Category: Bug of the Week

Salutations, BugFans,

Another celebration of (regrettably) anonymous bugs.  There are in the neighborhood of 100,000 insect species in North America, but not everyone has a biographer (note to self – it takes a lot longer to research the unsung species than the notorious ones).

HERAEUS PLEBEJUS (no common name): This pretty, little Dirt-Colored Seed Bug was a “life bug” for the BugLady – she knew it was in the “true bug” bunch, Hemiptera (which narrowed it down to 10,200 possibilities in North America) but she eventually stumbled across its identity and looked it up.  When the BugLady’s initial searches for species information draw a blank, she will back up to the insect’s genus and then to its family.  In this case, she struck out at pretty much every level – even the venerable An Introduction to the Study of Insects (Borrer and DeLong) in her home library had no info about Dirt-colored seed bugs.

So – it’s in the Dirt-colored Seed Bug family Rhyparochromidae (“rhyparos” means “dirt” and “chromus” means “colored”).  Rhyparochromidae used to be Rhyparochrominae, the largest and most diverse subfamily in the Seed bug family Lygaeidae (the family of the familiar milkweed bug).  Rhyparochrominae was elevated to family status about 30 years ago, and there’s been a lot of taxonomic fiddling ever since.  Most Rhyparochromids feed on seeds that they find on the ground, but some climb up plants for their supper, and there are a few blood-suckers in the crowd.  Some associate with ants, and a bunch of family members (but not today’s star), are able to stridulate (make noise by rubbing one body part against another).  Most have swollen-looking front legs armed with stiff spines that help them get a grip on seeds https://bugguide.net/node/view/742080/bgimage.  Some Rhyparochromids are economically important (in a negative way).

Heraeus plebejus is the most widespread of the four Heraeus species in North America; bugguide.net says that it occurs in “e. NA to AZ (QC-FL to IA-TX-AZ), Mex. / W. Indies,” and that it’s often found on sumac leaves.  Many of the seed bugs are pretty picky about what kind of seeds they eat, but the BugLady couldn’t find out anything about this species’ diet.  Insects foraging for seed on the ground probably aren’t choosy.  And that’s it.

ZENODOSUS SANGUINEUS (no common name) is a member of the Checkered beetle family Cleridae, which we have met before https://uwm.edu/field-station/checkered-beetle/.  The Clerids are a group of small, hairy, often-colorful, mostly predaceous beetles, many of whose larvae operate under the cover of tree bark, where they prey on the larvae of a variety of bark and cone-boring insects.  Adults feed on adult beetles that they find on flowers and other vegetation (though there are some outlier pollen feeders and scavengers).  Some species may prove to be effective biological controls of bark beetles.  American Beetles, Volume II tells us that “The higher classification of the Cleridae has undergone considerable categorical oscillations.”

Formerly known as Thanoclerus sanguineus, this little beetle is found from North Dakota to Arizona to North Carolina to Maritime Canada, under bark, in woody tunnels, and in galls and decaying fungi.  It is active but shy, and hides quickly when alarmed.  Adults overwinter under bark.  Other than that, this beetle’s internet presence is mostly on park and natural area biodiversity lists.  Glamour shot: https://bugguide.net/node/view/168452/bgimage.

EUPATORIUM/IRONWEED BORER MOTH (Carmenta bassiformis): Two groups of moths are called Clear-winged moths.  There are a few moths in the Sphinx moth family, including the wonderful Snowberry and Bumblebee clearwings that hover at bergamot and thistle flowers in summer (and lead the BugLady on a merry chase).  The other is the Clear-winged moth family Sesiidae, which we have visited before in the form of the squash borer moth https://uwm.edu/field-station/cornworms-and-hornworms-and-squash-borers/.  Their wings are “clear” due to an absence of scales https://bugguide.net/node/view/432923/bgimage. Many of these odd, little Sesiid moths are more waspy than mothy in appearance; they are bee and wasp mimics, a few even sporting yellow scales where bees would have pollen collecting equipment.  Some are agricultural pests and some are quite spectacular, with fancy anal tufts (in one species, the tuft is said to resemble the long, trailing, third set of legs of a wasp in flight) https://bugguide.net/node/view/484442/bgpage, https://bugguide.net/node/view/367514/bgpage, https://bugguide.net/node/view/1010752/bgimage, https://bugguide.net/node/view/1542393/bgimage.

There were actually lots of hits when the BugLady Googled Eupatorium Borer Moth, but the sum total of their information was “larvae feed in the roots of Ironweed, and probably also Eupatorium (Joe-Pye-weed).”  Eupatorium moths are found in grasslands and edges east of the Great Plains.  Females advertise by emitting “Come hither” pheromones; they subsequently lay single eggs at the base of Joe-Pye or Ironweed plants, and the larvae bore into the roots and feed.  They overwinter as larvae and tunnel up into the stalks before pupating in spring.  Adults are nectar feeders, and neither stage is considered a pest. For nicer picture than the BugLady’s: https://bugguide.net/node/view/669993/bgimage.

Kate Redmond, The BugLady

Howdy, BugFans,

Even in a group of damselflies that are called bluets, the Azure Bluet is an amazing color!

Bluets are damselflies in the Narrow-winged/Pond Damselfly family Coenagrionidae, which also includes the dancers, forktails and sprites. Most of Wisconsin’s 20 species of bluets are in the genus Enallagma (the American bluets), and except for two species that apparently didn’t get the memo (Orange and Vesper Bluets), males of most species have various amounts of blue and black on their thorax and abdomen (the front end of a Rainbow Bluet is so exciting that you don’t even notice the rear end).  For the sake of identification, bluets are divided visually into three groups.  If the abdomen is mainly blue, they’re in the “blue-type bluet” group; if it’s mostly black, they’re “black-type bluets; and if it’s about fifty-fifty, they’re “intermediate-type bluets.”  Bluets can be tricky to identify, and hand lens examination may be required.

Females are another story altogether; they’re greenish or tan far more often than blue, and when they are blue, they are less so than males.

Azure Bluets (Enallagma aspersum) are small (about 1 ¼”), black-type bluets.  In most bluet species the 8^th and 9^th segments, at the end of the abdomen, are blue, but the Azure Bluet also has blue on part of the 7^thsegment.  Female Azure Bluets don’t have tan or green forms, and they are almost as blue as males, but instead of a solid blue tip, their abdomen has a pair of “spats” on both segments 8 and 9.  Males have large “eyespots” (postocular blue spots) on the back of their heads, and females’ eyespots are smaller.

Bugguide.net tells us that the Azure Bluet has a wide range – “Most of the Eastern United States, also a disjunct population in Montana. In Canada, reported from Ontario, Quebec, New Brunswick, and Nova Scotia.”  Within that range it’s found in a variety of (preferably fish-free) shallow lakes, ponds, swamps, bogs, and wetland edges with a lot of vegetation, but it’s pretty adaptable and will colonize gravel pits and man-made ponds.  Paulson, in Dragonflies and Damselflies of the East, says that it is “a good disperser, and often is one of the first Odonate species to colonize new aquatic habitat.”  It’s not widely distributed in Wisconsin; Bob DuBois, in the excellent Damselflies of the North Woods calls it “local in our region, but may be abundant once found.”  It’s a “Most Wanted” species in Wisconsin.

With a few minor twists and turns, the life history of an Azure Bluet mirrors that of any bluet.  Males hang out along the shore chasing rival males away from good egg-laying spots and waiting for females, which don’t approach the water until they are reproductively ready.  After mating https://bugguide.net/node/view/1259233/bgimage, they fly in tandem, looking for a suitable spot for her to oviposit.  The period between mating and ovipositing can be dicey – rival males are ready to pirate the lady – so the male retains his grip on the back of her head (contact guarding).

After mating, a typical female bluet perches on a favorable stem at the surface and backs down the plant stem, inserting eggs into it as she goes (see the accompanying photo of a pair of Marsh Bluets); if she submerges, the male releases her.  Female Azure Bluets take the bull by the horns, find a good piece of vegetation, and march down it headfirst to oviposit near the base of the plant.  She may descend more than a foot below the surface and stay under for 15 or 20 minutes (she turns gray while she’s down there, according to Paulson).  It is theorized that this will allow her eggs to survive the drop in water level caused by a summer drought.  The male waits for her above-decks and reclaims her, but she’s no longer interested.

Like other damselflies, the immatures (naiads) are aquatic.  Here’s a picture of a just-emerged Azure Bluet: https://bugguide.net/node/view/385530/bgimage.  They are carnivores as adults and naiads.

An Azure Bluet’s amazing color is all the more amazing because no blue pigment exists in bugs (or vertebrates, either).  Before the advent of eyes (about 600,000,000 years ago) color didn’t matter.  The world was far from black and white – animals get some of their pigments in the foods they eat, so there probably was color in that dark world – but its appearance was unappreciated.  It was only AE (After Eyes) that color mattered.  Which gave rise to one of the BugLady’s favorite quotes: “The eye of the trilobite tells us that the sun shone on the old beach where he lived; for there is nothing in Nature without a purpose, and when so complicated an organ was made to receive the light, there must have been light to enter it.”  (Louis Agassiz, Professor of Zoology, Harvard, 1870). 

For better or worse, color makes its wearer conspicuous, which can be desirable (courtship displays or warning coloration) or undesirable (red sea slug on green kelp – oops!).  Lots of colors come from dietary pigments – flamingoes are pink because of a carotenoids that they get from the tiny crustaceans they eat.  Blue is tough to glean from dietary pigments.  It’s a structural color, formed when light reflects off of tiny structures within the layers of the cuticle, an arrangement that bounces blue light back at the beholder.  The intensity of the blue can vary depending on the amount of light and the angle of the viewer.

To find out more about this arrangement, see http://www.npr.org/sections/health-shots/2014/11/12/347736896/how-animals-hacked-the-rainbow-and-got-stumped-on-blue.  For a deeper, more technical dive, try this one http://what-when-how.com/insects/coloration-insects/.

Up until the third week of January, we were having “Winter Lite” here in God’s Country.  Since then we’ve had snow, more snow, a visit from the Polar Vortex, ice, and even more snow.  We haven’t had a long winter, but at the risk of sounding like wimps, we’re ready to start that slow climb toward spring (the BugLady heard a Cardinal singing the other day).  In that spirit, she offers this quote from Canadian broadcaster, reporter, and writer Peter Gzowski: “We need spring. We need it desperately, and, usually, we need it before God is willing to give it to us.”

Kate Redmond, The BugLady

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

Greetings, BugFans,

The BugLady found this striking spider at Riveredge Nature Center one early summer day.  What it lacks in size (it’s less than ½”), it surely makes up for in beauty (thanks for the ID, BugFan Mike).

There’s not a lot of information out there about the Variegated spider (Sergiolus capulatus).  Only one source gave it a common name, but most of the other species in its family don’t have common names, either.  It is found across the eastern US from the Atlantic to the Great Plains, usually on the ground, under leaf litter, and in grasslands, open areas, and in sunny spots in deciduous woods.  It favors dry habitats over moist ones.

Except for a few genera, its family members tend to be drab, and all of them sport conspicuous twin spinnerets at the end of their abdomen.  Scientists speculate that the Variegated spider’s color pattern mimics that of some species of velvet ants that can be found in the same neighborhoods (a velvet ant picture is included here).  Velvet ants (family Mutillidae) are actually flightless, female wasps whose stingers pack quite a wallop.  Nobody messes with velvet ants.

Like crab spiders and jumping spiders, Variegated spiders do not spin an elaborate trap web; they stalk their prey on foot (more about that in a sec).  Most sources call them nocturnal, but a few disagreed, calling them diurnal (daytime) hunters.  In any case, they spend their “down” time, and cooler days and nights, in a snug, silk-lined retreat.

The BugLady started finding good stuff (most of the good stuff is silk-related) when she researched the family rather than the species.  Variegated spiders are in the Ground spider family Gnaphosidae, aka the Flat-bellied or Stealthy ground spiders (one source said that Gnaphosidae is Greek for “living in the dark”).  There are about 2,000 species in the family; just over 300 of those are found in North America, where there are more species in the west than in the east.

To back review, spiders are capable of making different kinds of silk for use in different situations, like egg cases and trap webs and balloons and shelters and safety nets and more https://uwm.edu/field-station/the-wonders-of-webs-i-spider-silk/.  Not all spiders have or need all the options, and producing silk is “expensive,” energy-wise.

Ground/Gnaphosid spiders often go after prey that is as large as or larger than they are, like ants, and their fellow spiders (araneophagy).  It’s dangerous – a predator can get hurt in a wrestling match, and some prey may be venomous – but ground spiders have developed an impressive strategy for subduing struggling prey.  It’s called a “swathing attack.”

A hunting Gnaphosid spider approaches its prey and typically tries to make some tactile contact with it.  That touch allows it to gauge whether or not it will be able to subdue its food without a fight (by wrapping it in a “leg basket”).  If it does need to deploy silk, it targets the prey’s legs and mouth with thick, sticky globs of silk.  In an article in the Journal of Experimental Biology, researchers Wolff, Řezáč, Krejčí, and Gorb called it “hunting with sticky tape” (http://jeb.biologists.org/content/220/12/2250).

They point out that food-getting drives many adaptations.  Some animals avoid “risky prey,” but Gnaphosids have developed a modified spinning apparatus that produces an especially gluey silk that that is both stretchy and strong.  It allows them to immobilize prey very effectively, but at a cost.  When foraging spiders like Jumping spiders or Crab spiders launch themselves at their prey, they first attach a bit of web to their substrate; if their lunge takes them over the edge of a leaf, they’ve got an anchor/dragline.  Dragline silk also functions in navigation, communication, trap-web construction, and egg sac suspension.  Gnaphosid spiders aren’t able to make dragline silk, but it doesn’t seem to have bothered them much – Gnaphosidae is the 7^th-largest spider family, and its members are especially dominant in dry, open areas.

Ground spiders use a different kind of thread to make a sac for their eggs, and females stand guard until the eggs hatch, like the closely-related Clubionid spiders.  They also weave silk into mesh-like shelters that they stay in when they’re not hunting.

Here are a couple of neat spider sites: https://www.emporia.edu/ksn/v55-december2007/ and https://fieldguides.fieldmuseum.org/sites/default/files/rapid-color-guides-pdfs/390_1.pdf.

Kate Redmond, The BugLady

Howdy, BugFans,

The BugLady has been wanting to do an episode about Bess beetles for a long time, but she didn’t have a picture of one (many thanks to BugFans Tom and Joe for sharing).  Why Bess beetles?  Because they exhibit what’s called “pre-social behavior,” and they vocalize like crazy, and they have lots of names, and then there’s the phoresy.  The “Insects of Duke University” website calls them “one of the most delightful discoveries one can make upon overturning logs.”

Its common names pertain to its appearance and its voice.  Bess beetle seems to come from the Old English “buss” (“kiss”), a reference to a kissy sound the beetle makes, Peg beetle because when it’s sticking its head out of a log, it looks like a carpenter’s peg, and Patent leather beetle is self-explanatory.  Horn beetle probably refers to the horn on its face https://bugguide.net/node/view/270651/bgimage, although one author speculated that the beetle is shiny, like horn material.  The species has also gone through lots of scientific names since it was described by Linnaeus in 1764 (some of them, more than once), having been placed in five different genera and been given a half-dozen species names before arriving at Odontotaenius disjunctus.

Horned Passalus beetles are in the Bess beetle family Passalidae – a family with about 500 species of mostly New World, mostly tropical beetles.  There are two members of the genus Odontotaenius north of Mexico; one is limited to a single county in Florida, and the other is found in rotten logs and stumps in deciduous woodlands over much of North America east of the Great Plains.  But not in Wisconsin.  According to Kriska and Young in “An annotated Checklist of Wisconsin Scarabaeoidea (Coleoptera),” “Rauterberg (1889) reported this species to be widely encountered in Wisconsin, however, he provided no further locality data, and no Wisconsin specimens have been found. It is possible that this species has been extirpated from Wisconsin due to the loss of mature, old growth forests with downed timber of moderate to large diameter in the southern half of Wisconsin.”

Unlike the BugLady’s usual fare, this beetle is far from microscopic – measuring about 1 ½” long, with hefty mandibles and an impressive girth (females are the same length as males but tend to be broader across the thorax).

Horned Passalus beetles, like many other Passalids, live most of their lives within the confines of a hunk of rotting wood (they are especially fond of oak and hickory), though they will venture out to crawl around on the log by day or in search of a new home.  Their life in the log is somewhat climate-controlled and predator-free, and they will defend it from intruders.  They aren’t social in the extreme manner of honey bees and ants, but they are “presocial,” with several generations overlapping sociably “under one roof.”  They use their impressive mandibles to tunnel into wood and to eat it, and they raise their young in it, protecting them and tending to their needs (because the larvae are helpless), and the larvae eventually pupate in the tunnels.  The beetles will continue to use the same site for generations, as long as the wood holds up; a small hunk of wood will hold one family, but a large log could support several.  HPBs are not a danger to homes or decks, but are effective forest recyclers.

Males vie for territory/sections of the log and for females, using their horns to flip their rivals over.  Although open-air nuptial flights have been observed, HPBs mostly mate in the tunnels/galleries, and pairs remain monogamous throughout the summer.  The female lays 25 to 30 eggs (large eggs, which the adults pick up and carry around to good locations in the galleries), and she nestles her eggs into cozy nests of frass (bug poop).  Larvae are fed by both Mom and Dad on a diet of pre-chewed wood pulp mixed with “parental secretions” and frass, and the adults construct and maintain pupal cells for their larvae when the time comes.  Depending on climate and nutrition, the larval lifespan lasts from three to twelve months and adults live about a year.

Injured larvae may be cannibalized, and larvae may also be eaten by unmated HPB adults that attempt to invade their log home.

Newly formed pupae are a beautiful, pearlescent color that gets duller with time https://bugguide.net/node/view/314646/bgimage, and the newly-emerged adults (tenerals), are a rich red https://bugguide.net/node/view/3327/bgimage for a while before settling into their adult coloration.  Young adults overwinter in the family tunnels and disperse the next spring, but while they’re in the parental log, they may help to care for new siblings.  Scroll down to see pictures of stages, and be sure to listen to the audio tape at the bottom – http://entnemdept.ufl.edu/creatures/misc/beetles/horned_passalus.htm (or by-pass the pictures and go directly to http://entnemdept.ufl.edu/creatures/misc/beetles/horned_passalus15.mp3.

As they tunnel through/eat the wood, HPBs leave behind a trail of frass.  The frass is acted on by fungi and bacteria present in the woody galleries, and then it is re-ingested by the adults.  This (and the feeding of frass to the larvae) reinforces the rich microflora that allow the beetle’s gut to digest cellulose.

Seventeen different “vocal” communications have been observed in HPBs – a repertory that exceeds that of many vertebrates.  Researchers Reyes-Castillo and Jarman call this “the most elaborate system of sound communication known for any arthropod.”  Adults make sound by stridulation (friction), using structures located under their elytra (hard wing covers).  They rub rows of spines on their folded flying wings against the top of the abdomen; larvae “vocalize” by rubbing legs together.

Some sounds are defensive (here’s an HPB reacting to a person who insists on poking it with a stick https://www.youtube.com/watch?v=O1KonQZdSAU) and some sounds are social – used in courtship, larval management, or other colony-related purposes.  Buchler, Wright, and Brown observed that crows were distinctly put off by the noise, taking longer to attack, kill, and eat vocal HPB larvae or adults.

HPBs are almost never alone – many go through life with a variety of tiny mites attached to their exoskeleton.  Most of these mite species are not feeding on the beetles, simply using them as a taxi service to get to more favorable habitats (phoresy), because tiny mites have even tinier legs.  One source suggests that Passalids are susceptible to the mites because Passalids are big, dumb, non-predators (the BugLady has no comment about that).  Others say that mites like the same kinds of logs that Passalids like, that the beetles occupy a log long-term, not just seasonally, so there’s lots of time for interaction, and that mites that are thrown together on the beetle’s exoskeleton may use the opportunity to do some courting.  If all that the mites wanted was a ride, then any bark-dwelling critter would do, but they favor Passalids.  Mites find their rides by chemical cues, and they attach in nooks and crannies where they won’t get scraped off in the tunnels https://bugguide.net/node/view/169823.  The HPB has 16 species of mites that use it exclusively.

Fun HPB Fact #1 – Although they are fully capable of flight, these beetles prefer to hoof it (slowly) across their landscapes most of the time.

Fun HBP fact #2 – HPBs are very strong – studies show that they are able to pull 50 times their own weight, and stress can make them even stronger.  Females pull harder (their greater thoracic girth conceals a greater muscle mass), which suggests that they may do the lion’s share of excavating and pushing through tight spaces.  Interestingly, beetles with the longest horns were strongest.

Fun HPB Fact #3 – Because they are big and totally non-aggressive and easy to take care of, HPBs are popular as pets, in insect displays, and for lab work.

Kate Redmond, The BugLady

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

Greetings, BugFans,

Back in the summer of 2009, the BugLady found a spectacular grasshopper in the UWM Field Station prairie (she waded in, her desire to photograph it outweighing apprehension caused by the number of chiggers that live in that particular bit of grassland).  It was a Short-winged Bunchgrass Locust/Grasshopper (Pseudopomala brachyptera) (brachyptera means “short-winged”), also known as the Short-winged Toothpick Grasshopper, and she issued a special Bonus Bug (an “in-between episode”) to celebrate it.  This is a revision of that post, with some new information.

SWBGs are located in the Short-horned Grasshopper family, Acrididae, which BugFans have visited before in the form of the Meadow, Pine-tree spur-throated, Green-legged, and Green striped grasshoppers, and the Red-legged grasshopper/locust and Carolina locust.  There are about 8,000 species in the family worldwide, 620 in North America, and some species can occur in plague-sized quantities.  They’re in the Slant-faced grasshopper subfamily Gomphocerinae and in a group called Mermiria – the Toothpick grasshoppers.

The last time the BugLady wrote about grasshoppers/locusts (whose names, at least in the common usage, are often interchangeable) a knowledgeable BugFan sent her an explanation of the distinctions, which the BugLady “saved” but which (apologies) is nowhere to be found.  Here’s how Wyoming Extension Entomologist Vsevolo Latchininsky explains it in an article in the Encyclopedia of Animal Behavior (2010).  “All locusts are grasshoppers but not all grasshoppers are locusts.”  Locusts, he continues, are “short-horned grasshoppers (Orthoptera: Acrididae), distinguished by their density-dependent behavioral, physiological, and phenotypic polymorphism.”  That sentence takes a little unpacking.

Polymorphism refers to an organism that has several forms, like Mallard Ducks, with showy males and camouflaged females; and phenotypic refers to appearance.  When they occur in “normal” numbers, these grasshoppers are just grasshoppers, hopping around, solitary except when breeding.  When they have a population boom, usually in response favorable weather and a bumper crop of their favorite food, a very small number of species may respond by producing a generation that is gregarious, which can lead to swarming (density-dependent behavioral polymorphism), and that looks different because of changes in color or body structure (phenotypic polymorphism), and then we call them locusts.

Along with that distinctive face (http://www.montana.edu/yellowstoneinsects/orthoptera/pseudopomala_brachyptera.html, Slant-faced grasshoppers tend to have clear-to-yellowish/bluish hind wings that may be darker on the trailing edge, and they have a raspy area/file on the inner side of the hind femur that they rub against a similarly raspy area on the front wing to make sound (stridulate).  Males “sing” to females during courtship.  Their head shape causes some people to mistake them for walking sticks, and like walkingsticks, their slim legginess allows them blend into a grassy thicket.  The technical term for their wild-looking antennae is ensiform(from the Latin enis – sword, related to the Sanskrit asi, also meaning sword).

If, like the BugLady, you appreciate old scientific illustrations, see this 1902 drawing – https://www.flickr.com/photos/internetarchivebookimages/19178012629/.

SWBGs display sexual dimorphism – males are slightly smaller and darker in color than females and have longer wings (females’ wings are usually less than half the length of their abdomen).

Mermirids tend to be found in areas with thick, damp grass; SWBGs have a preference for tallgrass prairies (they’re sometimes described as an insect of prairie remnants), but they’re also found on poor soils, in sand prairies, and along forest and stream and weedy road edges (long stretches of roadside grasses provide an avenue for SWBGs and other insects to disperse along).  Their range stretches from north Texas to Idaho to British Columbia on the west, through the Great Plains and southern Canada, and east through the Great Lakes states to New England, and they’re mostly present in the southern half of Wisconsin.  SWBG populations tend to be “local” – found in small pockets over large areas, and both their numbers and their range may be increasing with recent droughts (but they’re not numerous enough to have an economic impact).

Their short wings suggest that migration is unlikely, but they are terrific hoppers, and they like to play peek-a-boo from the opposite side of a grass stem.

There’s not a huge amount of information out there about the population, reproduction, and daily schedule of SWBGs (a testimony to the low profile they keep).  Eggs are laid in late summer, and they probably overwinter in the egg stage; adults hop around throughout summer, not far from the areas they occupied as nymphs.  SWBGs feed on a variety of grasses (including Kentucky bluegrass) and a few sedges.

Thanks to BugFan Dennis for two corrections of last week’s episode about the Rusty-patched bumble bee.  This bee is listed as an Endangered species in Wisconsin (insufficient scholarship on the BugLady’s part), and the bumble bee that had the unfortunate encounter with the ambush bug is likely a Red-belted rather than a Brown-belted bumble bee.  Thanks, Dennis.

It takes a village.

Kate Redmond, The BugLady

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

Salutations, BugFans,

The summer of 2018 saw an encouraging number of sightings of Rusty-patched bumble bees in southeastern Wisconsin – encouraging because the Rusty-patched bumble bee is on the Federal Endangered Species list, and also because there seem to be a growing number of people who are aware of the bee and are looking for it.  Once found in a wedge that stretched from the Upper Midwest to Ontario to North Carolina, most of its present population is found from Minnesota to Indiana (http://www.xerces.org/wp-content/uploads/2008/06/affinis_range.png).  It is a Species of Special Concern in Wisconsin, and its conservation ranking is S1/G1 – critically imperiled in the state, and critically imperiled globally.  Most Wisconsin sightings are in the southern half of the state.

We depend on bumble bees for a variety of ecosystem services (see https://uwm.edu/field-station/celebrating-bumblebees/), and they are considered by some to be a “keystone species” – a species that shapes the ecosystem it lives in, and without which that ecosystem would be drastically different.

Here’s its pedigree: Rusty-patched bumble bees (Bombus affinis) are in the family Apidae, the Cuckoo, Carpenter, Digger, Bumble, Honeybee family, in the subfamily Apinae, the Honey, Bumble, Long-horned, Orchard, Digger bees, and in the Bumble bee tribe Bombini (and yes, Bumble bee is officially two words, not one.  Mea culpa).

Bumble bees can be tricky to ID – queens, female workers, and males come in different sizes and patterns (the “bumble bees” with the shiny, bald abdomens are really Carpenter bees, but it often takes the BugLady a sec to remember that).  Click the “identification” tab for a drop down of similar species https://xerces.org/rusty-patched-bumble-bee/.  The BugLady highly recommends this guide, which comes in a paper version and/or is downloadable https://www.fs.fed.us/wildflowers/pollinators/documents/BumbleBeeGuideEast2011.pdf.  RPBBs are moderate-sized bumble bees with all-black heads and short-ish hairs that are not as shaggy as those of some other bumble bees, and the queen doesn’t have a rusty patch.  The BugLady is including with this story some pictures of a few other bumble bees with reddish markings on their abdomens (all ID corrections gratefully received).

This is primarily a grassland bee that needs three habitats – a succession of wildflowers and shrubs to glean nectar and pollen from throughout its long flight period (they’re often pictured on wild bergamot, and here’s one that’s feeding in spring on an orange that was put out for orioles https://bugguide.net/node/view/1515649/bgimage), plus nesting sites, plus places for a queen to overwinter – all in close proximity.

RPBBs are one of the first bumble bee species to appear in spring and one of the last to tuck in for the winter – the large bumble bees we see foraging in spring are the queens, who get the nest and first brood “off the ground” singlehandedly.  Like honey bees, they are very social, but unlike honeybees, their nests have fewer workers (usually between 50 and 500) and are not maintained through the winter.  Queens mate in fall, burrow into loose soil, rotting logs or compost heaps to overwinter, and emerge in spring to locate a suitable site for a nest (she may use an old rodent burrow or a thicket of grasses above-ground).  After the infertile, female workers hatch, the queen concentrates on laying eggs, and the workers take over maintenance, defense, foraging, and care of the nursery.  Males and future queens are produced in late summer, and the queen dies before her colony does.

The big story around the RPBB is its population nosedive.  Very common historically, its numbers have dropped by a stunning 90% since the late 1990’s (other species of bumble bee are also in decline).  Loss of grassland habitat and changing land use patterns are big factors, along with pesticides (applied both on the ground and on flowers), climate change, and disease.

With the recognition of bumble bees’ very important role as pollinators (they’re the most efficient pollinators for some important agricultural crops) came the commercialization of those services.  Managed/commercial bumble bee colonies sometimes contain high levels of parasites and pathogens that are spread to wild populations as the bees forage.  One theory about the RPBB’s decline involves a fungus that invades the bee’s gut and causes swelling so significant that males become “too fat” to bend their abdomen and mate (https://www.theatlantic.com/science/archive/2017/02/rusty-patched-bumblebee-endangered-species/514388/).

SCENIC SIDE TRIP:  There is a story within the bumble bee story.  A group of bumble bees called Cuckoo bumble bees, also (presently) in the genus Bombus, make their living as bumble bee parasites.  Not blood-sucking parasites, but “social parasites” that, like Brown-headed Cowbirds and Old World Cuckoos, leave their eggs in the nests of other bumble bees for the host bees to raise.  Each species of CBB targets its own set of bumble bees.

CBBs have some fascinating adaptations that allow them do what they do. They have no social structure, just free-living females and males, and all the females are fertile.  Because they don’t support a nest, they have no pollen baskets; and because they don’t exude wax from between their abdominal segments, their body is more “armored” or solid.  They also have longer stingers and stronger mandibles, all of which serve them well in a dust-up with the resident bees.  CBBs emerge later in the season than their targets, allowing the host species’ colony to be well-established before they come calling.

A CBB finds her host’s nest by smell, but what happens next may vary.  Some accounts of their MOs describe a forcible takeover of the nest, in which the CBB kills the colony queen outright; others depict a more passive scene, in which the CBB settles into the host’s nest for a few days until she’s picked up the nest’s unique scent and can move about laying her eggs without challenge.  And there are also accounts of RPBBs eating “foreign” eggs and evicting CBB larvae or adults.

The Ashton cuckoo bumble bee (Bombus ashtoni) parasitizes the RPBB and two other species.  Because it has put all its eggs in one basket – it has no child care experience and so can’t live without its hosts – its populations are also declining and it’s listed as rare.  To learn more about CBBs, see https://entomologytoday.org/2018/10/29/cuckoo-bumble-bees-cheating-ways/.

FOR MORE INFORMATION – there’s ton information about RPBBs, pollinator associations, and citizen science opportunities out there.  Here’s a start:

Wisconsin Bumblebee Brigade – http://wiatri.net/inventory/bbb/ (see a key at http://wiatri.net/inventory/BBB/getInvolved/img/FieldGuide.pdf)

https://wisconsinbumblebees.entomology.wisc.edu/

https://www.fs.fed.us/wildflowers/features/posters/EasternBumblebeesPoster_reduced.pdf

https://fox11online.com/news/local/endangered-rusty-patched-bumble-bee-has-scientists-concerned

Thanks to sharp-eyed BugFan Becca for her RPBB pictures, taken in her own back yard.

Kate Redmond, The BugLady

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

Hi, BugFans,

Back in 2010, the BugLady wrote about the Swamp Metalmark, a lovely little butterfly that is fading from the Wisconsin scene and from other parts of its range in the Midwest (https://uwm.edu/field-station/swamp-metalmark/).  When she was in southern Ohio in June, she photographed a Northern Metalmark (Calephelis borealis).  Full disclosure: Northern Metalmarks are not found here; they occupy widely spaced pockets in a band from New Jersey/Connecticut on the east to southern Missouri/eastern Oklahoma on the west, but they don’t occur in Wisconsin.

Metalmarks, family Riodinidae, are a mostly New World, mostly tropical bunch that includes about 1,100 species (20 north of the Rio Grande; some just barely).  They are smallish butterflies (Northern Metalmarks have a wingspan of about 1 ¼”) that typically perch with their wings spread wide, but that often fly into vegetation and perch, moth-like, on the undersides of leaves (makes them hard to census).  Females walk about on six legs, but males use only four – each of their front legs is greatly reduced and modified into a spine.  Males scan the airways for females from a perch, rather than on the wing.

Like many other metalmark species, Northern Metalmarks are subtly beautiful, with patterns of silver/metal/rust on dark wings.  They look very similar to Swamp Metalmarks, but habitat requirements separate them in areas where their ranges overlap.  Some species in the Southwest and the tropics are unapologetically spectacular https://bugguide.net/node/view/159108/bgimage, https://bugguide.net/node/view/866024/bgimage, and https://bugguide.net/node/view/1024178/bgpage).  The tips of a NM male’s forewings are more rounded than are those of the female, and the undersides of his wings look pretty different than the upper sides https://bugguide.net/node/view/551483/bgimage.

Like the Swamp Metalmark (also pictured here), the Northern Metalmark has some very particular habitat needs, and like the Swamp Metalmark, this and other factors have put it on the threatened/endangered list in states where it occurs.  Another habitat specialist, the Lange’s Metalmark, is also endangered, (for an unusually-flowery-for-a-government-account of its revival efforts, see https://www.fws.gov/fieldnotes/regmap.cfm?arskey=36198.

NMs like open/dappled stream edges and meadows near woodlands with shale, limestone or serpentine rock barrens or outcroppings close by.  These are very sedentary butterflies, so the caterpillar food plants (two species of ragwort and one of fleabane) and adult nectaring plants must grow in close proximity.

Females place eggs, on at a time, on the underside of a host leaf, and the caterpillars, half-grown by the advent of cold weather, overwinter under the basal leaves of the host plant or burrow into the duff/soil, to emerge and continue their development in spring (for a picture of the caterpillar, scroll from page 74 to page 75 https://books.google.com/books?id=OWdD2bHSE-8C&pg=PA74&lpg=PA74&dq=northern+metalmark+caterpillar&source=bl&ots=Vd73rgy_-i&sig=mcQs6njQ7J7JAbn64Y6ik97tcCQ&hl=en&sa=X&ved=2ahUKEwj-rK3C79TfAhUm8YMKHXTDDCAQ6AEwDHoECAEQAQ#v=onepage&q=northern%20metalmark%20caterpillar&f=false).  Caterpillars form a chrysalis in spring, attached by a silk “button” to the underside of a host plant’s leaf.

Their historical range is believed to have been much larger.  Multiple factors have led to their decline, and it’s mostly a familiar chorus.

• Habitat destruction or fragmentation due to development (although powerline rights-of-way can create favorable habitat), and successional changes that shade out the host plants.

• Burning, mowing, or other management practices during the butterfly’s short reproductive season.

• Pesticides, including Btk, a strain of bacteria that is deployed as a “nonchemical alternative” for killing gypsy moths and some other agricultural pests but that is lethal to an assortment of other moths and to some butterfly caterpillars (the BugLady is not a fan of collateral damage).

• Invasives like barberry, autumn olive, and exotic grasses that shade out or crowd out the host plants.

• Lifestyle – there are some endangered animals whose biology and lifestyle simply makes their whole existence seem improbable (think Giant Pandas, whose solitary females are fertile for only two or three days, once a year).  NMs (and SMs) need a particular geography seeded with a very limited selection of food plants, and they exist in small, isolated groups, often of fewer than a dozen individuals (a great formula for reduced fitness due to genetic in-breeding).  They fly low, and only for short distances, so if something does happen to their home place, they are unlikely/unable to move to another favorable spot.

• And then there’s Butterfly vs Economy.  Where do the requirements of rare species (the canaries in our mineshafts) register on our civic scales?  Do/should the needs of a Northern Metalmark equal/surpass those of an individual or a community?  Is there a middle ground?  What is the applicable ethic, anyway?  The BugLady is recalling how, after the Dead Sea Scrolls were found, linguists were excited about how their understandings of some words were shifting, based on usage in those very old texts.  One case in point was the sentence “Increase, multiply, fill the earth and have dominion over it,” in which the verb that had always been translated “have dominion over” now seemed to be closer to “have stewardship over.”

Legislating an environmental conscience results in resistance and resentment.  Can we educate for one.  At the very least we should remember, as Aldo Leopold noted, that “To keep every cog and wheel is the firstprecaution of intelligent tinkering.”  See “The Case of the Disappearing Butterfly” at https://www.nytimes.com/2008/08/10/nyregion/nyregionspecial2/10preservect.html.

Stewardship.

[Editorial Aside: The BugLady gets solicitations all the time with pictures of the charismatic megafauna – gorillas, elephants, cheetahs, grizzlies, polar bears – and, yes, pandas.  Frankly, those animals seem almost fantastical to her – seeing them in the wild is not a part of her experience bank and is unlikely ever to be.  The groups for whom they are the poster children would have more success with her if they pictured the small, the winged, the six-legged, and the local.  There are four species of Federally Endangered birds in Wisconsin, three mammals, a reptile, five mussels (decidedly uncharismatic, those mussels), and four insect species.  The State Endangered and Threatened lists include five mammals, seven reptiles, 24 birds, 19 mussels, and 23 insects (https://dnr.wi.gov/files/PDF/pubs/er/ER001.pdf).  They need a bake sale, too.]

Apparently, the BugLady is starting out the New Year a little cranky.

Kate Redmond, The BugLady

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

New Year’s Greetings, BugFans,

In the spirit of New Year’s Day entertainment, this is a rerun, an article that the BugLady wrote for the January, 2009 BogHaunter, newsletter of the Friends of the Cedarburg Bog.

The BugLady, Wisconsin born and bred, is not particularly a winter person (though her camera does prod her to suit up and go outside periodically).  Winter is monochromatic and still, and then there are the flash-frozen fingers and feet.  It’s a really tough period for wildlife to weather, too, and they emerge from it stressed, hungry, and at their lowest populations of the year.

Most bird species deal with the season by migrating.  Temperature isn’t the issue – birds, after all, invented down jackets.  They migrate because their summer food sources aren’t available in winter, and many of the birds that remain adjust their diet to include more plant material (incidentally, Googling “birds, hibernation” and “birds, torpor” is instructional).  Birds that do stay, stay silently; other than the call notes of crows, jays, and chickadees, the soft “yank-yank” of nuthatches, and the polyglot utterances of starlings, the winter landscape is a quiet one.  Bird song, after all, is designed to advance breeding, a summer pursuit.

Invertebrates are cold-blooded, and with body temperatures that very nearly match the temperature of the surrounding air or water, their winter options are few.  Outside of a handful of insects that migrate, some form of “sleep,” with cells protected by “antifreeze” from the damage caused by freezing and thawing, is the only alternative to death.  Insect eggs, larvae, pupae, and even adults spend the winter in “diapause,” a state of suspended animation during which development ceases.

When it comes to mammals, the term “hibernation” is applied too loosely.  Winter sleep – the “period of adaptive winter inactivity” – is a continuum.  At one end are the very few true hibernators, and at the other end are a group of mammals that may “hole up” briefly during really severe stretches of weather but that are otherwise active throughout winter.  In the middle are a variety of light and heavy sleepers.  Whatever the duration of the nap, its purpose is to minimize the number of calories burned.

True hibernators put on an impressive layer of fat in late summer and fall, retire to a den, and then lower their metabolism, heart rate, breathing, and body temperature.  Hibernators sleep so deeply that they are hard to rouse.  Woodchucks are true hibernators whose spring awakening is driven not by a call to forecast our weather but by the imperative to reproduce (the BugLady just read in Wikipedia that yearling woodchucks may be called “chucklings”).

Jumping mice (Zapus sp.), 13-lined ground squirrels and some species of bats are also true hibernators. The respiration of a 13-lined ground squirrel drops from about 150 breaths per minute to a single breath every five minutes, and its heartbeat goes from 350 beats per minute to five.  The debate continues about bears, whose body temperature drops relatively little and whose sleep is fitful, but who, for over half a year, may not eat, drink or eliminate.  “Torpor,” a short (sometimes just overnight) drop in temperature and metabolic rate in order to conserve body heat, energy and fat reserves, might be a more accurate term.

“Deep sleepers” achieve torpor for a longer part of the winter.  They may be roused easily because their body temperature doesn’t drop very much or because they don’t put on a thick layer of fat and so must get up periodically to eat.  Chipmunks are classic heavy sleepers.  The BugLady’s chipmunks probably enter the winter with 25 pounds of birdseed stashed below-decks, and they may start their winter sleep in a nest of shredded grass piled on top of a mound of seeds.

Much of the food a chipmunk collects is cached in its underground tunnel system, which includes a room that serves as nest chamber, store room and bedroom, and, often, additional store rooms and a separate room for a latrine.  Because chipmunks are not well insulated, they must wake for a meal every few days.  By the end of winter, their grassy nest may be on the chamber’s floor, and if the cold lingers and they run out of food, they will emerge to forage while there’s still snow on the ground.

Light sleepers disappear for part of the winter but leave their tracks across the landscape during mild winter days and nights (many light sleepers enjoy the benefits of our bird feeding activities and of the warm motors of cars) (the BugLady’s mechanic loves her – she lets him keep all the mice he finds, free).  Skunks often hibernate in communal dens during the worst of winter – in some cases, up to a dozen females may cohabit with a single male, while other males may stay active and solitary all winter.  Raccoons and possums also den up during deep winter (pity the poor opossum, a southern mammal that is a relatively recent and ill-adapted arrival to God’s country, whose thin ear tips freeze and crack off during especially brutal winters).  The diet of all three of these omnivores includes a higher percent of small rodents in cold weather.

Squirrels trade their tree-top summer nests for leaf-lined winter lairs in hollow trees.  The nuts they store during the fall are fair game for any foraging animal, and the vast majority of nuts are found, but squirrels don’t bother to recover acorns that their noses tell them have rotted.  Squirrels are well adapted for short sleeps in severe weather.  Curled up with that bushy tail acting like a blanket, they can sit out a few days of harsh weather.

Deer (whose drab, winter coats are made up of hollow hairs that trap body heat), mice, voles, and cottontails stay active, as do muskrats, which live below the ice.  And what of foxes, coyotes, weasels, shrews, and other carnivores?  Most are active throughout the winter because they aren’t adapted for sleep, and there is still food available for them.  Watch for their tracks in the snow, too.

The BugLady read a neat story in the snow at Riveredge Nature Center the other day.  She found a snow-covered, sawed tree trunk lying across a thickety area.  There was a row of tracks along the length of the log where a coyote took the path of least resistance.

Kate Redmond, The BugLady

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

Season’s Greetings, BugFans,

As always, we pause to celebrate (while humming seasonal songs and drinking eggy, adult beverages), the Twelve Bugs of Christmas (plus one) – a baker’s dozen of bugs, many of whom have already starred in their own BOTWs but who posed nicely for the BugLady this year.

Acmaeodora pulchella – The BugLady is no fan of symmetry, and she likes that the lack of it in this picture creeps up on you.  The bookend beetles are called Spotted/Yellow-marked flower beetles (Acmaeodora pulchella) (“pulchellos” being Latin for “beautiful”), in the metallic wood borer family Buprestidae.

Azure Bluet Damselfly – Azure – “bright blue in color, like a cloudless sky.”

Praying mantis – There are some bugs that seem, well, just a little improbable, and there are some bugs that are really easy to anthropomorphize.  Praying mantises check both boxes.  Remember, the spelling of their name comes from their devout posture, not from the predatory aspect of those raptorial front legs.  This graceful youngster was photographed in southern Ohio.  Here’s a praying mantis bedtime story for your enjoyment https://thedragonflywoman.com/tag/mantids/.

A Racket-tailed Emerald dragonfly hangs from a twig like a small ornament

This Bald-faced hornet nest is 10 feet off a trail that the BugLady uses pretty often, and she walked past it without noticing it until fall, when some leaves dropped off the shrub and revealed it, like a present being unwrapped.  That’s the down-side of Bald-faced hornets – you can get pretty darn close to their paper abode before you see it, and they defend it vigorously (and, no, pitching rocks at it from a distance is not an alternative for the curious – they will find you).

Crab spider – There are two nifty bits of camouflage going on here.  First – the eternal wonder of a crab spider finding just the right spot to sit.  Second, – the “fly” that this spider has snagged is actually a beetle named Ripiphorus (of previous BOTW fame https://uwm.edu/field-station/its-a-beetle-really/).  The BugLady has no idea why it would be an advantage to look like a fly.

Orange Sulphur Butterfly – Occasionally (and, in the BugLady’s case, mainly by accident) the planets line up and you get something like this – an almost-in-focus Orange Sulphur coming in to feed on New England aster.

Red-belted bumblebee – Although she is not very good at identifying them, the BugLady surely loves taking pictures of bumblebees.  There were lots of sightings this summer of the federally-endangered Rusty-patched Bumblebee (more about that in a future BOTW).  The BugLady’s walks are going to take a whole lot longer if she’s checking the rear ends of every bumblebee she finds!

Virginia ctenucha moth – This striking moth was just starting to unfurl its wings.  Here’s what the finished product looks like https://bugguide.net/node/view/1536346/bgimage.

Pine tree Spur-throated Grasshopper – Grasshoppers can be tough to identify and even tougher to photograph, and the BugLady has never really been a grasshopper person.  Pine tree spur-throated grasshoppers, like this beauty, could convert her.

Sign-reading Grasshopper – That being said, she hopes that this Differential grasshopper finishes reading and moves on before it becomes a statistic.

DOR in Ohio – The BugLady found this foursome in the middle of a country road in Ohio after a dark and stormy night.  The main attraction is a shiny, green, road-kill Japanese beetle.  It’s being attended by a scavenging millipede and a daddy longlegs, both of whom are there for the free (and tenderized) protein.  The fourth member of the quartet?  Those tiny red ornaments on the daddy longlegs’ legs are mites that are acting like ticks (“So, naturalists observe, a flea/Has smaller fleas that on him prey;/And these have smaller still to bite ’em,/And so proceed ad infinitum…..” Jonathan Swift).

A Monarch Caterpillar, contemplating the miraculous road ahead of it https://uwm.edu/field-station/pupal-cases/.

May your holiday season be bursting with warmth and family and friends and festivities and music.

Kate Redmond, The BugLady

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

Howdy, BugFans,

The BugLady is entertaining deadlines for two different newsletters plus BOTW, so please enjoy this article, borrowed from the winter issue of the BogHaunter, the newsletter of the Friends of the Cedarburg Bog, whose current winter issue is one of the BugLady’s deadlines.

Snow – or the lack of it – plays a significant role in the lives of animals in the Bog. An inch of snow makes it hard for ground-feeding birds like turkeys to find food, but that same inch allows mice and shrews to tunnel, hiding them from hawks, owls, and foxes. Three or four inches throw a blanket over plants and small animals but still let in sunlight. A fox can move easily in six inches of the white stuff; any deeper and it must bound, using more energy. Just as hunting success becomes more critical, hunting gets harder. A foot of snow blocks almost all of the available light from above. The drifts that immobilize deer, restricting them to the cedar thickets, act as step ladders that let cottontails feed on twigs that are normally out of reach.

Weather reports are based on data collected in a louvered box about five feet above the ground, but the vast majority of animals never get five feet off the ground – they live a scant few inches above and below the soil’s surface, and what matters to them is the air at ground level.

The microclimate that forms between the snow and the ground is called the subnivean layer, but the Inuit call that zone the pukak. Snow is an effective insulator because of the air that is trapped between the small snow particles; and like a bird’s down feathers, these air spaces are warmed by heat from beneath (from the soil, in the case of snow). These snow-lined air-spaces are constantly changing – solidifying as water vapor diffuses through the snow; compacting; melting and enlarging. The result is an insulating layer that keeps the temperature below the snow at about 32 degrees, while the air above the snow bank may be 30 or more degrees colder. It literally is a blanket of snow.

A subnivean layer needs an uneven landscape with some plants at ground level to keep the snow from settling flat on the earth. There is no pukak zone on the ice-covered lakes in the Bog – their surfaces are too smooth – but the hummocky sedge habitat that makes up much of the Bog is ideal. In mountainous areas, the subnivean layer keeps the snow from being “glued” to the landscape and is a factor in avalanches. By the time the snow is a foot deep (some sources say 6”), the air temperature of the pukak is stable – chill but not frigid; warm enough even for some plants to stay marginally green.

But the pukak isn’t just an exercise in physics, it’s the winter home of animals like mice, voles, moles, and, yes, red squirrels (the largest pukak-dweller), plus hardy insects and other invertebrates. These animals modify the “warm” air spaces further, creating mazes of trails that allow them to live and feed under the snow. Spring snow-melt reveals hidden pathways and seed caches, the grassy residential domes of voles (Microtus), and the trunks of small trees that the voles have girdled. .

The down-sides of pukak-living are several: it can be restrictive – no new food is introduced into the system, air quality can suffer, and it’s pretty dark. And even under the snow, the inhabitants of the pukak are not safe. Predators like shrews and weasels follow their prey into their tunnels; foxes and coyotes cock their heads and listen first, then pounce on the snow to break through to the ground. Oxygen and carbon dioxide filter readily through the snow, and the tunnels made by shrews, mice and voles provide additional avenues for gas exchange. According to folklore, voles deliberately cut “windows” in the snow’s crust to vent carbon dioxide that’s given off by respiration and by decomposing plants, but researchers conducted a series of experiments that suggest that while the concentration of CO2 may be high in some areas of the pukak, the voles don’t seem to care.

Northern plants are adapted to take advantage of snow cover, too, and they may suffer when snowfall is light. A textbook example occurred in the Bog during the winter of 2003-2004. After a dry fall, January, 2004 was bitter cold and snow-less, and by February, the frost extended deep into the ground. Although the tamaracks did leaf out in spring, their roots had been frozen and their needles soon turned brown. Twenty percent of the Bog’s tamaracks died.

Skimpy snow accumulation is hard, too, on the small, pukak-dwelling animals that depend on the climate that develops in the subnivean zone.

To discover the pukak for yourself, pick a spot with undisturbed vegetation (lawns are too uniform) and make a person-sized clearing in the snow, all the way to the ground. Lie down in it and use a flashlight to get a vole’s-eye-view of the tunnels and caverns in the airspace below the snow. To experience conditions within the pukak, make a quinzee/Quinzhee (from an Athabascan word meaning “a small snow mound shelter”). Gather enough snow to make a head-high mound about ten feet across, pack it down well, and let it settle for an hour or so. Then hollow out a living space in the middle, leaving the walls and ceiling one foot thick. It’s not an igloo – igloos are made by piling blocks of snow in a circle.

For great information about the ecology of winter, try Winter World, by Bernd Heinrich.

The first day of winter is upon us, but remember – even though we get cranky about short winter days and lengthening nights, the Winter Solstice was/is celebrated because it marks the turn-around point when days start (very slowly) getting longer.

Kate Redmond, The BugLady

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