(Danaus plexippus)

With its distinct orange and black coloration and its long-distance flight, the monarch (Danaus plexippus) is an iconic butterfly species native to most of North America. Weighing less than a paperclip, a single butterfly can travel up to 3000 miles.

Perhaps the most interesting aspect of the monarch is its migration. In the Northeast, monarchs in southeastern Canada begin to migrate south in early fall (September and October). Many of these individuals will fly all the way to central Mexico where they overwinter in a single mountain forest in central Mexico. During this time, the monarchs will gather in oyamel fir trees.

In February and March, the overwintering monarchs will begin their journey north and east, laying eggs on milkweed as they go. The eggs that hatch into larvae are the next generation. The young caterpillars feed upon milkweed, becoming distasteful to predators in the process. Milkweed sap contains cardiac glycosides which both the caterpillars and adults sequester in their bodies as a defense against hungry predators. After pupating and emerging as new adults, these butterflies will continue the push north. Several more generations will follow, all continuing the journey north, until the last generation reaches Canada and continues the cycle all over again.

The bright orange coloring of monarchs makes them distinctive, both to people and to potential predators, as it serves as a warning to predators that they are toxic. In fact, other insects that have adapted to feeding on milkweed are also brightly colored, including milkweed bugs, milkweed beetles, and milkweed tussock moth caterpillars. Viceroy butterflies do not use milkweed as a caterpillar host plant but can look similar to monarchs. To tell the difference between monarchs and viceroys, look at the lower wings. If the lower wings have a black bar going across them, it is a viceroy. It’s important to note that male monarch butterflies will have a black spot on their hind wings (see photo below).

Conservation
It’s easy to help monarchs by supporting their life cycle needs. Did you know? Monarchs in Maryland need late season nectar resources the most! To help monarchs, follow these steps:

• Limit or eliminate pesticide use
• Plant nectar sources for adult butterflies
• Plant milkweed for caterpillars- common, swamp, and butterflyweed are best! Check out the Xerces Society Milkweed Seed Finder
• Reconsider purchasing and releasing monarchs​ (Xerces Society)
• Alternatives to Raising and Releasing Wildlife for Education
  
• Contribute to monarch research (see below)
• Educate others (see below)

For additional information, check out the Monarch Joint Venture.

Community Science
Help monarchs by reporting sightings and assisting with tagging studies. Check out the links below for more information:

• Journey North- report monarch sightings and track migration
• Monarch Larva Monitoring Project- monitor milkweed and monarch use
• Monarch Watch- consider creating a waystation, tagging monarchs, and more!

Education

• Great Monarch Migration Activity
• Monarch Lifecycle Activity
• Monarch Mission PreK-5th NGSS Curriculum
• La Misión Mariposa Monarca
• Teaching about the Magnificent Monarch: Resource Recommendations

For more information, please contact:

Maryland Department of Natural Resources
Wildlife and Heritage Service
Tawes State Office Building, E-1
Annapolis MD 21401
410-260-8540

Toll-free in Maryland: 1-877-620-8DNR
customerservice.dnr@maryland.gov