY in drinking water (5 mg / l H2O as in other insect studies), (2) Roundup® in drinking water (equivalent to 5 mg GLY / l H2O), and (3) GLY-free drinking water. The crickets’ thermal environments were also subjected to varying environmental temperatures—that is, crickets underwent a 2 × 2 factorial manipulation of GLY and temperature treatments. Half of the crickets experienced a control temperature cycle (19°C - 38°C each day), which averaged rearing temperature and fluctuated similarly to microhabitats used by adult G. lineaticeps in the field. The remaining half of the cricket cohorts were subjected to a warming temperature cycle (23°C - 42°C each day), which had the same thermal variation as the control temperature treatment but with a 4°C higher mean temperature to reflect projected warming. Our study is the first to examine interactions between GLY, Roundup®, and warming in an insect population, thereby providing critical insight into the complex dynamics between herbicides, plants, and herbivores in the context of climate change.