ダナオス(古代ギリシア語Δαναός )はゼウスの曾孫で、エジプトまたはリビアの神話上の王であり、アルゴスを建国した。プレクシッポス(Πλήξιππος )はアイギュプトスの50人の息子の一人で、ダナオスの双子の兄弟である。ホメロスのギリシア語では、彼の名前は「馬を駆る者」、つまり「騎手」または「御者」を意味する。[ 17 ] 『自然の体系』第10版の467ページの下部で、リンネは、パピリオ・プレクシッポスが属する属の区分であるダナイ・フェスティヴィの名前はアイギュプトスの息子に由来すると書いた。[ 18 ]リンネは、既知のすべての蝶の種を含む大きな属であるパピリオ属を、現在でいう亜属に分類しました。ダナイ・フェスティヴィ属は、色彩豊かな種を含む「亜属」の一つであり、ダナイ・カンディディ属は、鮮やかな白い翅を持つ種を含む亜属でした。リンネは次のように記しています。「ダナオルム・カンディドルム・ノミナ・ア・フィリアブス・ダナイ・アエジプティ、フェスティヴォルム・ア・フィリイス・ムトゥアトゥス・スント。」(英語: "The names of the Danai candidi have been derived from the daughters of Danaus, those of the Danai festivi from the sons of Aegyptus.")。
2齢幼虫は、白、黄、黒の横縞模様という特徴的なパターンを発達させる。幼虫の頭部には黄色の三角形があり、この中央の三角形の周りに2組の黄色の帯がある。もはや半透明ではなく、短い剛毛で覆われている。黒い触手が2対生え始め、胸部には大きな触手が1対、腹部には小さな触手が1対ある。2齢幼虫は通常、体長が6 mm (0.24インチ)から1 cm (0.39インチ)の間である。[ 39 ]
Holland, William Jacob (1898). The Butterfly Book: A Popular Guide To A Knowledge Of The Butterflies Of North America . Garden City, New York : Country Life Press . pp. 63 , 81. Retrieved December 26, 2023 – via Project Gutenberg . Linnæus は、気まぐれな理由でこの昆虫にPlexippusという名前を付けました。これはその種小名であり、他のすべての蝶と区別されます。これはAnosia属に属します。Anosia 属は、Euplœinæ 亜科を構成する属の 1 つです。Euplœinæ は、Nymphalidæ という大きな科に属します。タテハチョウ科は、チョウ亜目(Rhopalocera)に属するチョウ類であり、チョウ類は鱗翅目(Lepidoptera)の2つの大きな区分の一つで、昆虫綱(Insecta)に属し、昆虫綱は節足動物亜界の最高位の綱である。(63ページ)
Moffat, JA (1902). " Anosia archippus は冬眠しない".Report of the Entomological Society of Ontario . 32. Entomological Society of Ontario : 78–82 .( 「オオカバマダラの行動:渡り」で引用。閲覧室。MonarchWatch.org。2024年10月9日にオリジナルからアーカイブ。2025年10月6日に取得。)
Dyer, Harrison G. (1902). "Family LYMNADIDAE: ANOSIA Hubner" . Bulletin of the United States National Museum (52: A List Of North American Lepidoptera And Key To The Literature Of This Order Of Insects). Washington, DC: Smithsonian Institution Press : 33 . 2025年10月4日取得–インターネットアーカイブ経由。
↑ Ackery, PR; Vaine-Wright, RI (1984). Milkweed butterflies, their cladistics and biology: being an account of the natural history of the Danainae, subfamily of the Lepidoptera, Nymphalidae . British Museum (Natural History), London. p . 17. ISBN978-0-565-00893-2。
1 2 Hay-Roe, Miriam M.; Lamas, Gerardo; Nation, James L. (2007). " Danaus erippusとDanaus plexippus (Lepidoptera: Danainae) の相互交配における接合前および接合後の隔離とハルデーン則効果、およびクチクラ炭化水素の分化によって裏付けられ、これらが別種としての地位を確立する" . Biological Journal of the Linnean Society . 91 (3): 445– 453. doi : 10.1111/j.1095-8312.2007.00809.x .
Betz, RF (1989). Bragg, Thomas B.; Stubbendieck, James (編). "ミードミルクウィード ( Asclepias meadii Torrey ) の生態" (PDF) . Prairie pioneers: ecology, history and culture: proceedings of the Eleventh North American Prairie Conference held 7–11 August 1988 . Lincoln, Nebraska : University of Nebraska Printing. pp. 187– 191. OCLC 741871225 . 2022 年 10 月 16 日にオリジナルからアーカイブ(PDF) 。2024年3 月 10 日に取得– University of Wisconsin-Madison Libraries経由。
Penskar, MR; Higman, PJ (2000). " Asclepias sullivantii Engelm.: Sullivant's milkweed" (PDF) . Michigan Natural Features Inventory . Lansing, Michigan : Michigan State University Extension . Archived (PDF) from the original on September 5, 2012 . Retrieved January 15, 2024 .
↑ Borders, B.; Lee-Mäder, E. (2014). "第2章 ミルクウィードの生物学と生態". Milkweeds: A Conservation Practitioner's Guide (PDF) . Portland, OR: The Xerces Society for Invertebrate Conservation . p. 8. 2025年6月27日のオリジナルからアーカイブ済み(PDF) . 2025年7月27日取得.
↑ハワード、エリザベス;アシェン、ハーレン;デイビス、アンドリュー K. (2010). 「米国南部におけるオオカバマダラの越冬に関する市民科学観察」 . Psyche: A Journal of Entomology . 2010 : 1. doi : 10.1155/2010/689301 .
↑ Satterfield, DA; Maerz, JC; Altizer, S (2015). "渡り行動の喪失はチョウの宿主の感染リスクを高める" . Proceedings of the Royal Society B: Biological Sciences . 282 (1801) 20141734. doi : 10.1098/rspb.2014.1734 . PMC 4308991 . PMID 25589600 .
↑ Nail, Kelly R. (2019). "Butterflies Across the Globe: A Synthesis of the Current Status and Characteristics of Monarch ( Danaus plexippus ) Populations Worldwide" . Frontiers in Ecology and Evolution . 27 362. Bibcode : 2019FrEEv...7..362N . doi : 10.3389/fevo.2019.00362 .
Pocius, Victoria M.; Debinski, Diane M.; Pleasants, John M.; Bidne, Keith G.; Hellmich, Richard L. (2018年1月8日). 「オオカバマダラはすべての卵を1つのカゴに入れるわけではない:中西部の9種のトウワタへの産卵」 . Ecosphere . 9 (1) e02064. Ecological Society of America : 1– 13. Bibcode : 2018Ecosp...9E2064P . doi : 10.1002/ecs2.2064 .本研究では、最も好まれないトウワタ種であるA. tuberosa(選択なし、図2)とA. verticillata(選択あり、図3A)は、いずれも文献でカルデノリドレベルが低いことが記録されている(Roeske et al. 1976、Agrawal et al. 2009、2015、Rasmann and Agrawal 2011)。
↑ Pocius, Victoria M.; Debinski, Diane M.; Pleasants, John M.; Bidne, Keith G.; Hellmich, Richard L. (2018年1月8日). 「オオカバマダラはすべての卵を1つのカゴに入れるわけではない:中西部の9種のトウワタへの産卵」 . Ecosphere . 9 (1) e02064. Ecological Society of America : 1– 13. Bibcode : 2018Ecosp...9E2064P . doi : 10.1002/ecs2.2064 .本研究では、最も好まれないトウワタ種であるA. tuberosa(選択なし、図2)とA. verticillata(選択あり、図3A)は、いずれも文献でカルデノリドレベルが低いことが記録されている(Roeske et al. 1976、Agrawal et al. 2009、2015、Rasmann and Agrawal 2011)。
1 2 Brower, Lincoln (1988). "オオカバマダラに対する鳥類の捕食とその擬態理論への示唆". The American Naturalist . 131 : S4– S6. Bibcode : 1988ANat..131S...4B . doi : 10.1086/284763 . S2CID 84642806 .
↑ Fink, Linda S.; Brower, Lincoln P. (1981 年 5 月). 「鳥はメキシコのオオカバマダラのカルデノリド防御を克服できる」. Nature . 291 (5810): 67–70 . Bibcode : 1981Natur.291...67F . doi : 10.1038/291067a0 . ISSN 0028-0836 . S2CID 4305401 .
↑ Groen, Simon C.; Whiteman, Noah K. (2021年11月). "トウワタ草食動物の捕食者と寄生虫における心臓配糖体耐性の収斂進化" . Current Biology . 31 (22): R1465– R1466. Bibcode : 2021CBio...31R1465G . doi : 10.1016/j.cub.2021.10.025 . ISSN 0960-9822 . PMC 8892682 . PMID 34813747 . S2CID 244485686 .
↑ Zalucki, Myron P.; Malcolm, Stephen B.; Paine, Timothy D.; Hanlon, Christopher C.; Brower, Lincoln P.; Clarke, Anthony R. (2001). "It's the first bites that count: Survival of first-instar monarchs on milkweeds". Austral Ecology . 26 (5): 547– 555. Bibcode : 2001AusEc..26..547Z . doi : 10.1046/j.1442-9993.2001.01132.x .
↑ Hermann, Sara L.; Blackledge, Carissa; Haan, Nathan L.; Myers, Andrew T.; Landis, Douglas A. (2019年10月4日). 「オオカバマダラの卵と孵化直後の幼虫の捕食者は、これまで認識されていたよりも多様である」 . Scientific Reports . 9 (14304). Nature Research . doi : 10.1038/s41598-019-50737-5 . PMC 6778129. 2025年11月12日にオリジナルからアーカイブ済み。2019年2月22日に取得。
↑オーバーハウザー、カレン S. ; ソレンスキー、ミシェル J. (2004).オオカバマダラ:生物学と保全(初版). イサカ、ニューヨーク:コーネル大学出版局. p. 44. ISBN978-0-8014-4188-2。
↑ Mahoney, Erika (2021年1月7日). "A Winter Without Monarchs In Pacific Grove - Butterfly Town, USA" . Pacific Grove, California : KAZU . 2025年6月23日のオリジナルからアーカイブ済み。 2026年3月29日取得。
1 2 Ries, Leslie; Taron, Douglas J.; Rendón-Salinas, Eduardo (2015). "東部渡り個体群における夏と冬のオオカバマダラの傾向の不一致:異なる要因との関連性の可能性". Annals of the Entomological Society of America . 108 (5): 691. doi : 10.1093/aesa/sav055 . S2CID 85597731 .
↑ファティマ、パス(2014 年 6 月 18 日)。 "En espera de aprobación de la Profepa por tala ilegal en la Reserva de la Mariposa Monarca" 2014 年 9 月 3 日にWayback Machineにアーカイブされました。 cambiodemichoacan.com.mx。
12345Oberhauser, Karen; Elmquist, Dane; Perilla-Lopez, Juan Manuel; Gebhard, Ilse; Lukens, Laura; Stireman, John (November 2017). "Tachinid Fly (Diptera: Tachinidae) Parasitoids of Danaus plexippus (Lepidoptera: Nymphalidae)"(PDF). Annals of the Entomological Society of America. 110 (6). Oxford University Press: 536–543. doi:10.1093/aesa/sax048. Archived(PDF) from the original on December 28, 2024. Retrieved January 6, 2025.
12Brewer, Jo; Gerard M. Thomas (1966). "Causes of death encountered during rearing of Danaus plexippus (Danaidae)"(PDF). Journal of the Lepidopterists' Society. 20 (4): 235–238. Archived from the original(PDF) on March 25, 2009. Retrieved April 13, 2008.
12Stenoien, Carl; McCoshum, Shaun; Caldwell, Wendy; De Anda, Alma; Oberhauser, Karen (January 2015). "New reports that Monarch butterflies (Lepidoptera: Nymphalidae, Linnaeus) are hosts for a pupal parasitoid (Hymenoptera: Chalcidoidea, Walker)". Journal of the Kansas Entomological Society. 88 (1): 16–26. doi:10.2317/JKES1402.22.1. S2CID52231552.
↑Deep Look (October 11, 2022). "This Parasite is Cramping The Monarch Butterfly's Style". PBS Digital Studios. Retrieved March 7, 2026– via YouTube. Video: 5:04 minutes.
↑Leong, K. L. H.; M. A. Yoshimura, H. K. Kaya and H. Williams (1997). "Instar susceptibility of the Monarch butterfly (Danaus plexippus) to the neogregarine parasite, Ophryocystis elektroscirrha". Journal of Invertebrate Pathology. 69 (1): 79–83. Bibcode:1997JInvP..69...79L. CiteSeerX10.1.1.494.9827. doi:10.1006/jipa.1996.4634. PMID9028932.
↑Bartel, Rebecca; Oberhauser, Karen; De Roode, Jacob; Atizer, Sonya (February 2011). "Monarch butterfly migration and parasite transmission in eastern North America". Ecology. 92 (2): 342–351. Bibcode:2011Ecol...92..342B. doi:10.1890/10-0489.1. PMC7163749. PMID21618914.
↑"Do My Monarch Butterflies Have OE? Ophryocystis elektroscirrha". Butterfly Fun Facts. Archived from the original on March 4, 2015. Retrieved March 24, 2015.
↑Jepsen, S.; Schweitzer, D. F.; Young, B.; Sears, N.; Ormes, M.; Black, S. H. (2015). Conservation Status and Ecology of the Monarch Butterfly in the United States. NatureServe. pp.23–24.
↑Invasive species alert: Black swallow-wort (Cynanchum louisea) and pale swallow-wort (Cynanchum rossicum)Archived September 16, 2021, at the Wayback Machine. monarchjointventure.org
↑"Monarch Population Hits Lowest Point in More Than 20 Years". World Wildlife Fund. Washington, D.C.: World Wildlife Fund. January 29, 2014. Archived from the original on February 25, 2021. Retrieved October 12, 2021.
↑"Basic Facts About Monarch Butterflies". January 9, 2020.
↑Lemoine, Nathan P. (2015). "Climate Change May Alter Breeding Ground Distributions of Eastern Migratory Monarchs (Danaus plexippus) via Range Expansion of Asclepias Host Plants". PLOS One. 10 (2) e0118614. Bibcode:2015PLoSO..1018614L. doi:10.1371/journal.pone.0118614. PMC4338007. PMID25705876.
↑"monarchscience". Akdavis6.wixsite.com. August 10, 2015.
↑Hahn, Philip G.; Agrawal, Anurag A.; Sussman, Kira I.; Maron, John L. (January 2019). "Population Variation, Environmental Gradients, and the Evolutionary Ecology of Plant Defense against Herbivory". The American Naturalist. 193 (1): 20–34. Bibcode:2019ANat..193...20H. doi:10.1086/700838. ISSN1537-5323. PMID30624107. S2CID54076888.
↑"Climate change, pesticides put monarch butterflies at risk of extinction". National Geographic. December 21, 2018. Archived from the original on December 23, 2018. Retrieved December 31, 2018.
↑Larson, Christina (July 21, 2022). "Beloved monarch butterflies now listed as endangered". AP News. Archived from the original on September 29, 2024. Retrieved January 5, 2024.
U.S. Fish and Wildlife Service (December 31, 2014). "Endangered and Threatened Wildlife and Plants; 90-Day Findings on Two Petitions"(PDF). Federal Register. 79 (250): 78775–78778. Federal Register Document Number 2014-30574. Archived(PDF) from the original on June 30, 2024. Retrieved January 4, 2025.
"Endangered species listing for the monarch butterfly: What private landowners need to know"(PDF). Keystone, Colorado: Keystone Policy Center. June 2021. Archived(PDF) from the original on June 20, 2024.
U.S. Fish and Wildlife Service (December 17, 2020). "Endangered and Threatened Wildlife and Plants; 12-Month Finding for the Monarch Butterfly"(PDF). Federal Register. 85 (243): 78775–78778. Federal Register Document Number 2020-27523. Archived(PDF) from the original on September 28, 2024. Retrieved January 5, 2025.
Frazin, Rachel (December 15, 2021). "Trump administration punts on protections for monarch butterfly". The Hill. Archived from the original on October 1, 2021. Retrieved October 6, 2021. The Fish and Wildlife Service (FWS) determined that adding the butterfly to the list of threatened and endangered species was "warranted", but that it is unable to do so because it needs to devote its resources to higher-priority species. The FWS said that its "warranted-but-precluded" determination means that every year it will consider adding the butterfly to the list until it decides to propose listing it or determines that protections are not warranted.
"What is the fiscal year?". Xero Limited. 2024. Archived from the original on October 4, 2024. Retrieved January 16, 2025. Fiscal years are named using the year when the period ends. For example, the US federal government fiscal year starts on October 1, 2024 and ends on September 30, 2025; this is referred to as FY25.
U.S. Fish and Wildlife Service (June 27, 2023). "Endangered and Threatened Wildlife and Plants; Review of Species That Are Candidates for Listing as Endangered or Threatened; Annual Notification of Findings on Resubmitted Petitions; Annual Description of Progress on Listing Actions"(PDF). Federal Register. 88 (122): 41560–41580. Federal Register Document Number 2023-13577. Archived(PDF) from the original on June 27, 2023. Retrieved September 29, 2024.
Ibid., Monarch Butterfly, p. 41570.
↑Ibid., Previous CNORs, p. 41561. "We have been publishing CNORs since 1975. The most recent was published on May 3, 2022 (87 FR 26152). On September 21, 1983, we published guidance for assigning a listing priority number (LPN) for each candidate species (48 FR 43098). Using this guidance, we assign each candidate an LPN of 1 to 12, depending on the magnitude of threats, immediacy of threats, and taxonomic status; the lower the LPN, the higher the listing priority (that is, a species with an LPN of 1 would have the highest listing priority)."
↑U.S. Fish and Wildlife Service (December 12, 2024). "Endangered and Threatened Wildlife and Plants; Threatened Species Status With Section 4(D) Rule for Monarch Butterfly and Designation of Critical Habitat"(PDF). Federal Register. 89 (239): 100662–100716. Federal Register Document Number 2024-20855. Archived(PDF) from the original on December 26, 2024. Retrieved January 5, 2025.
↑U.S. Fish and Wildlife Service (March 19, 2025). "Endangered and Threatened Wildlife and Plants; Reopening Comment Periods for Three Proposed Rules; Announcement of a Public Hearing for One Proposed Rule"(PDF). Federal Register. 90 (52): 12694–12695. Federal Register Document Number 2025–04443. Archived(PDF) from the original on March 19, 2025. Retrieved May 12, 2025.
↑"Monarch". Government of Ontario. February 27, 2014. Archived from the original on September 12, 2015. Retrieved September 16, 2015.
↑"Monarchs now listed as an endangered species in Nova Scotia Canada - a prelude for things to come elsewhere". monarchscience. September 30, 2019. Retrieved December 12, 2019.
↑Crewe, Tara L.; Mitchell, Greg W.; Larrivée, Maxim (2019). "Size of the Canadian Breeding Population of Monarch Butterflies Is Driven by Factors Acting During Spring Migration and Recolonization". Frontiers in Ecology and Evolution. 7 308. Bibcode:2019FrEEv...7..308C. doi:10.3389/fevo.2019.00308. ISSN2296-701X.
↑Flockhart, D. T. Tyler; Larrivée, Maxim; Prudic, Kathleen L.; Norris, D. Ryan (June 21, 2019). "Estimating the annual distribution of monarch butterflies in Canada over 16 years using citizen science data". FACETS. 4 (1): 238–253. Bibcode:2019Facet...4..238T. doi:10.1139/facets-2018-0011. hdl:10150/633480.
↑Obama, President Barack (June 20, 2014). "Presidential Memorandum – Creating a Federal Strategy to Promote the Health of Honey Bees and Other Pollinators". Office of the Press Secretary. Washington, D.C.: The White House. Retrieved May 2, 2018.
"PBS-P100 Facilities Standards For The Public Buildings Service"(PDF). WBDG: Whole Building Design Guide. Washington, D.C.: National Institute of Building Sciences. March 1, 2015. p.12. Archived from the original(PDF) on January 8, 2024. Retrieved January 8, 2024. The P100 is a mandatory standard. It is not a guideline, textbook, handbook, training manual, or substitute for technical competence. The P100 represents the current state of practice in designing facilities to meet GSA's commitments, maximize the efficiency of business processes, and comply with the requirements of law.
"PBS-P100: Facilities Standards for the Public Buildings Service"(PDF). Landscape Requirements. Washington, D.C.: U.S. General Services Administration. March 1, 2015. pp.40–47. Archived from the original(PDF) on January 8, 2024. Retrieved January 8, 2024.
12Pollinator Health Task Force (May 19, 2015). "National Strategy to Promote the Health of Honey Bees and Other Pollinators"(PDF). Washington, D.C.: The White House. Retrieved May 2, 2018.
123EP News Wire Reports (May 19, 2015). "New U.S. pollinator strategy emphasizes science, industry collaboration". EPNewswire. Archived from the original on September 30, 2015. Retrieved January 5, 2024.
↑Pollinator Health Task Force (May 19, 2015). "Pollinator Research Action Plan"(PDF). Washington, D.C.: The White House. pp.1–3. Retrieved January 5, 2024.
↑"Pollinator-Friendly Best Management Practices for Federal Lands"(PDF). U.S. Department of Agriculture and U.S. Department of the Interior. May 11, 2015. pp.7 and 35. Archived(PDF) from the original on June 2, 2023. Retrieved March 8, 2024. (p. 35) Implementation: To determine those lands best suited for restoration and rehabilitation of monarch habitat, the following actions should be considered: • Ensure that native wildflowers are available, diverse, and abundant to provide nectar for monarchs. • Ensure that milkweed species (preferred by female monarchs for egg laying) are available; if not, implement a planting program for milkweeds: o In the Eastern United States, plant swamp milkweed, butterfly milkweed, and common milkweed. o In the Southern United States, plant butterfly milkweed, swamp milkweed, aquatic milkweed, white milkweed, pinewoods milkweed, and swamp milkweed. o In the Northern Great Plains, plant showy milkweed, common milkweed, plains milkweed, green comet milkweed, and whorled milkweed. o In the Southern Great Plains, plant showy milkweed, butterfly milkweed, whorled milkweed, swamp milkweed, spider milkweed, and green antelopehorn milkweed. o For the California population, plant California milkweed, heartleaf milkweed, woollypod milkweed, Mexican whorled milkweed, also known as narrowleaf milkweed and woolly milkweed. o For the intermountain west and desert southwest plant butterfly milkweed, cor kernel milkweed, spider milkweed and pine needle milkweed. o In the Pacific Northwest, consider using showy milkweed or narrowleaf milkweed. This article incorporates text from this source, which is in the public domain.
↑"Public Law 114–94: 114th Congress (129 Stat. 1312–1801)"(PDF). United States Government Publishing Office. Archived(PDF) from the original on June 25, 2021. Retrieved July 7, 2021.
"Sec. 1415. Administrative Provisions To Encourage Pollinator Habitat And Forage On Transportation Rights-Of-Way"(PDF). Public Law 114–94: 114th Congress (129 Stat. 1421). United States Government Publishing Office. Archived(PDF) from the original on June 25, 2021. Retrieved July 7, 2021.
"23 U.S. Code § 319 - Landscaping and scenic enhancement". Ithaca, New York: Cornell Law School: Legal Information Institute. Archived from the original on March 1, 2021. Retrieved July 7, 2021. (c) Encouragement of Pollinator Habitat and Forage Development and Protection on Transportation Rights-of-way.—In carrying out any program administered by Secretary under this title, the Secretary shall, in conjunction with willing States, as appropriate – (1) encourage integrated vegetation management practices on roadsides and other transportation rights-of-way, including reduced mowing; and (2) encourage the development of habitat and forage for Monarch butterflies, other native pollinators, and honey bees through plantings of native forbs and grasses, including noninvasive, native milkweed species that can serve as migratory way stations for butterflies and facilitate migrations of other pollinators.
↑"Attachment 1 - Strategy for Implementing Pollinator-Friendly Landscaping Design and Maintenance at Department of the Interior Sites"(PDF). Memorandum: Increasing and Improving Pollinator Habitat through Landscaping. Washington, D.C.: Office of the Secretary of the Interior. February 9, 2016. Archived from the original(PDF) on February 12, 2017. Retrieved March 8, 2024.
↑Pollinator Health Task Force (June 22, 2016). "Pollinator Partnership Action Plan"(PDF). Washington, D.C.: The White House. Retrieved January 5, 2024.
"Fact Sheet: The State Acres for Wildlife Enhancement (SAFE) Initiative"(PDF). Farm Service Agency: Conservation Reserve Program. United States Department of Agriculture: Farm Service Agency. December 2019. Archived from the original(PDF) on September 13, 2021. Retrieved October 6, 2021.
"Incentive Programs: Conservation Reserve Program (CRP): United States Department of Agriculture Farm Service Agency (FSA)". Monarch Conservation Toolbox. Montreal, Quebec, Canada: Commission for Environmental Cooperation. May 18, 2017. Archived from the original on January 15, 2020. Retrieved October 6, 2021.
↑Free, Stephanie (January 4, 2024). "Information Presentation: Pollinator Best Practices Resource Guide"(PDF). Washington, D.C.: National Capital Planning Commission. NCPC File Number 8510. Archived(PDF) from the original on February 4, 2025. Retrieved August 13, 2025. There are over 100 different species of milkweeds that are considered native to North America7, one of which stands out - Asclepias syriaca, or common milkweed. According to the U.S. Forest Service, Common milkweed is, "...among the most important food plants for Monarch caterpillars," and, "Nature's mega food market for insects. Over 450 insects are known to feed on some portion of the plant. Numerous insects are attracted to the nectar-laden flowers and it is not at all uncommon to see flies, beetles, ants, bees, wasps, and butterflies on the flowers at the same time." The Xerces Society has also identified Common milkweed as a priority species for habitat restoration efforts.8 Common milkweed also quickly spreads through rhizomatous roots and forms colonies which aids in its longevity. Therefore, common milkweed is clearly an important species that is critical to the survival of monarch butterflies.
Hopwood, Jennifer; Black, Scott; Fleury, Scott (December 2015). Pollinators and Roadsides: Best Management Practices for Managers and Decision Makers(PDF). Washington, D.C.: United States Department of Transportation; Federal Highway Administration. OCLC1252634388. FHWA-HEP-16-020. Archived(PDF) from the original on June 2, 2021. Retrieved July 9, 2021.
Hopwood, Jennifer; Black, Scott; Fleury, Scott (December 2015). Roadside Best Management Practices that Benefit Pollinators: Handbook for Supporting Pollinators through Roadside Maintenance and Landscape Design(PDF). Washington, D.C.: United States Department of Transportation; Federal Highway Administration. OCLC1252634401. FHWA-HEP-16-059. Archived(PDF) from the original on June 1, 2021.
Renkl, Margaret (September 16, 2019). "Tennessee Makes Way for Monarchs". The New York Times. Archived from the original on November 25, 2020. Retrieved July 7, 2021.
"Do I Need A Permit To Use Monarch Butterflies For Educational Purposes?". California Department of Fish and Wildlife. April 6, 2023. Archived from the original on May 23, 2025. Retrieved September 20, 2025. Q: Do I need a permit to use monarch butterflies for educational purposes? A: Yes, a Scientific Collecting Permit (SCP) is required to handle wild monarchs in California including for educational purposes. It is unlawful to collect, remove from the wild and/or captively rear monarchs in California without an SCP, per California Code of Regulations (CCR), Title 14, section 650(a)
"§ 650. Scientific Collecting Permits: Permits to Take or Possess Wildlife for Scientific, Educational, and/or Propagation Purposes. (a) General Provisions". Scientific Collecting Laws and Regulations. California Department of Fish and Wildlife. Archived from the original on June 18, 2025. Retrieved September 20, 2025. (a) General Provisions. Except as otherwise authorized by the Fish and Game Code or regulations adopted pursuant thereto, it shall be unlawful for any person or entity to take and/or possess live or dead wildlife, or parts thereof in any part of the State of California, for scientific, educational, and/or propagation purposes except as authorized by a permit issued by the department pursuant to this Section.
National Conference of State Legislatures (April 19, 2023). "Pollinator Health". Denver, Colorado, and Washington, D.C. Archived from the original on June 5, 2025. Retrieved August 31, 2025.
Blackledge, Steve; Kelly-Fischer, Patrick; Cummings, Deirdre (June 16, 2025). "A snapshot of state actions to protect pollinators: By limiting bee-killing neonics, conserving habitat and raising awareness, states are key actors in the campaign to protect pollinators". Denver, Colorado: Environment America. Archived from the original on June 25, 2025. Retrieved August 31, 2025.
↑Gerhard, Dale (September 14, 2014). "Dwindling monarch butterflies in Cape May County has legislators worried". The Press of Atlantic City. Linwood, New Jersey. Archived from the original on May 26, 2018.
↑"Integrated Roadside Vegetation Management Program". New Jersey Legislature. May 1, 2017. P.L.2017, Chapter 44. Archived from the original on December 1, 2024. Retrieved August 9, 2025.
"Adopt a Monarch Butterfly Waystation Act". New Jersey Legislature. January 8, 2018. P.L.2017, Chapter 250. Archived from the original on July 30, 2025. Retrieved July 30, 2025.
"Milkweed for Monarchs Act". New Jersey Legislature. January 8, 2018. P.L.2017, Chapter 252. Archived from the original on July 30, 2025. Retrieved July 30, 2025.
↑"Three Departments Partner on Pollinator Initiative in Tennessee State Parks: TDOT, TDEC, TDA benefit pollinators, spread awareness". Nashville, Tennessee: Tennessee Department of Transportation. June 18, 2019. Archived from the original on January 25, 2025.
Heiser, Carol A. (June 24, 2020). "Celebrate Pollinators!". Virginia Department of Wildlife Resources. Archived from the original on June 25, 2025. Retrieved August 13, 2025.
Ingram, Bruce (June 9, 2022). "Help the Bees, Butterflies, Bucks, and Bears: Create a Pollinator Plot". Virginia Department of Wildlife Resources. Archived from the original on June 27, 2025. Retrieved August 13, 2025.
↑"Project Monarch". Chicago, Illinois: Chicago Park District. 2025. Archived from the original on May 17, 2025. Retrieved August 13, 2025.
"Monarch City USA Members". Monarch City USA. Archived from the original on June 19, 2025. Retrieved August 13, 2025.
"Monarch Butterfly Recovery: City by City". Monarch City USA. 2014. Archived from the original on June 19, 2025. Retrieved July 29, 2025.
"Ways to help". Monarch City USA. Archived from the original on August 13, 2025. Retrieved August 13, 2025.
"Orange City recently named a Monarch City USA". South Daytona, Florida: Hometown News Volusia. July 25, 2019. Archived from the original on July 30, 2025. Retrieved July 30, 2025.
"Monarch City". Government of the City of Clemson, South Carolina. Archived from the original on March 29, 2025. Retrieved July 30, 2025.
"Signatories - Mayors' Monarch Pledge". Mayors' Monarch Pledge. Merrifield, Virginia: National Wildlife Federation. 2025. Archived from the original on August 13, 2025. Retrieved August 13, 2025.
"Mayors' Monarch Pledge Action Items"(PDF). Mayors' Monarch Pledge. Merrifield, Virginia: National Wildlife Federation. Archived(PDF) from the original on February 24, 2024. Retrieved August 13, 2025.
Garvey, Libby (June 21, 2016). "Monarch Pledge Day". Government of Arlington County, Virginia. Archived from the original on October 8, 2024. Retrieved July 29, 2025.
Adams, Ashley (August 3, 2023). "Pennsylvania's Conservation Heroes: 14 Municipalities Unite to Save the Monarch Butterfly: Municipalities across the commonwealth have pledged to create habitats and educate their communities to help save the monarch butterfly, which contributes to the health of the planet as a pollinator". The Keystone. Courier Newsroom. Archived from the original on June 7, 2025. Retrieved August 13, 2025.
"Mesa Mayor Mark Freeman Signs National Wildlife Federation's Monarch Pledge". MesaNow.org. Government of the City of Mesa, Arizona. March 19, 2025. Archived from the original on May 19, 2025. Retrieved July 30, 2025.
"About Bee City USA & Bee Campus USA". Bee City USA. Portland, Oregon: Xerces Society for Invertebrate Conservation. Archived from the original on September 21, 2025. Retrieved November 15, 2025. In 2018 Bee City USA and Bee Campus USA became initiatives of the Xerces Society for Invertebrate Conservation .... The steps that affiliates take to conserve our native bees, including creating safe habitats and hosting community events, will also help other pollinators including butterflies and moths as well as the non-native honey bee.
"Pacific Grove Municipal Code: Chapter 11.48: Monarch Butterflies". codepublishing.com. Archived from the original on January 13, 2026. Retrieved February 16, 2026. 11.48.010 Interference with prohibited. It is declared to be unlawful for any person to molest or interfere with, in any way, the peaceful occupancy of the monarch butterflies on their annual visit to the city of Pacific Grove, and during the entire time they remain within the corporate limits of the city, in whatever spot they may choose to stop in; provided, however, that if said butterflies should at any time swarm in, upon or near the private dwelling house or other buildings of a citizen of the city of Pacific Grove in such a way as to interfere with the occupancy and use of said dwelling and/or other buildings, that said butterflies may be removed, if possible, to another location upon the application of said citizen to the chief of police. [Ord. 210 N.S. § 8-3060, 1952].
"Monarch Grove Butterfly Sanctuary". Seemonterey.com. Archived from the original on February 2, 2024. Retrieved February 15, 2026. Touching or interfering with a butterfly in any way is illegal in Pacific Grove–the fine is $1000.
"Monarch Grove Sanctuary". Pacific Grove, California: City of Pacific Grove. Archived from the original on January 13, 2026. Retrieved February 16, 2026. The Pacific Grove Police Department enforces strict regulations that prohibit the "molestation of butterflies." The fine? $1,000.
Cariveau, Alison B.; Caldwell, Wendy; Lonsdorf, Eric; Nootenboom, Chris; Tuerk, Karen; Snell-Rood, Emilie; Anderson, Eric; Baum, Kristen A.; Hopwood, Jennifer; Oberhauser, Karen (2020). Evaluating the Suitability of Roadway Corridors for Use by Monarch Butterflies. Washington, D.C.: National Academies Press. Bibcode:2020nap..book25693N. doi:10.17226/25693. ISBN978-0-309-48132-8. LCCN2020935714. OCLC1229163481. S2CID218854539. National Cooperative Highway Research Program (NCHRP) Research Report 942. Archived from the original on July 29, 2020. Retrieved July 8, 2021.
Cariveau, A.B.; Caldwell, W.; Lonsdorf, E.; Nootenboom, C.; Tuerk, K.; Snell-Rood, E.; Anderson, E.; Baum, K. A.; Hopwood, J.; Oberhauser, K. (2019). "Evaluating the Suitability of Roadway Corridors for Use by Monarch Butterflies"(PDF). Washington, D.C.: Transportation Research Board. OCLC1152199695. Pre-publication draft of NCHRP Research Report 942. Archived(PDF) from the original on July 8, 2021. Retrieved July 8, 2021– via Northwestern University Library.
↑Davis, Andrew K.; Schroeder, Hayley; Yeager, Ian; Pearce, Jana (May 31, 2018). "Effects of simulated highway noise on heart rates of larval monarch butterflies, Danaus plexippus: implications for roadside habitat suitability". Biology Letters. 14 (5) 20180018. doi:10.1098/rsbl.2018.0018. PMC6012697. PMID29743264.
12Cariveau, A. B.; Caldwell, W.; Lonsdorf, E.; Nootenboom, C.; Tuerk, K.; Snell-Rood, E.; Anderson, E.; Baum, K. A.; Hopwood, J.; Oberhauser, K. (2019). "Evaluating the Suitability of Roadway Corridors for Use by Monarch Butterflies"(PDF). Washington, D.C.: Transportation Research Board. pp.2–3. OCLC1152199695. Pre-publication draft of NCHRP Research Report 942. Archived(PDF) from the original on July 8, 2021. Retrieved July 8, 2021– via Northwestern University Library.
Glassberg, J. (1995). Enjoying Butterflies More: Attract Butterflies to Your Backyard. Marietta, Ohio: Bird Watcher's Digest Press. ISBN1-880241-08-0. LCCN96202681. OCLC35808599. Retrieved March 9, 2020– via Google Books.
"Butterfly Gardening: Introduction". University of Kansas: Monarch Watch. Archived from the original on February 2, 2020. Retrieved March 9, 2020.
"Monarch Garden Plants"(PDF). San Francisco, California: Pollinator Partnership. Archived from the original(PDF) on March 9, 2020. Retrieved March 9, 2020.
"Monarch Waystation Program". University of Kansas: Monarch Watch. Archived from the original on June 2, 2017. Retrieved June 5, 2017.
Abugattas, Alonzo (January 3, 2017). "Monarch Way Stations". Archived from the original on June 5, 2017. Retrieved June 5, 2017– via Blogger.
"Plants for Butterfly and Pollinator Gardens: Native and Non-native Plants Suitable for Gardens in the Northeastern United States"(PDF). Monarch Watch. Archived(PDF) from the original on August 9, 2020. Retrieved October 18, 2020.
Borders, Brianna; Lee–Mäder, Eric (2014). "Milkweed Propagation and Seed Production"(PDF). Milkweeds: A Conservation Practitioner's Guide: Plant Ecology, Seed Production Methods, and Habitat Restoration Opportunities. Portland, Oregon: The Xerces Society for Invertebrate Conservation. pp.21–95. Archived(PDF) from the original on July 4, 2021. Retrieved July 12, 2021.
Landis, Thomas D.; Dumroese, R. Kasten (2015). "Propagating Native Milkweeds for Restoring Monarch Butterfly Habitat: Propagating Native Milkweeds: Seed Propagation"(PDF). International Plant Propagators' Society, Combined Proceedings (2014). 64: 302. Archived(PDF) from the original on February 24, 2025. Retrieved July 27, 2025– via United States Department of Agriculture: United States Forest Service. Any of the standard seed propagation methods (Landis et al., 1999) are effective with milkweed. Direct sowing of non-stratified seeds during the fall followed by exposure to ambient winter conditions can be effective, but the seeds must be mulched and protected. Cover sown seeds with a thin mulch; research has found that common milkweed seeds germinate better when planted 1 to 2 cm (0.4 to 0.8 in.) deep than when at the soil surface (Jeffery and Robison, 1971).
12"Asclepias syriaca, (Common Milkweed)". Bring Back The Monarchs. Monarch Watch. Archived from the original on December 8, 2023. Retrieved March 10, 2024.
↑United States Department of Agriculture (January 2017). "Maryland Conservation Planting Guide"(PDF). Mix 16: High Diversity Native Grass/Forb Mix for Mesic Sites. p.25. Archived(PDF) from the original on February 8, 2025. Retrieved August 2, 2025. This mix has a predominant wildflower component for optimum wildlife and pollinator habitat.
Cariveau, Alison B.; Caldwell, Wendy; Lonsdorf, Eric; Nootenboom, Chris; Tuerk, Karen; Snell-Rood, Emilie; Anderson, Eric; Baum, Kristen A.; Hopwood, Jennifer; Oberhauser, Karen (2020). Evaluating the Suitability of Roadway Corridors for Use by Monarch Butterflies. Washington, D.C.: National Academies Press. pp.79–80. Bibcode:2020nap..book25693N. doi:10.17226/25693. ISBN978-0-309-48132-8. LCCN2020935714. OCLC1229163481. S2CID218854539. National Cooperative Highway Research Program (NCHRP) Research Report 942. Archived from the original on July 29, 2020. Retrieved July 8, 2021. Could roadside mowing stimulate milkweed growth and support monarch breeding? Limited research in eastern North America has shown that spring or summer mowing can promote new growth and extend the availability of milkweed plants for monarch breeding. Mowing may stimulate the growth of some milkweed species, particularly those that spread through rhizomes like common milkweed (A. syriaca) and showy milkweed (A. speciosa). Summer (June or July) mowing in Michigan resulted in more monarch eggs on regenerated stems than on unmowed stems. Summer (July) mowing and burning can increase green antelopehorn milkweed (A. viridis) availability in the late summer and early fall in the Southern Great Plains, whereas in areas without mowing, the milkweed has senesced by August. In the West, showy milkweed will regrow after summer mowing and continue to support monarch breeding (Stephanie McKnight, personal observation). However, more research is needed in other areas to determine the optimal timing and frequency of mowing that promotes not only milkweed but also nectar plants. It is also unknown if the benefit of additional milkweed availability in the fall outweighs the costs of the larval mortality caused by summer mowing. The benefits are likely greater in areas that primarily have breeding monarchs in the spring and fall and where the dominant species of milkweed spread by rhizomes. Sources: Alcock et al. 2016; Baum and Mueller, 2015; Bhowick 1994; Haan and Landis 2019; Fischer et al. 2015
Higgins, Adrian (May 27, 2015). "A gardener's guide to saving the monarch". Home & Garden. The Washington Post. Archived from the original on May 31, 2015. Retrieved October 17, 2020. 'The monarch doesn't care where the milkweed grows, and putting it in residential neighborhoods makes perfect sense,' said Doug Tallamy, an entomologist at the University of Delaware, author and expert on wildlife habitat gardens.... The Smithsonian Institution's Butterfly Habitat Garden... and the Ripley Garden... are both good places to see milkweed integrated into a garden setting. At the butterfly garden, you can see the common milkweed... now looking pretty good in fresh, unblemished clumps. By late summer, it looks tall, tired, and tough. Tallamy says if you grow it, you should cut it back at least by half in June to produce soft foliage in late summer that will be more munchable for the caterpillars. If you do that, make sure there are no larvae on the plant before you chop it.
Abugattas, Alonzo (January 3, 2017). "Monarch Way Stations". Capital Naturalist. Archived from the original on March 8, 2021. Retrieved July 5, 2021– via Blogger. Virginia is blessed for instance with 13 native Asclepias species plus 4 climbing vines that Monarch caterpillars can feed on. For the best results, cut some of the stems back in late summer after they've bloomed. Fall is when we get the most Monarchs laying eggs on our milkweeds. Since the mother butterflies prefer young, more tender growth, you can provide this by timing your pruning so there are new leaves by September or so for the arriving Monarchs. Just make sure to leave a few to produce pods for seeds. The local monarch favorite is Common Milkweed (A. syriaca)
Gomez, Tony. "Asclepias syriaca: Common Milkweed for Monarch Caterpillars". Monarch Butterfly Garden. MonarchButterflyGarden.net. Archived from the original on March 16, 2015. Retrieved October 17, 2010. Cut- At midseason after the blooms have faded, cut some common plants back by about a third. This promotes fresh plant growth and could get you an extra generation of monarchs on the fresh new leaves. Leave some plants uncut if you want to harvest milkweed seeds in fall.
Borders, Brianna; Lee–Mäder, Eric (2014). "Milkweed Propagation and Seed Production: Stratification"(PDF). Milkweeds: A Conservation Practitioner's Guide: Plant Ecology, Seed Production Methods, and Habitat Restoration Opportunities. Portland, Oregon: The Xerces Society for Invertebrate Conservation. pp.28–29. Archived(PDF) from the original on July 4, 2021. Retrieved July 12, 2021.
Landis, Thomas D.; Dumroese, R. Kasten (2015). "Propagating Native Milkweeds for Restoring Monarch Butterfly Habitat: Propagating Native Milkweeds: Seed Propagation"(PDF). International Plant Propagators' Society, Combined Proceedings (2014). 64: 302. Archived(PDF) from the original on February 24, 2025. Retrieved July 27, 2025– via United States Department of Agriculture: United States Forest Service. Many sources of milkweed seeds require stratification (cold, moist treatment) before sowing. In a review of stratification requirements for common milkweed, recommendations varied from as short as 7 days to as long as 11 months at 5°C (41°F) (Luna and Dumroese, 2013). Butterfly milkweed (A. tuberosa) germination increased from 29 to 48 to 62% as stratification duration increased from 0 to 30 to 60 days, respectively (Bir, 1986). ..... Any of the standard seed propagation methods (Landis et al., 1999) are effective with milkweed. Direct sowing of non-stratified seeds during the fall followed by exposure to ambient winter conditions can be effective, but the seeds must be mulched and protected. Cover sown seeds with a thin mulch; research has found that common milkweed seeds germinate better when planted 1 to 2 cm (0.4 to 0.8 in.) deep than when at the soil surface (Jeffery and Robison, 1971).
Maeckle, Monika (March 13, 2013). "How to Get Texas Native Milkweed Seeds to Germinate". Texas Butterfly Ranch. Archived from the original on November 10, 2025. Retrieved February 7, 2026.
"Seed Germination". New Braunfels, Texas: Native American Seed. 2026. Archived from the original on December 4, 2025. Retrieved February 7, 2026.
Higgins, Adrian (May 27, 2015). "7 milkweed varieties and where to find them". Home & Garden. The Washington Post. Archived from the original on September 26, 2020. Retrieved October 17, 2020. Seed may be stubborn to germinate and may need a period of cold treatment.
Gomez, Tony. "Asclepias syriaca: Common Milkweed for Monarch Caterpillars". Monarch Butterfly Garden. MonarchButterflyGarden.net. Archived from the original on March 16, 2015. Retrieved October 17, 2010. Start seeds indoors 2 months before final frost- seeds must be cold stratified.
Stevens, Michelle. "Plant guide for common milkweed (Asclepias syriaca)"(PDF). United States Department of Agriculture: Natural Resources Conservation Service: National Plant Data Center. Archived(PDF) from the original on July 5, 2021. Retrieved July 5, 2021. If planting in flats or in a greenhouse, common milkweed seeds should be cold-treated for three months.
"Asclepias syriaca". Butterfly gardening & all things milkweed. Archived from the original on July 7, 2015. Retrieved July 7, 2015. germination: seed requires cold moist period.
Mader, Eric; Shepherd, Mathew; Vaughan, Mace; Black, Scott Hoffman; LeBuhn, Gretchen (2011). "Establishing Pollinator Habitat from Seed: Sowing Seed". Attracting Native Pollinators: Protecting North America's Bees and Butterflies: The Xerces Society guide. North Adams, Massachusetts: Storey Publishing. pp.113–114. ISBN978-1-60342-747-0. LCCN2010043054. OCLC776997073. Retrieved July 7, 2021– via Internet Archive.
Landis, Thomas D.; Dumroese, R. Kasten (2015). "Propagating Native Milkweeds for Restoring Monarch Butterfly Habitat: Propagating Native Milkweeds: Seed Propagation"(PDF). International Plant Propagators' Society, Combined Proceedings (2014). 64: 302. Archived(PDF) from the original on February 24, 2025. Retrieved July 27, 2025– via United States Department of Agriculture: United States Forest Service. Any of the standard seed propagation methods (Landis et al., 1999) are effective with milkweed. Direct sowing of non-stratified seeds during the fall followed by exposure to ambient winter conditions can be effective, but the seeds must be mulched and protected. Cover sown seeds with a thin mulch; research has found that common milkweed seeds germinate better when planted 1 to 2 cm (0.4 to 0.8 in.) deep than when at the soil surface (Jeffery and Robison, 1971).
↑Butterfly Society of Virginia (2019). "Growing Milkweed". Archived from the original on June 24, 2019. Retrieved December 25, 2023. I've grown butterfly weed, swamp milkweed, Asclepias currassavica (bloodflower), Asclepias syriaca (common milkweed), and Asclepias verticillata (whorled milkweed). I've found that butterfly weed is the least favorite of my Monarch guests in my Virginia Beach garden for laying eggs (perhaps the leaves are tougher?)
12Gomez, Tony. "Asclepias tuberosa: Butterfly Weed for Monarchs and More". Monarch Butterfly Garden. MonarchButterflyGarden.net. Archived from the original on July 29, 2016. Retrieved October 17, 2010. Rough leaves for monarch caterpillars, not typically a heavily used host plant.
↑Pocius, Victoria M.; Debinski, Diane M.; Pleasants, John M.; Bidne, Keith G.; Hellmich, Richard L. (January 8, 2018). "Monarch butterflies do not place all of their eggs in one basket: oviposition on nine Midwestern milkweed species". Ecosphere. 9 (1) e02064. Ecological Society of America: 1–13. Bibcode:2018Ecosp...9E2064P. doi:10.1002/ecs2.2064. Additionally, A. tuberosa has a layer of trichomes, which may inhibit oviposition or decrease a female's ability to sense leaf chemicals.
Pocius, Victoria M.; Debinski, Diane M.; Pleasants, John M.; Bidne, Keith G.; Hellmich, Richard L. (January 8, 2018). "Monarch butterflies do not place all of their eggs in one basket: oviposition on nine Midwestern milkweed species". Ecosphere. 9 (1) e02064. Ecological Society of America: 1–13. Bibcode:2018Ecosp...9E2064P. doi:10.1002/ecs2.2064. In our study, the least preferred milkweed species A. tuberosa (no choice; Fig. 2) and A. verticillata (choice; Fig. 3A) both have low cardenolide levels recorded in the literature (Roeske et al., Agrawal et al., Rasmann and Agrawal)
Abugattas, Alonzo (January 3, 2017). "Monarch Way Stations". Capital Naturalist. Archived from the original on March 8, 2021. Retrieved July 5, 2021– via Blogger. If you have hot, dry conditions, then try Butterflyweed (A. tuberosa).... It is the least favored by monarch caterpillars though because it has very little toxin (cardiac glycosides) in its leaves.
↑Pocius, Victoria M.; Debinski, Diane M.; Pleasants, John M.; Bidne, Keith G.; Hellmich, Richard L. (January 8, 2018). "Monarch butterflies do not place all of their eggs in one basket: oviposition on nine Midwestern milkweed species". Ecosphere. 9 (1) e02064. Ecological Society of America: 1–13. Bibcode:2018Ecosp...9E2064P. doi:10.1002/ecs2.2064. In no-choice tests, we saw the highest egg counts on Asclepias incarnata followed by Asclepias sullivantii and Asclepias syriaca (Fig. 2). In preference tests, over half of all eggs laid were on A. incarnata (Fig. 3).
12"Asclepias incarnata". Bring Back The Monarchs. Monarch Watch. Archived from the original on June 12, 2021. Retrieved July 5, 2021. Life span: In gardens most plants live two-five years but known to survive up to 20 years.... Propagation: Slow to spread via seeds.... Overhead Conditions: Not shade tolerant. An early successional plant that tends to grow at the margins of wetlands and in seasonally flooded areas. It is not a good vegetative competitor and tends to disappear as vegetative density increases and habitats dry out.
External links
Australian Museum fact sheet on monarch butterflies
Mission Monarch (Canada)
Monarch butterfly metamorphosis: time-lapse video (2:42 minutes)
Monarch butterfly on the UF / IFAS Featured Creatures website
Monarch Joint Venture – Partnering Across the U.S. to Conserve the Monarch Butterfly Migration
Monarch migration maps
Monarch Watch
PBS Nova documentary "The Incredible Journey of the Butterflies"