A fresh summer generation of Mourning Cloak (Nymphalis antiopa) is on the wing. Hearty and cosmopolitan, this butterfly ranges across North America and Eurasia. It even over-winters as an adult, slipping into cracks and crevices in tree bark or into buildings, and surviving with blood proteins, lipids and sugars that act as natural anti-freeze.

They also play dead. You can net a Mourning Cloak, remove it, and then gently lay it across your palm, where it will stay motionless until, presumably, it feels the time is right for an explosive getaway.

Next, from a wet meadow at 9000 feet above sea level, not far from the Continental Divide and the headwaters of the Colorado River, are two photos of Freija Fritillary (Boloria freija). I lost it when I found this butterfly. After that is Uhler’s Arctic (Oenis uhleri).

Many butterflies that are orange above are more cryptic in their markings below, perhaps making them less visible to predators when they snap those wings closed. The nice thing for butterfly watchers is that we get two sets of field marks to help with the species identification!

A chorus of Chuck-will’s-widows fills the pre-dawn darkness in the pine savannah of Croatan National Forest. Spring has arrived here in eastern North Carolina. I’m scouting for one of my Vermont Bird Tours trips to begin on Saturday. Below are two specialties: Bachman’s Sparrow, singing its slurred introductory note then a trill, and Loammi Skipper, now bouncing around the dunes at Fort Macon State Park. Lots more on my agenda.

While out bushwhacking in Groton State Forest on 13 Feb 2011, we encountered the remains of this caterpillar on a speckled alder. I took a closer look to find the shotgun pattern. One question became two: What was the caterpillar? And what made the holes?

Our hunch on the caterpillar species was a good one. It may be a member Noctuidae, a richly diverse family with more than 35,000 species around the world. It’s tough to know exactly which one we’ve got here, but it may belong to the genus Acronicta or Halysidota, which can be covered with those tufts of setae (“hairs”), most of which are long gone from this individual. Acronicta americana (American Dagger Moth), rather plain and brown as an adult, is a possibility, as is Halysidota tessellaris (Banded Tussock Moth), according to Charley Eiseman.

So what was the killer? Wasps do a lot of this kind of damage, stunning the host so that the wasp larvae can grow and feed in a particularly harsh form of evolution by means of natural selection. But one group of wasps – in the genus Aleiodes – kills slowly and with distinction. The caterpillar host is mummified.

North America has about 90 species (and counting) of Aleiodes wasps. An adult female finds, stuns and lays her eggs on a caterpillar, whose fate is sealed as a reluctant and doomed foster parent, a sort of King Tut among insects. The wasp larva feeds inside the caterpillar, eventually pupating to fly away as an adult through an exit hole, leaving behind the shrunken remains, which, on rare occasion, may be found by a group of guys out bushwhacking for the day.

Most caterpillar mummies show but a single exit hole. But here in the East, one species of Aleiodes is termed “gregarious” – Aleiodes stigmator, the Stigmata Mummy-Wasp.

“It is not unusual for 40-50 wasps to emerge from a single mummy,” writes Scott R. Shaw in his masterpiece guide, Aleiodes Wasps of Eastern Forests: A Guide to Parasitoids and Associated Mummified Caterpillars. “The emergence holes are evenly spread across the top of the mummy, from front to back, leaving a quite distinct appearance, as though pelted evenly by shotgun pellets.”

So here it is – another mystery solved. We can’t be absolutely certain about all this because so much remains to be discovered about moths and wasps and insects and their world. But perhaps the most amazing thing about this mystery is that, yeah, there’s a field guide to Aleiodes wasps! Shaw writes more on our species:

“The name ‘stigmata mummy-wasp’ is a reference to the exit holes that are produced in the host caterpillar. Thomas Say [who discovered this wasp in 1824] thought they looked like the stigmata in the hands and feet of the Christ.”

Many thanks to Hugh McGuinness, Trish Hanson, Dave Wagner and Charley Eiseman for help solving this mystery. And to Larry Clarfeld for first spotting the mummy!

Or so we’re told.

We often think of adult butterflies as the dominant phase in the life cycle of these insects. It is certainly the most elegant. After all, when you find your first Early Hairstreak of springtime, a prized butterfly about the size of a thumbnail, colored in cobalt blue and mint green, marked with little orange lightning bolts, you may want to quit your job, sell your house and become a lepidopterist. Adult butterflies surely get the glory, but most butterfly species live on the wing for only a week or two. Their primary role in life is to fly around and make more butterflies.

By November most of these butterflies are frolicking no more. A few species migrate, including the well-known Monarch, which heads off to Mexico. Most of the rest stay close to home over the winter – but not in the adult stage. Depending on the species, they remain beneath the snow as an egg, caterpillar, or pupa. They employ a form of hibernation, called diapause, which sees them through winter. By the following spring, each form will pick up where it left off in the progression from egg to caterpillar to pupa to adult.

But even through the coldest months of winter some adult butterflies remain among us. You want audacity of hope? Find it in the select species that survive our winters as adults.

One of them is the Mourning Cloak, with chocolate brown wings that feature a row of blue jewels above buttery yellow wing edges. Mourning Cloaks are rather pugnacious butterflies. Males take a favorite perch and dart out at most anything that floats or wanders by, including people. The Mourning Cloak has a long life span by butterfly standards. By now, as the day length wanes and temperatures drop, this butterfly, like a black bear to a den, will seek out a cavity in which to pass the winter. On a crisp fall day, I once watched a Mourning Cloak crawl between the layers of a black fleece jacket hanging on my clothesline. But it will often select a more secure place: in fissures between tree bark or in a slot beneath a loose clapboard on a house.

Antifreeze is the key to wintertime butterfly survival. Over-wintering insects often build up reserves of lipids – body fat – and thicken their innards by manufacturing glycerol or similar compounds, which displace water and protect them from freezing temperatures. There in a cozy cavity the Mourning Cloak will wait, usually until the warm days of spring.

But sometimes they launch before spring. On warm, sunny days of March, when the maple sap is running, some Mourning Cloaks take flight. And they won’t be alone. Marauding around in late March and April are small numbers of overwintering Milbert’s Tortoiseshells, sporting a shocking orange stripe across dark wings; Eastern Commas, which actually have a comma-shaped mark under their hind wings; and a few other enterprising species. Some rouse simply because their winter resting spots heat up fast in focused sunlight; others may find their way into – and fly within– garages or homes (where it’s tough to find a butterfly mate). The Vermont Butterfly Survey, which is tracking butterfly abundance and distribution, has documented butterflies in flight in every month of the year except December, January and February.

But that may change. In Great Britain, scientists and ordinary folks, who have been watching and documenting butterflies for decades, have found that some are breaking records for early-season appearances. This and other research suggests that butterflies might be viewed as sensitive indicators of a warming planet.

For some people, butterflies in flight on Valentine’s Day in Vermont or New Hampshire might be a welcome sight. But in mid-February I, for one, would rather see floating snowflakes than fluttering butterflies as part of winter. At the very least, it helps preserve the great anticipation of spring, when butterfly light will shine and flicker around us again.

While I was out searching for dragonflies on the Huntington River near Jonesville, Vermont, on Sunday, a Hackberry Emperor (Asterocampa clyton) touched down briefly to puddle on a gravel bar. He did a loop de loop around my head, then he was gone. This is a rare butterfly in Vermont. We find it in the vicinity of its host plant, Northern Hackberry (Celtis occidentalis). Hackberry, a tree, makes it way into Vermont in the Champlain Lowlands and the Connecticut River Valley, then “inland” a bit along major rivers, including the Winooski and some of its tributaries. Where the tree goes, the butterfly may follow. This was the first Emperor I’ve found in Vermont. I didn’t have my camera. These two images, from different sites in Missouri, including my pant leg, are a nice reminder that butterflies are not marked the same above (dorsally) and below (ventrally). By the way, Hackberry (North America has six native species) was once a member of the Elm Family (Ulmaceae) but is now considered a Hemp (Cannabaceae).

* As it turns out, the count was canceled today because of the rain. I’ll post an update when it’s rescheduled.