Bug o’the Week – Beautiful Jumper

Bug o’the Week
by Kate Redmond

Bug o’the Week Beautiful Jumper

Howdy, BugFans,

The BugLady was on a pier at Riveredge Nature Center when this spectacular jumping spider climbed out from between the planks.

Like the old joke about bacon being the gateway meat for vegetarians, jumping spiders seem to be the gateway spider for arachnophobes. Many are fuzzy (well, the spiders are – the BugLady can’t vouch for the arachnophobes), and because the front part of their cephalothorax (the combined head and thorax) is flat, four of their eyes face forward, https://bugguide.net/node/view/1940583/bgimage, and they look at you in a very human way. Plus, they are curious and they have attitude. If the BugLady had not already given her heart to crab spiders, these anthropomorphic little beauties would be at the top of her spider list.

The jumping spiders, family Salticidae (the Latin word “saltare” means “to leap, dance or hop”), comprise our largest spider family, with over 6,000 species worldwide and 315 species in North America.  They are a very diverse family, found everywhere except the very far North and the very far South.  Almost all are carnivores, but there are a few that have added nectar to their menus, and one species (with the fabulous scientific name of Bagheera kiplingi) that is primarily vegetarian.  

They don’t make trap webs like orbweavers, but they do spin little shelters from which they peruse their landscapes and in which they shelter during cloudy or rainy weather.  When likely prey comes along, they stalk it, orient their bodies, and then launch themselves at it (after attaching a “dragline” that controls both their jump and their landing and that provides a lifeline if they overshoot their mark). 

And how do jumping spiders jump?  Not with long, muscular legs, like grasshoppers, but via their hydraulic system.  According to Noel Kirkpatrick, writing for the “Treehugger” blog, when they want to jump, “the spiders cause an extreme change in hemolymph pressure (the spider equivalent of blood pressure) by contracting the muscles in the upper region of their bodies. This forces blood to their legs, and causes their legs to extend rapidly. This quick and sudden extension of their legs is what propels them in the direction they’re aiming.”  Some species may travel two or three body lengths, but others may jump 30 times their length. 

Jumping spiders have good hearing (though they “hear” not with ears but with sensory hairs that pick up sound waves and send messages to the spider’s brain), and they have spectacular vision.  Their eye arrangement – four facing front and four facing up – is characteristic only of the jumping spiders.  Those two, big eyes in the center of their face (AMEs – anterior median eyes) have moveable retinas and supply resolution, color, and telephoto vision.   The ALEs (anterior lateral eyes) on each side are not as sharp, but are far enough apart to allow some depth perception, and research suggests that they tell the AMEs where to look. 

The row of four, fixed “posterior” eyes across the top of their head allow the spider to see light, movement, and wide angles.  Their visual range is nearly 360 degrees, compared to our 210 degrees.  According to a Minnesota Department of Natural Resources website, jumping spiders “are able to identify prey, predators, and mates from up to 30 cm (1 ft.) away.”

In addition, aided by their great vision, jumping spiders can recognize landmarks and find their way home, can learn from their hunting experiences and improve their technique as they age, and can distinguish between animate and inanimate objects (which is pretty sophisticated).  Scientists don’t know how they do that.

And through the magic of TikTok, jumping spiders are having a moment. 

The BEAUTIFUL JUMPER (Marpissa formosa) isn’t particularly warm and fuzzy-looking – or very big – but it’s a striking spider.  It’s found, spottily, east of the Great Plains and around the Great Lakes (it’s a species of Special Concern in Minnesota), and it likes wetlands.  It’s one of those species that has stayed under the radar, so not much is known about it, but it’s presumed to follow the general jumping spider game plan.

Where many species of jumping spiders are chunky, Beautiful Jumpers are long and slim.  They are dimorphic – males (https://bugguide.net/node/view/887835/bgimage) and femaleshttps://bugguide.net/node/view/1867778/bgimage are different colors.  Females are about 3/8” long, and males are slightly smaller.  Like all jumping spiders, they move quickly. 

They eat spiders (including other jumping spiders) and small insects, and they may steal trapped insects from spider webs.  The Minnesota Department of Natural Resources says that “Having spotted a potential quarry, a jumping spider will slowly stalk the prey until it is within jumping distance. Then it lifts its front legs and pounces.”  

Like other jumping spiders, male Beautiful Jumpers dance and thrum for their ladies, displaying their color patterns and making species-specific clicks and buzzes and taps that travel through the substrate and are picked up by her sensory hairs.  Females deposit their eggs into a silk “tent” spun by the male, and then guard the eggs until they hatch and for a short time afterward, until the spiderlings make their first molt and disperse.  “Adolescent” spiders overwinter in silk shelters in logs or rock crevices and mature the following year. 

And, yes, you can find jumping spider stuffed toys online, but caveat emptor – the BugLady found one cute, little, felt jumping spider with cute little antennae.

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 XV – Royal Catchfly

Bug o’the Week
by Kate Redmond

Bug o’the Week And Now for Something a Little Different XV Royal Catchfly

Greetings, BugFans,

The BugLady had a long overdue “Oh Duh!!!”moment recently when BugFan Freda asked her if she realized why Royal Catchfly flowers were named Catchfly. Nope – hadn’t thought about it (insufficient scholarship).

Freda had just discovered, to her horror, that she might be aiding and abetting pollinator murder. Did the BugLady know that the Royal Catchfly was, in fact, a pollinator deathtrap? She had planted a small patch of native wildflowers in order to attract pollinators, and while she was admiring the Catchfly’s beautiful red flowers, she noticed a dead bumblebee. She took a closer look and saw a dead honeybee, one very much alive honeybee that was completely stuck and was trying to pull free from the sticky plant, and a small leafcutter bee that was in the same predicament (and when she gently pried a bee out of the glue, it remained so sticky that it couldn’t fly). There were at least two dead, and two dying bees in her pollinator patch.

Thanks, Freda, for the question (and for most of the pictures).

First off, what’s a Royal Catchfly?  It’s a brilliantly red, native wildflower in the Pink/Carnation family Caryophyllaceae and in the large genus Silene.  Silene is a complicated genus, and various aspects including its genetics, speciation, and the complicated reproductive strategies of some species have been studied for a long time.  Varieties of Silene are planted in perennial gardens and sold by florists, and some, like the non-native Bladder campion (Silene vulgaris) are eaten https://www.minnesotawildflowers.info/flower/bladder-campion.   

Royal catchfly is historically a plant of prairies, savannahs, woodland openings, roadside edges, and railroad rights-of-way, and today it’s considered widespread, but patchily distributed.  Over much of its range, which lies from Kansas and Oklahoma to Ohio, down to northern Florida, it’s considered to be Rare, Endangered or Threatened, and it’s been extirpated (driven locally extinct) from a few states due to habitat loss, invasive plant thuggery, shade, lack of fires, and humans with shovels.

Royal catchfly (Silene regia), and a number of other Silene species, are called “catchfly” because they catch flies.  They are adorned with sticky, gluey hairs (glandular trichomes) on the calyx (the green “vase” that’s formed by the sepals at the base of the flower) and on the upper stems.  The calyxes of older flowers that have shed their petals are a bit tacky, but not actively gluey like the younger flowers, and the leaves are fuzzy but not sticky.    

The sticky hairs (and some stiff, downward-pointing hairs toward the bottom of the plant) are very effective in stopping insects that might try to climb up the stem toward the flower (though one author had seen some aphids and their guardian ants navigating the stems).  They’re equally effective in deterring “nectar robbers” – insects like bumble bees whose tongues aren’t long enough to reach the nectar prize from the top of the flower, so they chew their way through the calyx from the side, sip the nectar, and don’t do any pollinating at all.  One author says that the plant is “selecting for” airborne pollinators,” the chief of which is the Ruby-throated hummingbird, though moths with long proboscises that hover in front of the tubular flower could get away with it, as can swallowtail butterflies.  Insects can’t see the color red (hummingbirds can), and apparently, although many insects can see ultra-violet light, a UV image of Royal catchfly doesn’t reveal any insect “come hither” signals.   

What happens after the bugs get caught? 

The logical leap is that having gone through the effort of catching them (producing the hairs requires an energy investment from the plant, after all) the catchfly uses them.  Some sources speculated that this kind of insect entrapment might be a step toward an eventual life of carnivory and wondered if the catchfly had any way to absorb the nutrients in its victims, like a sundew does.  In his Master’s Thesis in 2017, Garrett John Dienno held up two yardsticks to measure the Royal catchfly’s possible carnivory: “1) whether S. regia actively attracts, captures, and retains prey, and/or secretes digestive enzymes to facilitate nutrient absorption; and (2) whether it absorbs and translocates the resultant nutrients.”  Spoiler alert – No and No.  There is no insect-attracting nectar and no UV signal, and the glandular hairs do not secrete any digestive enzymes.  He concluded that “Instead, we propose the glandular trichomes on the S. regia calyx provide a passive defensive benefit to the flowers and seeds by protecting the very structures that are supporting their development.” 

The published word on the catchflies is a bit murky, though, and there’s some just plain bad information out there.  One otherwise respectable plant nursery noted that Royal catchfly comes from a carnivorous family (possibly the same nursery that once claimed that Cup Plant (https://www.illinoiswildflowers.info/prairie/plantx/cupplantx.htm) digests the insects that drown in the water pools formed by their perfoliate leaves).  The Pink family Caryophyllaceae is not known for carnivory, but the Order it’s in, Caryophyllales (a much bigger umbrella) does include some families with carnivorous plants (it also contains cacti and beets).  What a difference a few letters make!

A number of nursery catalogs and other publications state that because having small, rotting insects stuck to their stems would be unhealthy for Royal Catchflies, the plants get rid of the bodies by secreting enzymes that break them down before they “get putrid.”  Self-preservation rather than nutrition.  Way back in 1876, a Professor W. J. Beal wrote about a related plant that “We need not necessarily suppose that they are digested because they are captured by sticky plants.”  

A gardening site’s description of the related and equally sticky Night-flowering catchfly, which is pollinated by moths, said that “When the moth touches the plant it finds that it cannot get away easily and so is more likely to get covered in pollen, or release any pollen it is already carrying, as it tries to break free. This it will do, because the plant is not insectivorous and is only interested in temporary prisoners rather than permanent ones.”  So, happily, the plant’s intent is not to harm it.  

One nursery suggested that the stuck bugs might provide a feast for insectivorous birds.  The BugLady can picture the hummingbirds that come for nectar noticing the stuck insects and picking them off the plant (small insects are a regular part of their diets) but she can’t picture sparrows or chickadees doing that.  It’s possible that long-legged insects like wasps and yellowjackets, which forage for protein for their larvae, might check the catchfly’s offerings.

The British are not immune to this silliness.  Back in 2009, Scientists from the Royal Botanic Gardens, Kew and the Natural History Museum concluded that petunias, potatoes, and several other common plants were meat eaters – or at least on the way to being meat-eaters.  Why?  Because they have sticky hairs that trap bugs.  After making a big splash on both sides of the Pond, they walked it back a bit.  “However, some of the commonly accepted carnivores [like petunias] have not been demonstrated to have the ability to digest the insects they trap or to absorb the breakdown products.” 

They went on to say “Professor Mark Chase, Keeper of the Jodrell Laboratory at the Royal Botanic Gardens, Kew says, ‘…. many commonly grown plants may turn out to be cryptic carnivores, at least by absorbing through their roots the breakdown products of the animals that they ensnare. We may be surrounded by many more murderous plants than we think.’”  Nice save?

There’s a reason why scientists submit papers for peer review.

(The BugLady is reminded of Nathaniel Hawthorne’s short story “Rappaccini’s Daughter.”)

Kate Redmond, The BugLady

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

Bug o’the Week – Long-tailed Meadow Katydid

Bug o’the Week
by Kate Redmond

Bug o’the Week Long-tailed Meadow Katydid

Howdy, BugFans.

At first glance, Meadow Katydids look like small grasshoppers, but grasshoppers (family Acrididae) have antennae of a reasonable length, and katydids (family Tettigoniidae) have such long antennae (you have to back up a bit to get the whole antenna in a picture) that you wonder how they maneuver through the vegetation – and life (those antennae, of course are highly sensory and are exactly what allow them to navigate through life). In her “Naturally Curious” blog, Mary Holland writes “Insect antennae are among the most sensitive and selective chemical-sensing organs in the animal kingdom. They detect information crucial to an insect’s survival, including odors, sounds, humidity, changes in water vapor concentration and air speed. Antennae are capable of these feats because of the sensory receptors covering them which bind to free-floating molecules.” And they’re tactile, too.

Behaviorally, grasshoppers fling themselves into the air at the slightest provocation (remember, their action is driven by both legs and wings), while Meadow Katydids are more likely to skulk away into the thicket with a series of short hops onto the backsides of leaves. 

Meadow Katydids are in the tribe Conocephalini (literally “cone heads”), which is divided into the Greater Meadow Katydids (genus Orchelimum) and Lesser/Smaller Meadow Katydids (genus Conocephalus).  Lesser Meadow Katydids were mentioned briefly in an early BOTW (https://uwm.edu/field-station/tettigoniidae-two/), and one of the Greater Meadow Katydids was featured in a BOTW a few years ago https://uwm.edu/field-station/black-legged-meadow-katydid/.  There are about 160 species of Lesser Meadow Katydids worldwide and 18 in North America, and they’re found in grasslands and wetlands, and on woodland edges.  

With bodies under ¾”, they’re not huge.  They can be tough to tell apart when they’re just sitting on a blade of grass, and some species come both in a variety of color forms and with short or long wings, but if you get a good look, the females’ ovipositors are pretty distinctive, even as nymphs, and so are the males’ claspers (cerci) https://sina.orthsoc.org/g220a.htm.  Their songs, mostly sung in late afternoon and evening, can be hard to hear.  Straight-lanced Meadow Katydid are a fairly common species in Wisconsin – here’s a male nymph and an adult female https://bugguide.net/node/view/2218360/bgimage https://bugguide.net/node/view/1579703/bgimage.

Females use those impressive ovipositors to punch holes in vegetation, into the soil, or even under tree bark to deposit their eggs.  The eggs overwinter, and the nymphs pop out the next year looking pretty much like their eventual adult form (incomplete metamorphosis).  Meadow Katydids are omnivores, supplementing a diet of the leaves, seeds, flowers, and pollen of non-woody plants with the odd, tiny insect.

The BugLady always enjoys coming across nature articles by Matt Pelikan in the Martha’s Vineyard Times as she does her research.  Here’s one about Meadow Katydids https://www.mvtimes.com/2019/09/04/wild-side-meadow-katydids/.

Enter the LONG-TAILED MEADOW KATYDID (Conocephalus attenuatus), aka the Lance-tailed Meadow Grasshopper (both referring to the female’s ovipositor); Lisa Rainsong, in her “Listening in Nature” blogspot calls it the Red Marsh Katydid.  They are habitat specialists – residents of sedge and cattail marshes with standing water in much of the northeastern quadrant of North America.  They’re not common overall but can be locally numerous.  By all accounts, the BugLady was really lucky to see this one without resorting to a flashlight and hip waders.  

LTMKs feed on cattails and sedges, especially the seeds https://bugguide.net/node/view/1725335/bgimage.

Bugguide.net says that they’re “Typically either all red or red with green limbs.”  Rainsong points out that “The color blends very well with reddish cattail heads, and that’s a likely place to find this katydid.”  Here’s a short-winged male and female https://bugguide.net/node/view/1863860/bgimage and https://bugguide.net/node/view/1593979/bgimage, and a long-winged male and female https://bugguide.net/node/view/1588827/bgimage and https://bugguide.net/node/view/1119893/bgimage, and there’s a nice collection of pictures here http://listeninginnature.blogspot.com/2013/11/the-red-katydids.html.  Their soft song has been described as a continuous, pulsing rattle, rather than a whirr, sung mostly after sunset http://songsofinsects.com/katydids/long-tailed-meadow-katydid.

When LTMKs copulate, the male delivers a “twofer” – a sperm packet and an attached gelatinous glob called a spermatophylax.  The female plucks off the spermatophylax, which contains nutrients that may ensure successful egg-laying, but it’s a bribe.  As she eats, the sperm are being absorbed from the spermatophore at her opposite end.  When she finishes her snack, the female detaches the spermatophore, so while she’s eating, the clock is ticking for the male’s gene pool.  Chemicals in the spermatophylax may also dim her interest in other males temporarily.  For a good, illustrated, PG explanation of the process in one of the Greater Meadow Katydids, see https://natureinquiries.wordpress.com/2013/03/27/spermatophylax/

Kate Redmond, The BugLady

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

Bug o’the Week – Robust Katydid-hunting Wasp
by Kate Redmond

Bug o’the Week
by Kate Redmond

Bug o’the Week Robust Katydid-hunting Wasp

Greetings, BugFans,

OK – it’s not a super flashy wasp when it’s heading away from you (in fact, it’s not even very wasp-like), but it’s pretty cool when it’s heading toward you – those eyes. And what an awesome name (though not quite as awesome as the related Eastern Ant-Queen Kidnapper Wasp)! Both species are in the Square-headed wasp family Crabronidae, a family that we have met in previous BOTWs. Here’s a quick reintroduction.

The family includes Square-headed (https://uwm.edu/field-station/square-headed-wasp/) and Sand wasps (https://uwm.edu/field-station/sand-wasps/) and the Organ-pipe mud daubers (https://uwm.edu/field-station/organ-pipe-mud-dauber/). It’s a large, diverse bunch (1225 species here; almost 9,000 worldwide) that was carved off of the now-much-smaller wasp family Sphecidae (the thread-waisted wasps) not too long ago (in taxonomists’ years).

What Crabronids have in common, besides some anatomical features concerning the size and/or shape of the inner margin of the compound eyes, of the pronotum (the part of the thorax right behind the head), of a lobe in the hind wing, and of the almost non-existent “wasp waist” – on such things are identities hung – is their habit of caching insect prey in underground egg chambers for their eventual larvae to eat/parasitize.  A few species let other wasps do the hunting and then steal the results (kleptoparasitism).  Many species are picky about both prey and nest sites, and adults feed on pollen and nectar.

Robust Katydid-hunting Wasps are one of 34 mostly-similar-looking species in the genus Tachytes in North America.  Tachytes comes from a Greek word meaning “swiftness” or “speed,” and the genus is often called the Sand-loving wasps because of their preference for nesting in sandy soil types.  In his bugeric blog, entomologist Eric Eaton says they should be called the Green-eyed wasps.  The combination of their size, somewhat stout build, and scattering of short hairs makes some people (like the BugLady) mistake them for bees at first glance. 

Females tunnel from 3 inches to almost 3 feet into the ground, creating side tunnels and scooping out cells in the walls, and she provisions these cells chronologically, deepest first (shorter tunnels may contain only a single cell).  The genus specializes in grasshoppers, katydids, pygmy crickets and mole crickets.  Says Eaton, the “Female paralyzes the victim with her sting, then straddles it, grasps it by the antennae with her jaws, and flies it back to her nest.  There she deposits her prize in one of the cells.”  Researchers Evans and Kurczewski say that “many of the larger species emit a high-pitched buzz when flying with prey…..” 

While she’s provisioning a cell, a female may stash some bodies in a chamber inside the entrance temporarily.

ROBUST KATYDID-HUNTING WASPS (Tachytes crassus) are found from the Midwest through Canada and New England, plus several states in the Southeast.  They measure a shade longer than a half-inch, with green eyes and mostly caramel-colored legs.  Here are some glamour shots from bugguide.nethttps://bugguide.net/node/view/1277906https://bugguide.net/node/view/778850/bgimage.  Heather Holm, in her magnificent Wasps: A Guide for Eastern North America says that females have three silver bands on their abdomen and males have four.

According to Eaton, male Tachytes wasps emerge before females and often are more numerous.  They set up small territories near burrows where they expect females to appear, but after the females emerge, the males move their territories to nesting areas and nectar sites.  In some Tachytes species, the courtship is brief – he pounces on her back and pins her wings and then waves his antennae frantically in front of her face to soften her up https://bugguide.net/node/view/1013235.  

Females often dig their tunnels near those of other females.  Holm writes that “Tachytes crassus usually nests in sand although Evans and Kurczeski (1966) found a nesting aggregation in clay-loam soil.  Female excavates a deep, angled multicellular nest, then deposits soil around the burrow entrance, forming a tumulus.  The female may or may not leave the nest open while away hunting for prey.  When returning with prey to an open nest entrance, she flies directly into the nest without hesitation, clutching her prey beneath her.”  Holm quotes the eminent French Naturalist Jean Henri Fabre (1921) “The Tachytes clears the entrance to the home and goes in alone.  She returns, puts out her head and seizing her prey by the antennae, warehouses it by dragging backwards.”  Please take the time to read some of Fabre’s lovely account of the genus https://www.gutenberg.org/files/3462/3462-h/3462-h.htm#link2HCH0007

Holm continues, “She hunts for prey close to the ground in tall grass, meadows, or prairies where grasshoppers occur…..prey caught earlier in the growing season may be all nymphs; prey caught later in the season and later in the female’s life (cached in the upper cells) are more likely to be adults.  Between five and ten prey are provisioned in each cell.  A single egg is laid between the foreleg and midleg on one of the prey at the bottom of the cell.

RKHWs are common on Swamp milkweed flowers (Asclepias incarnata).  One would think that a swamp milkweed lover would also be a major swamp milkweed pollinator, but a study in 2003 by Ivey, et al, indicated that while the RKHW was a frequent visitor to the flower, it “was the poorest at removing, carrying, then subsequently transferring pollinia to other swamp milkweed flowers.”  Remember, pollination is an accidental, not an intentional act, and milkweed pollinia are saddlebag-shaped and sticky (see the legs of the dangling bee caught by the almost-invisible ambush bug).  Like RKHWs, Thynnid wasps (Myzinum sp.https://bugguide.net/node/view/1958377/bgimage are frequent visitors with a similar active, random foraging style, and yet they were far more effective pollinators.  What took them only six or seven flower visits to accomplish (removing and then inserting a pollinium) took some RKHWs up to 500 visits.

Kate Redmond, The BugLady

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

Bug o’the Week – Midsummer Memories by Kate Redmond

Bug o’the Week
by Kate Redmond

Bug o’the Week Midsummer Memories

Howdy, BugFans,

Last year the BugLady had so many midsummer stories to tell that she wrote one episode about dragonflies, and a second about “other” (because as seasoned BugFans know (well) her camera gravitates to dragons and damsels).  She’s got a heap of pictures to share again this year, but she’ll mix and match the groups in a two-part summer feature.

ROSE CHAFER BEETLE – The BugLady saw a single Rose Chafer last year and wrote about it https://uwm.edu/field-station/rose-chafer-beetle/.  This year, she found bunches of them – orgies of them (she’s not sure what the collective noun for Rose Chafers is, but she’s pretty sure it’s “orgy”).  And she was enthralled by the leggy designs they made on the undersides of milkweed leaves.  

COPPER BUTTERFLY – A highlight of the BugLady’s recent explorations of Kohler-Andrae State Park was finding two species of Copper butterflies – American Copper and Bronze Copper (she rarely finds Coppers).  The Coppers are in the Gossamer-wing butterfly family Lycaenidae, along with the Harvesters, Hairstreaks, Elfins, and Blues.  Their caterpillars feed on plants in the rose and buckwheat families (dock, sorrel, and knotweed).

VIOLET/VARIABLE DANCER – The BugLady was talking to a friend recently about the colors that dragonflies and damselflies come in.  Black, black and yellow, green, blue – even red.  But purple?

FLY ON PITCHER PLANT – This is just the way it’s supposed to work.  Insects with a “sweet tooth” get lured to the lip of the pitcher plant and partake of the (slightly narcotic) nectar there.  Judgment impaired, they mosey around a little, maybe venturing onto the zone of down-pointing teeth below the lip, and then onto the slick, waxy zone below that.  It’s all downhill from there.

GOLDENROD CRAB SPIDER on yarrow (not all Goldenrod crab spiders have red racing stripes).  Incoming insects have trouble seeing her, too.  Out of all the species of crab spiders in the world (about 3,000), only a very few have the ability to change colors, and that ability is limited to the female of the species.  Her color palette includes white, yellow, and pale green.  She sees the background color with her eyes, and because a wardrobe change takes her between three days and three weeks she tends to stay on her chosen flower.  Her base color is white, and switching involves either creating yellow pigment or reabsorbing and then sequestering or excreting it.  

Why?  Good question.  Scientists have tested spiders on matching and non-matching flowers (which they often sit on), and they saw no boost in hunting success when the spiders matched their background (she likes prey that’s bigger than she is, like bumblebees, because she has eggs to make.  She loses weight on a diet of small flies).  When spiders themselves are the prey, they are not picked off more often on non-matching flowers.  Maybe the color change gives her some sort of advantage when she forms her egg case, or maybe it’s a vestigial solution to a long-ago problem.

ORANGE-LEGGED DRONE FLY – This Syrphid/Flower/Hover fly is so serious about its bumble bee disguise that it makes a loud buzz when it’s flying

SEDGE SPRITE TUSSLE – the BugLady was in a bog not long ago when she saw two damselflies tussling on some leaves.  At first, she thought there was some predation going on, but that didn’t make sense because they were both Sedge Sprites.  He had grabbed her and was wrestling with her, and she was having none of it.  He suddenly flipped her around and clasped the back of her head with the tip of his abdomen (SOP for mating dragonflies and damselflies).  Rather than reaching forward and taking his sperm packet, she ultimately gave a couple of good shakes and dislodged him.  One small drama.

PHANTOM CRANE FLY – Flies come in all sizes and shapes, but this magical creature in white spats is the BugLady’s favorite.  It lives in dappled, brushy wetland edges where it flickers through the vegetation like a tiny wraith.

FORKTAIL AND POWDERED DANCER – Eastern Forktails are voracious hunters that go after other damselflies, even those close to their size.  The mature female forktail (in blue) found a teneral (young) Powdered Dancer (in tan) that was probably not a strong flyer yet.

Go outside – look at bugs,

Kate Redmond, The BugLady

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

Bug o’the Week – Chimney Bee by Kate Redmond

Bug o’the Week
by Kate Redmond

Bug o’the Week Chimney Bee

Greetings, BugFans,

In late spring, BugFan Sara sent some “Who-is-this-and-what-is-it-doing??” pictures – small “bumble bees” were excavating the outer surface of a clay bread oven in her back yard (the BugLady gave Sara bonus points for having a clay bread oven in her back yard).  While she was mulling her answer, the BugLady found a reference to an Anthophora bee that is sometimes referred to as the Chimney or Turret bee.  That looked promising, and her hunch was confirmed by BugFan PJ.  Thanks, folks.

Family Apidae is a big umbrella in the bee world that includes Bumble, Cuckoo, Carpenter, Digger, and Honey bees – 1,000 species of them in North America and 5,000 species elsewhere.  The star of today’s show is in the tribe Anthophorini, the Digger bees (68 species in our area and 766 worldwide).  What they all have in common is a bumble-bee-ish appearance and the habit of most species of making nest tunnels in the soil.

Chimney bees (Anthophora abrupta) are solitary bees that can be found in woodlands and grasslands from Texas to the western Great Lakes to New England (solitary bees don’t have a central hive, a queen, or workers, and each female cares for her own brood).  They’re chunky, medium-sized bees (0.50” to 0.60” long) that can be distinguished from bumble bees by their color pattern – dark heads, pale, golden thoraxes, and dark abdomens, and by their very, hairy legs https://bugguide.net/node/view/55084/bgimage.  Males’ faces are light yellow https://bugguide.net/node/view/2133729/bgimage with hairs around the edges, earning them another common name – the Mustached mud bee.  For some great macro pictures, see https://www.fs.usda.gov/wildflowers/pollinators/pollinator-of-the-month/anthophora-abrupta.shtml and https://www.marylandbiodiversity.com/view/3137.       

In 1929, entomologist Phil Rau published a paper about Chimney bees in the journal Psyche. The BugLady is interspersing her information with excerpts from Rau’s paper, written back in the days when scientific writing allowed a more lyrical tone. 

“They are neither timid nor aggressive, but they certainly are self-reliant…how conspicuous they are as they noisily swing their ponderous bodies to and fro on the wing, arrive home and scramble into their burrows or come tumbling out headlong and dash off into the sunny fields, with all the exuberance of boys just out of school. They have none of the shy, stealthy ways of maneuvering, whereby some of the smaller and daintier varieties of bees and wasps hold their own in a competitive world.”

Chimney bees are generalist foragers that pollinate a wide array of wildflowers, and they’re also important pollinators of agricultural crops like cranberries, asparagus, tomatoes, blackberries, raspberries, and persimmons.  Their docility (if you handle one roughly, it’s more likely to bite than sting), home-body ways, and gregarious nesting make them interesting to researchers looking for potential large-scale pollinators.  Their long tongues https://bugguide.net/node/view/925446/bgimage allow them to reach the nectar in clover flowers. 

Rau recalled watching female Chimney bees licking rust on old fence wire.  A colleague speculated that while carnivorous insects glean minerals from the blood of their prey, the nectar-feeding Chimney bees may get minerals from rust.

Chimney bees are on the wing from late spring through late summer.  Males emerge almost a week before females, and they attract females by deploying pheromones that are carried in their moustaches!  Mating occurs on flowers (she mates once, but he may mate several times).  After they mate, the female looks for a spot to excavate a tunnel, often in a clay bank above a stream, usually in the same nest area she emerged from. 

Some solitary bees and wasps won’t tolerate the nearby nests of their sisters, but chimney bees prefer company. As Rau wrote, “Since they work in colonies, or more correctly remain to build on the site where they were born, the result is a very conspicuous village, sometimes a very crowded and busy town of these masonry turrets … At a busy season when many of these huge bees are bustling about with very audible hum and zip, the entire village with its many wonderful towers and industrious citizens form a spectacle which is in itself quite capable of overawing any but the most unemotional individual.

She employs a pretty unique construction method – she brings water or mud to her site and uses it to soften the clay so she can dig.  Each mouthful of dampened clay that she removes goes into building a chimney.  Rau describes it: “With a portion of the water they would wet the hard, yellow clay, remove a mouthful of it, back out and apply it to the last ring in the chimney. The bees would carry the mud under the thorax with the front pair of legs, while the two hind pairs furnished locomotion; as the bee backed out of the nest to the opening, the ball of mud was passed to the hind legs, and she now held her footing with the front legs while with hind legs she slapped the mud onto the last layer and with many active thumps with the tip of the abdomen, punched and beat it into shape. ‘Punched’ is really the right word correctly to describe the gesture.

Chimneys may be very short or up to 3” long, and they are oriented randomly.  No one knows exactly why she makes the chimney (other than that it’s a convenient way to dispose of the diggings) – researchers have guessed that it protects the tunnel from rain and blowing debris, that it helps with thermoregulation of the nest, that there is social significance for the community, and/or that (as Rau suspected) it helps her find her tunnel among all the others https://bugguide.net/node/view/1592323/bgimage.

Two factors may limit the building of chimneys – drought and a lack of clay in the nesting area.  Rau wrote that “A. abrupta made nests either with or without turrets, and the turret-making activities were directly correlated with water conditions. They required water in abundance, and when it was plentiful, so too were the turrets; in droughty years they struggled on with few and small or no turrets, and their nesting activities were much reduced.

She creates up to seven cells along the length of the tunnel (which is about 4” long), and here’s the magic part.  The walls of the tunnel and of each of the egg cells are lined with a waxy substance she makes in a gland called a Dufour’s gland.  The liquid made by the gland starts out clear, but it dries to a solid, waxy sheet that keeps moisture out of the tunnel and the cells.  She carries pollen and nectar into the cell and mixes them with liquid from the Dufour’s gland, injects an egg into the mix (which one researcher describes as a “soupy mass”) and seals the cell with clay.  The tunnel is covered with a clay plug when all the egg cells are provisioned.  A large, communal nest may contain 5,000 cells. 

Because the females don’t cap their tunnels when they are out looking for water, nectar and pollen, other females may try to take them over.  Writes Rau “Not infrequently an animated fight was to be seen between two females, one evidently trying to usurp the burrow that had been made by another, and often dead bees were found at the foot of the bank.

Frequently, however, the fights appeared quite alarming without proving fatal. One pollen-laden mother was seen backing out of her hole with the front leg of an intruder in her mandibles. The visitor showed no fight, but resisted with all her might; at the foot of the hole, every little gain that the rightful owner made was offset by the intruder pulling her back. At last the intruder lost her hold, and as they went tumbling to the ground they engaged in a pugnacious embrace.

After laying in the “soup” for five days, the egg hatches, and the larva feeds on the provisions and the cell lining.  They overwinter as pre-pupae, finish their metamorphosis in spring, and emerge from the tunnel.

And if all that weren’t enough, male Chimney bees climb up grass stems in the evening, grip them with their jaws, and sleep suspended by their mandibles https://bugguide.net/node/view/1801603/bgimage.  

Here’s Rau’s whole article: https://www.researchgate.net/publication/27371655_The_Biology_and_Behavior_of_Mining_Bees_Antitophora_Abrupta_and_Entechnia_Taurea

Ain’t Nature Grand!!

Kate Redmond, The BugLady

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

Bug o’the Week – Gray Field Slug by Kate Redmond

Bug o’the Week
by Kate Redmond

Bug o’the Week Gray Field Slug

Salutations, BugFans,

The BugLady has been hitting all her favorite wetlands and taking pictures and editing pictures, and it’s July 4th, and she hasn’t quite gotten a crisp, new BOTW ready.  Since she has been a slug, writing-wise, she decided to rerun an episode from 2019 about slugs.  And besides, she is really tickled by the Scottish poem about slugs.

The BugLady found this impressive (1 ½” to 2”) slug climbing around on her cottage in early October.  It has been almost 11 years since we last considered slugs (time flies!).  For a quick Slugs 101 review, see https://uwm.edu/field-station/slug/.  Recent BugFans please note that slugs, while not insects, are fair game because BOTW uses the kindergarten definition of “bug,” not the entomological one.  Thanks (as always) to the very versatile BugFan Mike for help with the ID.

One reason that slugs seem so foreign to us is that they lack familiar landmarks like legs, wings, and body segments.  So, what are you looking at when you’re looking at a slug?  They lead with two pairs of retractable, regenerate-able, sensory tentacles.  The top (dorsal) pair, which is used for sight and smell, has eyespots at the tips (slugs can see light and dark and blurry shapes but can’t focus on images), and the lower pair is used for smell, taste and touch and to move food to the mouth.  These four appendages can be aimed in different directions simultaneously, but the lower pair is often pointed downwards in order to pick up cues from the slug’s substrate.  The mouth, complete with rasping “teeth,” is on the underside of the head. 

A saddle-shaped cover behind the tentacles, called the mantle, protects the slug’s innards; there’s an all-purpose opening on (almost always) the right side of the mantle called the pneumostome (one author calls it a “blowhole”), which has reproductive, excretory, and respiratory functions.  Beyond the mantle is the tail.  The muscular lower surface of a slug is the “foot;” its rhythmic undulation allows the slug to move, and it produces the infamous mucous/slime that keeps its body moist and “greases” its passage.  

 About that slime.  It’s a multipurpose substance that is both sticky and slippery, that aids in locomotion (some species use it as a bungee cord), that absorbs water, that protects slugs from bacteria and fungi, that leaves a trail for the amorous (and the carnivorous) to follow, and that discourages predators.  The BugLady found a tantalizing note about Hermann Lons, a German poet and malacologist (mollusc specialist) who discovered that slug slime tastes awful “in a particularly remarkable self-inflicted experiment” (about which she could find no further details).  Slug slime is also the strong yet flexible inspiration for researchers trying to develop a next-generation surgical adhesive.

Evaporation and slime production constantly rob slugs of their water reserves.  They can tolerate microclimates with a range of humidities as long as they can replenish liquid by eating and by absorbing water through their skin.  In hot, dry summer weather or when food is scarce, they will aestivate under debris or dirt, and they can fast for several months. 

To place slugs within their proper taxonomic sphere, they are in the very diverse Phylum Mollusca (octopi and squid, scallops and oysters, snails and slugs), in the Class Gastropoda (“belly-foot” – snails and slugs), and in a land slug family named Agriolimacidae.  

The GRAY FIELD/GARDEN SLUG (Derocerus reticulatum, aka Agriolimax reticulatum), one of about a dozen slug species in Wisconsin, is a European slug that’s described throughout both its historic and its more-recently-embraced ranges as a “synanthrope” – a species of plant or animal that lives in habitats modified by humans and that benefits from human association.  “Syn” means “with” and “anthropos” means “man,” and the term is applied equally to species we like (Golden retrievers) and species we don’t (Norway rats).  Across the Pond, it’s found in Western Europe and Africa; but it has hitchhiked (oh, so easily) pretty much around the world.  In North America, it’s found across southern Canada and the northern tier of states, plus a smattering of Central, Mid-Atlantic and Pacific Coast States.  It likes gardens, agricultural fields, roadsides, parks, and greenhouses. 

Slugs are hermaphrodites, which means that they have both male and female reproductive organs – an individual can be the fertilizer or the fertilizee’ (and they can self-fertilize), and all can lay eggs.  In our area, Gray field slugs reproduce in late summer and early fall – Mom-Dad meets Dad-Mom in an elaborate dance that involves slime, a chase, and the waving of the sacrobelum.  Eggs (as many as 700 in all) are laid in small bunches under stones and leaves and in crevices as fall rains soften the soil.  They generally overwinter as eggs, hatch in spring, mature by late summer, and die not long after laying eggs. 

Gray field slugs, notoriously, feed on the leaves and fruits of a wide range of agricultural and horticultural plantings and tree saplings, damaging leaves by rasping random holes in them.  They are also scavengers that eat dead, soft-bodied invertebrates like worms and other slugs. 

One of the questions that the BugLady always asks when she’s researching is “What does it eat?” and the next question is “What eats it?”  Members of the ground beetle family Carabidae are important predators of Gray field slugs both here and abroad.  This beauty, a (coincidentally) European ground beetle that is now established here and is a fellow synanthrope, is a slug connoisseur https://bugguide.net/node/view/632699/bgimage (business end https://bugguide.net/node/view/1566065/bgimage).  The Gray field slug, however, can detect the odor of its ground beetle stalkers with those sensory tentacles, and chemicals mimicking ground beetle scents may have a future in crop protection.  

When a ground beetle or other predator grabs a Gray field slug, the slug waves its tail back and forth and throws out lots of unpleasant, milky-colored slime (normally, its slime is clear).  The final trick in its playbook is to break off the tip of its tail and leave it in the mouth of its attacker as it scoots away.   

Gray field slugs operate within a home range where they revisit food plants and home sites.  The BugLady’s slug notwithstanding, they tend to be nocturnal, and Wikipedia tells us that they can travel as far as 40 feet in one night.   

Fun Slug Fact: when a slug ambulates across a copper surface, the copper reacts with chemicals in its slime and gives the slug a little shock.  

Another Fun Slug Fact: the defensive slime produced by the Australian Red triangle slug is so sticky that it can glue a pursuing frog to a branch.  For days. 

Final Fun Slug Fact: if you get slug slime on your person, it will be easier to remove if you let it dry and then rub it with a cloth than if you wash it with soap and water. 

The BugLady looked around for a nice, uplifting literary quote about slugs.  She couldn’t find any.  They’re all allude to slugs’ perceived negative attributes, like this “We have descended into the garden and caught three hundred slugs.  How I love the mixture of the beautiful and the squalid in gardening.  It makes it so lifelike” (Evelyn Underhill); and this, “Bob Dylan impresses me about as much as …well, I was gonna say a slug but I like slugs” (Don Van Vleit); and this, “It seems to me the worst of all the plagues is the slug, the snail without a shell. He is beyond description repulsive, a mass of sooty, shapeless slime, and he devours everything” (Cecelia Thaxter).  Oblivious to the fact that slugs are, yes, perfect (and that possibly they find us repugnant). 

Slugs in poetry?  The BugLady found this wonderful poem by George T. Watt; it’s dense, but lean into it and read it a few times http://www.scottishpoetrylibrary.org.uk/poem/slugs/ (Note – Ein Heldenleben – “A Hero’s Life,” is a work by Strauss). 

About slugs, Watt goes on to say that “Slugs haes trevelled awa on its ain journey, ye maun tak it whaur it’ll gang.”  

Words to live by.  

Kate Redmond, The BugLady

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

Bug o’the Week – Closed for June IV by Kate Redmond

Bug o’the Week
by Kate Redmond

Closed for June IV Fireflies

Howdy, BugFans,

The BugLady is getting ready for the annual firefly show (for BugFan Tom in the Deep South, the show’s almost over).  She has been seeing day-flying fireflies in the air in the wetlands she visits – for more about day-flying fireflies and about firefly natural history, see https://uwm.edu/field-station/lightning-beetle-again/ (after 5 years, not all of the links work).

Most important question first – are they fireflies or lightning bugs?  This is, of course, a question of great scholarly debate, and it was one of the questions on the wonderful, interactive Harvard American dialect survey of a decade ago.  Turns out that the “firefly” of the West, Western Upper Great Lakes, and New England is the “lightning bug” of the South and much of the Midwest https://www.rochesterfirst.com/weather/weather-blog/lets-settle-this-are-they-fireflies-or-lightning-bugs/.

Purists, of course, know that these are neither bugs nor flies, and that the term “lightning beetle” is more appropriate.  They’re in the family Lampyridae. 

Here are two articles about lightning beetles:

https://www.smithsonianmag.com/science-nature/illuminating-science-behind-fireflies-180982112/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=editorial&spMailingID=48316292&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2461641417&spReportId=MjQ2MTY0MTQxNwS2

https://www.smithsonianmag.com/smart-news/tens-of-thousands-of-synchronous-fireflies-will-soon-flash-in-unison-180982045/

Identifying fireflies isn’t quite as much fun as watching them.  Not everything with a colorful, shield-shaped thorax is a lightning beetle – there are some species in the closely-related Soldier beetle family (Cantharidae) that do a pretty impressive job of mimicking fireflies https://bugguide.net/node/view/478194/bgpagehttps://bugguide.net/node/view/285149https://bugguide.net/node/view/1068384/bgpage, and every time the BugLady looks through her firefly pictures, she finds a ringer.  She recommends Fireflies, Glow-worms and Lightning Bugs by Lynn Frierson Faust.  The BugLady tried to ID these to genus – fingers crossed.

Go outside.  Look for fireflies (and if you catch them, release them in a timely fashion).

Kate Redmond, The BugLady

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

Bug o’the Week – Closed for June Ii – Bugs! Love ‘em or – well — love ‘em by Kate Redmond

Bug o’the Week
by Kate Redmond

Closed for June II Bugs! Love ‘em or – well — love ‘em

Howdy, BugFans,

Here’s a pot pourri of articles about insects for your enjoyment.

Bug Love: the BugLady is aware that some BugFans read Bug o’the Week selectively, skipping episodes like the one about the Cockroach (you know who you are).  Why?  Because, among other reasons, certain bugs give us the heebie-jeebies.    https://www.npr.org/2017/03/26/520250032/to-put-you-at-ease-with-creepy-crawlies-entomologists-face-your-fears?utm_source=npr_newsletter&utm_medium=email&utm_content=20191031&utm_campaign=best-of-npr&utm_id=2548916&orgid=675

Crowded skies: we know that birds and bats and some charismatic insect megafauna like Monarch butterflies and Common Green Darner dragonflies migrate.  So do some of the little guys, and in Biblical numbers.  https://www.npr.org/sections/thetwo-way/2016/12/22/506581610/bugs-abound-if-you-think-the-skies-are-crowded-you-have-no-idea

How long have people been enthralled by insects?  Probably since they started slapping them and scratching the bites and discovering that they occupied the same caves.  For fellow History Geeks, a timeline of entomology – (be sure to click on the picture by van Kessel) https://en.wikipedia.org/wiki/Timeline_of_entomology_%E2%80%93_prior_to_1800

This week, June 19th to 25th is National Pollinator Week.  Bumble bees are the main pollinators of red clover (an important livestock food) because the nectar prize is deep in the floral tubes, and some species of long-tongued bumble bees have tongues long enough to reach it.  Here’s a guide to native pollinators: https://www.pollinator.org/pollinator.org/assets/generalFiles/3002022284_Bee-Identification-Guide.pdf.  

Kate Redmond, The BugLady

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

Bug o’the Week – Closed for June I – Scuds, encore by Kate Redmond

Bug o’the Week
by Kate Redmond

Closed for June I Scuds, encore

Salutations, BugFans,

The BugLady usually closes for the month of June so that she can hit the trails, find newly-minted insects (preferably ones that she hasn’t written about yet), and start building up a stash of pictures for future episodes – by spring, her picture files are dominated by unidentified insects.  Also, having hit 700 episodes at the end of March, the BugLady feels the need for a victory lap/vacation.  Never fear – there will be something buggy in your mailbox every Tuesday in June.

We’ve spent the last five weeks celebrating American Wetlands Month, but really, every day is Wetlands Day, so here’s an encore episode from 2011 that was in the queue when we ran out of Tuesdays in May.  New words; new pictures.

SCUDS

Sit down and put your feet up, it’s a long story.

OK, the BugLady could (and will) regale you with all sorts of arcane facts about scuds (aka amphipods or sideswimmers), but the main “take-home” here is that scuds are a hoot!  And they’re pretty cute, too.  What impresses people about scuds is their locomotion – they zip around in your collecting basin, pausing under the shelter of vegetation, and then they’re off again.  In The New Field Book of Freshwater Life, Elsie B. Klots says that they walk and crawl, “skittering’ on their sides by flexing and extending their entire body, and frequently rolling up on their sides or back.”  Anne Haven Morgan, in her Field Book of Ponds and Streams, adds that “Amphipods are accomplished water acrobats and can climb, jump, swim or glide with equal ease.”  

Their pedigree: Scuds aren’t insect “bugs”, but they are located under the giant umbrella of the phylum Arthropoda, along with insects, crayfish, scorpions, spiders, sowbugs, centipedes, fairy shrimp, and more.  Arthropods (“jointed legs”) are a mighty bunch that includes more than three-quarters of all animal species!  Within the arthropods, scuds are in the subphylum Crustacea, class Malacostraca, and the order Amphipoda.  That’s a bunch of big names for a small critter, and it doesn’t stop there – common names for this often indistinguishable bunch include freshwater shrimp, scud, sideswimmer, and gammarid (Amphipoda includes a large family, Gammaridae).  The taxonomy of these critters is, of course, under review.

Most Amphipods are Marine, but there are about 150 species of freshwater scuds in North America.  They are secretive bottom-dwellers, gracing cool, well-oxygenated springs and pools that have some calcium in the water for their shells (one source linked the size of scuds to the availability of oxygen in the water).  They prefer waters that are “fish-lite,” and they may grace these waters in huge numbers, up to 10,000 per square meter.  Look for scuds in tangled vegetation or under decaying leaves.  Through these thickets, they crawl and pull themselves along, using clawed legs and bodily contortions.  

Some species of amphipods are highly specialized, living in hot springs, caves, marine estuaries, or in deep, underground springs, and others are able to survive the drying of ephemeral ponds by burrowing into the mud.  The presence of some kinds of amphipods testifies to a waterway’s purity, but many species of scuds are tolerant of varying degrees of pollution.  They can’t live in poorly-oxygenated waters, and some species have fairly limited temperature “windows.”

The BugLady read of behemoth scuds that grow as large as an inch, but most are barely half of that.  Like a flea, a scud’s body is ultra-streamlined – arched and laterally flattened (if you look at them head-on, they’re pretty slim).  The front end (cephalothorax) consists of the head and the first segment of the thorax and is home to eyes, antennae, and mouth.  That’s followed by seven segments of thorax, with each segment bearing a pair of long climbing/walking legs (the first two pairs end in claws that are used in feeding and mating).  Gills are located at the base of the thoracic legs.  The last six segments are the abdomen, with six pairs of shorter appendages/legs that aid in locomotion and also push oxygenated water toward the gills (Amphipoda means “both kinds of foot”).  Scuds come in a variety of mostly neutral to pastel colors (influenced by their diet) and are often translucent.  Telling one genus from another may require a microscope.

So, how does a scud make sense of the world?  Scuds are light-averse, preferring starlight to sunlight.  Their two pairs of antennae are sensitive to both touch and smell.  While many amphipods see through well-developed, functioning, compound eyes, species restricted to caves and underground springs may be eyeless or have only vestigial eyes (but well-developed tactile hairs).  Normally-eyed species may evolve into blindness when restricted to permanently dark environs.

And where do little scuds come from?  Males and females swim piggy-back for days, preparatory to The Act.  If she needs to molt during that period, they separate briefly and then get back together after she has shed.  Like water sowbugs, female scuds have a structure called a marsupium on the underside of their thorax.  He passes sperm to her, and it mixes with the eggs (1 to 50 of them) in her marsupium.  She will carry the eggs around for one to three weeks until they hatch, and then she’ll carry the little tykes for an additional week.  If the dissolved oxygen in the water decreases, she may “ventilate” her marsupium by moving her first three pairs of abdominal legs to create a current.  The next time she molts, her fully-developed (but microscopic) young are released.  

The young scuds shed their exoskeleton eight or nine times on their way to adulthood (the exoskeleton splits across the back between two thoracic segments; the front half of the body is pulled out of the old exoskeleton first, and then the rear half), and adults continue to shed throughout their lives (which, if they’re lucky, may span more than two years).

The BugLady encountered a bit of amphipod ambiguity about whether a female breeds more than once.  Pennak, in his venerable Fresh-Water Invertebrates of the United States, states that most species of amphipods breed only once.  Other sources say that females can have several broods (up to 10) between April and October, but they must dance the dance each time.  According to Morgan, a female that produces 22 eggs every 11 days potentially has 24,221 offspring in a year (but egg mortality is high).

What do they eat?  Scuds are listed as detritivores, which means that they eat detritus – fragments of decaying organic stuff (including their own, shed skins) – from the water around them.  This “recycling” – breaking down organic materials into ever-smaller pieces for re-use by ever-smaller critters – is an important ecosystem service.  They also graze on the thin layer of algae, fungi and bacteria that covers submerged leaves, and although only a few species are predators, scuds may nibble on dying or freshly-dead aquatic critters.  They use those first two pairs of clawed feet to hold a morsel while they chew on it.  Scuds tend to live in waters too constricted and shallow for fish, but fish can be a major predator.  In the Western lakes where scuds were introduced as trout food, they make up almost a half of the trout’s diet.

If you Google “freshwater amphipods,” most of your hits will be photos and scientific articles, but if you Google “freshwater scuds,” you’ll find fishing sites and opportunities to buy scud-like lures. Several of the fishermen’s sites point out that scuds are related to shrimp and propose that although they are small, scuds might taste good in garlic sauce (what wouldn’t??). The presence of the usual compliment of parasites in scuds suggests culinary caution.

About the humble scud, the Pond Informer website says, “Apart from being nutrient recyclers, they collectively serve as a high-quality type of food for secondary consumers. They aren’t just consumed by fish; they are also a favorable prey type for larger crustaceans, wetland birds, amphibians, semi-aquatic reptiles, and riparian mammals. Gammarids are often considered ‘keystone’ species wherever they occur because their presence helps shape and establish working patterns for the existing ecosystem.” 

When she posted this episode in 2011, the BugLady said that it wasn’t known how scuds got from one pond to another.  She received an email from BugFan Don, who wrote, “Back in the good old days when I still went duck hunting, we would get ducks like bluebills and ring necks that had lots of scuds on their feet and leg feathers.  They would still be alive when we got the ducks home. To suggest that these diving ducks carry scuds from pond to lake is not unreasonable.

Duck hunters called them shrimp. I’ve heard stories about seeing retrieving dogs covered with the things.  These tend to be stories of the past, though.  No one seems to see scuds in such abundance any more.

The minnow sellers in western Minnesota have introduced fathead minnows into a lot of the big shallow lakes that were used by the divers [diving ducks] that fed on the scuds.  Bluebills leave Minnesota in worse shape than when they entered.  It takes a really severe winter to kill the fatheads so they tend to persist and they decimate the scud populations.  The divers responded by moving their migration and resting sites further west, into South Dakota.  The minnow merchants prospered, in spite of laws that prohibit moving live fish from pond to pond.” 

John Muir was right – everything IS connected!

Fun Fact about Scuds – according to J. Reese Voshell, Jr. in A Guide to Common Freshwater Invertebrates of North America, “scud” comes from a Norwegian word, skudda, which means “to push.”  The word was Anglicized as scud “and came to mean to move or run swiftly.”

Another Fun Fact about Scuds – an American scud that somehow made its way to Europe is out-competing the native scuds and is considered invasive.

Every day is a Wetlands Day.

Kate Redmond, The BugLady

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

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