Tag: insects

Bug o’the Week – Cruiser Dragonflies
by Kate Redmond

Bug o’the Week by Kate Redmond

Cruiser Dragonflies

Greetings, BugFans,

When the BugLady asked BugFan Freda what she should write about for BOTW#700 (!!!), the answer, not surprisingly, was dragonflies.  In this case, a very cool family of dragonflies that the BugLady hasn’t seen yet, but that Freda has photographed.

The Cruiser dragonflies, aka River Emeralds or River Cruisers, are not shrinking violets – they are powerful dragonflies that have a reputation among dragonfly fans as the most difficult of the dragonflies to net (maybe because they’re highly maneuverable and they can hit flight speeds of up to 40 mph).  Older books include them in the Emerald family Corduliidae, but they are now listed in the family Macromiidae, a small family with 9 species in two genera in North America, and about 120 species worldwide.

Look for Cruisers around shallow, sunny rivers, streams, bays, channels, and lakes with good water quality.  They’re found from coast to coast except in the Rockies and Northern Great Plains.

These are dark, shiny, long-legged, darner-sized dragonflies (2 ¼” to 3 ¼” long) with a pale thoracic stripe and with light markings on a long, slim abdomen that, in males, may be slightly clubbed toward the tip (or not) https://bugguide.net/node/view/1326249 (a field mark that can be seen when a Cruiser flies overhead).  Most adults have green eyes that touch on the top of the head https://bugguide.net/node/view/1326250/bgimage (the eyes of the Emeralds, the Darners (Aeshnidae), and the Skimmers (Libellulidae) also meet on the top of the head).  Their wings are thin and unspotted, and except for the size of the abdominal appendages, males and females are pretty similar. 

Female Cruisers don’t have an ovipositor, so they can’t insert eggs in plant stems or rotten wood.  Instead they fly near the surface and release eggs directly into the water as they tap it with the end of their abdomen. 

The aquatic, immature dragonflies – naiads (“nymphs,” if you must, but never “larvae”) – are large, long-legged, and round https://bugguide.net/node/view/827176/bgimage.  They’re called “sprawlers” because of their habit of sitting quietly, camouflaged by the debris on the bottom of the pond or stream (hairs on their exoskeleton encourage the detritus to stick to the naiad.), waiting for their prey (freshwater shrimp, tiny fish and tadpoles, and mosquito larvae) to wander past.  They typically spend two to three years as naiads.  

Like other dragonflies, adult Cruisers feed on flying insects that they grab out of the air, but they may also “glean” their prey – pick perched insects off of vegetation.

Cruisers are known for speeding straight down the middle of rivers and roads, a few feet off the surface.  When they land, they may hang down vertically or perch at an angle.  

The Wisconsin Odonata Survey (WOS) lists four species of Cruisers for the state –two species are found in the northern half of the state, one lives along the Mississippi in the southwestern part of the state, and one species exists as a historical note.  Good descriptions of all can be found at the WOS site https://wiatri.net/inventory/odonata/SpeciesAccounts/ – click on the Cruiser family and then on the desired species.  Dragonflies of Northern Virginia is also a great resource http://www.dragonfliesnva.com/; for the species list click on “65 Species” in the first paragraph and scroll down for the species list.  

The STREAM CRUISER (Didymops transversa) is the only Cruiser in its genus in Wisconsin.  These early flyers can be found over much of the continent east of the Great Plains.  The WOS lists them as “common” and describes their habitat as “streams, rivers, and lakes that are slow, forested and sandy-bottomed, not still or vegetated. Sometimes they are found in uplands, along edges of forested trails or fields.”  One Canadian dragonfly fan has seen them along woodland trails so often that he thinks they should be called the “Trail Cruiser,” and he says that this species takes relatively short flights and then perches at an angle. 

Their flight period is late May to mid-July in Wisconsin.  In the northern part of their range, the flight season stretches from early May to mid-September, with a peak time in early spring.

For more pictures, see https://marylandbiodiversity.com/view/689

The SWIFT RIVER CRUISER (Macromia illinoiensis) is made up of two subspecies – the more northern Illinois River Cruiser (Macromia illinoiensis illinoiensis) and the more southern Georgia River Cruiser (Macromia illinoiensis georgina).  The northern subspecies is said to be more boldly colored of the two (for pictures of the Georgia River Cruiser, see https://www.marylandbiodiversity.com/view/692, and for the Illinois River Cruiser see https://wiatri.net/inventory/odonata/SpeciesAccounts/SpeciesDetail.cfm?TaxaID=128.  And yes, where they overlap, they interbreed.  Their status in Wisconsin is “Fairly Common”

This powerful dragonfly can be found flying fast and straight over large rivers, rapid, rocky streams, and shorelines with some wave action (all well-oxygenated waters) in a patchwork of states in the northeastern quadrant of North America https://bugguide.net/node/view/130228/data.  On his Dragonflies of Northern Virginia website Kevin Munroe says “Watching Swift River Cruisers in the field is a treat – they’re Olympic athletes, even by dragonfly standards. Watching one patrolling his territory, jetting down the center of a sunny river a few feet above the water, you almost except to hear him break the sound barrier. A flash of his yellow abdominal band and brilliant green eyes, and he’s gone. His linear patrols are long, but regular – just wait a few minutes and he’ll be back for another pass. They also hunt for hours high over meadows and ball fields. Watch them as they zip, dip and dive circles around other feeding dragonflies.”  They are also seen above roads and paths. 

Their flight season in Wisconsin is between early June and early September.  

The ROYAL RIVER CRUISER (Macromia taeniolata) likes rivers and large streams and is found in southwestern Wisconsin in a few counties along the Mississippi, and across the eastern half of North America https://bugguide.net/node/view/39700/data.  Males patrol lengthy stretches along shorelines or over open water, and they perch vertically in vegetation near the water’s edge.  Munson calls it one of our largest dragonflies – larger, heavier, and slower than the Swift River Cruisers – and says that it prefers slower water and marshy river sections.  Royal River Cruisers may join feeding swarms of other dragonflies in late afternoon.

In the northern part of their range, the flight season is from mid-June to early September, and they’re a WOS “Most Wanted” species (documented, but more info about range, habitat, numbers, etc. is needed).

For more pictures, see https://www.marylandbiodiversity.com/view/693

There’s one old, Milwaukee County record for the GILDED RIVER CRUISER (Macromia pacifica) https://bugguide.net/node/view/477031/bgimage, but whether this was a single, wandering individual or whether the species’ range previously included the state is unknown  They don’t occur here today (and their present range is pretty disjointed https://bugguide.net/node/view/477069/data). 

Munson cautions hopeful Cruiser netters to be careful in their attempts because the Cruisers and the Emeralds are easily damaged.  Discretion is the better part of valor.

FUN FACT ABOUT CRUISERS:  The BugLady doesn’t know about the rest of the Cruisers in the world, but when the naiads of these four species emerge from the water, ready to metamorphose into adults, they trek 40 or 50 feet inland before settling on a good spot to climb out of their “skin” and start their aerial life.

Thanks for the pictures, Freda – the BugLady is adding these dragonflies to her wish list (Road Trip!).   

Spring is coming.  Dragonflies are coming.

Kate Redmond, The BugLady

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

Bug o’the Week – Flies without Bios II
by Kate Redmond

Bug o’the Week by Kate Redmond

Flies without Bios II

Howdy, BugFans,

The BugLady is always ambivalent about photographing flies, even when they pose nicely.  There are a whole heck of a lot of species of Diptera (“two wings”) out there – 17,000 in North America and 150,000 worldwide (some estimates of the eventual total go as high as a million species) – so unless it’s a really dramatic fly, there’s a pretty good chance the picture will end up in the “X-Files.”  On the bright side, with that number of species, you can expect quite a bit of diversity – these are not all house fly-shaped-objects: https://bugguide.net/node/view/1126926, https://bugguide.net/node/view/2223038/bgimage, https://bugguide.net/node/view/1476962/bgimage, https://bugguide.net/node/view/2225982/bgimage, https://bugguide.net/node/view/2034795/bgimage, https://bugguide.net/node/view/35812.

Most insects have wings, and most insects that have wings have four of them.  The conspicuous, membranous flying wings on these “two-winged” flies are actually the front pair of wings – the hind pair has been modified into knob-shaped structures called halteres https://bugguide.net/node/view/130687, which provide sensory feedback that helps the fly maintain stability in flight.  Most flies feed on liquids that they sponge/suck up (in species like horse flies and mosquitoes, the sponging mouthparts are augmented by cutting blades that get the juices flowing).  As a group, flies spread both pollen and disease, though the former is more common than the latter.

The “Without Bios” series celebrates insects whose profile is low – insects that are neither big enough nor bad enough nor beautiful enough to have been studied much, if at all.

SNIPE FLIES (family Rhagionidae) are also known as “downlooker flies” because of their habit of perching head-downward.  They’re called Snipe flies because someone (in a fit of poetic license) thought that their protruding mouthparts looked like a snipe’s bill https://bugguide.net/node/view/1219348/bgimage.  They tend to have long legs, and while most are drab-looking, some are spectacular.  They like woods and wetland edges, and they prey on small insects.  Bugguide.net tells us that their taxonomy “has been unstable.” 

[Brief aside for non-birders.  Yes, snipe are a thing.  They are long-billed, medium-sized shorebirds https://www.allaboutbirds.org/guide/Wilsons_Snipe/overview that are often seen in the shallow water at the edges of wetlands.  The snipe hunt you went on at Camp didn’t have anything to do with actual Snipe.] 

SNIPE FLIES #1 – One of the more spectacular species.The BugLady has poked around at IDing this pair of flies off and on for years.  The heavy markings on their wing veins resemble those of the very spiffy Golden-backed Snipe Fly (Chrysopilus thoracicus) https://bugguide.net/node/view/1974388/bgimage, but – no Chrysopilus (“golden hair”).  Turns out that they are Chrosopilus foedus (no common name).  About them, the BugLady found that the adults perch on vegetation and on dirt roads, the larvae eat small worms, soft-bodied insect larvae, and grasshopper eggs, and like the Golden-backed snipe fly, they have a late spring flight period. 

The BugLady is interested in the etymology of entomology, and she discovered that the species name foedus has several unrelated meanings.  The first (a noun) is a “treaty, league, tie, bond, or pact;” second (an adjective) is “disgusting, foul, loathsome, ghastly, unclean, obscene, etc.”

The BugLady encountered SNIPE FLY #2 (Rhagio hirtus) (maybe) along a woodsy edge, and she was fascinated by its behavior.  Every once in a while, as it ran around on the leaf, it would lower its head and push it around a bit on the leaf’s surface.  No idea.  (Well, two ideas – 1) some kind of myopic hunting behavior, or 2) it had been taken over by a brain-eating, zombie-making fungus.)

When she was prowling the dunes at Kohler-Andrae State Park last summer, the BugLady saw BEE FLIES, aka Humbleflies, (family Bombyliidae) of at least three species.  There are lots of Bee flies globally, but the lives of many of them are poorly known.  Adults are generally nectar feeders (they sip nectar through a non-retractable proboscis), and many are bee-mimics (and they make the requisite buzzing sound).  Larvae are parasitoids of ground-nesting insects like beetles, moths, and solitary bees and wasps. 

Mom locates a nest tunnel and lobs an egg into it while its creator is away looking for provisions for her eventual larvae (actually, Mom will throw an egg into any shadowy area that looks tunnel-ish, but she can afford to waste, because she can lay hundreds of eggs each day).  In order to add a little weight to the egg as she releases it, Mom picks up some sand, which she stores in a chamber (OK – a “psammophore“) at the tip of her abdomen.  Some sand adheres to the egg as it passes by, making it heavier and camouflaging it.  It’s theorized that since bee flies are soft-bodied, this method of laying eggs prevents them from close encounters with the owner of the tunnel, who may be upset by the intrusion and is packing a stinger.

The larvae are unusual in being very active in their first larval stage (hypermetamorphosis) – this lets them scurry down the tunnel and search for a host.  They let themselves into an egg chamber, and then settle down to normal larval speed, and eat the stored pollen and then the rightful owner of the cell.  The bee fly emerges the following spring in sync with the flight period of its target host. 

Bee Fly #1 – Exoprosopa fasciiata (probably), aka the Barred Bee fly, is pretty common east of the Great Plains.  “Fasci” means “band” and refers to the white band on the abdomen.

Bee Fly #2 – Exoprosopa fascipennis (no common name).  “Fasci” means “band,” and “pennis” means “wing.”  It’s found throughout the summer at beaches and sandy meadows over the eastern half of the continent.  It looks for the tunnels of Tiphiid wasps and sand wasps.  

Bee Fly #3 – Villa lateralis (probably) (bugguide says that because their markings are variable, “identification to species is tentative at best”).  Larvae of flies in the genus Villa feed on (in) the larvae of stag beetles, moths, horse flies, and ant lions that they find under the sand.

Available for all three bee fly species are extensive descriptions of every part of their anatomy, but not biographies.

The BugLady confesses (no surprise) that she’s always had a soft spot for predators, and ROBBER FLIES (family Asilidae) are amazing poster children for unapologetic meat-eaters.  There are lots of them – 7,500 robber fly species worldwide, 1,040 in North America, and about 100 in the Great Lakes area.  Robber flies have eyes worthy of a predator and long legs that the BugLady thinks look double-jointed somehow https://bugguide.net/node/view/1292828/bgimage).  They usually sport a beard (“mystax”- which is both Greek and Latin for “moustache”) https://bugguide.net/node/view/1692598/bgimage.  They like the sun, and they often perch on vegetation at woodland edges so they can scan for prey (the BugLady once saw one shoot straight up off a leaf in pursuit of a butterfly overhead).  They’ll go after bugs that are bigger than they are, including other robber flies, and one theory about the mystax is that it protects their faces from the stinging insects they catch.  Their larvae live in soil and rotting wood and eat small invertebrates that they find there.   

What happens when a robber fly’s hunt is successful?  Jeff Milton, in the Colorado Arts and Sciences Magazine, says it well: “Robber’s modified mouthparts form a stiff, hollow beak that serves first as a dagger, then as a hypodermic needle and finally as a straw. When robbers impale prey they inject both neurotoxins and digestive enzymes. The neurotoxins quickly subdue and soon kill the prey. The digestive enzymes turn the prey’s internal tissues to soup, but do not damage the tough chitinous exoskeleton, which now serves as a watertight container full of thick broth. Fluids are sucked through the beak until the carcass until is a dry husk.”

The STRIPE-LEGGED ROBBER FLY (Dioctria hyalipennis) (hyalipennis means “glassy wing”) is one of the more petite robber flies, and it’s easy to overlook.  It favors smaller prey like files, small wasps, sweat bees, and pygmy grasshoppers. 

According to Mike Reese in his awesome Wisconsin Butterflies website https://wisconsinbutterflies.org/ (which includes tiger beetles and robber flies), the SLRF is one of two non-native robber flies in North America.  It was first recorded in Boston in 1916 and was given a new name in its new country until scientists realized that it already had one in Europe.  It’s found across the northeastern quadrant of this continent and, inexplicably, in Oregon, and across Europe into North Africa.  The BugLady found articles about it in Finnish, Dutch, French, and Polish. 

Nota bene: when you’re writing the common name of a dipteran, the word “fly” is always separate – house fly, deer fly, etc.  When you write the name of a non-dipteran whose name includes “fly,” fly is incorporated – mayfly, dragonfly, firefly. 

Flies are some of the earliest insects to venture out onto the landscape in spring (especially the very cold-tolerant Chironomid midges).  Get ready!

Kate Redmond, The BugLady

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

Bug o’the Week – Coral Hairstreak Butterfly
by Kate Redmond

Bug o’the Week by Kate Redmond

Coral Hairstreak Butterfly

Howdy, BugFans,

Hairstreaks (and Blues and Coppers and Harvesters) are members of the Gossamer-winged butterfly family Lycaenidae (“Gossamer-winged” being a nod to the iridescent sheen on the wings of many family members).  Numbering nearly 5,000 mostly tropical species worldwide – 30% of butterfly species – Lycaenidae is the second-largest butterfly family (the Brush-foots outnumber them).  The BugLady associates hairstreak butterflies with butterfly weed and hot, sunny prairie days.

Family members share characteristics like indented eyes, striped antennae, a narrow face, reduced forelegs (males more than females), bright colors, and (frequently) hair-like “tails” on the edge of the hind wing.  The tails are often located near a blue-pigmented “eyespot” on the wing – hairstreaks often land head-down, and the eyes and antenna-like tails are said to present a predator with a “false head.”  The tails are fragile and can be worn off or may be bitten off by a misdirected predator (better to lose a chunk of a wing than your actual head). 

With the exception of the carnivorous Harvester larvae, the slug-like Lycaenid caterpillars are herbivores; adult Lycaenids feed at flowers and also get nutrients from damp mud, decaying fruit, and carrion.  Caterpillars of many species of Gossamer-wings are myrmecophiles – they have friendly relationships with ants, trading food for protection.  Caterpillars of some species are able to communicate with or summon their ants by producing vibrations that travel through the substrate.  

CORAL HAIRSTREAKS (Satyrium titus) aren’t gaudy, but they’re still pretty spiffy little butterflies.  They are hairstreaks without hairstreaks, and they don’t have blue eyespots on the edge of their wings, either https://bugguide.net/node/view/23133 (compare it to the similar Acadian Hairstreak, which has both https://bugguide.net/node/view/1490067/bgpage).  Coral Hairstreaks close their wings immediately upon landing, so the BugLady couldn’t find any picture of the dorsal side of their wings other than this pinned specimen https://digitalatlas.cose.isu.edu/bio/insects/butrfly/famlyc/satif.htm.  They have a wingspread of 1” to 1 ½”, and males and females look alike except that the male’s wings are somewhat more triangular in shape.  Here are more pictures https://www.marylandbiodiversity.com/view/513. 

Coral Hairstreaks are found across much of North America https://bugguide.net/node/view/4115/data.  They need two habitats, with adults visiting (and pollinating) flowers, especially butterfly weed, in open areas like grasslands, roadsides, clearings, pastures, and gardens; and caterpillars feeding on the new leaves, flowers, and even the new fruit of Black cherry and a few of its close relatives in young woods and around woodland edges.  Some hairstreak species are woodland-dwellers, but maturing woodlands become less attractive to Coral Hairstreaks, and land use practices affect their numbers. 

Aggressive males perch on vegetation and chase females and other insect intruders, and they court using pheromones (smells) and visual displays.  Females lay eggs on twigs, at the base of a host tree or in nearby leaf litter, leaving a scent mark to indicate to other females that the spot has been taken.  The eggs overwinter, hatching in spring as the new vegetation erupts https://bugguide.net/node/view/1683166/bgimage.  There’s one generation per year.

Although Coral Hairstreaks fly fast and erratically, most don’t disperse very far away from where they hatched.  On cool mornings, they warm up by sitting with wings closed, at right angles to the sun (lateral basking).  

According to the great University of Michigan Biokids website http://www.biokids.umich.edu/critters/Lycaenidae/, lacewings and ladybug beetles eat hairstreak eggs; ants, wasps, and the larvae of parasitic flies eat the caterpillars; mice and shrews feed on the pupae; and mantises, spiders, birds, frogs, and toads stalk the adults.  If they can connect with the proper species of ant, the caterpillars will be protected by them in return for allowing the ants to harvest drops of honeydew that caterpillars produce in a “honey gland” (dorsal nectary organ) http://www.pbase.com/spjaffe/image/125237720).  Caterpillars feed at night, attended by ants, and rest in the leaf litter below the cherry tree by day. 

Data from the marvelous Butterflies of Massachusetts website (https://www.butterfliesofmassachusetts.net/index.htm), where they have crunched the numbers for 150 years’ worth of butterfly sightings, suggest that warming temperatures due to climate change are causing Coral Hairstreaks there to begin their flight period two weeks ahead of the historical dates – at the beginning of July rather than the middle of July (and this is undoubtedly happening elsewhere).

Kate Redmond, The BugLady

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

Bug o’the Week – Cyrano Darner Dragonfly
by Kate Redmond

Bug o’the Week by Kate Redmond

Cyrano Darner Dragonfly

Howdy, BugFans,

It’s time for a dragonfly.  In fact, it’s past time for a dragonfly.  The BugLady has not seen this species yet (BugFan Freda has, and she contributed her pictures.  Thanks, Freda) but she’s looking forward to the end of the rain/sleet/graupel/freezing rain/snow season and to the return of the green so she can look for one.

BOTW has featured the stories of darners (family Aeshnidae) in a number of genera – Common Greens (Anax), mosaic darners (Aeshna), Spatterdock Darner (Rhionaeschna), Fawn Darner (Boyeria), Swamp Darner (Eipaeschna), and Springtime Darner (Basiaeschna).  Cyrano Darners are in the primitive darner genus Nasiaeschna, characterized by a stocky body, no “waist,” and a protruding “frons” (literally, the forehead or brow – the front part of the head between the eyes, the antennae, and the mouthparts).  Cyrano Darners (Nasiaeschna pentacantha) are the only members of their genus anywhere in the world, and their closest relative here might be the Swamp Darner.    

About that name.  Yes – this dragonfly was named after Cyrano de Bergerac, a character in a 19th century play.  Cyrano had a substantial nose, and this dragonfly’s frons is so protuberant https://bugguide.net/node/view/255298/bgimage that it can even be seen in flight (which is a good thing, because it doesn’t sit still a lot).  Kurt Mead, in Dragonflies of the North Woods, suggests an alternative genus name “Schnozz-iaeschna.”  “Nasi” means “of the nose,” but the species name, pentacantha (“five spines”), is a little more of a mystery, because females have spines near the tip of their abdomen, but often they have more than five. 

Cyrano Darners are an eastern-ish species https://bugguide.net/node/view/18152/data, and their habitat is sometimes described as “blackwater pools.”  They like bottomland forests, lakes, ponds, sluggish streams, and sheltered bays with plenty of leafy and woody debris underwater for their naiads to climb on.  The Wisconsin Odonata Survey lists 65 Cyrano Darner observations in Wisconsin, starting in 2009; their status here is a bit wobbly due to their few, scattered populations. 

Unlike the much larger Swamp Darner, the 2 ½” Cyrano Darner has geometric, green splotches on its abdomen rather than tidy, green rings, and it has jagged, green stripes on its thorax.  Here are more pictures: https://www.marylandbiodiversity.com/view/682. 

Cyrano Darners are an early-to-mid-season species, in the air from mid-June through July in Wisconsin.  Males fly three to six feet above the water to patrol territories and chase off the competition (one author said that they torpedo intruders, even intruders that are larger than they are), and sources describe their flight as slow, deliberate, and predictable.  They often fly with their wings elevated and the tip of their abdomen in a slight downward hook https://bugguide.net/node/view/122070.  Unlike other dragonflies, they generally don’t stray too far from water, but Paulson, in Dragonflies and Damselflies of the East, says that they may “cruise back and forth over clearings in forest at about head height but [are] rarely seen to perch, and then often well up in tree.” 

Females oviposit solo, inserting eggs into wet logs and soggy stumps below the water line or as high as ten inches above it.  Naiads climb around on underwater vegetation and grab passing aquatic insects and small tadpoles and fish by extending their lightning-fast labium (fused mouthparts https://bugguide.net/node/view/250311/bgimage).  When it has fed sufficiently, a naiad leaves the water to emerge as an adult.  Freda came across a newly minted adult Cyrano Darner that had crawled up onto a stick, shed its final naiad skin and was “unfurling” its wings and abdomen while it perched on the empty shell (exuvia).  Its pale colors would intensify over the next few days.

exuvia

Lots of dragonflies, especially the larger species, grab their prey out of mid-air, but Cyrano Darners are “gleaners” that fly down and pick off insects that are perched on vegetation – an unusual behavior among the darners.  They’ll go after some pretty large prey, and they’ll eat fellow dragonflies as large as clubtails.  Here’s one feeding on a Roseate Skimmer (which ought to be a sin) https://www.whatsthatbug.com/dragonfly-cannibalism-2/.  After plucking it from a branch or leaf, the darner lands and eats its catch (head first, says one source, so it won’t bite them).  Cyrano Darners may forage until dusk, but because of their uncommon hunting strategy, they do not join the feeding swarms of dragonflies that follow clouds of midges and other small insects over the grass-tops. 

The BugLady recommends the “Dragonflies of Northern Virginia” website, whose author posts great pictures and, in his Notes from the Field, recounts his personal experiences with each species.  Cyrano Darners are a favorite of his – check his adventures with this and other species at http://www.dragonfliesnva.com/My%20Documents/KevinPDF/pdf/identify/SpeciesList%20N%20VA-FINAL-HL.pdf.  

According to the fine folks at the Springfield Plateau Chapter of the Missouri Master Naturalists (the Cyrano Darner is the emblem of the Missouri Master Naturalists), the Missouri Conservationist publication once offered this advice on how to catch a dragonfly by hand: “Approach them with one hand making erratic circles in front of the insect. A few failures will indicate how close you can get.  Slowly move the other hand in from the rear and pick the dragonfly up by its tail. Then switch your hold to its thorax. When calmed down, they will accept and eat offered insects, such as mosquitoes.”  “Editor’s note: There were no instructions on how to hold the mosquito you are feeding it.”

Freda wondered if the BugLady could find out what the little lumps are that you can see on one exuvia.  Adults have a variety of lumps on their heads, and so do naiads, but the BugLady couldn’t find anything about lumps in other places, so she wonders if something that lived underwater with that naiad might have attached itself to the shell. 

Fun Fact about Cyrano Darners:  According to Mead, when the naiads are handled, they play dead, looking like a short stick.

Kate Redmond, The BugLady

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

Bug o’the Week – Bugs in the News
by Kate Redmond

Bug o’the Week
by Kate Redmond

Bugs in the News

Howdy, BugFans,

As usual, the BugLady’s “Bugs in the News” folder runneth over, so here’s a collection of articles to chew on.  Many come from the wonderful Smithsonian Daily Newsletter, which not only posts a lot of good stuff, it doesn’t put articles behind a paywall.  Support your Smithsonian!

THANKS, POLLINATORS – https://www.smithsonianmag.com/blogs/national-zoo/2022/06/29/8-reasons-to-bee-in-awe-of-pollinators/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=20220629-daily-responsive&spMailingID=47040669&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2263232055&spReportId=MjI2MzIzMjA1NQS2

SMALL BUT MIGHTY (get in line, Ben Franklin) – https://www.smithsonianmag.com/smart-news/honeybee-swarms-can-produce-as-much-electric-charge-as-a-thunderstorm-180981005/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=20221028daily-responsive&spMailingID=47569605&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2326297509&spReportId=MjMyNjI5NzUwOQS2

JUST MIGHTY – https://www.smithsonianmag.com/smart-news/scientists-just-discovered-the-largest-invertebrate-to-ever-live-an-ancient-9-foot-millipede-180979293/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=20211223-daily-responsive&spMailingID=46155101&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2142675899&spReportId=MjE0MjY3NTg5OQS2

HOW SPRINGTAILS SPRING – https://www.smithsonianmag.com/smart-news/springtails-are-natures-tiny-gymnasts-videos-reveal-180981094/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=20221109daily-responsive&spMailingID=47620026&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2341182089&spReportId=MjM0MTE4MjA4OQS2

SPIDERWEBS TRAP SOUND – https://news.cornell.edu/stories/2022/03/orb-weaver-spider-uses-web-capture-sounds

ANTS MAKE MILK – https://www.smithsonianmag.com/smart-news/scientists-discover-that-ants-make-a-milk-like-substance-180981237/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=20221205daily-responsive&spMailingID=47722949&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2360514556&spReportId=MjM2MDUxNDU1NgS2

AND THEY SERIOUSLY OUTNUMBER US – https://www.npr.org/2022/09/21/1124216118/ants-number-study-quadrillion?utm_source=npr_newsletter&utm_medium=email&utm_content=20220921&utm_term=7276606&utm_campaign=news&utm_id=2548916&orgid=675&utm_att1=

BUMBLE BEES PLAY – https://www.npr.org/2022/11/05/1134355887/bumblebees-can-play-does-it-mean-they-have-feelings-study-says-yes?utm_source=npr_newsletter&utm_medium=email&utm_content=20221107&utm_term=7492099&utm_campaign=news&utm_id=2548916&orgid=675&utm_att1=

MOTH NAVIGATION (AND ain’t technology grand!) – https://www.smithsonianmag.com/smart-news/scientists-study-how-deaths-head-hawk-moths-fly-along-a-straight-path-180980680/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=20220908daily-responsive&spMailingID=47344619&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2320890017&spReportId=MjMyMDg5MDAxNwS2

Kate Redmond, The BugLady

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

Bug o’the Week – Horsehair worm Redux
by Kate Redmond

Bug o’the Week
by Kate Redmond

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/183612, watering 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
by Kate Redmond

Bug o’the Week
by Kate Redmond

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/bgimage, https://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
by Kate Redmond

Bug o’the Week
by Kate Redmond

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/bgimage, https://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/

Become a Member

Take advantage of all the benefits of a Riveredge membership year round!

Learn More