By Gail Morris

September 18, 2019

Adult monarchs continue to appear in home gardens and public lands in the Western United States as they begin their fall migration. There are surprising numbers of reports of monarch eggs, larvae and pupae as well. Many people wonder why this is happening so late in the season. Will they will complete their life-cycle before winter arrives? An early dusting of snow in the higher elevations of Utah this week is fueling monarch watchers’ worries.

Despite the abundant numbers of monarchs reported this season in the Eastern range of monarchs, sightings in the West are still scarce in the northern states. But everyone is excited to see them when they appear! Jerry spotted his first monarch in Jerome, Idaho, on September 13 while Chrissy saw a monarch on her butterfly bush in Santa Rosa, California the same day. Anne in Richmond, California, reported five monarchs in her garden on September 15.

Kim lives in Durham, California. This time of year, a few monarchs appear to visit her pollinator garden and then are gone.

“They just pass through every few days.”

But Diane in Spanish Fork, Utah, had a different experience on September 6.

“I observed 6 Adult Monarch Butterflies and 2 caterpillars.”

Other Citizen Scientists in Utah, Nevada and Arizona were also reporting larvae and pupae as well.

Why do you think there are still monarch larvae and pupae appearing across the West? Do you think they will still migrate? The first cool weather front swept through the region this week. What effect do you think the cooler weather will have on the immatures still on milkweed in the fields?

You can help us all learn more about the Fall migration in the West as it unfolds. Be sure to report every monarch sighting so we can all learn more about monarchs in the West.

Look at our Journey North Maps for ways you can report sightings:

• Adult Monarchs
• Monarch egg
• Monarch Fall Roost
• Monarch larva
• Monarch Peak Migration
• Monarch Captive-reared

Gail Morris is the Coordinator of the Southwest Monarch Study (www.swmonarchs.org), a Monarch Watch Conservation Specialist, and the Vice President of the Monarch Butterfly Fund and the Central Arizona Butterfly Association. The Western Monarch Population News is based on comments provided to Gail Morris. We hope to increase the number of sightings and therefore photos and comments entered into the Journey North database. We rely on the volunteers who communicate regularly with Gail and who agree to participate in our effort to increase awareness of the population of western Monarchs.