Bug o’the Week – Neokolla hieroglyphica Leafhopper

Greetings, BugFans,

Although this cute little leafhopper has several names – Neokolla hieroglyphica and, formerly Graphocephala gothica (and see “Extra credit” below), it doesn’t have a common name.  It’s in the leafhopper family Cicadellidae (sik-ah-DELL-ih-dee says bugguide.net), a group that the BugLady used to call “pop-bugs” in her youth because they landed on her jeans in the fields, and when she touched their rear ends, they popped away.  There are about 3,000 species of these little bugs in North America and about 22,000 described species elsewhere, but experts estimate that there may be three times that number still awaiting discovery (it’s always refreshing to reaffirm that we don’t know everything yet).

You can tell leafhoppers from similarly-sized spittlebugs by the row of spines on the hind legs of the leafhoppers https://bugguide.net/node/view/1752304/bgimage.

Leafhoppers are small, usually less than 1/3 of an inch, and yet their numbers include a few migratory species that recolonize the north in spring and retreat in fall.  They’re in every habitat where you find vascular plants, and they feed on plant sap that they access by poking a hole in a stem with their sharp mouthparts.  They are among the insects that release excess food from their rear end in the form of a sugar solution called honeydew.  Honeydew is an important carbohydrate that is eaten by other insects, but leafhoppers are not farmed by ants like some other honeydew producers are.  Some leafhoppers are generalist feeders and some prefer only a short list of hosts.

Many are drab, but there are some pretty spiffy leafhoppers out there: https://bugguide.net/node/view/55317/bgpagehttps://bugguide.net/node/view/688689/bgimagehttps://bugguide.net/node/view/368756/bgpagehttps://bugguide.net/node/view/1262101/bgpage,

https://bugguide.net/node/view/318789/bgpage.

Female leafhoppers insert eggs into a plant, and depending on geography and season, the eggs hatch in a month to a year.  They have incomplete metamorphosis – the nymphs hatch out looking not-unlike their parents.  They eat and molt and grow, adding a few body parts and lengthening their wings, achieving adulthood in their final molt rather than via a resting stage in a pupal case.

Neokolla hieroglyphica can be found in grassy areas across the northern US and southern Canada (and south, in a few locales in California and the Southeast).  Bugguide.net calls it “The only pink leafhopper east of the Rockies” but adds that the color can be variable: (https://bugguide.net/node/view/1724691/bgimagehttps://bugguide.net/node/view/520961/bgimagehttps://bugguide.net/node/view/70866/bgimage, and https://bugguide.net/node/view/344994/bgimage.  An “M/omega”-shaped mark on the top of the head is diagnostic https://bugguide.net/node/view/734068/bgimage.

The translucent-ish nymphs look metallic https://bugguide.net/node/view/71461/bgimagehttps://bugguide.net/node/view/1350037/bgimage (what would we do without bugguide.net?).

Neokolla hieroglyphica is fond of alfalfa, and it may be a vector of a virus called alfalfa witches broom.  The wonderful Illinois Wildflowers (https://www.illinoiswildflowers.info/) associates them with goldenrods, and another source connects them with willows.

Fun Leafhopper Fact # 1: Neokolla is in the subfamily Cicadellinae, called the Sharpshooters because when they release honeydew, you can hear a faint sound like a teeny popgun.

Fun Leafhopper Fact # 2: leafhoppers sing, but we can’t hear them.  Structures on the abdomen allow them to make sound.

Fun Leafhopper Fact # 3: leafhoppers produce “brochosomes,” waxy substances made of proteins and fats that they distribute on their body to waterproof it.  Sometimes it’s smeared on unevenly and forms blotches https://bugguide.net/node/view/1370252/bgpage, and some species put some on their egg scars to prevent dehydration.  Check Wikipedia’s article about brochosomes, complete with pictures (https://en.wikipedia.org/wiki/Brochosome).

Leafhopper Fun Fact #4: you can buy one from BioQuip Biological Supply Company for $5.00.

Extra Credit:

For extra credit, the BugLady is including this write-up from the North Carolina biodiversity project about the classification of Neokolla hieroglyphica (these people seriously want to get it right!): “G. gothica and G hieroglyphica are somewhat of a taxonomic mess and can be quite confusing: while many experts treat these two species as belonging in Graphocephala, some place them in the genus Neokolla. Both species were initially described as Tettigonia gothica and T. hieroglyphica [BugLady note: Tettigonia is a European genus of katydids, which is a whole different discussion]. When they were elevated to Neokolla, both were synonymized under Neokolla hieroglyphica (in particular, T. gothica was N. h. atra and T. hieroglyphica was N. h. hieroglyphica). Young (1977), who revised Cicadellini comprehensively, treated Neokolla as a junior synonym of Graphocephala, something that has been followed by other leafhopper workers. Neokolla was later resurrected in a paper based on an interpretation of Say’s original description of the type species of Neokolla (hieroglyphica Say) that was contrary to those of prior authors (plus, Say’s description could apply to either hieroglyphica or gothica, as evident by both being placed under the same species within Neokolla). Neokolla species in general are quite variable in coloration, with some of these colors getting named forms, which some have then elevated to species status. As a result of this taxonomic disagreement, Graphocephala gothica is what some are currently calling Neokolla hieroglyphica, and Graphocephala hieroglyphica appears to be what some are calling Neokolla uhleri (though uhleri, considered for some time as a variety of hieroglyphica, was depicted in older literature as having quite different head markings). For now we will go with what takes precedence, following Young, but as you can see this taxonomic reshuffling has resulted in quite a bit of confusion and complexity.

And the stink bug nymph is pretty cute, too.

The BugLady

Bug o’the Week – Small Magpie Moth Mystery

Greetings, BugFans,

A few days ago, the BugLady was mulling over which insect she was going to feature in the next BOTW.  She headed out the door to hike to the mailbox, and there, on the inside of the storm door, trapped between it and the back door, sat this beautiful Small magpie moth.  The BugLady managed a few mediocre shots (on a west-facing glass door at twilight), but happily, other people have done better: https://bugguide.net/node/view/105683 (some have a broader band on the edge of the wing https://bugguide.net/node/view/1187270/bgimage),  https://bugguide.net/node/view/527448https://bugguide.net/node/view/1475330/bgimage,

https://bugguide.net/node/view/20549/bgimage, and https://bugguide.net/node/view/141026/bgimage.

Small magpie moths (Anania hortulata) are in the Crambid snout moth family Crambidae. Overall, it’s a pretty drab group of moths, with some delightful exceptions like these, of previous BOTW fame: Bi-colored pyrausta https://bugguide.net/node/view/851405/bgpage, Orange mint moth https://bugguide.net/node/view/1119674/bgimage, Raspberry pyrausta https://bugguide.net/node/view/1382922/bgimage and the White-spotted sable https://bugguide.net/node/view/37715/bgimage.  Crambidae is a small family of 157 mostly-tropical species; their larvae conceal themselves in fruits, stems, or rolled/webbed-together leaves while eating.

They’re in the subfamily Pyraustinae, and according to bugguide.net, Pliny the Elder said that Pyrausta was, “a winged insect that was supposed to live in fire.”  “Magpie” apparently refers to the moth’s flashy black and white scales (there’s a Clouded magpie and a regular magpie moth, too: http://www.wildlifeinsight.com/british-moths/magpie-moth-caterpillar-abraxas-grossulariata/, but not here).

Small magpie moths, it turns out, are not native to North America – they are at home across Eurasia – so the majority of the biographical information the BugLady found was on English nature websites (but, FYI, their Norwegian name is Nesleengmott).  They probably arrived on this continent (at Nova Scotia) in the late 1800’s, and their checkerboard range now includes the Canadian Maritimes and New England states, Quebec, Ontario, Michigan and Wisconsin (with a southern outlier specimen from Maryland), and the Pacific Northwest, to which, according to one source, they were introduced.

When they’re not sitting on storm doors (and it’s not winter), Small magpie moths are found in gardens, edges, hedgerows, and weedy waste spaces.  The BugLady could find no mention of the adults feeding, but the caterpillar https://bugguide.net/node/view/43983/bgimage eats the leaves of nettles (mostly), plus various mints, and bindweed.

There’s only one generation a year – caterpillars make a cocoon in a concealed spot in fall and spend the winter in it, pupating in spring without leaving the cocoon.  They emerge as adults not long after, with a May-to-September flight period.

But here’s the deal.  There’s no way this adult moth should have been on the landscape this week.  Yes, it’s been a mostly-mild winter here (once we got through November), and yes, the UK Butterfly Conservation site says that they “can be recorded as early as February and sometimes as late as November,” but it’s warmer overall in England, with the Gulf Stream, and all.  And one source says that larvae sometimes overwinter in attics (which the BugLady doesn’t have).  So where did this moth come from?  (And where did it go?  The BugLady looked down to fiddle with her camera and when she looked up again, the moth was gone – presumably into the house – no sightings yet.)

Rabbit hole alert:

For those who want to pursue the Pliny translation further, bugguide.net offers this link to the Tufts University Perseus Digital Library and Pliny’s writings about “An Animal Found in Fire” http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.02.0137%3Abook%3D11%3Achapter%3D42.  “That element, also, which is so destructive to matter, produces certain animals; for in the copper-smelting furnaces of Cyprus, in the very midst of the fire, there is to be seen flying about a four-footed animal with wings, the size of a large fly: this creature is called the ” pyrallis,” and by some the ” pyrausta.” So long as it remains in the fire it will live, but if it comes out and flies a little distance from it, it will instantly die.”  (Nota bene – there are little blue “forward” and “back” arrows if you can’t get enough Pliny).

Kate Redmond, The BugLady

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

Light Cascading From the Sky in the Darkness of Winter

The moon playing a game of peek-a-boo during a morning ski jaunt on Riveredge trails.

For many of us, winter can be a challenge. Not just slippery surfaces or shoveling snow or driving with greater care, but the lack of sunlight can make these the most trying months. Like any of the seasons, paradoxes abound in winter. Despite being the season of the longest darknesses, snow falling from the sky reflects light, effectively brightening those very twilights.

Personally, I used to have a hard time with winter. Fall reminded me that the long darkness would soon approach, signaling me to dread the lack of light and my mood would plummet until sometime in April. But then I discovered ways to not only survive the winter, but to look forward to them and flourish. I found that getting outside is the first step.

Cross Country skiing after a morning snow in the winter-only section at Riveredge Nature Center.

A few years ago someone gave me an old pair of cross country skis. I’d grown up skiing cross country with my dad, so the movement was familiar. I went skiing and realized that, even though it was a slog the first few tries, I started feeling better afterward. It was a different, better than being on a treadmill or lifting weights. I’d wake up the next day calmer, feeling more refreshed, and with a head full of ideas.

Scientists are publishing research behind the reasons why we feel better during and after being outdoors. In a recent study by Stanford University, researchers found that spending time walking in a forested environment positively affected participants brains in ways that taking a walk around the block did not. Myriad studies abound praising the effects nature has on the developing brains of children. If children learn to seek nature for rest and relaxation, they will be better equipped to deal with the stresses of each following day.

Students of The Riveredge School learning to cross country ski.

But it doesn’t have to necessarily be about athletic activity in the outdoors (although that generally makes life more comfortable when it’s cold out). Just being outside and breathing forest air has been shown to lower blood pressure, feelings of hostility, and symptoms of depression. It’s no accident that we associate the scent of pine forests with cleanliness and renewal.

Riveredge Members preparing to head out in search of the Yule Log.

At Riveredge, we host a number of programs throughout wintertime designed to get you outside, or at least get you out of the house in the direction of being outside (You’re already dressed for the weather…might as well go for a hike). A great start your weekend by getting outdoors during our Friday Night Candle-lit Hikes. But beyond that, these 10 miles of trails are here waiting for whenever you’re able to fit a little nature into your schedule. Even though winter may be the season of long nights, it’s also the only season when the trail twinkles alongside your steps.

 

– Ed Makowski, Riveredge Marketing & Communications Manager

Bug o’the Week – And Now for Something a Little Different VIII – What Are Those Things?

Greetings, BugFans,

The BugLady is recovering (slowly) from some computer issues, her convalescence complicated by the fact that she doesn’t speak the language.  This article is modified from one she wrote for the Winter, 2014 issue of the BogHaunter, newsletter of the Friends of the Cedarburg Bog.

Crusty green or gray growths that look like they’ve been pounded or sprayed onto rocks and tree trunks.  Small, shrubby clumps attached to tree branches.  Tiny gray-green chalices or gnarled, red-topped fingers.  Brilliant orange cups and tongues appropriately named “sunburst.”  What are those things?

Lichens.

Naturalists take great glee in telling their audiences that “a lichen is a fungus and an alga that have taken a liken’ to each other.”  Lichens are two organisms in one package – “composite organisms” – a fungus and (usually) an alga.  If you had been reading about them a few decades ago, they would have been classified as non-flowering members of the Plant kingdom in their own taxonomic division.  Today, because a fungus contributes the characteristic shape of most lichens, the majority of lichens are classified in the Fungus kingdom.  Only about 20% of fungus species are able to “lichenized,” and a lichen fungus without its alga partner is formless.

Most lichen fungi are very particular about who they partner with.  Green and yellow-green algae, the typical algal partners, used to be classified as plants, too, but today are recognized as members of a large mish-mosh of generally tiny (but some as large as giant kelp), unicellular and multicellular, not-closely-related organisms that photosynthesize.  Some lichens contain cyanobacteria, and others may house both.

There are between 3,500 and 5,000 species of these often-overlooked organisms in North America and around 20,000 worldwide; and they are said to cover 6% of the earth’s surface.  Fungi have been living the “lichen lifestyle” for a long time – possibly as long as 400 million years (they don’t fossilize readily).  Visually, they are cataloged by growth form; the three most common groups are the foliose (leafy), crustose (crusty), and fruticose (shrubby) lichens.  Ecologically, some prefer to grow on a substrate of rocks, others like tree trunks or logs and may be picky about the tree species that they sit on (they just sit – they’re not parasites), and some live on the ground.

Calling them composite organisms actually may be underselling them a bit.  In the rich vocabulary of ecology, they are holobionts – essentially, each is a small ecosystem, a host with a collection of closely-associated viruses, bacteria, fungi, and primitive single-celled critters on board.

The biology of lichens is complex, and the BugLady suggests starting with the well-illustrated Lichens of the North Woods by Joe Walewski (no, the BugLady doesn’t get a kick-back from her frequent recommendations of the North Woods series).  One thing that lichenologists, who seem to enjoy a good argument, agree on is that even with today’s scientific tools, the more we study lichens, the more questions we raise.

Lichens can take root just about anywhere and can tolerate some pretty extreme climates (they’ve been grown in simulated Martian conditions).  They survive drought and heat by suspending metabolism, but, according to Walewski, some species continue to photosynthesize even after temperatures drop below freezing.  They are pioneer plants, often the first to grow on bare earth or rocks, and they are soil-makers, penetrating the rock surface minutely and allowing moisture to enter, moisture that freezes and ultimately cracks off tiny rock flakes.  They grow slowly and may live for a long time (a crustose lichen in the Arctic may be 8,600 years old), but eventually, their decay adds organic matter to the surface and enables the later stages of succession – mosses, grasses, wildflowers, and trees.  Cyanobacteria are nitrogen-fixers that contribute to the fertility of the soil.

How do they work? The fungus provides structure and attachment, and it absorbs moisture and nutrients, primarily from the atmosphere.  It absorbs water and impurities indiscriminately, and some species, sensitive to air pollution, are considered indicators of air quality. The alga also gets water and minerals from the air, and the food it makes through photosynthesis is used by both partners.

This win-win partnership is often labeled as mutualism, a relationship from which both partners benefit.  Because the algal partner can exist in nature without the fungus, but not vice-versa, some scientists call it commensalism, a relationship in which one partner benefits and the other is unaffected.

Lichens can reproduce sexually or asexually/vegetatively. Vegetative lichen reproductive structures are little starter kits that contain cells of both (all) partners. They may be special structures (diaspores – algal material in fungal wrappers) produced and released by the lichen, or they may simply be a piece of the existing lichen that breaks off and grows where it falls.  Less commonly, lichens reproduce sexually, just like a mushroom, making spores that carry only the genetic material of the fungus.  It’s a chancy proposition, since the fungal spores must come in contact with the appropriate algae in order to grow.  The alga within the fungus can only reproduce asexually.

Lichens do not go unnoticed by wildlife.  Northern Parula Warblers and Ruby-throated Hummingbirds incorporate them into their nests, and lichens (which are protein-poor but carbohydrate-rich) are eaten by a variety of insects, snails, slugs, deer and reindeer.  Wikipedia tell us that “Lichens are also used by the Northern flying squirrel for nesting, food, and a water source during winter.”  Humans use them as an emergency food (George Washington’s troops at Valley Forge ate a soup made with rock tripe lichens), and the secondary compounds made by these “simple plants,” mainly for their own protection, turn out to be useful to us as dyes and as medicines – including antibiotic and antiseptic agents (because it looks like a lung, Lobaria pulmonaria was used to treat respiratory ailments).

 

Welewski quotes a lichenologist who describes lichens as “a fungus that has discovered agriculture.”

The winter landscape is a good place to discover lichens because they’re not hidden by leaves.  Go outside.  Take a hand lens.  Look at lichens.

Kate Redmond, The BugLady

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

Bug o’the Week – Clouded Plant Bug

Greetings, BugFans,

 

For several years the BugLady has been photographing this nifty little bug at the edges of Riveredge prairies.  She figured it was one of the (many) mirid plant bugs, but it’s been uninviting outside lately – damp and cloudy, with a chance of slush – so she applied herself and decided on the Clouded plant bug (Neurocolpus nubilus) (probably).

Miridae is a large family in the “true bug” order Hemiptera.  If you have an older insect field guide, Miridae is part of the former order Homoptera, which has been folded into Hemiptera.  With more than 10,000 species overall (about one-fifth of them in North America), mirids are the largest family of Hemipterans.  Many mirids are plant eaters, and some are unwelcome in gardens and agricultural fields, but Tarnished plant bugs are singlehandedly responsible for much of the family’s bad reputation https://bugguide.net/node/view/1494218.

 

Like all “true bugs,” a mirid’s mouthparts are adapted for piercing its food source (be it animal or vegetable) and sucking the fluids from it (the mouthparts are tucked along its underside when not in use, which can be seen in one of the BugLady’s pictures).  Its wings are membranous at the tips and more leathery where they attach to the body (Hemiptera means “half wings”).  A small downward “fold” of the wings toward the bug’s posterior is a mirid field mark.

Clouded plant bugs resemble many other mirids in that they are small, angular, and cryptically colored in various shades of brown (there are some spectacular mirids, though: https://bugguide.net/node/view/1672242/bgimagehttps://bugguide.net/node/view/284743/bgimagehttps://bugguide.net/node/view/1016022/bgpagehttps://bugguide.net/node/view/506088/bgpagehttps://bugguide.net/node/view/399110/bgpagehttps://bugguide.net/node/view/1294241/bgpage, and https://bugguide.net/node/view/1060593/bgimage).

 

The Clouded plant bug is found in the eastern and mid-western parts of North America, and Americaninsects.net describes it as “widespread, but not always common.”  Of the 14 species in the genus, some are nearly identical and could be a “species complex,” a slippery assemblage of very similar-looking, closely-related species that may or may not be able to interbreed successfully and that confuse biologists (but not each other – they know who they are).  Neurocolpus are less than ½” long, adults and nymphs have a swollen, bristly segment at the base of each antenna (https://bugguide.net/node/view/96507/bgpage), and they have heavy “thighs” on their third set of legs, which the BugLady didn’t even notice because she was so enthralled with the front end of the bug.  Nymphs are greenish, and their antennae are red-and-white striped https://bugguide.net/node/view/192135.

Both the adults and the flightless nymphs are generalist feeders, and the list of plants that they’ve been seen on has more than 40 species on it, both woody and herbaceous (mints are near the top, along with composites and a variety of bedding and perennial plants).  Cotton is on that list, too, and Clouded plant bugs are considered minor cotton pests that may be increasing as insecticide regimes have changed.  Their feeding causes round spots of dead tissue on leaves, and in cotton, the shedding of small buds, but their populations peak too late in the growing season to have a big impact on cotton yields.

 

Along with camouflage, lots of mirid species dodge predators by secreting nasty chemicals through pores in their sides, but this doesn’t always deter hungry birds, spiders, and insects.  Adults are quick to take flight, and nymphs dash around to the opposite side of a twig or under a leaf when danger threatens.

 

Females lay eggs deep in plant tissue.  There are several generations each year in middle and southern states, and the final generation overwinters in the egg stage.  Look for them here throughout the summer.

 

Kate Redmond, The BugLady

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

Bug o’the Week – Elm Sawfly

Howdy, BugFans,

The BugLady got a few “what’s this dynamite caterpillar?” pictures from a friend toward the end of summer – one of a larva, and one of a pupal case in not-very-good shape.  She usually gets “what’s this wasp/fly?” pictures of the equally-distinctive adult in June, like this one from BugFan Andy.

Sawflies are small, primitive wasps (ancestral sawflies were around 250 million years ago) that most people have never heard of, and they usually carry out their business below the radar.  They’re in the large order Hymenoptera (ants, bees, wasps, and sawflies) and in the family Cimbicidae, which includes about 200 species (12 in North America).  Cimbicids lack that famous “wasp waist,” have prominently knobbed antennae, and some of the heftier species can be mistaken for hornets https://bugguide.net/node/view/1544361/bgimage.  Their larvae resemble moth or butterfly caterpillars until you compare eyes (sawflies have fewer) or count legs (sawflies have more).  There have been a number of previous episodes about sawflies – here are two of them: https://uwm.edu/field-station/sawflies-among-us/ and https://uwm.edu/field-station/slug-sawfly-a-skeletonizer/.

With ¾” adults and 2” larvae, the Elm sawfly (Cimbex americana) is the largest (or “among the largest,” depending on who you read) sawfly in North America.  The (usually) blue-black adults are sexually dimorphic (“two forms”).  Females have thickened femurs on the second and third pair of legs, and they usually have pale, wrap-around stripes on the abdomen that don’t quite touch at the midline https://bugguide.net/node/view/610402/bgimage.  Males’ legs are massive https://bugguide.net/node/view/1099589/bgimage, and they may have a red or black abdomen.  Both have smoky wings, orange antennae, and a white spot at the base of the thorax.

As Eric Eaton says in his bugeric blog, “They do not have a stinger.  Both genders simply look intimidating” http://bugeric.blogspot.com/2012/06/wasp-wednesday-elm-sawfly.html.

The pebbly-textured larvae come in a rainbow of colors: https://bugguide.net/node/view/1724940/bgimagehttps://bugguide.net/node/view/1495194/bgimagehttps://bugguide.net/node/view/1421517/bgimagehttps://bugguide.net/node/view/1525493/bgimage, and,

rarely, pink https://bugguide.net/node/view/708165/bgimage,

with a creepy-looking head https://bugguide.net/node/view/1700150/bgimage that looks like something that the BugLady saw in an X Files episode.

These amazing larvae are chemically defended – glands near the spiracles (breathing pores along the sides of the body) produce unwholesome liquids that can be released through the pores.

The “saw” in sawfly comes from the female’s egg laying apparatus, which she uses to make a hole in the underside of a leaf (or twig, say some sources) in late spring.  She may deposit several eggs on one leaf, and she can lay more than 125 of them, total.  True to her name, elm is the main host plant, but she also oviposits on willow (another favorite), and incidentally on maple, birch, willow, basswood, cottonwood, poplars, ironwood, plum, alder, boxelder, and apple.  The larvae eat their host’s leaves, wrapping their rear half around twigs while feeding https://bugguide.net/node/view/1716690/bgimage (and curling up tightly at rest https://bugguide.net/node/view/1006040/bgimage).  When they’re almost-mature, they drop to the ground to make a pupal case in the leaf litter, and they complete their metamorphosis in spring https://bugguide.net/node/view/931802/bgimage.  Or they may decide to stay tucked inside their cocoon until the following spring.

They are vegetarians as larvae and adults.  Adults have sturdy jaws that they use to pierce and even girdle the bark of twigs so they can feed on the sap.  Larvae are attacked by a number of parasites/parasitoids, and larvae and pupae are eaten by mice and shrews.  Populations can be somewhat cyclical, and the larvae may be minor forest pests in peak years, but harm is minimized because they’re feeding late in a tree’s growing season.

Kate Redmond, The BugLady

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

Bug o’the Week – Spinybacked Orbweaver– A Spider for Snowbirds

Greetings, BugFans,

 

This episode is dedicated to BugFan Tom.  Tom has a day job, practices suburban agriculture afterwards, and conducts field research by night, so the BugLady really appreciates his fitting spider studies into his off time.  He has an insatiable curiosity – and a camera – and he provided many pictures and lots of wonderful running commentary and deep thought about a cast of backyard spiders that he got to know personally (his BugFan wife suggested that he may have taken more pictures of those spiders than of his offspring’s childhood, a complaint that the BugLady’s parents would have been sympathetic to).

 

As Tom says, “There is a lot going on here, which is why they need eight legs.”

 

Ask a birder what a snowbird is and they’ll tell you it’s a Dark-eyed Junco, a bird whose idea of “flying south in winter” may only bring them from their nesting grounds in Canada to bird feeders here in God’s Country (though some do reach the Gulf Coast); 844 juncos were tallied during the Riveredge Nature Center Christmas Bird Count on Dec. 14.  Ask Chambers of Commerce of communities along the southern edge of the US what a snowbird is, and they’ll tell you that snowbirds are Northerners who fly south for the winter months.  If you’re a snowbird, check the bushes, orchards, edges, and gardens from the Deep South and the Caribbean west through southern California, and south into South America for these unique spiders; you won’t find them in Wisconsin.

They’re called Spinybacked Orbweavers (Gasteracantha cancriformis), in the orb weaver family Araneidae.  According to bugguide.net, “gaster” and “acantha” are Greek for “belly” and “thorn,” and “cancriformes” is Latin for “crab-shaped.”  Not surprisingly, they’ve picked up lots of common names – Crab-like Spiny/Crab-like Orbweaver, Jewel Box/Jewel Spider, Spiny-bellied Orbweaver, Smiley Face Spider, and Crab Spider (though they’re not related to our goldenrod crab spiders in the family Thomisidae).  Early taxonomists sometimes mistook the different color variations for separate species.

Tom’s great macro photography makes them look larger than they are – females are about a half-inch long and a little wider, and males are much smaller.  Females have six, sturdy spines on their abdomens, and males are just lumpy https://bugguide.net/node/view/1111533/bgimage.

 

Males court warily in fall, first hanging from her web by a thread, and then tapping in a four-tap rhythm.  He approaches her, and she responds by wrapping him in silk (her favorable response apparently starts out the same as her unfavorable response would) and, with the web vibrating, they copulate.  He staykus at her web afterwards and dies six days later.  She sits in her webs, making an egg sac that contains as many as 260 eggs, then she spins a silk pad on to the underside of a nearby leaf, and fastens the egg sac to it.  She covers it with cream-colored or yellow silk, runs a dark green silk line down the center, and finishes it with a canopy of coarse, green threads.  When the protective case is finished, she dies

The spiderlings overwinter and hatch within the silken nest, finally exiting by February (southern climes, remember?)  The BugLady found several different phenologies for Spinybacked orbweavers – they are, alternatively, present in the egg case in November through January and as spiderlings and adults for a few months after that; present as adults over winter until they reproduce in spring; or, in Florida, present all year as adults (females), or present except in December and January (males).  Tom, in Mississippi, sees eggs sacs in October and early November and doesn’t start seeing the webs until mid-spring.  The BugLady suspects that location must be the key.

 

Like almost all spiders, they’re (mostly) carnivorous, feeding on the small insects that fly into their webs.  The catch of the day may be eaten immediately or paralyzed, wrapped, and stored.  BugFan Tom wrote about dodging biting flies by ducking under spider webs.  The hard carapace and spines make her unappealing to predators, but her egg cases do get parasitized.

Two things about the Spinybacked orbweaver:

 

First – Why?  A brightly-colored spider with spines sharp enough to puncture human skin if handled roughly (her bite isn’t dangerous).  Form is function – the sturdy spines certainly discourage birds and other large predators, and one source mused that it would be tough for a solitary wasp to drag a spiny spider underground to provision its young.  But, why red, orange, yellow and white?  The “prey attraction hypothesis” says that spider prey is attracted to the bright colors, but research does not support this – spiders that were painted black captured more prey.  The bright colors are more likely “aposematic” (warning) coloration.   Some color forms may be regional.

 

Second – so much has been written about that wonderful web.  She spins a new one every night (Tom observed one spider at work on a new web before 7:30 AM and wrote “So I still have no idea when she dismantles the capture spiral from the previous day. I have to sleep sometime.”), and she will sometimes destroy her web in a rainstorm, gathering it into a glob that she presses to her mouth before discarding it (she may be harvesting both moisture and nutrients from it).

Here’s Tom’s description of a web in progress: “Check out the attached image. This is the right side of her web, she is moving clockwise (toward the ground on this side of the web), and has just attached a strand to the radial immediately above her and is reaching out to grab the next one, which is barely visible to her left, and toward the bottom of this shot. Notice that the radial to which she has just attach a new capture spiral strand is not straight, but is bent (stretched) downward toward her just to the right (from your perspective) of her rightmost rear leg. You can see the new length of capture spiral extending from her spinneret back to the previous radial. Now, check out the point where the radial is ‘bent’ toward the ground, as described previously. There you can see a fine strand extending vertically to the top of the slide, and downwards toward and beneath the spider, though I cannot see it clearly beyond the spider and to the bottom of the slide. This is, I believe, a pre-capture spiral (might not be the right name), and these are mainly not visible to the naked eye, or to mine at least. She moves along these and the radials as she lays new capture spiral, pulling the radial toward her, attaching the new line, then releases the radial and moves to the next.

 

She deposited about 40 new lines within the capture spiral, but did not continue these to the center of the web, and next attached bird visibility tufts to the otherwise bare radials extending to the center of the web.

Webs are formed at a slight angle to the ground, in vegetation or on structures (males stay near female’s webs).  At the center is a disc where she rests, and she may extend as many as 30 radii.  She leaves a gap just outside the center, and then she starts spinning the sticky “capture spiral,” working clockwise (Tom had one ambidextrous spider that sometimes worked counter-clockwise), and the capture spiral may be two feet across (half-inch spider, remember).  Females orient themselves in the web “belly up,” with their backs toward the ground, presenting a dark surface in the central disc; it’s not certain if this is for camouflage/counter-shading or for thermoregulation.

They attach little white tufts of silk to the web, and there’s much discussion about that.  Do they make the web more conspicuous (web advertisement), so larger animals can see and avoid it, like the zigzag stabilimentum in the web of a Black and yellow orb weaver/garden spider?  Or, do the tufts reflect UV rays and attract prey?

 

Researchers Gawryszewski and Motta painted the white tufts black and saw no change in the quantities of prey captured, and the painted webs didn’t get damaged any more or less frequently than unpainted.  They reject both hypotheses and “propose that silk tufts might be an aposematic signal.

 

Here’s a neat article about comparative web-spinning techniques in orb-weavers: https://www.conservation.unibas.ch/team/zschokke/pdf/zschokke1995eje.pdf

 

Thanks a million, Tom.

 

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 VII – Attack of the Killer Shrews

Howdy, BugFans,

 

This is a revised version of an article that the BugLady wrote for the winter, 2013-14 issue of The BogHaunter, the newsletter of the Friends of the Cedarburg Bog, an organization that partners with UWM and the DNR to educate people about the Bog and to preserve it.  The Bog is the BugLady’s church and her shrink.

 

Northern short-tailed shrews (Blarina brevicauda) are one of the most common small mammals between the Great Plains and the Atlantic, but they are rarely seen.  In winter, when they aren’t sheltering in out-buildings, they’re found in the intranivean and subnivean layers – the spaces between the ground and the top of the snow.  The meandering, inch-wide tunnels they make just below the snow’s surface offer some protection from predators, though foxes and owls can hunt by ear, and shrew bones are common in owl pellets.

 

Largely nocturnal in summer, they spend the daylight hours under rocks or logs, in leaf litter, and as deep as 20 inches underground in tunnels that they dig with their front paws (they also use burrows made by voles and moles).  In winter, they hunt during the balmier daylight hours.  They’re habitat generalists.

A short-tailed shrew’s winter diet includes mice, voles, and other shrews.  In warm weather, they add insect larvae (shrews can be valuable controllers of pest insects), snails, slugs, earthworms, crickets, salamanders, snakes, and even small birds to their diets.  They eat some roots, seeds and berries year-round, and they may also scavenge on dead animals.  They usually dine underground, and they are known to cache food caught when they’re full, for use in leaner times.

 

Shrews are always operating in overdrive; their heart rate of 800 to 1300 beats per minute exceeds that of a hummingbird, which goes from 250 beats per minute at rest to 1250 in flight.  Their high metabolism requires them to feed every two to three hours and to eat up to three times their weight daily in order to keep going. They hunt for about five minutes out of every 30.

 

Because they have glands that produce poisonous saliva (few other mammals do), short-tailed shrews can pick on critters their own size.  The venom isn’t injected through hollow fangs; the shrew has to gnaw on its victim a bit.  The venom, a neurotoxin, slows their prey’s heart and respiration rate and can kill them or can paralyze them for future use.  Short-tailed shrew bites are dangerous for dogs and cats, and even humans experience burning and significant swelling at the site of a bite.

 

Although they look mouse-like, short-tailed shrews are not rodents, but are grouped with moles in the order Insectivora.  They are three to four inches long (males are a bit larger than females) plus an inch-long tail that they hold up in the air as they travel (they walk on those short legs, rather than hopping), and they weigh about an ounce.  They have a pointy snout, short, gray fur that can be brushed in any direction, and they lack the large external ears that characterize the rodents.

Like most tunnel-dwellers, their vision is poor (one source said that their eyesight is so bad that they sometimes find their prey by bumping into it accidentally), but their senses of touch and hearing are well-developed.  Some sources say that they have a good sense of smell, but others disagree.  They scent mark their tunnels with a foul-tasting musk that’s manufactured in glands on their belly, but if their sense of smell is poor, this could be a warning to other species.  They communicate using a vocabulary of squeaks and clicks (some of which we can’t hear), and navigate underground using echolocation, like bats.  They are said to growl contentedly while feeding, which the BugLady thinks is charming.

 

Except during the breeding season, short-tailed shrews tend to be solitary and territorial.  Three or four litters are born each year, and the young of early litters may be parents themselves by the end of fall.  A three-year-old shrew is a very old shrew; winter mortality is high, and most don’t make it to their first birthday.

 

Add short-tailed shrews to the growing list of animals that are making themselves at home in the big city.  In a study of shrews reported in a blog called Urban Habitats, Virgil Brack, Jr writes about short-tailed shrews nesting in a vegetable garden, on an island in a parking lot, and in a crabapple tree in Cincinnati.  He told of one shrew that entered a garage and fed on a package of hamburger stored there (captive shrews love beef).  Brack also noted that short-tailed shrews are known to come to bird feeders.  Shrew tunnels are common in the snow below sunflower feeders, and it’s not known whether they are preying on invertebrates found there or feeding on the seed itself, but caches of corn have been found in the wild.

 

The BugLady regrets that the only pictures she has of short-tailed shrews are of dead ones (dead insects can often be posed to look like live insects, but alas, a dead shrew only looks like a dead shrew).  The BugLady figures that the dead shrews she finds have simply run out of gas; alternatively, that they were killed by predators that were subsequently discouraged by the shrew’s chemical defenses.  This article from the National Park Service offers another interesting explanation for shrew die-off in the section titled “Live Fast, Die Young, Leave a Smelly Corpse” (https://www.nps.gov/articles/netn-species-spotlight-short-tailed-shrew.htm).

 

The Missouri Department of Conservation puts out lots of great material about wild animals.  See https://mdc.mo.gov/blogs/discover-nature-notes/no-taming-shrew for some good pictures of short-tailed shrews, plus an overly-lurid video whose narrator is having way too much fun.

 

Wikipedia tells us, perhaps unnecessarily, that short-tailed shrews cannot be domesticated.

 

Kate Redmond, The BugLady

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

Bug o’the Week – Water Penny Redux

Howdy, BugFans,

 

In the spirit of New Year’s Eve, here’s a rerun about a really spiffy little aquatic insect, revised from 10 years ago with some new words and pictures and also a correction.  In the original episode, the BugLady erroneously referred to adult water penny beetles as riffle beetles, but they aren’t riffle beetles (despite the fact that they hang out near riffles); true riffle beetles are members of the nearby family Elmidae.

 

Scooping for aquatic invertebrates is a great “gateway” to nature studies for many people – who knew that the world below the water’s surface was peopled by such an amazing bunch of critters!

 

Whether tadpole, fairy shrimp, leech, snail, planarian, or one of the myriad insects for whom the water is either a temporary nursery or a permanent home, aquatic animals face some common challenges.  They need a way to breathe, eat and locomote under water.  They need shelter from predators, a habitat that fills their needs, and a plan for overwintering.  And if an animal lives in swift currents, it has one more problem – staying in one place.  Some inhabitants of moving waters are streamlined, some attach with glue or silk, and others (like the sculpin that faces upstream with its fins braced against adjacent rocks) have structural adaptations to grab their surroundings so they don’t end up downstream.

Water penny beetles are in the family Psephenidae, a family whose immature or larval stage is much better known than its adult stage.  Adults – hairy, quarter-inch beetles https://bugguide.net/node/view/131447/bgimage – can be found in the water or basking on rocks and logs just above the water line, and also, according to Voshell, in his outstanding A Guide to Common Freshwater Invertebrates of North America, on rocks on wave-washed lakeshores.  There are 16 species of water pennies in North America; fewer than three hundred species occur world-wide, and the greatest diversity is found in the Orient.

 

Called water pennies for their shape and color, the larvae look like tiny, oblong suction cups https://bugguide.net/node/view/477142/bgimage dressed in camouflage.  They live underwater on rocks in rapid currents – an unusual habitat for a beetle larva, but one that offers some protection from predators (we have trouble finding them, but it’s said that trout don’t).

[Etymology alert: the official name for the larva’s shape is “platyform” – “platy” means “flat.”  Platyform is somewhat synonymous with “onisciform,” a word that refers to the flattened body shape of a wood louse (or sow bug or pill bug or roly-poly or potato bug or whatever regional name you learned as a kid).  Interested in the etymology of entomology? See https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1001&context=onlinedictinvertzoology].

 

Head and mouth are located at fore end, and filamentous gills are found at the aft end https://bugguide.net/node/view/207646/bgimage (great series of pictures).  Swift currents tend to be oxygen-rich, and the gills of water pennies grab dissolved oxygen from the active waters they live in (they also have spiracles for taking air in ala terrestrial insects).  Water pennies are indicators of waterways that are high in oxygen and low in pollution.

 

The claws on a water penny’s tarsi (feet) help it latch onto rock surfaces, and the “plates” that make up the tops of its body are flexible, allowing it to mold to the shape of a rock so that water flows over it.  The edges of the plates are fringed with hairs that enhance its grip.  It’s not physically suctioned to the rock, just very streamlined.

 

A female water penny beetle crawls “below-decks” into the swift currents to lay her eggs on the lower surfaces of algae-covered rocks, though she may deposit eggs just above the water’s surface, too.  The hairs on her body hold a film of air for her to breathe.

 

The larvae of some species are marginally social, tolerating nearby larvae, but they’re mostly solitary.  In colder climates, water pennies may take two years to mature, but they usually metamorphose into adults the next year.  They pupate in damp spots on land near the water’s edge or in air-filled chambers underwater, beneath that wonderful larval skin.

 

Adult water penny beetles’ basking days are brief, and they probably don’t eat (not much is known about them).  Water penny larvae are classed, diet-wise, as “scrapers” that ingest the algae and diatoms that live on rocks (a moderate algal film is desirable, but a thick algal mat is not water penny-friendly).  Voshell says that to this end, they are well-adapted.  Their cup-shaped jaws have a sharp inner edge to dislodge food, similar to a paint scraper, and hairs at the base of the jaws to help push the dislodged material into their mouths.  Other sources say that they have scrapers on their legs.  They are light-sensitive, clinging by day to the lower surfaces of rocks, migrating at night to the upper surfaces of rocks where the more nutritious algae grow.

 

So, in summary, these 6 mm critters live in strong currents and are the epitome of “streamlined.”  They don’t get swept away, and under the cover of their “shell,” the material that they scrape and loosen to eat doesn’t get swept away either, because it’s trapped.  What happens under a water penny, stays under a water penny.

 

Kate Redmond, The BugLady

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

Member Guide to Winter at Riveredge

Trail Update January 30, 2020

With Sunday night snow our trails are in fantastic shape! Come visit for an adventure with your skis or snowshoes – we also have snowshoes for rent. All Access Riveredge members are able to check out snowshoes for free! Join us for our Friday Night Candle-lit Hike.

Winter Trails

Winter provides exciting exploration opportunities, as some of the vulnerable trail areas that are otherwise off-limits to foot trafffic are able to be explored once the ground is frozen (see trail map below). We ask that anyone wearing boots or snowshoes walk on either side of identified ski trails in wintertime. Our trails are plenty wide, offering space for everyone to explore in their preferred manner. Trail conditions  are checked by Riveredge staff on a regular basis. Consult the Visitor’s Center for suggested trails and current snow conditions.

Checking out Snowshoes

At Riveredge, snowshoes are free for All Access Members to checkout for use on the Riveredge property and are able to be checked out when we have in excess of 6 inches of new fluffy snow or 4 inches of packed snow. Without sufficient snow, snowshoes will be damaged by digging into the gravel beneath the snow (plus it would probably be easier in boots anyway). Snowshoes are checked out on a first come, first served basis, and can be reserved ahead of time for events. Please affix snowshoes to your boots outside at the head of the trail; do not walk in snowshoes indoors or on brick, gravel, or wooden structures such as the back deck as this damages both the surface and the snowshoes. Snowshoes are available for checkout and must be returned before the building closes and for special events when the building is open (such as Friday Night Candle-lit Hikes).

Pop Up Hours

The Riveredge Visitor Center is generally closed on Saturdays and Sundays in winter, however if we have a decent snowfall and anticipate people having interest in checking out snowshoes, we will have weekend pop-up hours in the Visitor Center.

Winter Trail Map