Bug o’the Week – Horsehair worm Redux

Bug o’the Week

Horsehair worm Redux

Howdy, BugFans,

This is a somewhat rewritten rerun from 2009.  New words, no new pictures.

It’s a good thing that the common usage of the term “bug” is so inexact, because once again we are stretching its boundaries to/past the limits.

Horsehair worms are in the Phylum Nematomorpha (which is different from the Nematode worms (https://uwm.edu/field-station/nematodes/).  They’re skinny and long; this individual was maybe five inches long, but some species grow to one or two feet long.  They have a hard, chitinous covering that, says Ann Haven Morgan in her Field Book of Ponds and Streams, stiffens them so that “in their slow coiling and uncoiling they seem to be so much living wire.” They come in opaque yellow to tan to brown to black colors.  They’re wiry and cylindrical, with little tapering at either end (unlike the nearby Nematodes).

Adults live in damp-to-wet habitats from the tropics to the cold-temperate regions.  Morgan goes on to say that they “lie like twisted roots or loose-coiled wire, on the bottom of brooks, springs, ponds https://bugguide.net/node/view/183612watering troughs, and rain-barrels.”  Horsehair worms tend to occur in clusters; Pennak, in Fresh-water Invertebrates of the United States, describes them as “a single writhing mass in the springtime.”  They look a bit like the snags used to appear on the BugLady’s old casting reel.  She doesn’t see them very often – this [picture is an old, scanned color slide.

The adults do not eat – their only function is reproductive.  Pennak says that not only is their digestive tract “degenerate and functionless”, they have “no special circulatory, respiratory or excretory structures” (and not much of a brain, either).  Their muscle layer runs the long way, making them “slowly undulating swimmers.”  But the simplicity of the adults is more than compensated for by their offspring.

Mom lays more than a million (!!!) eggs in a gelatinous string, maybe 8” long, and the string breaks down into smaller pieces and disperses.  Soon after they hatch, the microscopic larvae attach to vegetation along the shoreline and form a protective cyst on the plant.  When water levels drop, land critters like grasshoppers, crickets, cockroaches, and beetles can reach the aquatic vegetation, and the larvae are inadvertently eaten (“engulfed”) by grazing.  They may also be ingested when their host drinks the water, and they can be swallowed by the aquatic immatures of mayflies, dragonflies and caddisflies that escape the water as adults, die, and are eaten by scavenging grasshoppers.  Lots of paths.

Once consumed, the cyst dissolves and the larva burrows through the gut wall and into its host, and begins absorbing nutrients from the nearby tissue.  Some potential hosts have the ability to encapsulate the cyst with a layer of toxic chemicals after they’ve ingested it.

Mother Nature is careful of the species but careless of the individual – she has produced an exuberance of horsehair worms, and only a vanishingly small percentage will ever find hosts, but that’s enough to keep the species going.  An animal that produces that many eggs “expects” a high mortality rate. 

When it matures, the larva needs to exit the host’s body, which doesn’t sound like a benign process (although one source said that it’s possible for the host to survive it).  It’s best for the larva if the host is near water when this happens, and it is believed that the maturation of the larva somehow causes its host to seek water, by some mechanism that is not fully understood.  If the host is nowhere near water when the horsehair worm matures, “c’est la vie” – few hairworms find hosts, and few of those that mature in the bodies of grasshoppers will ever get back to water.  If the host is near water when the larva is mature/nearly mature, then it “breaks through/burrows out of body wall and becomes free-living.” 

Horsehair worms are not a public health issue – all Horsehair worm hosts are invertebrates.  A couple of Exterminator sites inform us that horsehair worms show up in toilets from time to time (the current would seem to be going the wrong way for such a feeble swimmer to accomplish that), but one site confessed that it’s more likely to happen if someone just disposed of a grasshopper in the toilet.

A picture for your head:  According to Morgan, a common species of horsehair worm reaches about a foot in length, and its larvae have been found in 2 species of cricket.  If you’re wondering how they do that, the BugLady is, too (and, of course, there’s a video – https://www.sciencealert.com/watch-impossibly-long-parasite-exits-it-living-host).

These are also called “Gordian Worms,” in honor of the Gordian Knot tied by King Gordius of Phrygia, a knot that only the future king of Asia would be able to untie (Alexander the Great “thought outside the box” and used his sword).  The name “horsehair worms” is a nod to folk tales about horsehairs which say that “a hair will turn to life if you leave it in water or in the town watering trough overnight.”   

Kate Redmond, The BugLady

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

Bug o’the Week – Cockroach 101

Bug o’the Week

Cockroach 101

Greetings, BugFans,

The BugLady has been wanting to write about cockroaches for a long time (she has fond memories of the “X-Files” episode about them).  She asked BugFan Tom if he had any pictures he could share, because she’s rarely seen one (expect when she spent a summer in Coastal Florida, where they call their lunker cockroaches Palmetto bugs), and her attempts at photographing them have failed miserably.  He suggested that she has lived a sheltered life, indeed, and his friend, BugFan Joe, subsequently sent this picture.  Thanks, Joe.  This overview includes info about cockroaches in general and about cockroaches as the Bugs We Love to Hate.  Maybe someday there will be a Cockroaches 102, exclusively about native roaches (send pictures!).  Meanwhile, BugFan Joe’s picture of a Smokey Brown Cockroach will stand in as Everyroach.

Before we start, here are a few roach-related vocabulary words: “synanthropic” (referring to an undomesticated animal that lives in close association with people and benefits from their activities), “anthropophilic” (preferring human beings to other animals), and katsaridaphobia (cockroach phobia).  The collective nouns for cockroach are an “intrusion,” a “swarm,” or a “crunch” of cockroaches.

The BugLady had five assumptions when she started researching cockroaches, and we’ll get to them in a minute.  

First of all, who are they?  They’re members of the Order Blattodea, the Cockroaches and Termites.  The Blattodea are divided into three Superfamilies that are further divided into nine families.  Blattodea comes from a Latin word “blatta,” meaning “an insect that shuns the light,” and “cockroach” was Anglicized from the Spanish “cucaracha.”  There are about 4,600 cockroach species worldwide, including 70 species in North America; of the global species, fewer than three dozen are affiliated with human dwellings, and of the North American species, that number drops to about four.   

These are remarkably adaptable organisms.  Many thrive in the tropics, but others can live as far north as the Arctic if they can find shelter and food; their ability to make “antifreeze” lets them survive at below-freezing temperatures.  Native cockroaches are generally found in moist woodland habitats like leaf litter, under logs and bark, etc. but some species live in dry areas, others in treetops, and there are aquatic cockroaches that dive for their food.  They are mainly nocturnal and are programmed to avoid light.  They come from a primitive line – their ancestors (called “roachoids”) appeared some 320 million years ago. 

With some notable tropical exceptions, most cockroaches are dark-to-reddish–brown, oval and flat, and about an inch long https://bugguide.net/node/view/300360/bgimagehttps://bugguide.net/node/view/157662. Their spiny legs help them locomote on tricky surfaces, they can walk on the undersides of ceilings and tables, and they can squeeze through tiny crevices.  They have long, sensory antennae, and although many have wings, few use them.  Some species are highly gregarious, recognize their relatives, and have social systems and a group decision-making process.  Some species make sound. 

As a group, roaches use a variety of reproductive strategies, a story for another time.  In some cockroach congregations where males are uncommon, females may reproduce without male input, by parthenogenesis (“virgin birth”).

They are omnivores with chewing mouthparts – they eat lots of carbs and have gut flora that allow them to process cellulose.  House-dwelling cockroaches eat starch from book bindings, glue from postage stamps, pet food, bits of exfoliated skin and hair, dead insects, cork, the insoles of shoes, food crumbs, soda and beer (so rinse out those empties), etc.  The BugLady saw a note about roaches eating eyelashes as their owners slept, but that was a particularly dense infestation.  On a submarine.  On the other hand, as one website pointed out, cockroaches are part of the clean-up crew that rids the planet of rotting organic material. 

There are a number of wasps whose offspring parasitize cockroaches, and so do horsehair worms https://bugguide.net/node/view/1440973, which grow inside the cockroaches and then order them to a watery grave so that the worm can escape.  Native roaches are food for nocturnal reptiles, amphibians, mammals, and birds that are quick enough to catch them (the nymphs of many species protect themselves with gluey defensive chemicals.), and cockroaches are a staple of the pet store trade for keepers of cold-blooded vertebrates and for people who enjoy having them as pets.  Broiled, grilled, fried and/or dried cockroaches are consumed in many parts of the world (but not here), and they are raised for medicine in the Far East (Chemicals present in the American cockroach have anti-tumor, anti-bacterial, anti-viral, anti-inflammatory, and analgesic properties.).

Unless you specify the name of a native species when you Google “cockroach,” the internet will serve up one (or all) of the synanthropic Big Four that inhabit buildings in North America – the German cockroach (Blattella germanica), the Brown-banded cockroach (Supella longipalpa), the American cockroach (Periplaneta americana), and the Oriental cockroach(Blatta orientalis).  Truth in advertising – the German cockroach originated in southeast China; the Brown-banded possibly came from Africa; the American cockroach is native to Africa and the Middle East but has been here for 500 years and (probably) came over in slave ships; and the Oriental cockroach is, well, Oriental.  They have differing requirements for moisture and temperature and so are found in different parts of and different types of buildings.  The Wisconsin Pest Control sites say that we have all four of them here, but the range maps at bugguide.net say we have none of them (so maybe the BugLady isn’t the only Wisconsinite who has trouble photographing them). 

Wisconsin also has native Pennsylvania Wood Cockroaches that lead blameless lives out under the stars but occasionally come in with a bundle of firewood (or their eggs do).  They don’t want to be inside – it’s too dry – and they soon leave or die. 

We export cockroaches to other countries, of course, and new species continue to find their way to our shores.  We accidentally import green Cuban cockroaches in shipments of bananas (the pretty, green roach whose picture is linked above), Surinam cockroaches in pots of exotic plants (just another reason to plant native species, folks), and Australian cockroaches (and Joe’s Smokey brown cockroach) in pallets made in the southern US.   

Here are the BugLady’s five original premises.  True or False

1) There’s a ton of information about them on the internet. 

SO TRUE.  But – 99.9% of the info that’s available seems to come from Exterminators and University Extension sites and is about the Big Four.  And not all the info out there is completely accurate – one exterminator’s site proclaimed that there are only four species of cockroach in Wisconsin.  You would think that there are no native species – even when you specify “native cockroach,” the internet assumes that you want to hear about the invasives.  It’s a classic Catch 22 – unless you Google a native species by its name, it’s unlikely to pop up, but unless Google tells you the names of the native species, you won’t know to Google them (thank goodness for bugguide.net). 

2) They’re speedy little devils.

TRUE.  Cockroaches can hit speeds of 3 mph, which, said several sources, is equivalent to a human running about 200 mph.  They can cover 50 body lengths per second.

3) They’re not a sign of slovenly housekeeping, so stop being so judgy.

FALSE-ish.  A little spilled sugar does not a slovenly homemaker make, but to create a less-attractive cockroach habitat, keep the countertops and floors free of crumbs and the garbage and trash spaces clean and secure, and make sure there are no water leaks under the sinks or in the basement or the crawl space.  The reason you want to avoid the anthropophilic varieties (besides the panicky exodus of roaches when you walk into a room and flip on the light, or the creepy feeling of being watched – that little movement out of the corner of your eye) is that they stink; they make the surfaces they walk across stink; they stink even more when you squish them (because they store uric acid); you don’t know where those feet have been, but you have suspicions, so you don’t want them dancing on food preparation surfaces; they can carry pathogens from the seamier parts of your home that may cause food poisoning; and their saliva, droppings, and shed skins can trigger allergic and asthmatic reactions (one site suggested that some food allergies may be caused by FDA-allowable amounts of cockroach parts in foods) 

4) They live a long time.

TRUE.  Some cockroaches live only a year, but others live three or four years.

5) They will survive the Apocalypse

OH! SO! TRUE!

  • Some can fast for a month even while remaining active and go without water for two weeks; some can go without breathing for 45 minutes; and the body of a decapitated cockroach can function in default mode for weeks while its separated head will continue to wave its antennae and eat for a few hours.
  • During a three or four year life span, they develop an immune system – an immune system that recognizes previously-encountered pathogens and toxins (including pesticides) and defuses them when they are exposed to them again.
  • A lethal dose of radiation for a cockroach is much higher than a lethal dose for humans (but it really messes them up), and a fruit fly’s LD is apparently even higher than that!). 

Finally, as tempting as it is to reach for that can of roach spray, please think twice (and then think twice again) about using toxic sprays in enclosed areas and/or where children or people who are confined to bed are living.  Do your homework about chemicals.

Kate Redmond, The BugLady

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

Bug o’the Week – Carolina Leaf-roller Cricket – a Snowbird Special

Bug o’the Week

Carolina Leaf-roller Cricket a Snowbird Special

Howdy, BugFans,

A while back, BugFan Tom sent these pictures of a Carolina leaf-roller cricket from the Deep South.  Carolina leaf-roller crickets (Camptonotus carolinensis) are in the family Gryllacrididae, the Raspy crickets, a family we haven’t encountered before.  And with good reason – although there are about 600 species in the family, all but one live elsewhere (with one-third of the known species, Australia is especially Raspy-cricket-rich).  There’s only one genus in the family in North America, and only one species in that genus.

Raspy crickets are typically (but not always) wingless and nocturnal.  They make silk with glands in their mouths (their silk is similar to that of silkworms) and use it to construct their daytime retreats in leaves or soil.  The ability to make silk is pretty common among insects (think cocoon), but Raspy crickets are unusual because they can make silk as both nymphs and as adults.  The “rasp” in their name refers a sound they make when they’re disturbed; the catch is that most animals that make noise have ears to hear it, and Raspy crickets don’t.

With bodies that are only about a half-inch long, Carolina leaf-roller crickets (CLRCs) are not imposing.  Some come in green https://bugguide.net/node/view/1110118/bgimage, but most are a warm, honey color, and females have a conspicuous, up-curved ovipositor and a dark patch on their rump that one blogger thinks makes them look waspy.  When it comes to antennae, though, CLRCs are overachievers – a half-inch of cricket may have three to four inches of antennae.  CLRCs get around pretty fast, and although most sources say that they don’t jump, a few say that they do, and quite well. There are some great shots here https://www.marylandbiodiversity.com/view/8177 and here (scroll about half way down) http://listeninginnature.blogspot.com/2017/09/the-silent-ones.html.   The BugLady thinks they’re pretty cute.  

The map at bugguide.net, which relies on submissions of pictures by its members, shows a range that stretches from New York to Florida to Texas to Illinois https://bugguide.net/node/view/29828/data, but the BugLady found additional reports of the cricket in Ontario, North Dakota, and Iowa.  Within that range, they’re found in trees and shrubs in deciduous forests, and they’re easily overlooked.  The crickets are nocturnal (and so is BugFan Tom).   

When they’re disturbed, CLRCs make sound by inflating their abdomen, stiffening a few of their legs, and then flexing the others to do push-ups.  Sound is made as raised “pegs” on the abdomen rub against the legs on the way up and down.  Stridulation is a noise made by the friction of rubbing two body parts together, and this is called defensive stridulation. 

The BugLady was curious about an insect that makes sounds that it can’t hear, so she did a kittle reading about sound production in Raspy crickets, mostly in papers about Australian species of Gryllacrididae.  They discuss defensive stridulation, to which the cricket may add a visual intimidation display and mandible-clicking, and which may get more frenetic if the intruder doesn’t get the message.  Also in the Raspy cricket arsenal are foot-stomping and sending out vibrations by drumming on the substrate during courtship – males and females may perform a drum duet.  

CLRCs are opportunistic feeders that hunt for aphids, caterpillars, and other small, soft critters https://bugguide.net/node/view/1881543/bgimage.  It’s not uncommon for members of the grasshopper and cricket bunch to augment their diet of vegetables with the odd bit of protein, and many of the Gryllacrididae are omnivores and/or seed or nectar-feeders, but the BugLady didn’t find any reference to CLRCs eating plant matter.  They are preyed upon by a wasp named Sphex nudus https://bugguide.net/node/view/982571/bgimage that captures them and drags them into her tunnels to provision her egg chambers https://bugguide.net/node/view/1313/bgimage

After a night of hunting, CLRCs spend the day in a shelter that they create by bending a leaf, fastening it with web https://bugguide.net/node/view/212744/bgimage, and sealing themselves in.  Here’s how the Field Guide to Grasshoppers, Katydids, and Crickets of the United States describes the process “During the day, individuals shelter in leaf rolls made by cutting into the edge of a leaf, folding over a flap, and holding the surfaces together with silk spun from the mouth. Somehow, the long antennae are completely contained within the shelter.”  Bugguide.net adds that CLRCs “Sometimes use the pods of Bladdernut, Stahpylea trifolia, as a shelter instead of a leaf.”  One Australian paper on Raspy crickets said that they reuse shelters, that they find their way back to the shelters by laying down a pheromone trail and using their very-sensitive, sensory antennae to follow the trail back, and that the pheromones produced by each individual are not generic but are unique to it.   

common bladdernut

There were a few pictures online of CLRCs afflicted by a zombie fungus, a fungus that attacks arthropods, grows into and consumes their organs, and as the coup de grâce, overrides the insect’s brain and directs it to seek high ground rather than shelter.  When the fungus is ready to shed its spores, its victim is up in the breezes where the spores will be distributed most effectively https://bugguide.net/node/view/240236/bgimage.  For more grisly details, see http://jimmccormac.blogspot.com/2018/09/zombie-fungus-rides-again.html.

Thanks for the pictures, Tom.

Kate Redmond, The BugLady

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

Bug o’the Week – Big Sand Tiger Beetle

Bug o’the Week

Big Sand Tiger Beetle

Howdy BugFans,

Last fall, BugFan Joanne told the BugLady about a fabulous tiger beetle she saw in the dunes at Kohler Andrae State Park, and the BugLady was determined to find one this year.  Tiger beetles are a wonderful group in the Ground beetle family Carabidae.  They’re varied and beautiful (and surprisingly cryptic); they’re unapologetic predators as both larvae and adults; and they have a bunch of very cool adaptations – big eyes, excellent eyesight, long legs, and massive jaws https://bugguide.net/node/view/2047252/bgimage – that allow them to live and hunt pretty much out in the open.  Tiger beetles have a lot of fans.  For Tiger Beetle 101, see https://uwm.edu/field-station/tiger-beetles-revisited/.

The Big Sand Tiger Beetle (Cicindela formosa) is in the tribe Cicindelini (the “Flashy Tiger Beetles”) and in the genus Cicindela (the “Temperate Tiger Beetles”) and its species name formosa means “handsome.”  Big Sand Tiger Beetles are divided up into six subspecies, most of which occupy fairly small ranges that lie to the west of us (https://bugguide.net/node/view/8190/bgpage, click on the subspecies and then click on the Data tab above the pictures for range map) (and be sure to click on some of the pictures) (alert BugFans will note that bugguide.net shows only five subspecies, but Cicindela formosa gibsoni was recently split). 

Big Sand Tiger Beetles (BSTBs) occupy a sizable chunk of real estate in the center of the continent.  Oddly, although there’s plenty of apparently-favorable habitat from the Carolinas to Texas, BSTBs are not found there.  Our local subspecies is Cicindela formosa generosa, also called the Eastern Sand Tiger Beetle (glamour shot https://bugguide.net/node/view/1481712/bgimage).  As their name suggests, Eastern Sand Tiger Beetles (ESTBs) are found in sparsely vegetated, dry sandy areas, dunes, sandbars in rivers, pine barrens, blowouts, and roadsides in roughly the northeastern quadrant of North America https://bugguide.net/node/view/232879/data.  They have little competition for these inhospitable habitats. 

At about three-quarters of an inch long, they are big – the ESTB is the largest Cicindela species in the Upper Midwest.  The background color can vary, as can the width of the pale, scroll-like markings on the elytra (wing covers) https://bugguide.net/node/view/740607/bgimagehttps://bugguide.net/node/view/1588160/bgimage.

The BugLady couldn’t find anything about tiger beetle courtship, other than a comment that for all their excellent eyesight, males sometimes attempt to mate with other males and even with other species – not all of the cues they use to distinguish gender and species have been discovered by scientists (or indeed, by the beetles themselves), but they usually get it right https://bugguide.net/node/view/1984279/bgimage.  Female tiger beetles lay one egg at a time, each in a carefully selected spot – BSTBs bury their eggs in the sand.  Tiger beetle larvae https://bugguide.net/node/view/1277687/bgimage dig tunnels, and BSTB larvae dig the deepest tunnels of all tiger beetles – from one foot to more than six feet deep.  In the Field Guide to the Tiger Beetles of the United States and Canada, Pearson, Knisley, and Kazilek, speculate that “Apparently the great depth of their burrows allows larvae to survive the winter below the frost line.”  Depending on food supply and latitude, BSTBs may live two or more years; usually a long insect life span is spent mostly in the larval stage, but BSTBs may overwinter either as larvae or as adults.  Look for them in May and June and again in August and September. 

They eat small insects and spiders, which the adults chase and catch, and the larvae ambush from the shelter of their tunnels https://bugguide.net/node/view/1277194/bgimage.  ESTBs are said to be particularly fond of ants (one field guide showed a picture of a tiger beetle with the detached head of an ant clamped to its antennae by the ant’s jaws), but adult ESTBs are big enough to attack insects as large as other tiger beetles.  

Tiger beetle larvae in their tunnels are susceptible to the larvae of bee flies, and the BugLady did see several kinds of bee flies in the dunes.  Female bee flies lob their eggs into the entrances of the tunnels that solitary bees, wasps, and tiger beetles dig to lay their eggs in, and when they hatch, the fly larvae hike down the tunnel and feed on the larvae they find there.  Birds and robber flies feed on the adults, but they have to be quick.  

Temperature control is critical for sand-loving species.  ESTBs adapt to the hot surface of the sand partly by coloration – like many species of Tiger Beetles their underside is covered with white hairs https://bugguide.net/node/view/2047251/bgimage that deflect heat from below.  They stand “on tiptoes” (“stilting”) to get farther from the heat, and they will face the sun (they have white upper “lips” https://bugguide.net/node/view/2047252/bgimage) to minimize the surface area exposed to its rays.  They shelter in the vegetation at night, and, because of their size, it takes ESTBs longer to warm up and get out on the sand than smaller species.

FUN FACTS ABOUT ESTBs: In Tiger Beetles of Minnesota, Wisconsin & Michigan, Matthew Brust reports that “the adults are strong fliers, and perhaps due to their large size, emit an audible buzzing noise.  Commonly fly 20 to 60 feet.  Curiously, adults typically bounce or tumble when landing.”  [Nota bene: Because they must hold their elytra out to the side when they fly in order to uncover the membranous flying wings (like a tiny bi-plane), beetles make lots of awkward landings.]

The BugLady recommends Brust’s book, not only because it is comprehensive and regional and gloriously illustrated, but because of its prose: “Males are apparently very protective of their paternity, and a behavior called contact guarding is commonly observed.  In this case a male will remain coupled with a female (a male remains on the back of the female, using his mandibles to grasp her thorax) for some time after copulation so as to prevent another male from mating with that female and possibly removing his sperm.  In some cases, the male may guard the female for up to an hour.  It is common for females to actively hunt for prey while the male is still coupled.  However, it seems the interests of the males and females are often very different. While the male is usually very concerned about protecting his paternity, the female typically seems more concerned with foraging and other routine behaviors.  So while the male tries to remain coupled with the female as long as he can, the female will often use a variety of tactics to attempt to dislodge him.  These female behaviors typically involve violent shaking initially, but if such tactics do not work, females will often run through dead vegetation in order to clothes-line the male.  In extreme cases she may actually simply stop in a direction that points the male’s back directly at the sun, thereby cooking him off (the male will quickly overheat if he does not disengage).”

Kate Redmond, The BugLady

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

Bug o’the Week – Red Velvet Mite Again

Bug o’the Week

Red Velvet Mite Again

Salutations, BugFans,

We’re in the trough between Christmas and New Year’s Day.  No-one knows exactly what day of the week it is, but whatever is on TV is sure to be a rerun.  This BOTW is, too (well – a few new words).  And a few corrections – when she posted the original episode in 2011, the BugLady threw in a few extra “h’s” where there aren’t supposed to be any – she misspelled both the (probable) family and the genus.  They should be Trombidiidae and Trombium.

The BugLady has forever been amazed by Red Velvet Mites.  Is there anything more unlikely than a wee arachnid that looks like a plump, brilliantly red plush Beanie Baby (though the BOTW series has been filled with the “unlikely”)?  But seriously, why would a critter that dwells in soil and leaf litter bother to be so fancy?

The RVM du jour is in the family (probably) Trombidiidae (you need a side-view of the mouthparts to confirm their family, but the BugLady is, as always, willing to go out on a taxonomic limb here), and in the genus (maybe) Trombium, which prefers moist, organic soils.  At about 5mm long, it is considered a giant among mites, except for the Giant RVM (more on GRVMs later).  Scientists suspect that some of those red hairs may act as sensors in the mite’s often- gloomy world.  While the eight legs of many other arachnids appear to radiate from a central point, spreading out like spokes on a wheel, the RVMs’ legs sprou from four spots on the underside of the cephalothorax.  For a ventral view, check out https://www.cirrusimage.com/Arachnid_velvet_mite/

The RVM’s on-line presence is dominated by pictures (with occasional YouTube appearances) and misinformation.  Pictures because the RVM is so photogenic, and misinformation because the mite bunch includes the even-tinier, similar-looking Red Spider and Clover Mites (family Tetranychidae) that feed on flowers, and the Harvest Mites (family Trombiculidae) whose offspring are the notorious chiggers.  And that’s almost enough Latin for today. 

Exterminators and some gardening websites lump them all and espouse universal mite-i-cide (and many Bloggers pass along the “facts” they pick up at these sites).  But, neither adult nor immature Trombid RVMs bite your plants or your pets or you.  Young RVMs are parasites (blood-suckers) on grasshoppers, daddy long-legs, beetles and other ground-dwelling, cold-blooded critters (including plant hoppers, apparently), which they attach to and ride around on.  Adult RVMs eat insect eggs and prey on very small invertebrates (including ants – the BugLady isn’t sure, in the ant-mite picture, exactly who was inviting whom out to dinner, but both ants and RVMs will take on prey that’s larger that they are).  If RVMs are on your plants, they’re hunting for something you probably don’t want there.  Because they consume some insects that are plant pests, and because they eat the animals that eat the fungi and bacteria that carry out the important work of decomposition, RVMs are considered helpful to ecosystems. 

They have an exotic love life, described by scientists Liam Henaghan and George Hammond, as “not to be missed.”  A male places his sperm droplets on elevated surfaces like twigs and grass blades, creating what Heneghan calls a “love garden” and what Hammond (possibly not a romanticist) compares to “tiny golf balls on tees.”  Then the male issues an invitation to the female in the form of an intricately woven trail of silk (“In Xanadu did Kubla Khan a stately pleasure dome decree.”).  If she is dazzled by his artistry, she will enter the garden and sit on/pick up the sperm, but if a rival male encounters the garden, he will trash it and substitute his own genetic material.  Eggs are deposited in the soil, where a newly-hatched larva will find its first meal ticket.  The young RVM larva goes through several stages before molting into an adult. 

RVMs in the News:  If you think a 5mm RVM is fun, how about a 12mm (half-inch) RVM?  The Giant RVM (Dinothrombium sp.) lives in some parts of North America, especially the Southwest. They’re also called Rain Bugs, because they emerge and feed after it rains (some species have both spotted and unspotted individuals, and the BugLady thought that this one was pretty cool https://bugguide.net/node/view/435107/bgimage).  An equally large GRVM (Trombium grandissimum) lives in India and is sold in the bazaars there.  The deep, red GRVM oil is used to treat paralysis and is also called “Indian Viagra.  Recent scientific studies indicate that various GRVM components have both antifungal and antibacterial properties.

And their awesome red color??  Aposematism (warning coloration)!  Red is one of Mother Nature’s warning colors, used to advertise that its wearer is poisonous or distasteful or both.  Scientists who were curious about the somewhat-related Red Water Mite, of previous BOTW fame, powdered some and tried to feed the powder to fish (which turned up their noses).  They expanded their experiment to include powdered terrestrial RVMs and got the same reaction from the fish.  There are accounts of intrepid researchers who consumed RVMs and wished they hadn’t, but the source of the “flavor” is not known.  Scientists speculate that the bad taste developed after the color, in order to protect this very conspicuous critter from predators.  They also think that the orange pigments may offer some protection against the sun – RVMs desiccate easily, and some genera produce a waxy substance to coat themselves against water loss.  The BugLady could not find any accounts of any RVM predators, and researcher George Hammond (the “golf tee” guy) reports “I’ve put them on an anthill and no ant would touch them.” 

Kate Redmond, The BugLady

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

Bug o’the Week – The Twelve Bugs of Christmas 2022

Bug o’the Week

The Twelve Bugs of Christmas 2022

Greetings of the Season, BugFans,

Wow!  The 10th annual installment of The Twelve (or Thirteen) Bugs of Christmas!  The Bugs of Christmas features shots, taken throughout the year, of insects and spiders who have already had their own BOTW, but who posed nicely.

The next two paragraphs were borrowed from Christmas 2016, because the BugLady is still amazed by the history of this ubiquitous Holiday Classic.

The Twelve Days of Christmas” is an English carol that was probably borrowed from the French and that was originally an acapella chant/call-and-response/children’s memory game.  There’s an alternative explanation about the various lords, rings, etc. being Christian code words for catechism during a time of religious repression (which seems a bit like playing Beatles songs backwards).  It first appeared in writing in 1780, and there were (and still are) many variations of it, though the words were more-or-less standardized when an official melody was finally written for it in 1909 (and the insect verse was, alas, dropped.  “Thirteen Bugs a’ buzzing”).

See https://en.wikipedia.org/wiki/The_Twelve_Days_of_Christmas_(song) so you can hold your own in Holiday Trivia at parties (I’ll take Christmas Songs for $300, Alex).  With apologies to all those Lords a’ Leaping, it’s time once again to celebrate a year of bugs with this baker’s dozen collection of the beautiful, the odd, and the mysterious.  Gifts.  Right under our noses.  All the time.

POTTER WASP – Throughout this BOTW series, we have noted the many places where insects deposit their eggs – in plant stems, in underwater vegetation, in dead trees, in flower buds, in mushrooms, in the BugLady’s wind chimes, in carcasses, in holes and tunnels underground, in other insects, in cells made of wax or paper, in egg sacs.  The BugLady’s favorite is the small, mud pot attached to a twig or leaf by a potter wasp. 

SEDGE SPRITE – The BugLady is a tall person, and Sedge Sprites (her favorite damselflies) are tiny damselflies, barely an inch long, that mostly fly at altitudes lower than her knees.  Photographing one involves tracking an insect the size of a sewing needle through sedges and other boggy vegetation.  What a beauty!

BUMBLE BEE – The plant is called Common Hound’s-tongue (Cynoglossum officinale) (aka houndstooth, dog’s tongue, Gypsy flower, and Rats and Mice (because it’s said to smell like them).  Lots of small flowers on a plant that may grow 4 feet tall.  It’s from Europe; it probably came over in the 19th century in a bag of agricultural seed, and it’s considered a noxious weed in parts of North America (but it’s rare in Ireland).  It contains chemicals (alkaloids) that are toxic to livestock, its bristly seeds are not wholesome to ingest, and they irritate the skin, too.  Historically, it was used as a cure for madness and to treat inflammatory diseases, lung issues, and “it heals all manner of wounds and punctures, and those foul ulcers that arise by the French pox’” (Culpeper’s Complete Herbal).

The bumble bee doesn’t know any of that, and doesn’t care.

LADYBUG and SHINING FLOWER BEETLE – Multicolored Asian Ladybird Beetles come in a variety of shades of red and orange with spots ranging from zero to many, but you can tell them by the “W” or “M” on the thorax (depending on whether they’re walking toward you or away from you).  Adults eat aphids and scale insects, and their larvae eat even more aphids and scale insects, and some eggs of butterflies and moths.  The BugLady couldn’t find anything that suggested that they might chow down on a small beetle like this Shining flower beetle, but the ladybug sure was interested in it and followed it all around the surface of the leaf.

GIANT ICHNEUMON WASPS are among the BugLady’s favorite insects (Why?  See https://uwm.edu/field-station/giant-ichneumon-wasp/).  There are two species of rust and yellow Giant Ichneumons around here https://bugguide.net/node/view/1701906/bgimage, plus Black Giant Ichneumonid Wasp https://bugguide.net/node/view/1742321/bgimage.  This is a male Black Giant Ichneumonid Wasp.  

SPIDER WEB – an abandoned trap web, toward the end of summer.

DARNER EXUVIA – In today’s usage, the empty, shed skin of an insect or spider is (mostly-but-not-always) called an exuvia (Pl. exuviae), from the Latin for “things stripped, drawn, or pulled from the body”.  The BugLady, who likes etymology as well as entomology, wanted to find out more about the word, so down the rabbit hole she went.  She discovered that even her two favorite dragonfly and damselfly books don’t agree with each other. 

The British use “exuvium” for the singular and “exuvia” or “exuviums” for the plural.  When she did a bit more delving into “exuvium,” the BugLady found this awesome excerpt from a letter written by Sir Thomas Browne to his son Thomas, dated May 29, 1679: “I have sent you, by Mrs. Peirce, a skinne of the palme of a woemans hand, cast of at the end of a fever, or in the declination thereof; I called it exuvium palmæ muliebris, the Latin word being exuvia in the plurall, butt I named it exuvium, or exuvia in the singular number.  It is neat and is worthy to be showne when you speake of the skinne. …. A palmister might read a lecture on it.” 

A post in a bugguide.net discussion further muddies the waters by stating that the cast-off skin of an insect should be referred to in the plural (exuviae) because “a single cast skin is a collection of insect parts and is thus an exuviae.” 

There’s no logical equivalent in Classical Latin, but Scientific Latin takes liberties with the Classical.  The entomology community tacitly agrees that it’s a “we-know-it’s-not-correct-but-we’re doing-it-anyway” situation. 

The snail had nothing to do with the emerging dragonfly and, the BugLady guesses, is passing by.

BUMBLE FLOWER BEETLES – When the BugLady found some of these and wrote about them one fall https://uwm.edu/field-station/bumble-flower-beetle/, BugFan Chris told her that they’re also around in the spring.  Sure enough – she spotted this one in mid-May. 

MOURNING CLOAKS aren’t splashy, and they eschew wildflowers in favor of dripping sap, but they’re pretty spiffy nonetheless, and they’ve got a cool life story.  In a group (the order Lepidoptera) where the adult portion of a lifespan is usually measured in a few, short months, these are long-lived and complicated butterflies.  They overwinter as adults, mate, and lay eggs in spring.  Their offspring feed on willow leaves, form chrysalises, and emerge as adults in late spring or early summer.  After feeding for a while, they go into a state of aestivation (summer dormancy) to avoid wear and tear.  They wake in fall, feed some more, and then overwinter as adults in a state of suspended animation called diapause, which is similar to hibernation, tucked up in a cloistered spot called a hibernaculum that shelters them from the elements, and protected from the effects of freezing by glycerol (antifreeze) in their bodies.  They may fly during a January thaw or on mild days in late winter, but they can reenter diapause when the temperature drops.  When they emerge and mate in spring, they’re about 10 months old. 

This pretty CLICK BEETLE by the name of Ampedus sanguinipennis (sanguinipennis means “blood wing”) is found in wooded areas – its larvae develop in, feed on, and then pupate in very rotten wood, emerging as adults by fall, but hunkering down within the pupal cell for the winter.  Adults are pollen feeders that shelter under loose bark.  Somewhere in its travels, this beetle encountered some mites, which hitched a ride.  The harmless transporting of other organisms is called phoresy.  Here’s a glamour shot https://bugguide.net/node/view/20063.

If you’re a CRAB SPIDER and you don’t spin trap webs, you need a different strategy for finding dinner.  Crab spiders employ camouflage and ambush.  The flower is a tallgrass prairie plant called leadplant. 

COMMON GREEN STINKBUGS (Chinavia hilaris) are considered persona non grata in agricultural fields and orchards because both the nymphs and the adults feed on fruit and developing seeds.  And yet.  Hilaris means “lively” and “cheerful,” and that’s the vibe this stink bug was sending on a sunny day.

And an EASTERN AMBERWING Dragonfly in a pear tree. 

Kate Redmond, The BugLady

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

Bug o’the Week – Two Stink Bugs

Bug o’the Week

Two Stink Bugs

Howdy, BugFans,

The BugLady thinks stink bugs are cool https://bugguide.net/node/view/1685642/bgimage, and she loves finding species she hasn’t seen before.  This year, she saw two new ones – the first one in a sand dune, and the second in a bog – but she suspects that habitat is secondary in the stink bugs’ game plan to the availability of food.

They’re called “stink bugs” because they have glands in the thorax that produce, as Eric Eaton says in the Field Guide to Insects of North America, “volatile aromatic compounds sure to repel all but the most desperate predators.”  One author adds that “Stink bugs can smell pretty bad. Even my hens turn up their beaks when one crawls by…..”

Some stink bugs are predaceous, but most are plant-eaters, and many, including today’s pair, aren’t picky about the plant species they feed on.  They are “true bugs” in the order Hemiptera (Hemiptera means “half-wing,” which refers to wings that are leathery at the near end and membranous at the far end https://bugguide.net/node/view/471688/bgimage), and they’re in the family Pentatomidae.

Like other Hemipterans, they feed by puncturing their food with their piercing-sucking mouthparts https://bugguide.net/node/view/1864018/bgimage, injecting enzymes that soften the tissues, and then sucking out the contents.  If they’re feeding on, say, a peach, the puncture may inadvertently inoculate the immediate area with bacteria, causing rot, and soft fruits develop “dimples” called cat-facing, both of which make the fruit less attractive in your grocery store. 

Both of today’s species are divided up into several subspecies, and the BugLady was surprised to see that there were differences within each species not only in color, but also in the spiny-ness of their “shoulders,” depending on their geography and even season.  

RED-SHOULDERED STINK BUGS (Thyanta custator) occur across North America from Canada to Guatemala, and from sea to shining sea; the BugLady found this lovely, pastel stink bug in the dunes.  There are three subspecies, the most common of which is Thyanta custator accera.  

At about ½” long, Red-shouldered stink bugs (Thyanta custator) are fairly large, as stink bugs go.  They come in varying shades of green and tan, and the red on their shoulders can be very conspicuous or absent https://bugguide.net/node/view/1228797/bgimagehttps://bugguide.net/node/view/253073,

https://bugguide.net/node/view/1035753/bgimage, , https://bugguide.net/node/view/401270/bgimage

And so can their spines https://bugguide.net/node/view/1312629/bgimage.

Young stink bugs (nymphs) are often much more colorful than their elders https://bugguide.net/node/view/710344/bgimagehttps://bugguide.net/node/view/768528/bgimage.   

Females lay clusters of barrel-shaped eggs on the leaves and stems of plants https://bugguide.net/node/view/1625073/bgimage, and the nymphs feed on young leaves, buds, flowers, and developing seeds of their natal plants.  When they mature (in about a month) and have functional wings, they spread out to neighboring plants.  The RSSB has been found on many species of plants in more than a dozen plant families, some of them agricultural crops like wheat, beans, alfalfa, some fruits, and hemp, but they’re not on USDA Wanted Posters because they mainly damage seed production.

They overwinter as adults in leaf litter, but like other stink bugs, they will happily spend the colder months in a warm house.  In spring, they awake and spread out to find vegetation – and other RSSBs https://bugguide.net/node/view/41009/bgimage.   

The second species was the nymph of (probably) a DUSKY STINK BUG (Euschistus tristigmus luridus). Of the two forms/subspecies in North America, Euschistus tristigmus luridus) occurs the farthest north.  The subspecies that’s found in the South and into Central America, Euschistus tristigmus tristigmus, is smaller, and the front edges of its thorax are pointier https://bugguide.net/node/view/1993459/bgimage.  Dusky stink bugs are found in grasslands, woodlands, and riparian edges (and, apparently, bogs).

Quick Euschistus tristigmus luridus Dictionary Side Trip: Five hundred years ago, “lurid” meant “pale (so pale that you glow in the darkness), sickly, the color of bruises, ghastly, or yellowish.”  By the 1700s, its meaning was shifting and the word was used to describe the faint red glow of a fire shrouded by smoke.  In about 1850, its meaning changed again, to something like today’s common usage – “sensational, shocking, horrifying, or bright, intense, and vivid.”  

Here are the three spots suggested by “tristigmus,” though not all individuals have them https://bugguide.net/node/view/73486/bgimage

The broad strokes of the Dusky stink bug’s natural history are similar to those of the RSSB, with adults overwintering and laying eggs as vegetation starts growing in spring.  It uses a different set of food plants than the RSSB, including some wildflowers like clover, goldenrod, and Black-eyed Susan, some ash and oak species, fruits like blackberries and red delicious apples, and some field crops (and bugguide.net says that it is “occasionally predaceous”). The BugLady sees nymphs of other bugs, like leaf-footed bugs, near bird droppings; they get minerals from them, and she wonders if stink bugs do, too.  Like the RSSB, it has little to no economic impact (and it sure is cute).

The BugLady gives thanks for dragonflies (and she would like to know where the mosquito that she photographed in her house on November 11 has been for the past month).

Kate Redmond, The BugLady

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

Bug o’the Week – Tall Flea Beetle

Bug o’the Week

Tall Flea Beetle

Howdy, BugFans,

Sometimes, the BugLady gets a surprise as she’s researching an insect, and that was the case this week.

She saw a cluster of these pretty beetles when she was on a boardwalk in a wetland.  Their pedigree?  They are leaf beetles in the huge family Chrysomelidae; within that family, they’re in the tribe Alticini – the flea beetles, and they are (probably) Disonycha procera (Disonycha means “double-clawed”).  There are 470 members of that tribe in North America, and more elsewhere.  The BugLady has photographed one other, equally pretty flea beetle species when it was feeding on her pussy willows https://bugguide.net/node/view/2175205/bgimage.

Disonycha procera is very similar to Disonycha pensylvanica (not a typo, simply an old misspelling that is now embedded in the taxonomy of a few species), and in fact, it is in the “Disonycha pensylvanica species group,” about which bugguide.net says “The three species of the D. pensylvanica- group are not always safely identified – last hope is male genitalia, in some cases.”  So the BugLady has repaired to her well-worn seat, far out on that taxonomic limb, and is calling it Disonycha procera.  Only one source gave it a common name, but there was no explanation why this small insect might be called the Tall flea beetle.   

Tall flea beetles are found east of the Rockies, but not solidly, and into Central America, wherever their food plants grow.  Because some of their food plants grow on the edges of wetlands, Tall flea beetles are listed as semi-aquatic beetles by a few sources. 

The BugLady couldn’t find much about their life history.  Bugguide.net says that you can find both adult and larval Tall flea beetles feeding together on host plants, and a write-up about another genus member said that it overwinters as an adult, wakes up in spring, and lays eggs on or near the host plant, and the BugLady assumes that the Tall flea beetle does the same. 

Many Chrysomelids are attached to and named for their specific food plants, and for some flea beetles, those plants are agricultural crops like spinach (the Spinach flea beetle), beets, eggplant (the Eggplant flea beetle), and cruciferous plants like broccoli, cauliflower, cabbage, kale, (the Crucifer flea beetle).  But some Disonycha beetles eat invasive plants like Leafy spurge and are considered beneficial.  Adults chew holes in various parts of the plants – stems, leaves and petals (they like to feed in sunny weather) – and larvae may feed on the undersides of the leaves or on roots.  Tall flea beetles feed on plants in the genus Polygonum – knotweed, smartweed, bindweed, and tear-thumb (and it would be nice if a whole bunch of them would gang up on the very invasive Japanese Knotweed).   

Some Flea beetles shelter in the soil during bad weather and emerge when the rain quits and the sun is out again.  In Germany, this has earned them the name Erdflöhe (earth flea).  

So, here’s the funny thing about the Tall flea beetle.  Flea beetles (tribe Alticini) are so named because they jump around (like fleas) when they’re disturbed.  The BugLady certainly didn’t see any jumping – they were about as staid a bunch of beetles as you could hope to find – and she couldn’t find a video of it.  In this jumping they are aided by disproportionately large hind legs https://bugguide.net/node/view/915939/bgimage (all the better to jump with, my dear), though they get around routinely by walking and flying.  There are jumpers in a few other groups of beetles, too, like the weevils, Buprestids (jewel beetles), and marsh beetles.

Flea beetles jump using particular tendons that act like springs when initiated by the tensing and release of the leg’s extensor muscles.  Quoting two other researchers’ work in their paper, Nadein and Betz said that “They suggested that the high take-off acceleration, high velocity and short take-off time are compatible with jumping based on a spring-driven mechanism”.  Another group of researchers likened the movement to a catapult, and they based their design for a bionic jumping leg on the beetles’ anatomy (don’t ask the BugLady to explain anything more about this, but she can share links to a few articles).  

Mother Nature creates; man imitates.  

Monarch butterflies are nearing their destinations https://maps.journeynorth.org/map/?year=2022&map=monarch-adult-fall.  The BugLady will be interested in the numbers on the wintering grounds this year – Monarchs were scarce here this summer.

Kate Redmond, The BugLady

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

Bug o’the Week – Mottled Sand Grasshopper

Bug o’the Week

Mottled Sand Grasshopper

Howdy, BugFans,

From July into September, the Creeping Juniper Nature Trail at Kohler Andrae State Park is ruled by grasshoppers, and the BugLady had lots of fun chasing them around this summer (she stayed on the boardwalk, of course) (well, until the Swamp Darner flew past).  She especially liked the aptly-named Mottled sand grasshopper (Spharagemon collare).  MSGs are not restricted to Lake Michigan dunes, they have a range that stretches from Arizona and New Mexico diagonally back through the northern Great Plains and the Great Lakes, and well into Canada.  Plus, inexplicably, North Carolina, Delaware and Maryland.  Within that wedge of North America, they’re found in sunny, sparsely-vegetated areas with dry, sandy, and/or disturbed soils.  They’re especially common along the edges of wheat fields, says Wikipedia.

MSGs can vary quite a bit in appearance, and that’s probably tied to the habitat they live in.  They have banded, yellow wings https://bugguide.net/node/view/1424686/bgimage, and their hind tibias are red https://bugguide.net/node/view/585687/bgimage.  They can be a speckled gray, tan, brown https://bugguide.net/node/view/1254388/bgimage, or even reddish https://bugguide.net/node/view/22245/bgimage, depending on the soil they sit on, and some morphs are “collared” https://bugguide.net/node/view/585680/bgimage.  Habitats that are less sandy and more vegetated have “plainer” grasshoppers https://bugguide.net/node/view/2106847/bgimage (they’re not like tree frogs or goldenrod crab spiders that actively change colors, it’s just that the grasshoppers that match their background survive to pass along their genes will produce more grasshoppers that look like themselves, and regional color morphs are born).    

When a territorial male sees another grasshopper, he approaches and stridulates a few times (rubs one part of his body against another part – in this case, the hind leg against the forewing).  If it’s another male or a different species of grasshopper, he will attempt to oust it from the area.  A female who’s not in the mood will shake a hind leg and stomp on the ground (similar to the signals a male sends to an intruding male). If the female is willing, they mate https://bugguide.net/node/view/336164/bgimage, and then she uses her abdomen to excavate about a half-inch into the soil.  She oviposits (each egg pod contains about 25 eggs) and then camouflages the hole by brushing sand and debris over it.  MSGs overwinter as eggs and hatch in late spring/early summer. 

It takes MSG nymphs about six weeks to reach the adult stage, and males mature faster than females.  They tend to stay in the same area where they hatched, and adults may be present until the first frosts. 

Their eating habits get them into a little trouble with farmers and ranchers in the western part of their range, but they usually don’t occur in high enough densities to be called pests.  For the most part, they feed on pieces of prairie grasses and a few wildflowers that they find on the ground.  MSGs may reach up with their front legs and pull down a grass to feed on, and they sometimes climb up onto a grass stalk to sever a leaf or stem, but they feed on it after they climb down again.   

They are good flyers, and a male sometimes makes a buzzing sounds as he flies (crepitation – a clicking or snapping noise made by the wings).  They also crepitate when they’ve been startled into flight, during courtship, or when they’re defending their territory.  One study in Colorado clocked sustained flights by males at three to eight feet and by females at nine to ten feet, but in a Michigan study, researchers saw males flying 100 feet and females farther than that, and at heights up to 30” above the ground.  Despite their strong flight, they are geophilus (today’s vocabulary word) meaning “ground-loving.” 

MSGs are diurnal (active during the day), and they spend the night on the ground in the open, under a thatch of grasses, or up in a plant.  They wake slowly, warming up by basking for a few hours before they become active, exposing first one side to the sun and then the other.  When the temperature on the ground gets too hot (over 100 degrees F), they rest in the shade and emerge in late afternoon as the ground cools a bit.  They bask again before sheltering for the night.

They’re in the family Acrididae, the Short-horned grasshoppers, and in the subfamily Oedipodinae, Band-winged grasshoppers.  

Side note – spiders are using the mild spell to change locations – the BugLady sees the slender strands of spider parachutes on her shrubs each morning.  For the story on that, see https://uwm.edu/field-station/spider-flight-rerun/.

(and – oops – the BugLady used a picture of an MSG in an earlier episode, mistakenly ID’d as a Seaside grasshopper)

Kate Redmond, The BugLady

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

Bug o’the Week – Autumn Meadowhawk Dragonfly

Bug o’the Week

Autumn Meadowhawk Dragonfly

Greetings, BugFans,

We’ve just had an all-too-brief Indian Summer – it got warm enough for the flies to fly, the tree crickets to sing, and yes, for a few very late Monarch butterflies to drift past on their big journey.  The BugLady spent some time on boardwalks in wetlands, enjoying the last dragonflies of the year.

Meadowhawks, in the Skimmer family Libellulidae, are a genus of 15 species, nine of which have been recorded in Wisconsin.  They can be tricky to identify (understatement).  They start to appear in late June/early July and are with us for the rest of the summer and well into fall, but other than a few tenacious White-faced Meadowhawks, the final meadowhawk on the scene is the Autumn Meadowhawk (called the Yellow-legged Meadowhawk in older field guides) (the BugLady thinks that their legs are flesh-colored, rather than yellow, but she can see why that name would be a non-starter).  Here’s an early BOTW about meadowhawks https://uwm.edu/field-station/meadowhawks/.

Autumn Meadowhawks (Sympetrum vicinum) can be found in Southern Canada and much of the US, except for the northern Rockies, the arid Southwest, and a few of the Gulf States.  Some meadowhawks are picky about habitat, but not Autumn Meadowhawks, which are equally happy in shallow, permanent ponds, lakes, marshes and swamps, bogs, flooded meadows, and even slow-moving streams, especially if there are woodlands nearby. 

This is a pretty small/small, pretty dragonfly, only about an inch-and-a-quarter long.  Mature males are red – often cherry red – and females and immature males start out yellow https://bugguide.net/node/view/1959185/bgimage and then turn red and tan https://bugguide.net/node/view/1895278/bgimage.  Females have a prominent egg spout below the end of their abdomen. 

Along with the mosaic darners, Autumn Meadowhawks are the last dragonflies to emerge, and once they do, they spend more time than most dragonflies do away from the water.  The “Dragonflies of Northern Virginia ” website paints this picture, “Autumns can actually be abundant at times.  Hundreds of golden tenerals rise out of shallow wetlands in early summer, and bright red adults fill the same wetlands in fall.”   Large-scale emergences start at marshy pools in June, at which point juveniles take to the woods and grow up in sunny woodland clearings. They don’t seem to reappear at ponds and marshes until fall, often staying quite late into the season, hence their name.

Meadowhawks can be very common from mid-summer on, yet the BugLady rarely sees them at the waterfront with the other dragonflies.  Several meadowhawk species do oviposit into shallow water with emergent vegetation, but others have different ideas about where to leave their eggs.  White-faced Meadowhawks gamble, bobbing up and down in tandem as the female drops eggs onto the ground in a dry pond basin or on an edge that might be underwater by spring. 

In many dragonfly species, mature males patrol the shoreline and beat their figurative chests, waiting for females to arrive; females come to the water only when they’re reproductively ready.  Autumn Meadowhawks finish their development away from water, and by the time they get back to it, they have already found a female and are flying in tandem.  Legler, in Dragonflies of Wisconsin (aka “The Bible”) says that “the sexes form tandem pairs in midday https://bugguide.net/node/view/715052/bgimage, away from the water, then fly to water where they make dipping motions imitating oviposition.  They then mate and proceed to lay eggs while pair is in tandem.  Female trails and she will have mud on end of abdomen because she alternately strikes water surface and muddy stream bank or grassy area above the water line.  Eggs are deposited in mud or wet moss.  She alternately dips abdomen in water probably to clear the egg spout https://bugguide.net/node/view/351265/bgimage.  Eggs will survive the winter and hatch during rains and high water the next spring.” 

Unlike many other dragonflies, male Autumn Meadowhawks don’t defend territories along the shore, and, possibly because they aren’t territorial, they are unusually tolerant of other Autumn Meadowhawks.  Legler says that “Ovipositing by one pair attracts other pairs to same site for ovipositing.” 

The eggs hatch when (if) they’re inundated by water the following spring, as the water heats up to 50 degrees.  The naiads eat and grow and shed for six or seven weeks, emerging as adults at night in August or September.  They may fly into November if there isn’t a hard freeze; this they can do because they collect heat by basking in the sun and by sitting on warm rocks (Sympetrum means “with rock”).  With this boost, they are able to fly even when the temperature dips to 50 degrees F.  

They routinely perch higher off the ground than other meadowhawks, but on cooler days, they’re found on the ground.

Adults feed on small, soft-bodied invertebrates that they spot from a perch and then fly out and “hawk” from the air (one source said that their pursuits are successful 97% of the time).  The aquatic naiads https://bugguide.net/node/view/249117/bgimage, called “sprawlers,” hunt from concealment and grab a meal (fly larvae, daphnia, tiny fish, tadpoles, and smaller dragonflies) as it swims/walks past (nice video, but, no, never “larvae” https://www.kqed.org/science/1915435/a-baby-dragonflys-mouth-will-give-you-nightmares). 

Both above and below the water’s surface, Autumn Meadowhawks have an important place in the food web, both as eaters and eatees.  They’re food for ducks and other birds, fish (one source said that largemouth bass pick off ovipositing pairs from below), frogs, crayfish, mantises, and other dragonflies.  Another source reported that a snake that bites a naiad may get bitten back hard enough to convince it to drop its prey (and that the naiad may make sounds to startle predators).  With populations that peak as migration begins, Autumn Meadowhawks supply important fuel to southbound birds.  

Go outside – look at bugs – it’s not too late……

Kate Redmond, The BugLady

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

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