Novel genetic association with migratory diapause in Australian monarch butterflies
Hemstrom W, Freedman M, Zalucki MP and others. BMC ecology and evolution, May 2025.
Read the paper Free to read · doi:10.1186/s12862-025-02384-w
What this paper is about
Monarchs reached Australia in the nineteenth century and settled down as residents. One Australian population has recently started migrating again, after hundreds of non-migratory generations.
The authors looked for the genetics behind it and found an association with migratory diapause that had not been reported before.
Summarised here from the abstract below. Not the authors’ words.
Abstract
BackgroundMonarch butterflies (Danaus plexippus) are a charismatic and culturally important North American butterfly species famous for their unique, dramatic migratory life history. While non-migratory populations of the species are widespread and apparently stable, migratory populations in North America have recently seen declines, prompting concern that the migratory phenomenon in North America may be at risk of disappearing. In contrast, a relatively recently-established monarch population in Australia has rapidly re-acquired a migratory life history following hundreds of generations of residency and successive bottlenecks as the species island-hopped across the Pacific during the late 1800s and early 1900s. The process by which migration re-emerged in Australian monarchs is not currently known.ResultsWe raised and sequenced individuals from Queensland, Australia under environmental conditions associated with migration initiation and found strong variance in reproductive diapause, a key migratory trait, between families which was associated with variation at the spectrin beta chain protein Karst. This protein is known to be involved in diapause termination in monarchs but has not previously been identified as associated with migratory life history variance. The most strongly associated migratory SNPs are also present at a low frequency in North America, suggesting that the Australian population is leveraging standing variation which persisted across repeated bottlenecks as Monarchs spread across the Pacific.ConclusionsOur results provide an intriguing example of how the temporary loss of migration-in this case likely over hundreds of generations-may not entail the loss of genetic variation associated with this complex life history strategy.
Abstract reproduced from the published paper, which is licensed CC BY. Copyright remains with the authors.
Key terms
Find the paper
Cite this page
This page is licensed CC BY 4.0. Quote it, adapt it and reuse it, including commercially, as long as you credit Milkweed USA and link back.
Milkweed USA. (2026). Novel genetic association with migratory diapause in Australian monarch butterflies (listing). Retrieved DATE, from https://milkweedusa.com/research/novel-genetic-association-with-migratory-diapause-in-australian-monarch-2025/
"Novel genetic association with migratory diapause in Australian monarch butterflies (listing)." Milkweed USA, 2026, https://milkweedusa.com/research/novel-genetic-association-with-migratory-diapause-in-australian-monarch-2025/. Accessed DATE.
Milkweed USA. "Novel genetic association with migratory diapause in Australian monarch butterflies (listing)." Last modified 2026-08-01. Accessed DATE. https://milkweedusa.com/research/novel-genetic-association-with-migratory-diapause-in-australian-monarch-2025/.
@misc{milkweedusa_researchnovelgeneticassociat,
title = {Novel genetic association with migratory diapause in Australian monarch butterflies (listing)},
author = {{Milkweed USA}},
year = {2026},
url = {https://milkweedusa.com/research/novel-genetic-association-with-migratory-diapause-in-australian-monarch-2025/},
note = {Accessed DATE}
}