Phenology: The Other Orange Butterflies

This summer I wrote several anonymous articles about monarch butterflies, Danaus plexippus, and some other species of butterflies. There’s a reason why those articles are anonymous. They are not examples of great nature writing in the usual sense. They are examples of one genre of Search Engine Optimization: writing readable, only slightly strange, sentences around the maximum possible number of phrases that search engines use to select the first articles they recommend in response to specific search terms. If the article is about monarch butterflies it needs to mention “monarch butterfly migration,” “monarch butterfly eggs,” and so on down a list, to persuade the computer that it is the article that people looking for information about monarch butterflies want to read. Well, writing this way is an honest living, and educational.

During the writing process, a revolution took place in the way we think about butterflies. That revolution was a fascinating bit of cultural history.

It started when a clueless Californian posted pictures of what person thought were monarch butterflies. They weren’t.

“Those are Painted Ladies,” commenters agreed.

“But they migrate in masses just as Monarchs are supposed to do,” the Californian insisted, and some entomologists at universities in the Western States checked this claim and found it true.

Monarch butterflies are the world’s undisputed champions of dramatic annual migrations. Though only about one-quarter of all Monarchs actually do it, these butterflies flap leisurely, in great flocks that probably get some lift from the air currents generated by each other’s flapping, all the way across the Gulf of Mexico every year, in the autumn, and then again in early spring. They spend the winter hibernating on fir trees in Mexico. Most years, a Monarch who flew to Mexico just after emerging from her chrysalis, spent most of the time between November and February sleeping, and was able to digest some flower nectar along her way, will make it to the Cat Sanctuary and flap around laying her eggs on milkweed sprouts in March. The odds are against those eggs hatching, but a few do.

Monarchs are “sole rulers” of the fields where they flap and graze, although you might occasionally get to watch a courting couple flying together, racing and chasing and play-fighting before they mate. There is a reason for this. While a male Monarch might choose to travel shorter distances and romp with more females, the female Monarch instinctively knows that each of her eggs needs to be placed on a separate milkweed sprout so that each caterpillar can spend its whole juvenile life eating milkweed leaves without damaging the plant.  And she may lay anywhere from two to eleven hundred eggs. (She will lay her eggs over the course of a month or two, and the caterpillars that hatch will probably have paternal DNA from two or more different males.) So, although hibernating and Gulf-crossing individuals appreciate the safety of numbers, once they start breeding Monarchs like to spread themselves as far apart as possible. If an egg laid in March hatches into a female caterpillar, and that caterpillar isn’t killed by a late frost and becomes a butterfly in May, she won’t want to find a mate and lay more eggs at the Cat Sanctuary. She’ll head north in search of milkweed plants that sprouted later and have not yet been used by Monarch caterpillars. She’ll travel through Pennsylvania, New York, maybe up into Canada by June. 

Some years, like this year, I do see “our” Monarch of the season laying her eggs in May, which means that cold weather interfered with her mother’s generation getting here in March. Butterflies can smell where other butterflies of their kind have been, and female Monarchs won’t lay eggs on recently used plants if they can help it. 

So you rarely see more than one or two Monarchs in a season. Allowing for some overlap there are basically four generations of this species every year, and each generation can be said to migrate, following the weather and the milkweed plants’ growth cycle, making a four-generation cycle between Mexico and Canada. For people who recognize them, this butterfly species creates emotional drama all across the continent. All people of good will love them and are glad to see them.

So, if the summertime Monarchs, who don’t cross the Gulf and hibernate, can still be said to be part of a multigenerational migration cycle, can’t the same be said for the less melodramatic butterflies who merely “migrate” to warmer and cooler places during the summer?

Why, yes, of course it can. In California the Monarchs don’t cross the Gulf of Mexico; they do migrate toward western Canada in spring, back to southern California in the fall, and masses of them migrate in eucalyptus groves on the Southern California coast. Smaller butterflies, like those Painted Ladies, don’t hibernate but some of them do migrate in considerable numbers. Places like Sacramento, which are far enough north of the Monarchs’ hibernation sites that people there see only one or two Monarchs in a season, can indeed celebrate the Return of the Painted Ladies, when flocks of pretty little orange butterflies flutter through town at about the same time each year. People who pay attention will probably be able to identify multi-generation migration patterns for other species in the next few years.

Americans tend to like whimsical, picturesque names for butterflies, like Painted Ladies and Mourning Cloaks. British butterfly watchers call the latter species Camberwell Beauties, celebrating a year when several of them stayed in Camberwell, though they’ve not stayed there every year since; and Europeans call the former species Cosmopolitans, because either Vanessa cardui or a closely related, very similar-looking species is found in almost every temperate part of the world. (Some people, especially in places like Virginia where we see both V. cardui and V. virginiensis, call this whole group Vanessas. The genus Vanessa includes some species that look different from V. cardui as well as some species that only experts using microscopes can sort out.)

In addition to the orange species in the genus Vanessa, in Virginia we also see orange or partly orange butterflies known as Checkerspots (including Maryland’s rare iconic species, the Baltimore Checkerspots, whose black, vermilion, and white wings display what Marylanders call the Baltimore colors), Anglewings, Fritillaries, Coppers, Buckeyes, Commas, Question Marks, Metalmarks, and also the Silver-Spotted Skippers. While many orange butterflies are primarily pollinators who live on flower nectar, Silver-Spotted Skippers are primarily composters who fly up to warn us if we might be about to step into wet mud or nastier stuff.

We don’t see most of these butterflies every single year. Baltimore Checkerspots have probably always been rare. Not actually looking for them, but only noticing them because their Baltimore colors are so conspicuous, I’ve seen this species only once, in Virginia, in my lifetime. The ones I saw were caterpillars, bright red-orange caterpillars with black bristles, not at all camouflaged on a weed they were devouring beside a creek, depending for survival on a strategy of trying to look like baby stingingworms. (Baby stingingworms are also red-orange with black stinging hairs, and travel in groups, at the tops of oak trees.) Since their bristles don’t sting and they’re not all that poisonous to the birds that eat them, their survival strategy has probably never been enough to allow very many of this species to survive. The butterflies are distinctive, though, and pretty.

I’ve noticed several butterflies this year. After several years of germ warfare against the dreaded gypsy moth, which reduced the numbers of all moths and butterflies in the Blue Ridge Mountains, the animals are finally starting to evolve resistance. What really helps our orange butterflies, however, is reducing the use of “herbicides” that kill their host plants. Nearly all butterfly caterpillars live in a healthy, sustainable balance with one or more of the wildflower species stupid people call “weeds.”

I don't think it's a coincidence that as "Roundup" (the popular glyphosate product used in the United States) was pulled off the market for medical reasons, I've seen more butterflies each month. All the big, colorful butterflies shown below live on "weeds."

Raising Painted Ladies is a fairly easy science project many elementary school students choose. The caterpillars are so hardy that it’s possible for suppliers to guarantee that three out of four will become butterflies—a much higher survival rate than can be expected with most moths and butterflies—and the butterflies are so cute and harmless that nobody minds if you release more of them into the world. As caterpillars Painted Ladies eat thistles. There are a few other “roadside weeds” they can eat, and the ones sold in kits survive on a synthetic food paste. They live faster than Monarchs. If you can build a “sleeve cage” around a thistle plant to keep off birds and put a Painted Lady caterpillar inside it, in a few weeks you’ll probably be opening the cage to release a butterfly. Though they will travel as the weather changes, Painted Ladies don’t need as much space as Monarchs, so they’re not compelled to move on as fast. Children who rear Painted Ladies can usually watch their “pets” flit around the garden for a few days, maybe a week, before they move along.

Most butterflies are harder to rear in captivity than Painted Ladies, but if people stop killing their host plants, they do a pretty good job rearing themselves in the wild. (Baltimores are one of a minority of species that might benefit from professional help. Some of the Fritillaries are others.)

I’ve seen several orange butterflies flitting along roads in Virginia this summer. We all know how butterflies are. You can stand still and watch them warm their wings in the sun, sometimes for ten or fifteen minutes on a cool day. Then, the minute you take out a camera, off they go. Good butterfly photos usually feature dead butterflies. Fortunately this does not mean that nature bloggers need to kill butterflies; it merely means that our blog posts lag behind the actual phenology of the butterflies’ lives. Butterflies live only a few weeks. Generational cycles for several species are similar enough that at certain times of the year you’re likely to find several butterflies with near-intact, healthy-looking wings, dead or dying of old age. These butterflies all expired in early September. I’d seen them and their relatives flying in August. Some of them have heirs that are flying now, possibly further south, and some will have heirs that will fly next summer. 

I'm guessing this one has the species nickname of "Question Mark," though a few other species look similar. When it's resting with its wings up over its back, it displays a faint white mark that often looks like a ? on the underside of the hind wings. The hind wings are drab and camouflage the butterfly as a dead leaf. Only its intimate friends, and those who happen to see it either spreading its wings in the sun to warm up or lying dead on the ground, see how colorful it is.

This one would be a Buckeye Butterfly. 

And this one, I think without looking it up, would be one of the dozens of Fritillaries, most of which look very much like the others. You really need to have a guidebook handy when looking up these things; I didn't.

Here, thanks to the Internet, are decent-quality (Wikipedia) pictures and fun facts about the species I did and did not photograph…

The iconic Monarch, photographed by Kenneth Dwain Harrelson. Nothing else really looks like this one, close up; several other orange and yellow butterflies get some survival advantage from looking a bit like it at a distance, but nearly all of them are smaller and all have different patterns of markings. (In fact, even males and females have consistently different patterns, though the main difference is usually not visible even when the butterflies spread out their wings--males have an extra white dot along the front edge of the hind wings, which is usually covered by the forewings.) 

The most obvious mimic of the Monarch is known as the Viceroy, Limenitis archippus. It is smaller and has a different arrangements of spots and stripes. Some years Viceroys have been abundant in the Blue Ridge Mountains; I've not seen one this year. They eat willow, poplar, and cottonwood leaves, and in places where the less common species of Danaus are found they may resemble Queens or Soldiers more than Monarchs. This specimen, photographed By Benny Mazur from Toledo, OH - A Viceroy ButterflyUploaded by berichard, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=8630237, resembles a Monarch.

The Queen, Danaus gilippus, photographed by Korall, is thought to be a fairly close relative of the Monarch. It is basically a Central American species but is often found in the southernmost tier of the United States. This one was caught pollinating the same milkweed plant a Monarch caterpillar was eating; Queen caterpillars resemble Monarch caterpillars about as much as the butterflies resemble one another, but at all stages these are obviously different species.

The Soldier or Tropical Queen, Danaus eresimus, here photographed in French Guiana by By Didier Descouens - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=19043652, is basically a tropical species but is sometimes found in southern Florida and Texas. 

The Giant Swallowtail or Orange Dog, Papilio cresphontes, here photographed By <a href="//commons.wikimedia.org/wiki/User:Dger" title="User:Dger">D. Gordon E. Robertson</a> - <span class="int-own-work" lang="en">Own work</span>, CC BY-SA 3.0, Link , is the biggest North American butterfly, bigger even than the Monarch. As you might expect from its size, it's found only in Florida, where the alarmingly large caterpillars can be a nuisance in citrus groves (they eat citrus leaves). How is it possible to confuse this animal with the Monarch? If you've only ever seen them in books, maybe...

Some now consider this pale Tiger Swallowtail to be a separate species, the Appalachian Tiger, presumably a hybrid of the Eastern and Canadian species of Tiger Swallowtails. Photo credited to Joe Mueller - from original description: The Taxonomic Report, Vol. 3, No. 7, 15 Jn 2002, Attribution, https://commons.wikimedia.org/w/index.php?curid=1208507. A paler, browner shade of yellow is its most distinctive feature. I saw one flying this August. To me, it was possible to wonder whether it was a Tiger Swallowtail, but not to mistake it for a Monarch. It takes all kinds.

Tiger Swallowtails have three distinct looks. Males are always bright yellow with black stripes. Females can be yellow with black stripes and iridescent blue spots, or black with iridescent blue spots. When I've seen pairs the females sometimes looked smaller than the males--size can depend on the conditions in which individuals grew up. This is the state butterfly of Virginia. It's about the same size as the Monarch, though wing proportions vary. 

This is probably the world's most typical type of Painted Lady, Vanessa cardui, as photographed in Belgium By Jean-Pol GRANDMONT - Self-photographed, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=27747981 . There are distinctively American and Australian species; they can have typical looks that are slightly different from V. cardui, but enough individual variation exists that where the species' ranges overlap with V. cardui only experts can tell them apart. 

Question Mark, Polygonia interrogationis, photographed from above by Derek Ramsey. 

Typical specimen photographed from below, showing an imperfect ? on the hind wing. This photo was donated to Wikipedia By John B. - Flickr: Question Mark, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=16219753

But they can be more colorful, even below. This gaudy specimen, photographed By Judy Gallagher - https://www.flickr.com/photos/52450054@N04/25097157843/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=54632796 , shows a general pattern similar to the subtler markings on the gray individual above.

As caterpillars they eat elm, hops, and nettle leaves. As butterflies they are primarily composters but sometimes sip flower nectar. While some female butterflies travel great distances to place each egg on a separate food plant, female Polygonias tend to drop their eggs where they feel like it and let the caterpillars find their own food as best they can, which probably helps prevent overpopulation. As a species they seem to complete a multigenerational migration with some individuals flying to Canada in summer and some to northern Mexico, though not across the Gulf, in winter. 

A similar (group of) species are the Commas, which typically have the white crescent but not the extra white dot on the underwings. This Eastern Comma, Polygonia comma, was photographed by By Aaron Carlson from Menomonie, WI, USA - Eastern Comma (Polygonia comma), Chippewa Co., WI, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=47375024 . It is typically found in the Eastern States; there are other species of Commas around the world. They can look darker, with all black hind wings, if exposed to cold weather, or mostly orange all over if they've basked in warm weather all their lives.

Commas are also primarily nettle eaters; several species also eat tree leaves. They circulate, and can be said to migrate to some extent, into the edges of other Polygonia species' territory. The northern species, P. gracilis, sometimes eats currant leaves in New England and Canada, and there's a species in the Western States and Canada that eats gooseberry leaves, but these butterflies are not numerous enough to become pests. 

There are different species of Buckeye butterflies, and individuals within the same species can look fairly different as well.

This collection of Junonia coenia was photographed By Meganmccarty - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=5017961 . 

This group, photographed by Alan Schmierer, https://www.flickr.com/photos/sloalan/20835897802/, includes several different species. Junonia butterflies are found on every continent except Antarctica. As shown here, they neither seek out nor avoid the company of other Junonias of their own or different species...though some individuals claim private territories and try to chase everyone but their mates away from those.

Baby Buckeye butterflies eat several kinds of weeds--not the buckeye tree, whose nuts, like the spots on the butterflies' wings, resemble deer's eyes. Plantain, toadflax, and wildflowers in the genus Ruellia are the favorite food plants of the North American species in this genus. (Several larger and more colorful species in this genus are found on other continents.) 

Speyeria cybele, the Great Spangled Fritillary, photographed By MONGO - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=4570414, is a large, showy, fairly representative fritillary. Females tend to be darker than males, western individuals tend to be brighter than easterners, and they all look quite a bit like a few other species of Speyeria. Caterpillars seem to eat violets more than anything else and to be distributed in good proportion to their food sources. 

Finally, here's one Speyeria that's unlikely to be found in the Blue Ridge Mountains, but I had to mention it because there is an egregious web site at which someone has stated, erroneously, that female Monarch butterflies are blue. No Monarch butterfly is blue. Female Speyeria diana are, however, blue, and bigger than the male photographed here by Megan McCarty. These butterflies are found mostly in Arkansas, where they are the official state butterfly.