Bug o’the Week – Bugs without Bios XVIII

Bug o’the Week

Bugs without Bios XVIII

Howdy, BugFans,

Bugs without Bios is dedicated to insects that stay below the radar (our radar, anyway) as they move through the world – they don’t make it into the field guides, and their internet presence is meager.

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

Bugs without Bios XVIII

Howdy, BugFans,

Bugs without Bios is dedicated to insects that stay below the radar (our radar, anyway) as they move through the world – they don’t make it into the field guides, and their internet presence is meager.

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

Bugs without Bios XVIII

Howdy, BugFans,

Bugs without Bios is dedicated to insects that stay below the radar (our radar, anyway) as they move through the world – they don’t make it into the field guides, and their internet presence is meager.

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

Bugs without Bios XVIII

Howdy, BugFans,

Bugs without Bios is dedicated to insects that stay below the radar (our radar, anyway) as they move through the world – they don’t make it into the field guides, and their internet presence is meager.

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/

Bug o’the Week – Western Conifer Seed Bug

Bug o’the Week

Bugs without Bios XVIII

Howdy, BugFans,

Bugs without Bios is dedicated to insects that stay below the radar (our radar, anyway) as they move through the world – they don’t make it into the field guides, and their internet presence is meager.

Here’s the rest of the story.

Western Conifer Seed Bugs (Leptoglossus occidentalis) (aka Pine seed bugs) are in the True bug order Hemiptera (“half-wing,” a reference to the two different textures of the front wings https://bugguide.net/node/view/38458/bgimage) and in the Leaf-footed bug family Coreidae, a large family of sometimes-dramatic-looking, sap-sucking insects https://bugguide.net/node/view/430144/bgpage with pretty cute little nymphs https://bugguide.net/node/view/1644287/bgpage.  Coreids produce a buzzing sound in flight and an odor when provoked.

WCSBs are native to this continent, but their original range was mostly on the far side of the Rockies.  They started moving east about 70 years ago (with the help of interstate commerce), reaching Michigan in 1987 and Pennsylvania in 1992, and they are now common throughout much of North America except the far Southeast.  They’ve also managed to cross The Pond, were recorded in Italy in 1999 (where they’ve taken a liking to the culinary pine nut industry, with disastrous results), and are now spread throughout Europe and Asia.  Look for them in conifer trees and (like Asian multi-colored ladybugs, Box elder bugs, and now Brown marmorated stink bugs) lined up to come inside in fall.  They’re presently working on expansion south of the border. 

That kind of range expansion is only possible for a generalist feeder that can be sure of finding something to eat wherever it lands.  WCSBs feed on the sap from the developing seeds and flowers of about 40 species of conifers including fir, hemlock, spruce and pine trees (the BugLady included a picture of the female flower of a Norway spruce because they’re just so spectacular).  They also sip sap from conifer twigs and needles, and they may move to non-coniferous trees if times are tough.  They puncture the plant with piercing-sucking mouthparts that they tuck in under their body when not in use https://bugguide.net/node/view/740148/bgimage, and when they pierce a twig/seed/flower, they inject digestive juices that soften the plant material so they can suck it out.  Many of their favored trees protect themselves from grazing by producing terpenes, which deter the WCSB not a bit.

Spruce flower

WCSBs locate their food with the help of infrared sensors on their abdomens.  The growing reproductive tissue in cones emits infrared radiation (whether mechanical or metabolic is not clear) that makes them hotter – by as much as 60 degrees F – than the surrounding needles, and the bugs’ sensors can “see” that!  An infrared photo of a conifer with developing cones has been likened by several researchers to a lit-up Christmas tree https://naturescrusaders.files.wordpress.com/2008/11/a1790_22061.jpg.  The WCSB is not the only insect with this super power.  The BugLady is blown away by both the bug and the plant sides of this.

They’re about ¾” long, and adults come in a variety of shades of brown https://www.marylandbiodiversity.com/view/11012.  Nymphs are orange-ish https://bugguide.net/node/view/1999752/bgimage, especially right after they molt.

There’s only one generation per year in much of its range.  Eggs are laid in rows along needles https://bugguide.net/node/view/115877/bgimage, and when the nymphs hatch in about 10 days, they start extracting sap from the most tender parts of the cone.  Nymphs grow and molt throughout summer, becoming adults on their final (5th) molt in late August. 

Adults feed on seeds through early fall and then start considering their winter options.  In the wild, these include crevices under bark or in soft, dead trees, or in bird or rodent nests.  Whether indoors or out, WCSBs overwinter in a state called diapause, a suspended animation where development is stalled.  They prepare for diapause in fall by stocking up on nutrients like fats, carbs, and proteins that not only help them enter it but give them enough energy to come out of it at the end of winter.  Adults emerge from their winter abodes in spring and feed on developing conifer seeds and flowers, and the beat goes on. 

Sources seemed to agree that while this might be considered a minor tree pest, it’s a bigger human pest. When the autumn air starts to chill, urban and suburban WCSBs gather on sunny southern exposures and start moving inside.  Male aggregation pheromones may call hundreds of their confreres to a potential winter home (the BugLady has never seen more than a few WCSBs at one time in any season).  

As winter houseguests they get mixed reviews.  Notwithstanding some people’s (inexplicable) aversion to having six-legged housemates, WCSBs rarely bite or sting (the occasional poke has been recorded) or eat the drapes or the dogfood or the houseplants (and so they don’t poop), they don’t reproduce or carry any diseases, and they pack up and leave in spring.  But when bothered, they may release an odor (a combination of hexanal and hexyl acetate) that most sources described as pungent, foul-smelling, and noxious, but that one source described it as “piney” or “vanilla-like.”  Once they’re inside, it’s hard to get them out, so an ounce of prevention (in the form of sealing leaks in windows, eaves, etc.) is worth a pound of cure.

Thanks to BugFan Elaine for suggesting this one.

Kate Redmond, The BugLady

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

Bug o’the Week – Bugs in the News XII

Bug o’the Week

Bugs in the News XII

Greetings BugFans,

The Bugs in the News file is bursting at the seams again.  Smithsonian magazine’s Daily Newsletter, the source of many of the news items in her file, is a great online resource, and the BugLady recommends that you sign up for it.

We have long known that flowers “train” their pollinators, rather than the other way around.  Generations of adaptations go into a flower-pollinator “fit” like this one, and the reward for the pollinator’s hard work is being able to access a resource that no one else can (unless they cheat and tunnel into the flower’s base, of course).  https://www.smithsonianmag.com/smart-news/new-madagascan-moth-species-holds-tongue-record-with-nearly-foot-long-proboscis-180978834/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=20211007-daily-responsive&spMailingID=45744650&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2100749469&spReportId=MjEwMDc0OTQ2OQS2.

OK – the BugLady is ambivalent about this one; in fact, she once turned down an offer to appear in the same program with someone who created magnificent art pieces with dead insects.  She supposes that’s a way to sneak in the back door when people aren’t insect enthusiasts, but no insect is ever harmed in the making of a BOTW.

https://www.smithsonianmag.com/arts-culture/the-creepy-crawling-history-insect-art-180979288/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=20211223-daily-responsive&spMailingID=46155101&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2142675899&spReportId=MjE0MjY3NTg5OQS2.

Another argument for clean air – and another example of how, when the dominos start to fall, they build momentum: https://www.smithsonianmag.com/smart-news/air-pollution-makes-it-harder-for-insect-pollinators-to-find-flowers-180979465/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=20220126-daily-responsive&spMailingID=46307031&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2162879922&spReportId=MjE2Mjg3OTkyMgS2.

It’s never too early to think about mosquitoes: https://www.smithsonianmag.com/blogs/national-museum-of-natural-history/2021/08/19/secret-life-worlds-most-hated-insect/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=20210819-daily-responsive&spMailingID=45486503&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2064448016&spReportId=MjA2NDQ0ODAxNgS2.

Kleptoparasites are animals (in this case, insects) that take advantage of another insect’s hard work, robbing them of the fruits of their labor: https://whyevolutionistrue.com/2021/11/06/readers-wildlife-photos-1454/.

Getting by with a little help from Mom: https://www.nationalgeographic.com/animals/2019/02/wasp-eggs-fumigate-nests-with-gas/?cmpid=org=ngp::mc=crm-email::src=ngp::cmp=Editorial::add=Animals_20190214::rid=2030610309.

And speaking of adaptations that allow an organism to take advantage of the existing resources: https://phys.org/news/2021-11-bees-dead-meat-eating-vulture-sport.html?fbclid=IwAR3sNnjf3PbkGkp_Jvhj_3MptabVaCz6dZuIJHIWP_61_KHPLHLfGnzNJdM.

People always want to know if millipedes really have 1,000 legs.  Most fall far short, but… https://www.smithsonianmag.com/smart-news/finally-a-millipede-that-actually-has-1000-legs-180979269/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=20211220-daily-responsive&spMailingID=46136420&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2142287410&spReportId=MjE0MjI4NzQxMAS2.

And finally, a timely issue from the UW Madison Department of Entomology’s Insect Diagnostic Lab newsletter https://insectlab.russell.wisc.edu/2022/01/31/insects-on-snow/.  You can subscribe to this one, too.  (Go Outside – Look for Bugs!)

Feb 2 is Groundhog Day.  In Wisconsin that means that if the groundhog sees its shadow, winter will last another month and a half, and if it doesn’t see its shadow, we have six more weeks until spring. 

Kate Redmond, The BugLady

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

Bug o’the Week – Gulf Fritillary – a Snowbird Special

Bug o’the Week

Bugs in the News XII

Greetings BugFans,

The Bugs in the News file is bursting at the seams again.  Smithsonian magazine’s Daily Newsletter, the source of many of the news items in her file, is a great online resource, and the BugLady recommends that you sign up for it.

This is not your grandfather’s fritillary (unless your grandfather is a Southerner).  Gulf Fritillaries are in the Brush-footed butterfly family Nymphalidae, along with a whole bunch of familiar Wisconsin butterflies, and they’re with the fritillaries in the subfamily Heliconiinae (which used to be its own family).  But, unlike our familiar fritillaries, they’re in the tribe Heliconiini, aka the Heliconians or Longwings, many of which occur in tropical climes and have long, slim, spectacular wings https://bugguide.net/node/view/1480877/bgpagehttps://bugguide.net/node/view/1478862/bgpagehttps://bugguide.net/node/view/309768/bgimage.  The larvae of many Heliconians feed on parts of passion vines and leaves, and the adults eat nectar of a number of flowers, plus fruit and sap, and many make or save toxic chemicals for defense.  Adults often spend the night in communal roosts https://bugguide.net/node/view/6260/bgimage (a group of butterflies is called a roost or bivouac).   

The Gulf Fritillary (Agraulis vanillae) (Dione vanillae in some books) is also known as the Passion butterfly because of its caterpillar host plant, and the Online Guide to the Animals of Trinidad and Tobago refers to it as the Silver Spotted Flambeau.  Carl Linnaeus gave it the species name “vanillae” based on a life cycle painting of the butterfly on a vanilla plant https://www.rct.uk/collection/921180/vanilla-with-gulf-fritillary done by the amazing 18th century naturalist/painter Maria Sibylla Merian, but the species doesn’t use vanilla plants.  If you’re not familiar with her, here she is https://en.wikipedia.org/wiki/Maria_Sibylla_Merian

Its range is described as Neotropical, which covers the ground from central Mexico and the Caribbean to southern South America.  In North America it is most common across our southern tier of states and the West Indies, and less so as you travel north http://mothphotographersgroup.msstate.edu/species.php?hodges=4413.  It’s one of the most common butterflies some in parts of Florida, where it has multiple generations per year; it was introduced to Southern California in the late 1800’s and is established there; it’s also established in Hawaii, and it has been recorded in Guam.  Gulf Fritillaries fly north in spring, breeding across the Southeast, and move back south again in fall, with Florida seeing dramatic migrations in both directions.    

It has a wingspan of two-and-one-half to almost four inches; females are larger than males and may have darker markings https://bugguide.net/node/view/666672/bgimage.

Courtship is exotic.  As a male and female circle each other in the air, he calms her flight response by releasing aphrodisiac courtship pheromones from “hair pencils” on his abdomen, and after she perches, he may hover above her, dusting her with more pheromones.  He perches beside her, they shift to face each other at a 45 degree angle, and he claps his wings open and closed, enveloping her antennae with each clap, delivering more pheromones from structures on the top side of his front wings and letting her know he is the same species (butterfly eyesight isn’t that great).  For Gulf Fritillaries, it’s “Ladies’ Choice” – females actively pick the males they mate with, so he really has to sell it. 

Rabbit hole #1: If she accepts his advances, his sperm packet, delivered when they mate, includes what’s called a nuptial gift.  The BugLady has written about nuptial gifts in spiders, katydids, tree crickets, and dance flies, but she had no idea that some butterflies produce them (they’re an energy-intensive investment for the male).  The sperm packet includes nutrients that will help her form eggs.  In the case of one of the European Comma butterflies (Polygonia c-album), the spermatophores are edible, containing both food and sperm, and the female, who mates with multiple males, can rate a male by the quality of plants he ate as a caterpillar (nettle is preferred) (Toto, I don’t think we’re in Kansas anymore).  

She lays her eggs, one by one, on or near a passion vine (purple passionflower has the best flower ever https://en.wikipedia.org/wiki/Passiflora#/media/File:OQ_Passion_flower.jpg), usually on the top surface of a leaf.  When they hatch, the caterpillars eat their egg shells – and sometimes neighboring eggs – and then start in on the leaves, often feeding in small groups.  

In the far southern US, Gulf fritillaries are in the air all year long, producing multiple generations.  They are said to overwinter as adults, but one researcher concluded that after passion vines die back in Florida in early winter, caterpillars can survive in diapause (dormancy – they halt development and resume when conditions improve).  They can also enter diapause in the chrysalis stage, though temperatures under 30 degrees are not good for them (or for most Floridians).  Here’s a nice series of a caterpillar forming a chrysalis https://bugguide.net/node/view/1589936/bgimage.  

Gulf Fritillaries are well-defended.  Adults can produce stinky fluids when alarmed.  The vegetation of many passion vine species is chock full of chemicals including glycosides that release cyanide when eaten, alkaloids, and strychnine and nicotine relatives, making their caterpillars a bad choice for predators.  And if that weren’t enough, the caterpillars are spiny https://bugguide.net/node/view/2047275/bgimage

Rabbit hole #2 was peripheral and was kind of like when you find out that deer eat baby birds (yes, deer eat baby birds, and so do chipmunks). 

In order to produce mating pheromones and “build” nuptial gifts, male butterflies in some species in the subfamily Danainae (the Milkweed and Glasswing butterflies) may want to boost their alkaloid load.  They can get extra alkaloids by scratching toxic leaves with claws on their tarsi (feet) and sipping the resulting sap, but researchers in the Sulawesi area of Indonesia noticed that some Danaine upped the ante by ingesting chemicals from caterpillars that had been feeding on plants in the dogbane family (which is closely related to milkweed).  Seven species were observed scratching dead or dying caterpillars and sipping the fluid (researchers don’t know if the scratching part had contributed to the dead and dying part).  They went after healthy caterpillars too (“subdued them” said the researchers), to harvest the toxic chemicals that the caterpillars sequester from their food plants for their own defense.  In their defense, it may be that the butterflies were attracted to leaves that were already scratched and oozing, and the caterpillars were just in the neighborhood.  Scientists had to coin a new term for this unique practice – “Kleptopharmacophagy” – literally “stealing chemicals for consumption.” 

One of the researchers, Yi-Kai Tea, referred to caterpillars as “essentially bags of macerated leaves; the same leaves that contain these potent chemicals the milkweed butterflies seek out.” Fortunately, our iconic Monarch has not (yet) been implicated in this behavior, which is a good thing because the BugLady wouldn’t be able to look one in the eye.

The great Roger Tory Peterson once said that a good birder always looks twice.  In his 1970 book Butterflies of Wisconsin, Ebner dismissed some early Gulf Fritillary records as “rather dubious,” and the Wisconsinbutterflies.org website lists it as a rare stray to the state.  Gulf Fritillaries are pretty distinct, but if you glance at a large fritillary and are about to write it off as another Great Spangled Fritillary https://bugguide.net/node/view/1990523/bgimagehttps://bugguide.net/node/view/1887246/bgimage, give it a second look, just to be sure.  

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 XVII

Bug o’the Week

Bugs in the News XII

Greetings BugFans,

The Bugs in the News file is bursting at the seams again.  Smithsonian magazine’s Daily Newsletter, the source of many of the news items in her file, is a great online resource, and the BugLady recommends that you sign up for it.

EYED BAILEYA MOTH

EYED BAILEYA MOTH – Back at the beginning of June, while the BugLady was poking around the Ephemeral Pond at Riveredge, she spied this lovely (and, she thought, distinctive) moth.  It took her a while to put a name with it.  The Eyed Baileya (because of the small eyespots on the forewings) is in the family Nolidae, which was carved out of the Owlet moth family Noctuidae.  It’s primarily an Old World family (named for Nola, Italy), and the 40 species that live in the New World represent about two percent of its total species.  Nolids have hearing organs on the thorax, and they’re called tuft moths because many have tufts of raised scales on their forewings.  Their caterpillars feed within webbed or folded leaves and overwinter in keeled, silk cocoons with a vertical slit for their eventual exit.

Eyed Baileya moths (Baileya ophthalmica) are found from the Great Plains to the Atlantic and north into Canada, in deciduous, often damp, woods and edges, where their caterpillars eat the leaves of hazel, American hornbeam, and hop hornbeam trees https://bugguide.net/node/view/936581/bgimage.  

They come in a variety of shades of gray and brown, and they have a wingspan of about 1 ¼ inches.  The subfamily Acontiinae in Owlet moth family are officially called the Bird Dropping moths https://bugguide.net/node/view/528934/bgimage; but other, unrelated moths, like this one, are referred to as (lower case) bird dropping moths because of their nifty camouflage.  One of the Eyed Baileya moths’ field marks, a fuzzy thorax, is kind of worn on the BugLady’s moth https://bugguide.net/node/view/754045/bgimage.

They on the wing from early spring until mid-summer (in the north), and they have one or two broods here in God’s country.  They overwinter inside a pupal case https://bugguide.net/node/view/1829824/bgimage that is inside a cocoon that they make by chewing strips of leaves and incorporating them into the cocoon wall https://bugguide.net/node/view/1769307/bgimage.

ANALEPTURA LINEOLA BEETLE

The ANALEPTURA LINEOLA BEETLE is a member of the charismatic Long-horned beetle family Cerambycidae, and it’s in the flower longhorn subfamily Lepturinae.  True to their name, Flower longhorns are diurnal (day-flying) beetles that are often seen browsing for nectar on flower tops.  They are long-legged, and they often appear wedge-shaped or “big-shouldered” – sometimes exaggeratedly so https://bugguide.net/node/view/524704/bgpage.  There are about 200 species of flower longhorns north of the Rio Grande divided among about 60 genera; and Analeptura lineola is the only species in its genus.

Analeptura lineola (no common name) has an interesting range.  It’s found from May through August over much of the eastern half of North America, well into Canada, but not, says bugguide.net, around the Gulf Coast.  Wikipedia tells us that it is also found across Europe from France to Russia, and indeed, a good number of the hits that the BugLady got in her searches were in the “translate this page” category.

Their offspring lead an inconspicuous life, chewing tunnels (galleries) beneath the bark of dead or dying birch, ironwood, hornbeam and pine trees (they’re not considered pests).  Their specialized intestinal flora (microbiome), reinforced by fungi ingested from the rotting wood, allows them to digest cellulose. 

A dried specimen will cost you $3.00 on-line.

LUMP-LEGGED SWAMP FLY

The awesomely-named LUMP-LEGGED SWAMP FLY(Anasimyia chrysostoma)is a syrphid-flower-hover fly in the family Syrphidae.  Some British genus members are called Duck hoverflies and Duckflies (Anas is a genus of duck, and myia comes from a Greek word referring to the invasion of vital tissues).  Their larvae are aquatic, so the adults are found around swamps, bogs, and other wetland edges, mostly in the northeastern quadrant of the continent.  There are about six members of the genus in our area – the Moon-shaped, Two-lined, Smooth-legged, Short-spurred, Long-spurred, and the Lump-legged swamp fly (which comes by its name honestly https://bugguide.net/node/view/1911511/bgimage).

Adults hang around on flowers – especially fleabane, says one source (they’re great pollinators) – and the larvae are filter-feeders on organic debris in shallow, stagnant waters.  They are among the “rat-tailed maggots” that breathe through a tube that extends from their rear to the water’s surface https://bugguide.net/node/view/815670.  

The BugLady got into “translate this page” territory pretty fast with this one, too.  In the 190 years since it was named and described, the Lump-legged Swamp fly has gone through at least five scientific names – Eristalis chrysostoma, Lejops relictus, Lejops chrysostomus, Helophilus relictus, and Anasimyia chrysostoma (as one source says, “the systematics of the family are in flux”), and it’s equally anonymous under all of them. 

Fun Fact about the Lump-legged Swamp Fly:  according to the Flower Flies of Minnesota, “Males are aggressively territorial and can sometimes be observed fighting.”

Kate Redmond, The BugLady

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

Bug o’the Week – And Now for Something a Little Different XIII

Bug o’the Week

Bugs in the News XII

Greetings BugFans,

The Bugs in the News file is bursting at the seams again.  Smithsonian magazine’s Daily Newsletter, the source of many of the news items in her file, is a great online resource, and the BugLady recommends that you sign up for it.

Its reputation as a nest-robber (mostly-undeserved) and its feistiness at the feeder make it unwelcome in some backyards, but its antics endear it to many feeder-watchers (including the BugLady), who secretly confess, “I know it’s a troublemaker, but I love watching it.” Its role as the neighborhood watchdog benefits other songbirds. And, it plants trees.

Ravens, crows, and Blue Jays (Cyanocitta cristata) are members of the Crow family and are considered to be very intelligent birds. As proof, scientists point to the richness of their vocabulary and the tightness of their family bonds. Blue Jay vocalizations are complex, and along with their loud “Jay, Jay” and “pump handle” sounds, they have a number of softer, more “conversational” call notes.

They can imitate the calls of several species of hawks, though scientists aren’t sure whether the jay is checking to see if hawks are around, is psyching out other songbirds, is scaring everyone else away from the feeder, or is just having fun. If it encounters a bird of prey, a Blue Jay’s excited “mobbing calls” attract other birds to harass the predator. A glance at its expressive crest can tell you if a bird is scared (a bristling crest), aggressive (an erect crest), or peaceful (a flat crest).

Males and females collaborate to build a cup-shaped nest, preferably in an evergreen, in which the female lays an average of four or five eggs. Totally helpless when they hatch, young Blue Jays continue to be incubated for a week or two, and they stay with their parents for two months. Both parents care for them.

Blue Jays are never totally absent in winter from the territory they inhabit in summer, but their migratory habits are quirky. Studies are contradictory, suggesting that from fewer than 20% to almost 50% of Blue Jays migrate in a given year, and huge flocks can be seen along the Great Lakes and Atlantic coasts (this fall, a hawk counter on the shores of Lake Michigan tallied more than 2,600 jays in four hours!).  While both old and young birds may migrate, some birds travel one year and not the next, and one banded Blue Jay become a first-time migrant at the age of five.

They migrate by day, coming down for a rest around midday and then resuming their flight. Blue Jay migration is probably food-driven, and the increasing popularity of bird feeders may encourage them to stay home. These are not long-distance migrants – many travel only a few hundred miles – but migration is still a dangerous undertaking, and birds that stay home tend to live longer.

Blue Jays measure nine to twelve inches – a little bigger than a robin – and males and females look alike. Their feathers are actually a dull brown, the blue color caused by physics, not by pigments (life is physics). It’s called a “structural color,” and it’s the result of the light bouncing off of feather barbs and being scattered by tiny air pockets in the feather’s “skeleton.”

They are omnivores, but only about one-quarter of their diet consists of animals like insects, spiders, snails, small frogs, mice or salamanders. Fruit, seeds, and nuts make up the rest (they are frequent flyers at the BugLady’s peanut feeder), and most of what they eat is wild, not cultivated. They may cache food, hiding it for later use, although in 1895, an observer noted that jays do not cache food unless they are permanent (rather than summer) residents of an area. According to the Cornell University Lab of Ornithology’s All About Birds site, “Their fondness for acorns is credited with helping spread oak trees after the last glacial period.”

Blue Jays are preyed on by hawks, and their eggs and nestlings are eaten by squirrels, cats, hawks, owls, crows and raccoons. Although the record for a wild bird is seventeen years, a seven-year-old Blue Jay is an old Blue Jay. Both jays and crows have been hit hard by West Nile Virus.

So, the Blue Jays that spend the winter at your feeder might be the same crew that you fed all summer, or they could be birds that migrated south to get there and replaced the summer residents, or they could be a little of each.

[Credit where credit is due: A version of this article (written by the BugLady, wearing a different hat) first appeared in The BogHaunter, the newsletter of the Friends of the Cedarburg Bog.]

Kate Redmond, The BugLady

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

The Uncommon Beauty of the Oak Opening

I must admit, when I first encountered an Oak Opening, I had a hard time initially wrapping my brain around what was unique about the habitat. I looked up and could recognize that it contained oak trees, standing high in their far-reaching, craggy-branched splendor. “Ok, they’re oak trees,” I shrugged. Then one day it dawned on me: an Oak Opening possesses a vast amount of open space compared with what I understood a forest to look like.

A great distance of space can exist between trees, sometimes 100-feet from one another. This is why these habitats are also known as “Oak Openings,” and is the name for this one-acre area at Riveredge Nature Center overlooking the Milwaukee River. This portion of the property also boasts uniquely untilled original soil and a rarely seen guild of native plants. But what else is unique about Oak Openings?

The Oak Opening, as the name suggests, is a surprisingly open forest.

Oak Openings have become incredibly rare

The numbers of Oak Savanna (a somewhat similar habitat with less tree density than an oak opening) previously standing and currently in existence are staggering. Of the 5.5 million acres that once existed, according to the Natural Heritage Inventory, less than 500 acres exist that had plant assemblage similar to the original Oak Savannas. Similar to savannas, Oak Openings are one of the rarest and most threatened habitats in the world. Summarily, many of the plant and animal species that flourished in these systems have perished, or their populations have taken hits as they struggled to find other, less suitable habitats.

Autumn Oak leaves in the sun at Riveredge

Pre-settlement, wildfires and fires set by Native Americans took place across the US throughout the year, burning off smaller trees and invigorating understory plant seeds to sprout. Oaks have thick bark and a deep taproot, which equips them uniquely to tolerate fires more than other woody species. After a fire the only plants that stood throughout the charred landscape were oak trees, such as Bur Oak.

What happened to Oak Openings?

Prior to settlement, about half of Wisconsin was covered in Oak ecosystems (such as oak woodland, oak savanna, oak opening). When settlers moved west into this territory, these oak ecosystems appeared, and proved to be ideal areas for farmland and more readily cleared than a dense forest. Many of the soils were rich in nutrients after centuries of plants and animals had built up the soil. The removal of indigenous peoples, their customs, and traditional ecological knowledge, as well as the removal of fire fuel continuity by turning over original ground with the plow, worked to suppress fires that had been previously afforded greater affect on the landscape.

The Riveredge Maple Sugarbush, across Highway Y from the Oak Opening.

Oak trees provided ideal building material for houses and barns, and if any was left over it became firewood. Millions of linear board feet would be shipped to become furniture, tool handles, and flooring throughout cities such as Milwaukee. While the wood lasted, logging was a bustling business in Wisconsin.

In areas of Oak Savannas that still stood, without fire management or grazing by wild or domesticated animals, smaller trees would begin to grow up between oaks, competing for sunlight and rain. Invasive species such as Buckthorn would begin to fill in areas that were previously the domain of native plants that grow more slowly. When we picture a forest, this, comparably more cluttered, landscape is likely what we imagine.

Today, an oak opening gives the same reprieve from a forest’s overstory as it always has; however, it now represents some of the best of what many areas have lost. For ecologists, oak openings and other similar rare habitats now act as living libraries of species and their interconnected assemblages, to reconstruct in our restoration efforts.

This summer, experience Wisconsin’s natural heritage by visiting the Oak Opening at Riveredge Nature Center, and continue visiting throughout the seasons. This location is also one of our most picturesque locations from which to view the Milwaukee River. In this now uncommon location, you can experience the tranquility that can only be found within trees that live for hundreds of years.

Overlooking the Milwaukee River from the Oak Opening at Riveredge Nature Center.

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