Tag: beetle

Bug o’the Week – Bugs at the End of Summer

Bug o’the Week
by Kate Redmond

Bug o’the Week Bugs at the End of Summer

Howdy, BugFans,

The Autumnal Equinox is fast upon us, alas, and even though it was a very hot one, the BugLady would like to push that Restart button and go back to the beginning of August.  Failing that, here are some of the bugs that crossed her trail in the second half of summer.

BARK LOUSE – Bark lice (order (Psocidae) are often seen in herds, both as adults and nymphs https://bugguide.net/node/view/1716157/bgimage.  This species, Cerastipsocus venosus, is known collectively as Tree cattle.  Bugguide.net says that they feed on “accumulations of fungi, algae, lichen, dead bark and other materials that occur on tree trunks and large limbs.”  And on the BugLady’s porch rails.  So, they clean up after the BugLady outside, and the silverfish take care of the inside of her cottage. 

YELLOW-HORNED FLOWER LONG-HORNED BEETLE – The YHFLHB (Strangalia luteicornis) is in the Longhorned beetle family Cerambycidae and the subfamily Lepturinae, the flower longhorns.  Flower longhorns are often found on flowers by day, feeding on the protein-rich pollen, and many (but not all) species are wedge-shaped – sometimes dramatically so.  Their larvae feed on dead and dying woody material, and certain fungi that they ingest as part of their meal then aids the grub’s ability to digest cellulose (in some species of flower longhorns, Mom inoculates the eggshell as she lays it with a yeast that becomes part of the grub’s intestinal microflora). 

AMBUSH BUG – What would summer be without the extraordinarily-well-camouflaged (and voracious) ambush bugs – one of the BugLady’s favorites? 

LEAF-FOOTED BUG – Late summer is True bug season (remember – only one insect order, the Hemiptera, can officially be called Bugs).  This particular bug is the almost-grown nymph of a leaf-footed bug called Acanthocephala terminalis (no common name).  Newly-hatched nymphs, with their spiny butts and improbable antennae, are pretty cute https://bugguide.net/node/view/933082/bgimage. 

SPIDER WEB AND PREY – All wrapped up and nowhere to go.   

BALD-FACED HORNET – The BugLady corresponded this summer with a man who was stung twice in his mouth by a Bald-faced hornet (now called Bald-faced aerial yellowjacket).  These are the gals that build the closed, football-shaped, paper nests that hang in trees, and while they are valiant/dangerous in defense of their homes, they don’t defend the flower tops where they feed.  The BugLady’s correspondent was apparently walking along blamelessly when his open mouth encountered a flying hornet.  Stings on the face, and especially in the mouth, can be dangerous because of swelling, even if you’re not allergic. 

An entomologist named Schmidt went around deliberately getting stung by the ants, hornets, bees, and wasps of the world and writing descriptions of his discomfort that are sometimes reminiscent of a wine-tasting.  He rated the Bald-faced hornet at a 2 out of 4 on his pain scale – “rich, hearty, slightly crunchy.  Similar to getting your hand mashed in a revolving door” https://reliantpest.com/north-american-schmidt-sting-index/.  Not surprisingly, lots of exterminator companies have posted the scale because they want to sell us something.   

COMMON WOOD NYMPH – A medium/large Satyr butterfly of sunny fields, Common Wood Nymphs are not often seen nectaring on flowers, preferring fungi and rotting fruit.  They lay their eggs on grasses in late summer, but when the caterpillars hatch, they go into hibernation immediately, without feeding, to continue their development the following spring. 

CANDY-STRIPED LEAFHOPPER – what glorious things sometimes come in ¼” packages!  And, they have superpowers!  Leafhoppers suck plant juices.  Most plant sap has a sugar concentration of only a few percent, so leafhoppers have to consume a lot of it to get enough calories, and they excrete the excess (honeydew) “under pressure” with a tiny, but sometimes-audible, “pop.”  Because of this, they’re called “sharpshooters.”  And – they vocalize, but too softly for us to hear.

BROWN WASP MANTIDFLY – Yes, those poised, mantis-like front legs are used to grab smaller insects (mantidflies also sip nectar); and yes, this mantidfly does look like a paper wasp at first glance (but – no stinger).  Scroll down to see how this very flexible species has evolved to imitate different species of wasps in different parts of the country (the mantidfly is on the left) https://bugguide.net/node/view/4825. 

Their stalked eggs are attached to leaves https://bugguide.net/node/view/216544/bgimage, and when the eggs hatch, each larva waits for a passing spider, hitches a ride (feeding on the spider like a tick), and eventually infiltrates the spider’s egg sac, where it spends the rest of its larval life eating spider eggs.

WHITE-FACED MEADOWHAWK – You rarely see this species in tandem flights out over the water or ovipositing into shallow water.  They often “speculate” – bobbing up and down in damp areas by a pond’s edge, with the female lobbing her eggs onto the ground.  The plan is that spring rains will wash the eggs into the water. 

RED-SPOTTED PURPLE – What a classy butterfly!  Three Fun Facts about Red-spotted Purples: 1) the red is on the underside of the wings https://bugguide.net/node/view/557370; 2) though they are “tailless,” they are mimicking Pipe-vine Swallowtails, which are poisonous https://bugguide.net/node/view/2264557/bgimage; and 3) partly-grown caterpillars spend the winter inside a leaf that they’ve rolled into a tube and fastened to a twig, and they emerge and resume eating the following year (scroll down for a picture of a hibernaculum and for a bonus lesson about “frass spars” https://entnemdept.ufl.edu/creatures/bfly/red-spotted_purple.htm).  Within their leafy tube, they drop about 1/3 of the water weight in their body in order to avoid cell damage from freezing.

CRAB SPIDER – Nothing to see here, folks, just move along.

GREEN STINK BUG – Another common sight in late summer, along with their flashy, almost-grown nymphs https://bugguide.net/node/view/885566.  Some stink bugs are carnivores, and some are herbivores, and some of the herbivores are considered crop pests.  They aren’t chewers, they suck plant juices with mouths like drinking straws, which can deform fruits and seeds, damage twigs, and wither leaves.  Green Stink bugs (Pentatoma hilaris) (hilaris means “lively or cheerful”) feed on a large variety of plants (they’re “polyphagous”).  Newly-hatched green stinkbugs aren’t green https://bugguide.net/node/view/127137/bgimage.

TIGER SWALLOWTAIL CATERPILLAR – No – those aren’t eyes.  They’re pigment spots that are designed to fool you into thinking it’s a snake.  Young Tiger Swallowtail caterpillars start out as bird poop mimics https://bugguide.net/node/view/1883543/bgimage, but midway through their development, they go into snake mode, completing the effect by everting, when they feel threatened, a two-pronged, soft, orange, odorous projection (the osmeterium) that looks like a snake’s forked tongue https://bugguide.net/node/view/2214191/bgimage.  Tiger Swallowtails have two generations per year.  Caterpillars of the butterflies we see in June don’t spend long in the chrysalis, emerging in mid-August and getting to work on the next generation.  This caterpillar will overwinter as a chrysalis.  Don’t tell the other insects, but Tiger Swallowtails are the BugLady’s favorites.

As she visited her usual haunts this summer, the BugLady was dismayed at the lack of insects.  Sure, the goldenrods are full of flies, bees and wasps of various stripes, and the grasshoppers and tree crickets are singing their September songs.  But she saw six Tiger Swallowtails this summer.  Total.  And maybe a dozen meadowhawks.  During one mid-summer Dragonfly count years ago, the BugLady simply stopped counting meadowhawks when she got to 250 because it was distracting her from the other species.  Common Wood Nymphs used to emerge in early July by the score to filter through the grasses.  Even crab spiders and ambush bugs seemed scarce this year. 

What good are insects?  Sometimes it’s hard to drum up sympathy for a group that many people routinely swat, stomp, spray, or zap.  But insects provide food for birds and for other insects; they’re pollinators, and they provide other ecosystem services including pest control and garbage pick-up. 

(And, of course, they’re awesome.)

Kate Redmond, The BugLady

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

Bug o’the Week – Euderces picipes Beetle

Bug o’the Week
by Kate Redmond

Bug o’the Week Euderces picipes Beetle

Greetings, BugFans,

When the BugLady saw these two tiny (5mm/¼”), black insects on a flower, her first thought was “ants,” followed immediately by a mental head slap.  They were piggyback – worker ants don’t do that, and royal ants have wings, and males are way smaller than females.  A (much) closer look revealed two long-horned beetles, Family Cerambycidae.

The Cerambycids (aka the longicorns, borers, girdlers, sawyers, or timber beetles) are a large group of beetles (1,000 species in North America; 30,000 worldwide).  Some are spectacular https://bugguide.net/node/view/1767144/bgimage, https://bugguide.net/node/view/2247879/bgimage, https://bugguide.net/node/view/226098/bgimage,; some are humble – https://bugguide.net/node/view/119390/bgpage, https://bugguide.net/node/view/1285181/bgpage,; some are just odd – https://bugguide.net/node/view/1472921/bgimage, https://bugguide.net/node/view/2198732/bgimage, https://bugguide.net/node/view/1569423/bgimage; and at least one species graces a Wanted Poster – the large, non-native Asian Longhorned beetle that’s been threatening our hardwoods since 1996 https://bugguide.net/node/view/631192/bgimage.  A number of native species are also persona non grata, especially with the lumber industry. 

Many (but not all) Cerambycids have long antennae (“horns”) – some spectacularly long https://bugguide.net/node/view/2119609/bgimage.  

Cerambycid larvae are often called round headed borers, and it’s the “borer” part that gets them in trouble.  They feed on the tissue within the stems, trunks, and roots of plants (woody and herbaceous).  Depending on the species, they may (or may not) wait for a tree to be compromised and bore into dead or dying wood – they are part of the recycling process.  They may be found in untreated lumber which, if it’s part of your house, you may not be ready to recycle yet.  Female Cerambycids locate the correct host species for their offspring by analyzing the chemical signatures of plants, and some damage trees by girdling twigs while they’re ovipositing.  Adults variously eat sap, nectar, pollen, fruit, fungi, foliage, and bark, or nothing at all.

The star of today’s show represents a tiny drop in the great Cerambycid bucket – there are only four species in the genus Euderces in North America (60 total), and bugguide.net calls them “among the smallest of our longhorns.” 

EUDERCES PICIPES (no common name) is found in the first half of summer, east of the Great Plains.  Its larvae feed under the bark of hickory, black walnut, oak, elm, dogwood, and locust branches.  According to the excellent Illinois Wildflowers website, adults are found on flowers in the aster, sumac (cashew), carrot, holly, honeysuckle, mint, rose, greenbriar, and buckthorn families, and many of the bugguide.net pictures show them on white flowers.

Along with the black morph beetles that the BugLady saw, Euderces picipes also comes in red https://bugguide.net/node/view/2047840/bgimage.  The black morph is more common in the northern part of its range, and the red is more common in the south.  Both colors are found in transition zones, and mixed pairs can be seen piggyback.  Apparently, they know who they are. 

Many of the species in the genus Euderces and in their tribe, Tillomorphini, are ant mimics, but ant mimicry (myrmecophily, pronounced myr’ me coph’ i ly) is not limited to beetles – spiders do it https://en.wikipedia.org/wiki/Ant_mimicry#/media/File:Ant_and_jumping_spider_Gorongosa_National_Park,_Mozambique.jpg and crickets https://en.wikipedia.org/wiki/Ant_mimicry#/media/File:Macroxiphus_sp_cricket.jpg, and so do other arthropods.  There are even ants that mimic other ants, though scientists aren’t sure why.

There are several reasons why it might be beneficial to look like an ant.  One reason is to eat, and another is to avoid being eaten.  Besides its morphology (size, shape, structure), an insect or spider that wants to insert itself among the ants in order to eat them (aggressive mimicry) must also act and smell like an ant (or, at least, not like a spider).  An ant mimic that wants to avoid being eaten (protective mimicry) is taking advantage of ants’ reputation for protecting themselves by biting, stinging, formic acid, or all of the above, as well as for having an anthill full of sister ants that are always on call in an emergency (all of which the BugLady learned at an early age).  Not many organisms mess with ants.  

Especially not the BugLady.

Kate Redmond, The BugLady

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

Bug o’the Week – Midsummer Memories by Kate Redmond

Bug o’the Week
by Kate Redmond

Bug o’the Week Midsummer Memories

Howdy, BugFans,

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

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

American Copper
Bronze Copper

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

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

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

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

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

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

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

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

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

Go outside – look at bugs,

Kate Redmond, The BugLady

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

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

Bug o’the Week
by Kate Redmond

Closed for June IV Fireflies

Howdy, BugFans,

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

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

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

Here are two articles about lightning beetles:

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

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

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

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

Kate Redmond, The BugLady

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

Bug o’the Week – 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 – 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 – 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 – Bugs at the End of Summer

Bug o’the Week

Bugs at the End of Summer

Howdy, BugFans,

The general rule of thumb is that if you want to find insects, look at flowers.  Even though summer is fading, there are still flowers in bloom.  Some Liatris/blazing stars linger, along with brown-eyed Susan, wild sunflowers, asters and goldenrod (more than a century ago, Asa Gray said that the 12 pages about goldenrods in his Manual of the Botany of the Northern United States, from New England to Wisconsin and South to Ohio and Pennsylvania Inclusive (aka Gray’s Manual) were the most uninteresting in the Manual).  Late summer and early fall are dominated by flies, bees and wasps, and by grasshoppers, katydids, and crickets.

Most adult insects die by the first frosts, leaving behind the next generation in the form of eggs or pupae (occasionally as nymphs or larvae), so the clock is starting to tick pretty loudly.  As BugFan Mary stated dispassionately many years ago, they’re dead and they don’t know it yet.  Meanwhile, their activities are centered on eating and on producing the next generation.

AMBUSH BUG (pictured above) – One of the BugLady’s favorite insects is the ambush bug (she’s always had a soft spot in her heart for predators).  Ambush bugs tuck themselves down into the middle of a flower and wait for pollinators.  They grasp their prey with their strong front legs, inject a meat tenderizer, and slurp out the softened innards.  They’re paired up these days (the BugLady has a picture of a stack of three), and she has several pictures where the female is multitasking – eating an insect while mating.

BUMBLE BEE – A bumble bee forages for nectar and pollen for the brood well into September, but the brood will not survive the winter.  Only the newly-fertilized queens will see the spring and establish a new colony.  Moral of the story – plant Liatris/Blazing star.

PUNCTURED TIGER BEETLES (aka Sidewalk or Backroad Tiger Beetles) are named for the rows of pits on their very-slightly-iridescent elytra (hard wing coverings).  They’re common across the continent in dry, sandy, bare spots, and as one of their names suggests, they’re sometimes seen on sidewalks.  Like their (much) larger namesakes, Tiger beetles chase their prey https://bugguide.net/node/view/1106590/bgimage.  For more info http://www.naturenorth.com/Tiger%20Beetle/The%20Tiger%20Beetles%20of%20Manitoba.pdf.  

Some Punctured tiger beetles are “plain” https://bugguide.net/node/view/1343674/bgimage, and some are “fancy” https://bugguide.net/node/view/223895, and some are green https://bugguide.net/node/view/2025474/bgimage.  

FAMILIAR BLUETS signal the end of the damselfly season.  Big, robust, and startlingly-blue, they’re one of the BugLady’s favorite bluets.  

EASTERN COMMA – There are two generations/broods/”flights” of Commas (and Question Marks – the “anglewings”) each year.  The second generation overwinters as adults, tucked up into a sheltered spot (a hibernaculum).  They sometimes emerge during a January thaw, but they quickly resume their winter’s sleep.  They fly briefly in spring – one of our early butterflies – and produce the summer brood.

FALL FIELD CRICKET – Poking her ovipositor into the soil and planting the next generation.  Her eggs will hatch in spring, and her omnivorous offspring will eat leaves, fruits, grain, and other invertebrates. 

The BugLady loves their simple songs http://songsofinsects.com/crickets/spring-and-fall-field-crickets and is happy when a cricket finds its way indoors in fall.  Males form a resonating chamber by setting their wings at a certain angle; then they rub their wings together to produce sound (one wing has a scraper edge and the other has teeth).  There are mathematical formulae for calculating the ambient air temperature based on cricket chirps that give you the temperature in the microclimate on the ground where the cricket is chirping (add the number of chirps by a single field cricket in 15 seconds to 40). 

CANADA DARNER – Common Green Darners are robust dragonflies that fill the late summer skies with dramatic feeding and migratory swarms.  There are other darners, though, primarily the non-migratory mosaic darners (like the Canada, Green-striped, Lance-tipped, and Shadow Darners) whose abdomens have blue and black, “tile-like” patterns.  Identify them by the shape of the colored stripe on the thorax and by the shape of the male’s claspers (lest you think it’s too easy, females come in a number of color morphs – this is a green-form female Canada Darner).  

MONARCH BUTTERFLIES were alarmingly scarce this summer – the short-lived Gen 3 and Gen 4, whose job it is to build the population in the run-up up to the migratory Gen 5, simply weren’t there.  But, on one of the BugLady’s recent stints on the hawk tower, she saw 289 Monarchs heading south during a six-hour watch.  Moral – Plant goldenrod (and native milkweeds).

GOLDENROD CRAB SPIDER – Like ambush bugs, crab spiders live on a diet of pollinators.  They don’t build trap nets and wait for their prey to come to them, they pursue it.  Sometimes they lurk on the underside of the flower, but their camouflage makes hiding unnecessary.  This female looks like she’s sitting at the dinner table.

RED-LEGGED GRASSHOPPERS are very common in sunny grasslands at this time of year from coast to coast.  They eat lots of different kinds of plants (including some agricultural crops, which does not endear them to farmers), but they prefer plants in the Legume/pea family and the Composite/aster family.  As the air temperature increases – and when predators are around – they eat more carbs.  Grasshoppers are food for spiders, many birds, and other wildlife.  Moral of the story – plant wild sunflowers.

PAINTER LADY – You don’t get to be the most widespread butterfly in the world (found everywhere except Antarctica and South America) by being a picky eater.  It migrates north in spring – sometimes in large numbers and sometimes in small.

THIN-LEGGED WOLF SPIDER – This Thin-legged wolf spider formed an egg sac (with about 50 eggs inside), attached it to her spinnerets and is going about her business.  When the eggs hatch, her young will climb up on her abdomen and ride around piggyback for a few weeks before dismounting and going about their lives. 

Great black wasp
Great golden digger wasp

GREAT BLACK WASP and GREAT GOLDEN DIGGER WASP – Two impressive (1 ¼” long) wasps grace the flower tops at the end of summer.  Both are good pollinators, both are solitary species that eat pollen and nectar, and both dig tunnels and provision chambers with paralyzed insects for their eventual offspring.  Great Black Wasps https://uwm.edu/field-station/great-black-wasp/ select crickets and grasshoppers for their young’s’ pantry, and so do Great Golden digger wasps https://uwm.edu/field-station/great-golden-digger-wasp-family-sphecidae/.  Neither is aggressive.  

The moral of the story?  Plant lemon horsemint.

Kate Redmond, The BugLady

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

Bug o’the Week – Black-margined Loosestrife Beetle

Bug o’the Week

Black-margined Loosestrife Beetle

Howdy, BugFans,

Purple loosestrife is a beautiful plant, with great wands of magenta flowers waving in the breeze.  Some say that, like a long list of other invasives, it entered the country in the ballast of ocean-going ships; others say that it was imported deliberately because it’s a medicinal plant as well as a great honeybee plant.  The BugLady knew a beekeeper who seeded purple loosestrife from the back of his snowmobile one winter, before he knew better (repent at leisure).  At any rate, it’s been here for 150 years or so, but it really started getting our attention in the 1970’s.  On its home turf, it exists in proportion to other wetland plants; here, it crowds out native vegetation, its dense stands discourage nesting waterfowl, and it’s not used by wildlife as a food plant (insects sure love the flowers, though). There are native loosestrifes, but they’re not invasive.

All those spectacular flowers produce masses of seeds (a single plant’s output can be in the millions of seeds, annually).  In gardens and upland situations, they fall to the ground and they grow or they don’t and that’s fine – the seeds stay pretty close to the parent plant.  In wetlands, the seeds fall into the water and float away to colonize other corners of the marsh or pond edge or ditch.  At the start of the battle against the purple loosestrife invasion in the 1980’s, Montezuma National Wildlife Refuge, at the north end of Cayuga Lake in NY, an area whose massive cattail marshes historically supported a thriving chair caning industry, had become wall-to-wall loosestrife.

It’s hard to get people psyched up about whacking beautiful plants.  It frustrated the BugLady’s husband that as some people were working to get purple loosestrife banned, nurseries continued to sell it (he also worked hard on our county fair officials to ban its use in their flower arranging competition).  Somewhere there exists a photo of our oldest at age 5, decked out in her Purple Loosestrife Task Force tee-shirt, dwarfed by the bundle of loosestrife that she’s holding.  You get the picture.  In some states, including Wisconsin, it’s now illegal to buy, sell, or plant it, but seeds are available online. 

This is a story of (very carefully vetted) biological control. 

When purple loosestrife began taking over American wetlands, scientists visited the Old Country to identify the grazers that the plant had left behind, and they found three species of weevils and two leaf beetles (family Chrysomelidae), Galerucella calmariensis and G. pusilla – the “Cella” beetles.  The BugLady thinks that she photographed the Black-margined Loosestrife Beetle (Galerucella calmariensis) (BMLB) (some are “bandier” than others https://bugguide.net/node/view/399423).   

The BMLB’s native range is the Palearctic realm – Europe, most of Asia, and North Africa.  It was introduced to this side of the Pond in 1992, after an impressive testing regime that involved inviting the beetle to sample some 50 species of North American plants to see if it would stray to another food plant.  The tests were done in Europe instead of risking an escape here. In the tests, the Cella beetles vastly preferred purple loosestrife (they were mildly interested in our native Winged loosestrife (Lythrum alatum) in the lab, but preferred purple loosestrife in the field).  Since then, the beetles have been introduced in southeastern Canada and 27 Northeastern, Northwestern, and Upper Midwestern states, and they’re doing a fine job, indeed.  The two Cella beetles and two of the European weevils have been in play in Wisconsin since 1994.

Both the larvae and the adult BMLBs feed on purple loosestrife – the larvae on buds, shoots, and leaves (where they skeletonize the lower surface) (at a high density, the larvae alone can defoliate a plant), and the adults on the leaves, where their feeding causes a distinct “shot hole” defoliation.  Their one-two punch diminishes seed production and impairs photosynthesis, so that the plant stores less starch in its roots, killing or making them less vigorous.  As loosestrife plants decline, native plants can move back in. 

The biographies of the two species of Cella beetles are very similar, except for a small difference in timing – one species leads off, and the other bats cleanup.  According to bugguide.net, “N. calmariensis emerges about a week before N. pusilla, first eating the leaves, shoots, and buds; then the N. pusilla eats the new growth, weakening the loosestrife, and after a few years the plants die off.”

Adults eat, meet, and mate https://bugguide.net/node/view/2004790/bgimage on purple loosestrife, and females lay 300 to 400 eggs in batches on its stem and leaves.  They are not shy about striking out and finding new patches of loosestrife plants to colonize.  The larvae feed and then drop down and pupate in the soil (or in the plant stem, if the water is high), emerging as adults before the frosts to feed again.  Adults overwinter in the leaf litter at the base of the plants, emerging as the loosestrife starts growing again. 

Biological control of purple loosestrife isn’t quite as easy as tossing a bunch of Cella beetles out into a marsh and watching the loosestrife fade away.  The beetles are very susceptible to pesticides; they’re not attracted to loosestrife that’s growing in the shade or in high water; and a couple of species of lady beetles, a ground beetle, and a stink bug consider BMLBs delicious, slowing them but not stopping their spread.  According to the Cornell University (Go, Big Red!) College of Agriculture and Life Sciences’ Biological Control website, it’s estimated that once established, the work of the weevils and leaf beetles will reduce the loosestrife populations by about 90% over about 90% of its present range.  But it’s a long game – it may take three to five years (one source says seven to ten) for the beetles to build up to levels where they can significantly impact purple loosestrife. 

And the long, long game?  According to Reinartz’s Law of Biomass Availability, eventually native species will recognize that this vast mess of plants is edible (simply put – “If You Grow It, They Will Come”).

Check with the Wisconsin DNR for information about rearing Cella beetles for release https://dnr.wisconsin.gov/topic/Invasives/loosestrife.html.

Kate Redmond, The BugLady

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

Bug o’the Week – Rose Chafer Beetle

Bug o’the Week

Black-margined Loosestrife Beetle

Howdy, BugFans,

Purple loosestrife is a beautiful plant, with great wands of magenta flowers waving in the breeze.  Some say that, like a long list of other invasives, it entered the country in the ballast of ocean-going ships; others say that it was imported deliberately because it’s a medicinal plant as well as a great honeybee plant.  The BugLady knew a beekeeper who seeded purple loosestrife from the back of his snowmobile one winter, before he knew better (repent at leisure).  At any rate, it’s been here for 150 years or so, but it really started getting our attention in the 1970’s.  On its home turf, it exists in proportion to other wetland plants; here, it crowds out native vegetation, its dense stands discourage nesting waterfowl, and it’s not used by wildlife as a food plant (insects sure love the flowers, though). There are native loosestrifes, but they’re not invasive.

Rose chafers can be found in grasslands, gardens, and viney edges over much of eastern North America as far west as Colorado and Montana, although distribution gets spotty the farther South you get. They especially like sandy areas (more about that in a sec).  Bugguide.net considers the western records to be “iffy” because of the possibility of confusing the Rose chafer with one of the other two species in the genus Macrodactylus that live north of Mexico (https://bugguide.net/node/view/939033/bgpage, and https://bugguide.net/node/view/1253988/bgimage), but insects can find an infinite number of ways to hitchhike.

They’re about a half-inch long (females are bulkier than males), covered with yellow hairs that rub off with age (or in the case of the female, with mating), exposing the dark cuticle beneath.  The official name for their antennae is “lamellate,” which means “plate or leaf-like” https://bugguide.net/node/view/110081.  The legs are spiny and the feet/tarsi are clawed (all the better to hang on with, my dear) https://bugguide.net/node/view/1275119/bgimage.  Several sources said that the beetles may resemble a wasp while in flight (maybe because of the dangling legs?).

The BugLady does not garden.  She puts her geraniums out on the porch in May, waters them when she thinks of it (they’re very patient), and hauls them back in at the end of October, at around midnight as the first killing frost is descending, and she wouldn’t know what to do with a rose bush if she had one.  Rose chafer beetles feed on the leaves and flowers and maybe the nectar and pollen of lots of different kinds of plants.  Their jaws are weak, so they eat the tender tissue between the leaf veins, skeletonizing the leaf; they make holes in petals; and they eat soft fruits like raspberries and grapes. 

Some sources say that the beetle is only a slight nuisance, doing mainly cosmetic damage; others give instructions for all-out warfare.  Their populations wax and wane, and when there’s a Rose chafer population boom, the beetles may consume a substantial portion of a leaf’s photosynthetic surface and may also impair pollination.  Plus, they may feed in groups.  Interestingly, the North Carolina State Extension write-up about Rose chafers calls them a “relatively minor pest of roses that at one time was apparently much more abundant.”

With many insect “pests,” it’s the larvae that do the most damage, but with the chafers, it’s the adults who are the problem.  Rose chafer larvae feed underground on the roots of grasses and other plants, and although a bumper crop of larvae can stunt a plant, they don’t seem to be a real threat to turfgrass or ornamentals. 

Rose chafers can be seen during June and July here in the North.  The plants that they feed on also serve as Social Clubs where males and females meet and mingle https://bugguide.net/node/view/265114/bgimage.  When this “What’s going on here?” picture https://bugguide.net/node/view/120287/bgimage was posted on bugguide.net, entomologist Eric Eaton responded “I don’t think they are ‘eating’ the milkweed. This kind of aggregation is usually associated with mating or “sleeping.”  This seems to be another example of insects chewing on plants; plants releasing volatile compounds to discourage that; and those compounds, perversely, attracting a crowd.  The Rose chafers use their antennae to key in on those plant “odors.”

The female oviposits in the soil, digging down as far as six inches below the surface (!!!), which is why she prefers plants that grow in sandy soil.  She may lay from six to forty eggs, and when they hatch in a few weeks, the larvae locate roots to feed on.  They will move up and down in the soil, depending on soil moisture and soil temperature, and they will overwinter deep in the ground, below the frost line, moving up toward the surface to pupate when the earth warms in spring. 

Many of the scarabs are nocturnal, but Rose chafers are abroad during the day.  They are strong fliers.

Rose Chafer Surprise:  Rose chafers produce cantharidin, a caustic chemical mainly found in beetles in the blister beetle family Meloidae (see https://uwm.edu/field-station/blister-beetle/)!  Although the author of one gardening blog noted that he had been picking them off of plants for decades with no ill effects (the skin on our fingers is pretty tough), he joined the chorus of authors who stressed that the beetles are poisonous to chickens and other birds.

In his “Living with Insects” blog, entomologist Jonathan Neal explains “Their toxicity to chickens led to one of the early scientific studies of toxins in insects. In 1909, George Lamson, Jr, of the Connecticut Agricultural Experiment Station investigated reports of a flock of chickens that died after feeding on the abundant Rose Chafers. Lamson fed Rose Chafers to chickens and determined the numbers required to kill week-old (15-20 Chafers) and 3-week-old chickens (25-45 Chafers). In the early 1900s, chickens were commonly allowed to range free and could easily consume large numbers of Rose Chafers in years with high populations. Lamson recommended that chickens be excluded from areas that contained large numbers of Rose Chafers.  Lamson made an extract of Chafers and demonstrated that the extract was toxic to both chickens and rabbits. These tests proved that the deaths were due to a chemical toxin and not a physical effect from the insect spines or other physical properties. Lamson reported his findings in the Journal “Science” in 1916.”

Kate Redmond, The BugLady

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

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