Low-Level Dietary Clothianidin Exposure Preferentially Causes Prepupal Mortality of Monarch Butterflies (Danaus plexippus)
Bargar TA. Environmental toxicology and chemistry, July 2024.
Go to the paper May need a subscription · doi:10.1002/etc.5944
What this paper is about
Earlier work suggested monarchs are more vulnerable to the insecticide clothianidin just before pupating than as feeding caterpillars. This study tested whether the doses that kill at that stage are ones monarchs actually meet in the field.
Larvae were raised on contaminated swamp milkweed across a wide range of leaf concentrations, and deaths concentrated at the prepupal stage.
Summarised here from the abstract below. Not the authors’ words.
Abstract
Data from prior research indicate the prepupal stage of the monarch butterfly life cycle is more sensitive to clothianidin exposure than the larval stage. A set of experiments was conducted to determine if the dietary clothianidin exposures that cause prepupal mortality are environmentally relevant. Monarch larvae were raised from egg to pupae on clothianidin-contaminated swamp milkweed plants (Asclepias incarnata). Larval growth as well as larval and prepupal survival were monitored throughout the experiments, in which the exposures ranged from 1.4 to 2793.1 ng/g leaf. Exposures of 5.4 to 46.9 ng/g leaf resulted primarily in prepupal mortality, whereas higher exposures of 1042.4 to 2793.1 ng/g leaf resulted exclusively in larval mortality, indicating the prepupal stage is more sensitive to clothianidin exposure than the larval stage. A median lethal concentration and a 10% lethal concentration of 37 and 6 ng/g leaf, respectively, were estimated for prepupal mortality. Both effect concentrations are within the range of clothianidin concentrations reported in leaves collected from wild milkweed plants, indicating prepupal mortality is an environmentally relevant effect. Environ Toxicol Chem 2024;43:2039-2044. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
Abstract reproduced from the published paper, which is licensed CC BY. Copyright remains with the authors.
Key terms
Milkweeds in this paper
- Swamp Milkweed Asclepias incarnata
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title = {Low-Level Dietary Clothianidin Exposure Preferentially Causes Prepupal Mortality of Monarch Butterflies (Danaus plexippus) (listing)},
author = {{Milkweed USA}},
year = {2026},
url = {https://milkweedusa.com/research/low-level-dietary-clothianidin-exposure-preferentially-causes-prepupal-mortality-2024/},
note = {Accessed DATE}
}