Host plant specificity of the monarch butterfly Danaus ple

What this paper is about

A systematic review and meta-analysis of which milkweeds monarchs choose and which ones their caterpillars actually survive on.

The two do not always match. Females sometimes lay on plants that support poor larval survival, because preference, palatability and survival are separate things that need not line up.

Summarised here from the abstract below. Not the authors’ words.

Abstract

The preference-performance hypothesis explains host specificity in phytophagous insects, positing that host plants chosen by adults confer the greatest larval fitness. However, adults sometimes oviposit on plants supporting low larval success because the components of host specificity (adult preference, plant palatability, and larval survival) are non-binary and not necessarily correlated. Palatability (willingness to eat) is governed by chemical cues and physical barriers such as trichomes, while survival (ability to complete development) depends upon nutrition and toxicity. Absence of a correlation between the components of host specificity results in low-performance hosts supporting limited larval development. Most studies of specificity focus on oviposition behavior leaving the importance and basis of palatability and survival under-explored. We conducted a comprehensive review of 127 plant species that have been claimed or tested to be hosts for the monarch butterfly Danaus plexippus to classify them as non-hosts, low performance, or high performance. We performed a meta-analysis to test if performance status could be explained by properties of neurotoxic cardenolides or trichome density. We also conducted a no-choice larval feeding experiment to identify causes of low performance. We identified 34 high performance, 42 low performance, 33 non-hosts, and 18 species with unsubstantiated claims. Mean cardenolide concentration was greater in high- than low-performance hosts and a significant predictor of host status, suggesting possible evolutionary trade-offs in monarch specialization. Other cardenolide properties and trichome density were not significant predictors of host status. In the experiment, we found, of the 62% of larvae that attempted to eat low-performance hosts, only 3.5% survived to adult compared to 85% of those on the high-performance host, demonstrating that multiple factors affect larval host plant specificity. Our study is the first to classify all known host plants for monarchs and has conservation implications for this threatened species.

Abstract reproduced from the published paper, which is licensed CC BY. Copyright remains with the authors.

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.

APA

Milkweed USA. (2026). Host plant specificity of the monarch butterfly Danaus plexippus: A systematic review and meta-analysis (listing). Retrieved DATE, from https://milkweedusa.com/research/host-plant-specificity-of-the-monarch-butterfly-danaus-plexippus-2022/

MLA

"Host plant specificity of the monarch butterfly Danaus plexippus: A systematic review and meta-analysis (listing)." Milkweed USA, 2026, https://milkweedusa.com/research/host-plant-specificity-of-the-monarch-butterfly-danaus-plexippus-2022/. Accessed DATE.

Chicago

Milkweed USA. "Host plant specificity of the monarch butterfly Danaus plexippus: A systematic review and meta-analysis (listing)." Last modified 2026-08-01. Accessed DATE. https://milkweedusa.com/research/host-plant-specificity-of-the-monarch-butterfly-danaus-plexippus-2022/.

BibTeX

@misc{milkweedusa_researchhostplantspecificity,
  title  = {Host plant specificity of the monarch butterfly Danaus plexippus: A systematic review and meta-analysis (listing)},
  author = {{Milkweed USA}},
  year   = {2026},
  url    = {https://milkweedusa.com/research/host-plant-specificity-of-the-monarch-butterfly-danaus-plexippus-2022/},
  note   = {Accessed DATE}
}