Red Admiral Butterfly

Red Admiral Butterfly

American Lady Butterfly

American Lady Butterfly

Painted Lady Butterfly

Painted Lady Butterfly

West Cost Lady Butterfly

West Coast Lady Butterfly

This is a web site to coordinate observations of territorial behavior, migration, life history, population studies, seasonal variations in abundance and body size, and number of broods per year (voltinism) of butterflies in the genus Vanessa, including Vanessa atalanta, V. cardui, V. virginiensis, V. annabella, V. tameamea, and V. kershawi. (Red Admiral, Painted Lady, American Lady, West Coast Lady, Kamehameha Butterfly, and Australian Painted Lady).

Although the lady butterflies of the genus Vanessa are not as familiar or as well-studied as the Monarch (Danaus plexippus), their behavior and migration are likewise well worth observing. Much remains to be discovered about their habits and how their behavior and seasonal distribution varies by geographic location. Observers and experimenters ranging from casual to serious can discover new and valuable information about these butterflies. The list above links to more detailed information, including summaries of published findings and methods for observing these fascinating butterflies.


Royce J. Bitzer, Ph.D., Department of Entomology, Room 10 Genetics Laboratory, 2333 Pammel Drive, Iowa State University, Ames, Iowa 50011, U.S.A.
Phone: (515) 451-9057   e-mail: mariposa@iastate.edu

This site was most recently updated on July 5, 2019.

Recent News

July 5, 2019

Large numbers of Painted Ladies have been emerging in central and western Iowa and in the Omaha, Nebraska area (and most likely elsewhere in Iowa and the upper Midwest).  In central Iowa, the numbers of adult butterflies were relatively low up to and on June 27.  However, large numbers of mature 5th-instar larvae were observed feeding on thistles near Dawson, Iowa on June 17, and larvae were also reaching pest levels in some Iowa soybean fields - suggesting a huge irruption was about to occur.  Then, beginning on June 29, the next generation suddenly emerged in huge swarms, with hundreds along a typical mile of Iowa roadside.    Painted Ladies had not yet emerged in northeast Iowa as of July 3, but larvae were present. suggesting that the irruption there is just a matter of time, and is likely to be accompanied by other butterflies arriving from more southerly regions.

These are the abundant offspring of a previous generation of butterflies that arrived in Iowa this spring from the western U.S., perhaps from regions such as Colorado or New Mexico, where large outbreaks had occurred from early April to mid-May.  The butterflies emerging now are perhaps the fourth or fifth generation since the first ones appeared in the southwestern U.S. and northwestern Mexico late last winter. 

April 30, 2019

Red Admirals continue to become more abundant in the upper Midwest and southern Ontario, despite several intervening interludes of cold weather. They migrated in on days when warmer, moister air was flowing up from the south. The first of two migration waves occurred on April 15-16, resulting in an abrupt increase in both butterflies and observers noticing them for the first time this year. Locally, I observed Red Admirals flying consistently northward on the 16th, as well as a threefold increase of Red Admirals in territories late that afternoon, as compared with a previous survey a week earlier. After a cooler period, a second and perhaps larger wave arrived in various parts of the Midwest from April 21 -24, again resulting in a further increase in the local population. Observers in Minneapolis, southern Wisconsin, southern Michigan, and southern Ontario reported large increases in Red Admirals, and some substantial northward migrations occurred in southern Ontario, raising the question of whether Red Admirals were actually crossing Lakes Erie and Ontario.

A subsequent period of cooler weather has quieted their activity recently, with far fewer seen during a local survey on April 29th than during a previous one on April 23. Whether this is due to the butterflies sheltering from the cool weather or to an actual decrease in numbers remains to be seen.

-- Royce Bitzer, April 30, 2019

April 30, 2019

There was an extensive northward migration of Painted Ladies in southern Oregon from at least between April 21 to April 25, 2019.  Three different observers recorded migration rates ranging from between 68 northward in 2 hours on April 23 to 300 northwestward in 15 minutes on April 25.  These butterflies are likely part of a second generation that originated farther south somewhere in California.  From other reports I've received, conditions in California and southern Nevada have been so favorable that two generations of Painted Ladies grew and thrived there on an abundance of nectar and larval food plants.

-- Royce Bitzer, April 30, 2019

April 11, 2019

As I was writing here last month, I’ve been following the enormous Painted Lady migration that’s been happening in California and the Southwest since late January to early February.  While this migration continues northward, it’s now also time to turn more attention eastward as wind and weather patterns have become favorable for Red Admirals and American Ladies to migrate northward into the upper Midwest,  the eastern states, and southern Ontario.  Painted Ladies may be arriving in our area somewhat later this spring, perhaps from the west, or perhaps from a smaller population that overwintered in Texas.

Red Admirals have arrived in the upper Midwest, and are already here in Iowa – they seem to have come with the warm southerly wind last Saturday, April 6, resulting in sightings in central Iowa's Story and Boone Counties on that day.  They were also spotted in Omaha, Nebraska on April 2, and in Kansas City, Missouri on April 5.  Chip Taylor, the director of Monarch Watch, spotted his first two in Lawrence, Kansas on April 6th, while suggesting that Red Admirals could have arrived there a few days earlier.  A first-of-the-season Red Admiral was also seen on April 8 in Kingsville, Ontario, near Point Pelee National Park.

Since yesterday, it's likely that any further northward Red Admiral movement will be literally stopped cold (at least temporarily) by an enormous low-pressure system passing through the northern Great Plains, Minnesota, and Wisconsin.  This storm has brought us two days of high winds in central Iowa, and heavy snow in states to our north.  To our south, temperatures were in the 60s F in southern Iowa and in the low 80s in Kansas.  Under these conditions, any additional Red Admirals arriving from farther south might stop migrating and accumulate in these areas, resulting in a sudden increase in the number present.

-- Royce Bitzer, April 11, 2019

March 19, 2019

Painted and West Coast Ladies are not the only butterflies in the western United States to be undergoing an outbreak. California Tortoiseshells have also been present to abundant in some places in northern California and Oregon where Painted Ladies probably have not yet arrived in any large numbers.  They look like this: https://bugguide.net/node/view/1447798.  While they are interesting butterflies in their own right, and worthy of further study, they are not Painted Ladies, so please be careful not to confuse the two when reporting Painted Lady sightings.  Also, according to a March 18 posting on DesertLeps, California Tortoiseshells have also become abundant in the area of southern California around the Santa Rosa and San Jacinto Mountains National Monument, replacing the Painted Ladies, which are surprisingly not that common there now and seem to have mostly departed the area.  However, Painted Ladies were still abundant in southern California on March 16 near the Mescal Range in San Bernardino County, CA, about 138 miles (222 km) to the north-northeast; no California Tortoiseshells were observed there. 

-- Royce Bitzer, March 19, 2019