Why So Blue When You Can Be White, Yellow, or Pink?

Back on 21-23 May 2012, I was in northwest Indiana to conduct Karner Blue Butterfly (Lycaeides melissa samuelis, aka Plebejus melissa samuelis) monitoring.  My coworkers may think I'm being a fairweather fieldworker on days that I do these surveys, as they have to be conducted between 8 AM and 6 PM, it can't be raining, it can't be too cloudy or windy, and it has to be above 60 degrees Fahrenheit, but I assure them I'm doing it for the butterflies.  It is no lie that I look forward to spending perfect field days searching for a Federally Endangered butterfly.  Does fieldwork get any better than this?

Male Karner Blue Butterfly on Bracken Fern (Pteridium aquilinum var. latiusculum)

With the strange weather this spring, picking the best week for my surveys was like me throwing a dart at an accelerating Ferrari.  As I pointed out in a previous post that discussed the life cycle of the Karner Blue Butterfly, each individual lives just one week, and it is best to conduct surveys during the peak flight of the population.  Luckily, I had some help from some friends at The Nature Conservancy and Indiana Dunes National Lakeshore in deciding when to conduct my first brood surveys .

Female Karner Blue Butterfly on Wild Lupine (Lupinus perennis var. occidentalis)

The Blues (Lycaenidae) are an interesting group of small blue butterflies.  There are several similar species or subspecies with very small geographical ranges scattered throughout North America, such as the Palos Verde Blue (Glaucopsyche lygdamus palosverdesensis) in the Palos Verde Peninsula of California, the El Segundo Blue (Euphilotes battoides allyni) in southern California, the Miami Blue (Cyclargus thomasi bethunebakeri) in southern Florida, the Fender's Blue (Icaricia icarioides fenderi) in the Willamette Valley of Oregon, and most famously the Xerces Blue (Glaucopsyche xerces), an extinct species previously known from San Francisco whose demise was said to be a result of habitat loss due to urban development.  Luckily for me as a botanist who does butterfly surveys, there aren't too many species around here that look similar to the Karner Blue, and those species that do look somewhat similar can be easily distinguished with a bit of patience.

Male Eastern Tailed Blue

Take a close look at the butterfly in the photograph above.  This is an Eastern Tailed Blue (Cupido comyntas), a species that can be confused with the Karner Blue, that lives in the same habitat (but a broader range of habitats), and that also feeds on legumes.  Looking at the hind wing, you can see a small "tail" that easily allows you to tell that this is not a Karner Blue.  In addition, Eastern Tailed Blues may have a couple of orange spots on the hind wing, but there isn't as much orange as on a female Karner Blue, and the male Karner blue has no orange spots on the upper surface of the wings.  Eastern Tailed Blues are generally slightly smaller than Karner Blues, and with some experience you can begin to see differences in the flight patterns of the two species.

Male Spring Azure

Yet another small blue butterfly that inhabits savannas and prairies (as well as other habitats) is the Spring Azure (Celastrina ladon), which is nearly impossible to tell from the Summer Azure (Celastrina neglecta) aside from time of year that they are flying.  The azures can easily be distinguised from Karner Blues, as they lack orange entirely on their wings.  Still, when doing surveys for Karner Blues, it's worth checking every small blue butterfly that you see.

Of course, while doing butterfly surveys, I have to photograph a few plants that grow in the same plant communties where Karner Blue Butterflies occur.

Wild Lupine

It is impossible to discuss Karner Blue Butterflies without discussing Wild Lupine (Lupinus perennis var. occidentalis).  Wild Lupine is considered the "host plant" for the Karner Blue Butterfly, meaning that the larvae feed on the foliage of Wild Lupine.  The problem is that Wild Lupine is the only host plant for the Karner Blue Butterfly, and habitat for Wild Lupine is declining.  This variety of Wild Lupine is known from the Great Lakes and many Atlantic Coast states, where it grows in sandy soils of prairies, oak savannas, woodlands, pine barrens, and dunes.

Wild Lupine

On occasion while searching through Wild Lupine populations you come across an oddball, such as the plant pictured above.  Wild Lupine plants with white flowers are known as Lupinus perennis var. occidentalis forma leucanthus.  You can see that one of the flowers in the inflorescence above is close to the normal color, so this plant seems almost intermediate between the typical form and forma leucanthus.

Hairy Puccoon

It is nearly impossible to talk about Wild Lupine without mentioning Hairy Puccoon (Lithospermum croceum), as the two are almost always found growing together, they flower at the same time, and their flower colors compliment each other so well.  In addition, Hairy Puccoon is one of the Karner Blue Butterfly's nectar species, meaning that the adults feed on its flowers.  Hairy Puccoon can be confused with Hoary Puccoon (Lithospermum canescens), with which it sometimes grows.  The leaves of Hairy Puccoon have a rougher pubescence and the leaves are more pointed at the tips, whereas those of Hoary Puccoon are soft gray pubescent and more blunt at the tips.  Hairy Puccoon is known from much of the central part of North America, where it grows in sandy soils of prairies, savannas, barrens, dunes open woodlands, and beach ridges.

Sand Coreopsis

Sand Coreopsis (Coreopsis lanceolata) is another showy early-blooming species of sandy prairies, savannas, barrens, and open woodlands.  It, too, is a Karner Blue Butterfly nectar species.  Although the North American range of this widely distributed composite includes two Canadian provinces and the entire lower 48 minus the Dakotas, Montana, Idaho, Nevada, Utah, and Arizona (it is even introduced in Hawaii), its range in Indiana is much smaller than one might think, being found naturally primarily only in the northwest corner of the state.  Sand Coreopsis is widely planted and seeded in prairie "restorations" as well as in native landscaping outside of its true range.

Pasture Rose

Also in the sand prairies and savannas of northwest Indiana that Karner Blue Butterflies call their home grows a low-profile thorny species with large pink five-petaled flowers that have a wonderful fragrance.  This is Pasture Rose (Rosa carolina var. carolina), a shrub of the eastern half of North America.  Carolina Rose, as it is also known, grows in sandy or rocky soils of prairies, savannas, open woodlands, and glades.  Karner Blue Butterflies also feed on the nectar of this species.

Clasping Milkweed

I've posted about the ecological functionality of the milkweeds (Asclepias) in the past, so I won't go into detail here.  If you look at the left side of the inflorescence in the photogrpah above, you will see a caterpillar of a Monarch (Danaus plexippus), a butterly species that uses milkweeds as its host plant.  You can also see the broadly clasping and wavy-margined leaves characteristic of this species in the photograph... this is Clasping Milkweed (Asclepias amplexicaulis), a species of prairies, savannas, sand blowouts, glades, open woodlands, and dunes throughout the eastern half of the United States.  Although this species is apparently not a known Karner Blue Butterfly nectar species, several other members of the genus Asclepias are, and I wouldn't be surprised to find a Karner Blue feeding on Clasping Milkweed flowers.

Woolly Beachheather

When you think of Indiana, you probably don't have a mental picture that looks like the photograph above, with sparse vegetation in pure sand.  The minimal amount of this habitat in the state is why the shrub in the photograph is considered threateneed in the Indiana.  This is Woolly Beachheather (Hudsonia tomentosa), a plant known from an area northeast of a line from the Northwest Territories to North Carolina.  Sand Heather, as it is also called, is a species of conservation concern in six additional states.  It grows in sand blowouts, savannas, dunes, and pine barrens in areas with little competition from other plants.

I must be a botanist... this post started out about butterflies and ended with photographs of more plant species than butterfly species!