Bug of the Week – Gray Comma Butterfly – the Other Comma

Bug o’the Week

Gray Comma Butterfly The Other Comma

Howdy, BugFans,

Gray Commas (Polygonia progne) are in the Brush-footed butterfly family Nymphalidae – “brush-footed” because their front pair of legs is small and “brush-like” and tucked in close to their body https://bugguide.net/node/view/1386003/bgimage, making them look like four-legged butterflies.

These are butterflies with somewhat northern proclivities; they’re found across Canada and the northern part of North America but are mostly missing from our southern tier of states https://www.butterfliesandmoths.org/species/Polygonia-progne.  In Butterflies of the Great Lakes Region, Douglas and Douglas speculate that their original (pre-settlement) habitat was probably sunny areas that opened up within dense woodlands when trees fell over and left a hole in the canopy.  Today they’re found in clearings in deciduous and mixed woodlands, along stream edges, and along dirt roads, and also in gardens and yards.  Mead, in Butterflies of the North Woods, says that they are “maybe the most widespread of all the anglewings.”  The (fabulous) Butterflies of Massachusetts website suggests that Gray Commas “may be vulnerable to range contraction as climate warms.

Because of the outlines of their wings, Question Marks and commas (genus Polygonia) are called anglewings.  There are five anglewings in Wisconsin – Gray Commas, Eastern Commas and Question Marks are found throughout the state, and Green Commas and Satyr Commas live “Up North.”

They’re called anglewings because of the cut of their jib, and “comma” because of the silvery punctuation marks on the undersides of their wings.  The Gray Comma’s comma resembles a Nike swoosh https://bugguide.net/node/view/197220/bgimage compared to the Eastern Comma’s thickened and hooked mark https://bugguide.net/node/view/1567724/bgimage, and the Question Mark’s question mark https://bugguide.net/node/view/1583855/bgimage.  

According to the Missouri Department of Conservation’s online Field Guide, “Congratulations if you can tell the difference between a gray comma and eastern comma! This shows you’ve definitely progressed beyond a “beginner” level in butterfly identification.”  By that yardstick, the BugLady hasn’t quite arrived yet, but she’s getting closer.  She likes taking their pictures and putting their images up on the monitor, pulling out a field guide, and worrying them a little bit. 

Here’s why you have to look twice when you’re identifying anglewings:

Gray Comma – https://bugguide.net/node/view/1214968/bgimage

Eastern Comma – https://bugguide.net/node/view/1620700/bgimage,

Question Mark – https://bugguide.net/node/view/1774878/bgimage.  There are some handy tips for distinguishing them at https://wisconsinbutterflies.org/butterfly/subfamily/17-true-brushfoots

With a wingspread of about 2 inches, these are nice-sized butterflies, and seeing one with its wings open in the sunlight is a real treat!  When they’re sitting on a tree trunk with their wings closed, https://bugguide.net/node/view/1937383/bgimage, they can be remarkably-well camouflaged. 

Like other anglewings, there are two generations of Gray Commas each year.  The second generation emerges in mid-fall, but instead of mating, they overwinter as adults, tucked away in a sheltered spot called a hibernaculum (they may fly briefly during a winter thaw).  They emerge in April and May and go about the business of producing the summer generation.  Like other anglewings, Gray Commas are “seasonally dimorphic” – the summer brood has darker hind wings, https://bugguide.net/node/view/197221/bgimage than the winter brood https://bugguide.net/node/view/742721/bgimage.  

Gray Commas are jumpy and nervous, and they have lots of attitude.  Males scout for receptive females from a perch at the edge of a clearing; they are territorial and will engage with anything that crosses their turf.  Females lay eggs singly on the leaves of host plants – gooseberries (genus Ribes), plus the odd currant (also in the genus Ribes), plus azalea and elm. 

Early spring butterflies (and other insects) must have a way to get warm and stay warm (to this end, they are often hairier than later-season species); Gray Commas often warm up by basking in the sun (they have favorite perches), and they can also generate heat by shivering the muscles in their thorax (muscular thermogenesis).

It’s not often, when the BugLady researches insects, that the dramatic plot twist concerns the insect’s diet.  The Gray Comma’s menu looks pretty straightforward on the face of it, but there’s a backstory that the BugLady heard a very long time ago and then forgot.  Like other butterflies that emerge early, commas rarely visit flowers, preferring to sip the juices of rotting fruits, carrion, and dung, to visit sap drips, and to glean minerals from damp soil.  Caterpillars https://bugguide.net/node/view/937966/bgimage feed on the undersides of gooseberry leaves, and the butterflies readily adopted European gooseberries that were introduced by the Settlers (the caterpillars were considered pests of cultivated gooseberries in some places).  Food was plentiful.  Life was good. 

The Butterflies of Massachusetts website tells us what happened next: “Then, around 1910, an American nurseryman imported thousands of white pine seedlings which were infected with European white pine blister rust, for which Ribes plant species are the alternate hosts. Our native white pine, Pinus strobus was not resistant, and this commercially important species was threatened. To protect the lumber industry, importing or cultivating all currants and gooseberries was banned in most New England states. In the 1920’s and 1930s both native and cultivated Ribes plants were ripped up all across New England and the Great Lakes areas, as well as further west. By 1966 the ban was lifted in many areas, but is still in place in Massachusetts (Cullina 2002: 221-2). The host plants for Gray Comma therefore declined dramatically, as did the butterfly.”  (Since that was written, limited quantities of Ribes may be planted in Massachusetts, by permit only.  All clear in Wisconsin since 1966.)

Fun Fact about Gray Commas: their caterpillars rest below the leaf in a U-shape, hanging on with only their middle set of prolegs (the fleshy, “false” legs behind the three pairs of true legs on the thorax https://bugguide.net/node/view/1578095/bgimage).  When they’re alarmed, they wave their spiny front and rear ends around, which apparently makes a predator think again.

May is American Wetlands Month!  Wetlands support vast numbers of insects as temporary nurseries (for dragonflies and damselflies and more), as permanent homes, and as hunting grounds. 

Go outside – appreciate a wetland!

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Bugs without Bios XVIII

Bug o’the Week

Gray Comma Butterfly The Other Comma

Howdy, BugFans,

Gray Commas (Polygonia progne) are in the Brush-footed butterfly family Nymphalidae – “brush-footed” because their front pair of legs is small and “brush-like” and tucked in close to their body https://bugguide.net/node/view/1386003/bgimage, making them look like four-legged butterflies.

IPSILON DART MOTH   

There’s actually plenty of information out there about the Ipsilon dart because its caterpillar loves to eat a variety of agricultural crops, but (except for one little twist) its biography is pretty straightforward.  It’s one of those species whose adult and larval stages have different names – caterpillars are called Floodplain/Black/Greasy cutworms (one source described the larvae as greasy-looking), and another name for the adults is Dark Sword Grass Moth.  It’s an Owlet moth (family Noctuidae) in the Cutworm/Dart moth subfamily Noctuinae, and its name comes from the roughly “Y’-shaped” markings on the wings and from a misspelling of the Greek letter upsilon, which corresponds with the letter “Y.”  

The Ipsilon dart (Agrostis ipsilon) is a native moth that’s found across the continent into southern Canada and that has traveled around the world (except for very hot or very cold locales).  It’s unwelcome wherever it goes because the caterpillar’s diet includes clover, corn, lettuce, potatoes, tobacco, alfalfa, strawberries, sorghum, sugar beets, cotton, and a variety of grains and grasses.  If the eggs hatch before the crops sprout, the larvae sustain themselves on non-native roadside weeds like pigweed and curly dock and then move into the fields when they’ve finished the “weeds.”  Adults feed on nectar.  Here’s the life cycle https://bugguide.net/node/view/1225712/bgimage

Although eggs are laid on low leaves, the caterpillars do their damage below the soil.  There are multiple generations per year in the South; one or two in the North; and the last brood overwinters as pupae.  And here’s the twist – in the northern half of its range, winters are too cold for the pupa to survive.  Adults from the final generation in the north head south to escape the cold (southbound moths don’t reproduce), and in spring, moths migrate north to escape the heat.  According to “Featured Creatures,” a great newsletter of the Entomology and Nematology Department of the University of Florida, “moths collected in the central region of USA in March and April are principally dispersing individuals that are past their peak egg production period. Nonetheless, they inoculate the area and allow production of additional generations, including moths that disperse north into Canada.”

ICHNEUMON ANNULATORIUS

There are so many Ichneumon wasps out there – according to bugguide.net, an estimated 60,000 species worldwide with possibly 40,000 more to discover and describe – so many species that even among those that are named, their life stories are incomplete.  They come in all sizes, shapes and colors; their larvae make a living by parasitizing other insects and even some spiders (and they tend to be very specific about their targets); and they (mostly) don’t sting. 

The BugLady was trying, unsuccessfully, to identify this handsome wasp; she finally asked for help (thanks, PJ), and it turned out to be an Ichneumon wasp.  The BugLady is disappointed that the shiny new wasp book she bought doesn’t cover the Ichneumons, but if it did, she probably couldn’t lift it. 

Ichneumon annulatorius (no common name) can be found in the northeastern quadrant of North America, from Newfoundland to Virginia to Iowa.  Not a lot is known about it, but some of its life history has been inferred from observations of its close relatives.   

In a 1971 article in the Ohio Journal of Science called “Hibernating Ichneumonidae of Ohio.”  Clement Dasch points out that in spite of the fact that ants, bumble bees, and some paper wasps overwinter as adults, hibernation is a relatively uncommon habit in the Hymenoptera (ants, bees, and wasps).  Yet, while looking for hibernating wasps in Ohio, 39 species of Ichneumonids were collected. 

Insects pick their hibernacula carefully, aiming for high humidity and minimal fluctuation in temperature (sunny spots are out).  Ichneumons most frequently chose places under the loose bark of fallen trees on north-facing (shaded) slopes, close to the ground, or in deep ravines.  Other sites included the soft, rotten wood of an old stump or dead wood that was heavily tunneled by other insects.  Some species – including Ichneumon annulatorius – liked thick growths of moss on rocks or trees.  Favorable sites often housed multiple wasps.  

Of the 5,275 wasps he collected, Dasch found only a single male – these species produce a single generation per year, and males died after mating in fall.  Pregnant females entered hibernation by late October and emerged in early April when the air temperatures stayed above freezing, and when they emerged they immediately looked for a host to lay eggs on/in.

GRACEFUL SEDGE GRASSHOPPER

The BugLady was in the Bog on a fine fall day in 2015 when she spotted this jumpy grasshopper on the boardwalk.  It allowed two pictures and then departed.  The BugLady searched unsuccessfully for a grasshopper with the combination of striped head and thorax, glorious red on the femur, and white band on the tibia, and she finally sent it out to a grasshopper expert (thanks Chuck!). 

The Graceful sedge grasshopper (Stethophyma gracile/gracilis), aka the Northern sedge grasshopper/locust (in the short-horned grasshopper family Acrididae) occurs across southern Canada and the northern US, as far south as New Jersey and Nebraska.  It was probably more common 100 years ago, and bugguide.net speculates that it “seems to have disappeared from much of its southern range.”  It’s considered widespread but local, favoring sedge meadows, brushy swamps, stream edges, and other sunny, wet areas, and in the West, it prefers cool uplands.  The grasshoppers live in and eat sedges.

According to an article called “The Orthoptera of North Dakota” in the Proceedings of the Academy of Natural Sciences of Philadelphia (Vol LXXXVII 1925), “it reaches maturity late in the season and is not apt to be found adult before the first of August……”though the males are active, fly vigorously and stridulate loudly, the heavier females are less easily found, then usually ready to leap down into the thickest tangle of grasses at the first alarm.”  The BugLady found an article that suggested that when male grasshoppers stridulate (make noise by rubbing one body part against another) they are more likely to be talking to other males than wooing females. 

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Black Blow fly

Bug o’the Week

Gray Comma Butterfly The Other Comma

Howdy, BugFans,

Gray Commas (Polygonia progne) are in the Brush-footed butterfly family Nymphalidae – “brush-footed” because their front pair of legs is small and “brush-like” and tucked in close to their body https://bugguide.net/node/view/1386003/bgimage, making them look like four-legged butterflies.

The family Calliphoridae (Blow flies) includes Carrion flies, Blow flies, Bluebottle and Greenbottle flies, Cluster flies, and the notorious Screwworm flies.  These often-metallically-colored flies are common in many habitats around the world, including urban areas, where they bask on sunny walls.  The name Blow fly (which was coined by William Shakespeare) comes from an old English term for meat that flies have laid eggs in – such meat was said to be “fly blown.” 

Most Calliphorid larvae (maggots) make their living as recyclers, which conjures up a more wholesome image than does saprophagous (feeding on decaying organic material) or sarcosaprophagous (“feeding on decaying animal material”) (to complete the set, scato/coprophagous refers to feeding on excrement and phytosaprophagous to feeding on rotting plant material.  Quadruple word scores all around).  Maggots eat dung and/or carrion, excreting proteolytic enzymes that break down its proteins, and a few species are parasites.  

Adult blow flies get carbs from nectar and are minor pollinators (they’re attracted to flowers with strong, “meaty,” odors), but they also visit carrion and dung to get protein.  The BugLady photographed one fly as it fed on sap that was leaking from the cut trunk of a small tree in early spring.   

In a blog post titled “Ten reasons why blow flies are stink’n awesome” from the Insect Ecology and Communication Lab at Ohio University, the author writes, “……All joking aside though, blow flies don’t really smell, it’s the resources they are associated with (garbage, poop, carrion, etc.) that smells. The purpose of this post is to make you fall in love with appreciate blow flies! Blow flies are considered filth flies because they are a terrible nuisance to people and are thought of as disease vectors.  Overall, blow flies have a bad reputation because of their less than socially approved eating habits (the BugLady is not going to list the ten – read the article https://bekkabrodie.com/2014/05/20/ten-reasons-why-blow-flies-are-stinkn-awesome/).  On the negative side – you know where that mouth and those feet have been.  On the plus side – they don’t bite.

Experienced BugFans can see where this is going.  The BugLady will try to tell the story as delicately as possible, but this lifestyle is just a part of the magnificent panoply that is the insect world and, well – blow flies happen.

THE BLACK BLOW FLY (Phormia regina), the only species in its genus, is a cold-loving fly that can be found across North America and around the world, especially in rural areas near water.  It’s seen more commonly during spring and fall in the northern half of its range, and in winter in the southern half.  In an article in the Martha’s Vineyard Times, Matt Pelikan (who writes nice natural history articles) says “Nobody seems to know where it originated; perhaps it had succeeded in colonizing much of the globe on its own even before human commerce began transporting wildlife from continent to continent. Or perhaps Phormia began hitching rides so early on in human history that it was already established most places by the time the first biologists turned up and began looking at flies.”

Both male and female Black blow flies need protein to fuel their mating and reproductive activities, and they get this protein from dung, which they ingest via “sponging” mouthparts.

Adults emerge from their winter shelters under tree bark and fallen leaves (sometimes putting in an appearance during a January thaw), and when the air warms consistently to about 50 degrees, the dance begins.  In the case of Black blow flies, the singles scene revolves around animal droppings, and males with larger hat sizes tend to be more successful at getting the gals.  After mating, the female “sniffs” the air, and tracks down some carrion.  Although adults get their nutrients from animal droppings, their eggs are laid on dead meat (up to 250 eggs, in various nooks and crannies).

The eggs hatch quickly in their meaty substrate; they have three instars (the eating stages between molts), and a feeding, metabolizing mass of third-stage maggots generates so much heat that the temperature within the mass can be 50 degrees F (or more) warmer than the ambient temperature.  It’s called the “maggot mass effect,” and it not only keeps everyone toasty, it gooses development and protects against predators and parasites.  The larvae survive the stress of this shot of heat by creating “heat shock proteins” (the BugLady was going to attempt a brief explanation of heat shock proteins, but she got into deep water pretty fast).  Maggots leave the nursery carcass and form pupal cases on the ground; their run from egg to pupa can be as brief as 6 days, with an additional week in the pupal case, but in cooler temperatures they may take up to 12 days longer to mature.  The faster their development is, the smaller the adults are. 

Sources disagreed about whether Black blow flies routinely come inside (most say no), but one suggested that if you see a cluster of blow flies in/around the house, they might be attracted to the odor of a gas leak.

Black blow flies are exquisitely sensitive to the smell of a recently dead animal.  They are among the first to arrive at the scene, which is why they are favorites of the CSI folks and why their chronologies have been so minutely charted. 

Another service provided by a number of blow flies, including the Black blow fly, is wound care (called biotherapy or maggot therapy).  Super-clean maggots are applied to open wounds with stubborn infections because those proteolytic enzymes break down the necrotic tissue for the maggots to eat and leave the healthy tissue alone.  Pick your blow flies carefully – some species (but not this one) sweeten the pot by adding antibiotic secretions to the wound, and other species will feed on healthy tissue.  Unwanted maggot infestations are called myiasis, and they happen to livestock (mostly), in warmer climes (mostly).  

Final Cool Fact about Blow Flies, from the Insect Ecology and Communication Lab “Blow flies are able to fly with such precision that we are never able to swat them.  This is because of the very tiny second pair of wings called halteres, which function like mini gyroscopes and help the fly to calculate in flight maneuver instantly.  Scientists use Blow flies to study flight muscles and split second flight maneuvers. They have discovered flies in mid-turn have the ability to roll on their sides 90º or more (flying upside down) just like a jet fighter.”

According to a 1922 report of the Kansas State Board of Health, “The robin and the bluebottle fly are the early harbingers of spring.”

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Small Blue Butterflies redux

Bug o’the Week

Gray Comma Butterfly The Other Comma

Howdy, BugFans,

Gray Commas (Polygonia progne) are in the Brush-footed butterfly family Nymphalidae – “brush-footed” because their front pair of legs is small and “brush-like” and tucked in close to their body https://bugguide.net/node/view/1386003/bgimage, making them look like four-legged butterflies.

Today’s episode considers three small, blue “look-alike” butterflies – the Spring Azure and the Summer Azure, often referred to as the Spring Spring Azure and the Summer Spring Azure, and the Eastern Tailed Blue.  The Spring Azures have long been considered to be one large and gloriously diverse species made up of several subspecies.  Now they’re thought by many to be a number of full species. For an explanation, see https://wisconsinbutterflies.org/butterfly/species/53-spring-azure.  Besides the Spring Azures, a number of other species of Blues/Azures occur in Wisconsin. 

BugFans who want to finesse identification can always refer to them thoughtfully as the “Spring Azure Complex” and can indulge in a bit of Bug “one-up-man-ship” by lamenting the lack of DNA sequencing on the group.  Remember, though, the words of biologist William Keeton, who said that humans are the only organism to whom this taxonomic lumping and splitting and nattering makes any difference.  The organisms themselves know who they are – in this case, they are butterflies in the family Lycaenidae, the Gossamer-wing butterflies, a large group of butterflies that can be found around the globe.  The BugLady knows them as tiny bits of sky that flicker through sun-dappled swamps, stream sides, woods openings and edges.

SPRING SPRING AZURES (SpSpAz)

SpSpAzs typically emerge early and can survive the frosty nights of mid-spring.  Compared to the Summer Spring Azure, the SpSpAz is darker, and its black spots may be larger and more distinct.  Both species are sexually dimorphic (“two forms”); in this case, the females’ wings have wide black borders and the males’ don’t.  Their wingspread is 1” to 1 ¼”.  Most references say that Wisconsin’s SpSpAz is the species Celastrina ladon (or the subspecies C. ladon ladon).  Others point out that because C. ladon’s chief food plant, flowering dogwood, doesn’t grow in Wisconsin, our earliest SpSpAz is likely C. lucia (or C. ladon lucia).

In order to fly in April and May, SpSpAzs overwinter as a pupa/chrysalis. Adults don’t live long or eat much.  They may drink a little nectar or get liquid and minerals from the mud (a behavior called puddling), and males may gather on damp ground in groups.  Males patrol for mates in forest openings and edges and along forest trails, sometimes ascending to the tree-tops in the thin sunshine of spring.  A female will mate within hours of emerging.  She lays her eggs the next day on the flower buds of host plants like maple-leaved viburnum, black cherry, and sumac, and then she dies. 

When her eggs hatch, the caterpillars – green, conspicuously segmented, and covered with white stubble https://wisconsinpollinators.com/Caterpillars/C_SpringAzure.aspx – eat the flowers first and then the developing fruits.  The flowers they eat tend to be frequented by ants (unsung pollinators of flowers), which discover, care for and protect the caterpillars (here’s an ant on a different species https://bugguide.net/node/view/45799/bgimage).  In return, the ants harvest honeydew produced by the caterpillars.  The larval stage takes about a month, but the resting/pupal stage is a whopper, lasting from early summer until the next spring.   

SUMMER SPRING AZURE (SuSpAz)

The second Azure, which succeeds the first chronologically, is the “Summer” Spring Azure (Celastrina neglecta), sometimes listed as a subspecies C. ladon neglecta.  If you get one to sit still for you, you may note that the SuSpA has lighter underwings than the SpSpAz, and its black spots are smaller and less distinct (to see an Azure with its wings folded is to miss the point; it is the tops of their wings that give Azures their name).  An Azure seen after mid-June is most likely a SuSpAz, but it never hurts to check.  SuSpAzs fly from June until the first frosts in parks and open fields as well as wood openings and edges.

Its life cycle is similar to that of the SpSpAz, with the same symbiotic assist from ants.  Its larval host plants include later-blooming relatives of the SpSpAz host plants.  The pupae of the two species are very similar, and one reference noted that if they are separate species, they separated recently (geologically speaking), perhaps as little as a few thousand years ago.  The chrysalis of the SuSpAz does not rouse when the soil warms in spring; it waits until early summer to emerge.  There are at least two broods each summer, so SuSpAzs decorate the landscape into the fall. 

A Wild Card Azure is the recently-recognized (2005) Cherry Gall Azure (CGAz) (C. serotinahttps://bugguide.net/node/view/1113261/bgimage, which has been recorded in Wisconsin and is said to take up the slack between the decline of the SpSpAz and the emergence of the SuSpAz.  The caterpillar of the CGA has adapted to feeding on the nipple galls created by eriophyid mites (of previous BOTW fame) on cherry leaves. 

EASTERN TAILED-BLUE(ETB)

The tails of the Eastern Tailed-Blue (Everes comyntas or Cupido comyntas, depending on what book you look at) are not visible in flight – in fact, the tails for which they are named are fragile, and wear-and-tear renders many Tailed-Blues tail-less.  They can still be told from the Azures by the two orange spots on the underside of the hind wing right above the tail (and just for fun, check out some pictures of hairstreaks https://wisconsinbutterflies.org/butterfly/subfamily/12-hairstreaks).  The upper wings of Eastern Tailed-Blues are darker than Azures’ wings – the top surface of a male’s wings is purplish blue, and a female’s wings are brownish -.

They change seasonally, too; the first brood of summer has brighter males and bluer females than the last.  ETBs are common, tiny (they can be half the size of a SuSpAz), sun-loving butterflies of fields, restored prairies, power line rights-of-way, gardens, and other open areas. 

Adult ETBs have a short proboscis and so feed at flowers with easy-to-reach nectar, and adult males gather at mud puddles.  Caterpillars eat the flower buds, flowers, seeds and new leaves of their host plants in the Legume family like yellow sweet clover, alfalfa, vetch, white clover, wild pea, bush clover; and tick-trefoil.  As food generalists, they can use a succession of host plants and produce several broods that fly during the summer and well into fall.  ETBs overwinter as caterpillars (often in the seed pod of their legume host) and pupate the following spring.

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Olympia Marble Butterfly

Bug o’the Week

Gray Comma Butterfly The Other Comma

Howdy, BugFans,

Gray Commas (Polygonia progne) are in the Brush-footed butterfly family Nymphalidae – “brush-footed” because their front pair of legs is small and “brush-like” and tucked in close to their body https://bugguide.net/node/view/1386003/bgimage, making them look like four-legged butterflies.

Interrupted fern fiddlehead

The Olympia Marble (Euchloe olympia), aka Olympian Marble and Olympia Marblewing, is in the family Pieridae (the Whites, Sulphurs, and Yellows).  It’s found in a wedge-shaped patch of ground in the middle of North America, plus some disjunct populations in the Appalachians and Texas https://www.butterfliesandmoths.org/species/Euchloe-olympia, and it’s the easternmost of the seven North American Marbles (Wisconsin and Michigan have the greatest numbers of the species).  Within its range, it is local and uncommon; according to The Butterflies of Iowa, “populations are often small; only single individuals are observed at a given time.  This, in combination with the emergence of this species before most other species, has led Loess Hills lepidopterist Tim Orwig to call it ‘our loneliest butterfly.’”  It’s a habitat specialist – look for it in dry meadows and knolls, barrens, open woodlands, sand prairies, dunes, and (today’s vocabulary word) “alvars.” 

[Scenic Side Trip #1 – alvars and alvar pavement grasslands.  Alvar comes from a Swedish word that refers to barrens and grasslands growing on very thin soils over limestone or dolomite bedrock.  Sometimes there’s no soil covering the rock at all, and plants grow in deposits of organic material caught in fissures (“grikes”).  Alvars may have floods in spring and droughts by mid-summer.  They’re an uncommon plant community – many kinds of alvars are globally imperiled – and they’re found most commonly in the Baltic region of northern Europe, counties Clare and Galway in northwest Ireland, and around the Great Lakes (one Wisconsin alvar is protected as a State Natural Area).  Mosses, lichens, grasses, and sedges are common; the sparse woody vegetation is often stunted; and these unique plant communities often host rare plant and animal species.  Here are some pictures: https://mnfi.anr.msu.edu/communities/photos/10702/alvar]. 

Olympia Marbles are just a shade smaller than the very common Cabbage Whites, and individuals that live on Great Lakes coastal dunes are slightly smaller than those inland.  When newly-emerged, they wear a rosy pink wash on the undersides of the wings https://bugguide.net/node/view/9417/bgimage, and when they sit on a plant and close their wings, they tend to disappear https://bugguide.net/node/view/1786977/bgimage.  The more-heavily-marbled Large Marble https://bugguide.net/node/view/47032/bgimage lives north and west of Wisconsin.

These are weak, but direct, flyers that stay pretty close to the ground and have a short flight period.  Males patrol on hilltops in May, flying back and forth purposefully just above the ground.  What do dry meadows and knolls, barrens, open woodlands, sand prairies, dunes, and alvars have in common?  Rock cress (formerly Arabis/now Boechera spp.) – straggly, low-growing members of the mustard family (click on any picture for a slide show https://www.illinoiswildflowers.info/woodland/plants/sm_rockcress.htm).  Females lay single eggs on a flower bud; the young caterpillars eat the flowers and seed pods, and the older caterpillars https://bugguide.net/node/view/52515/bgimage feed on the fruit, leaves, and stems.  Apparently, the Whites – members of the subfamily Pierinae – have a habit of nectaring on the same species that host their young, but adults also feed at phlox, lupine, chickweed, and wild strawberry flowers, and several others.   

By the end of June, the show is pretty much over.  Caterpillars turn a purplish color when they’re about to form a chrysalis, and the fresh chrysalis is also rosy, too, but it turns brown in fall so it’s camouflaged through the winter https://bugguide.net/node/view/54866/bgimage.  They spend 11 months as an inconspicuous chrysalis attached to a host plant, emerging in May (one source said that under certain circumstances, they might remain in the chrysalis for three years).  There’s a single generation per year.  

Early butterflies need strategies for warming up in the cool temperatures of mid-spring.  Olympia Marbles expose the sides and the upper surfaces of their wings to the sun (lateral and dorsal basking) – a passive way of collecting the sun’s warmth in order to heat the thorax so they can fly.  Some insects add “muscular thermogenesis” – quivering muscles within the thorax to raise its internal temperature – but Olympia Marbles don’t have that in their bag of tricks.

How can we make the world a better place for these butterflies?  Preserve favorable habitat with plenty of host plants.  They are susceptible to pesticides used to control gypsy moths and to prescribed burns.  Because they are such specialists, it doesn’t take much habitat destruction to wipe out a small, local population. 

[Scenic Side Trip #2 – Gypsy moths.  After much discussion within the Entomological Society of America, 50 scientists voted recently on a new name for the Gypsy moth, because the former name was considered offensive to the Romani.  From more than 200 suggestions they picked the “Spongy moth,” a reference to its sponge-like egg cases.  The French were way ahead of us – the moth is already called “spongieuse” in France and in parts of Canada.  The BugLady is all for not insulting people, but seriously – the best they could do is Spongy moth???  Next up – the Japanese beetle, because some feel that the strong language used by some pest control businesses can cross the line into the xenophobic.] 

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Become a Member

Take advantage of all the benefits of a Riveredge membership year round!

Learn More