Category: Bug of the Week

Salutations, BugFans,

A common green darner was reported near La Crosse (WI) on March 24 of this year, and a few others have been seen since then (and even though the winter of 2016-17 has been “Winter Lite,” the BugLady is ready for spring and dragonflies).  The BugLady wrote very brief biographies of the green darner in 2010, in BOTWs about spring dragonflies and about dragonfly swarms, but there’s much more to the common green darner story.

They are in the darner family Aeshnidae, a group of large, powerful dragonflies (“darner” because their long, darning needle-like abdomen has led to folk tales about their sewing people’s lips or ears shut).

Most of our Wisconsin darners are in the famously-confusing mosaic darner genus Aeshna.  Common green darners (Anax junia) (“Lord of June”) are one of two species of Anax darners found in the state.  Common green darners are, well, very common, not just here but across the country.  And Central America.  And Hawai’i.  And Canada.  And there are populations in Tahiti and the West Indies.  And strong winds have blown individuals to Great Britain, China, and Russia.  The other Anax, the stunning Comet darner (Anax longipes) is a rare visitor and even rarer breeder in Wisconsin.

Green darners have a 3” long body and a 3 ½” wingspan; their striking “wrap-around” compound eyes may be made up of as many as 50,000 simple eyes, apiece.  They practice sexual dimorphism – both males and females have a green thorax, but males have a predominantly blue abdomen with a purple stripe, and females have a rust-colored abdomen with a darker stripe.  Tenerals (newly-emerged adults) may take a week or more to solidify their adult color patterns and have female-ish coloration in the interim, and a chilly darner is a darker-colored darner.  Both males and females have prominent cerci (claspers) at the abdomen’s tip.  Common green darners have a characteristic bull’s-eye spot on their “forehead” that comet darners lack.  They can move each wing independently, which lets them hover, and even fly backwards.  They perch vertically, frequently in low vegetation, so they usually spot the BugLady before she spots them.

The long, slim, immature green darners (naiads) are found in still or very slowly-moving, shallow waters, preferably without sunfish and bass (nice set of naiad pictures here http://bugguide.net/node/view/238726/bgimage).  Adults frequent the air above those habitats but may be seen far from water.

Two populations of common green darners – one migratory, the other resident – form tag teams in the air over Wisconsin.  Migrants from the south arrive early, often in late April, as their prey (small, aerial insects) start to appear.  They are the offspring, or the offspring’s offspring, of the darners that flew south in the fall (no, they apparently do not return to their natal ponds).  “Shivering” their wing muscles to heat up the thorax allows them to be active in cool weather, and they also bask in the sun.  This is so effective that temperatures as high as 110 degrees have been measured inside the thorax (which challenges the whole definition of cold-bloodedness).  The picture of the female with the battered wings was taken in early July, suggesting that she was a migratory female who was reaching the end of her trail.

The migrants mate and die by the end of June, leaving their eggs in the water, just as the naiads of the resident population emerge as adults.  These residents live a month or two as adults, depositing their eggs in late summer as the migrant adults emerge.  Resident naiads overwinter under the ice in a state of suspended animation called diapause and take 10 or 11 months to mature (possibly more, in the chilly waters “Up North”), while the migrant naiads need less than half that time.

Mating commences when a male clasps a female at the back of her head in mid-air (one source said that she can reject his advances), then they retire to a perch to mate.  Females oviposit in the open, in woody and herbaceous plant material below the water’s surface.

The books say that these are the only darners that oviposit in tandem.  The books also say that a couple flying in tandem may be strafed by rival males.  The attendant male doesn’t have many options; he may flap his wings at the intruder, shake his abdomen, land in vegetation, and even bite his challenger.  According to Paulson, in Dragonflies and Damselflies of the East, females may curl their abdomen under and close their wings when under attack.  The BugLady photographed (badly) an unattached male as he dive-bombed a second male whose abdomen was deeply submerged (presumably with an ovipositing female at the other end of it).

The BugLady once found a female stuck in an especially dense and sticky, dragonfly-eating patch of blanket algae.  Did the female attempt to perch on the algae as she oviposited and get her wings stuck, only to be abandoned by her mate?  Or, alternatively, did she get thirsty and then get stuck?  Dragonflies “drink” by immersing their abdomen – water enters through the exoskeleton (the BugLady was able to fish her out with a stick).

The naiads are active predators that will eat anything they can grab using their foldable “lower lip” (labium) – zooplankton, other aquatic insects (including dragonfly naiads), tadpoles, larval salamanders, and fish fry are all fair game.  In his wonderful write-up of the common green darner, Kurt Mead (Dragonflies of the North Woods) muses that “If dragonfly larvae were eight to sixteen inches long, as they probably were 300 million years ago, we would dare not swim in fresh water for fear of being attacked” (read the whole account at http://www.mndragonfly.org/html/behavior.html).  Despite their spiny exteriors and their ability to shoot forward by expelling a spurt of water forcefully from their abdomen, they are eaten by frogs, fish, and by other aquatic insects.  There’s even an “aquatic” parasitic wasp that lays its eggs in those of the green darner.  Aprostocetus polynemae, apparently walks down a twig or leaf stem into the water to find dragonfly eggs.

Adults catch insects in the air and may eat them in mid-flight or on a perch.  They can also pick prey from a leaf or from the ground, and they’ve been known to stake out bee hives, to the distress of the bee-keeper.  At least one ambitious common green darner killed a hummingbird, and this fact is mentioned every darner write-up, though the BugLady suspects it’s pretty uncommon.  Adults are preyed on by robber flies, birds, spiders, and by other dragonflies; the people who monitor the fall raptor migration tell us that the southward movement of American Kestrels synchs with that of the darners, and that kestrel migration is fueled by darners.

So, green darners migrate. Like birds, they respond to a suitable weather front – cold fronts for the southern flight and warm fronts for the far less conspicuous northern trip.  The journey south may take several weeks of stop-and-start flying (averaging 7 miles a day but capable of far more, depending on the wind), and they may be accompanied by black saddlebags and variegated meadowhawk dragonflies.  They migrate dramatically, sometimes in huge swarms that may take hours or days to pass a fixed point.  Bluffs on the west edge of Lake Michigan are great places to catch the show at eye level.  Dragonfly swarms are a late summer phenomenon, so tuck this address away for reporting swarms and contributing to Dragonfly Woman’s database: https://thedragonflywoman.com/dsp/report/.

The common green is the State Insect of Washington – so much more exciting than Wisconsin’s honeybee (and you thought the state insect was the mosquito!).

As always, don’t eat them – they carry parasites.

Kate Redmond, The BugLady 

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

This is (drum roll) episode #450 by the BugLady’s count.  From its humble beginnings in the summer of 2007.

Howdy, BugFans,

The BugLady took a walk on the first day of spring along a nearby dirt road.  Automobile drivers are seldom happy with that road, but masses of millipedes, spiders, dragonflies, and butterflies enjoy its damp and dappled surface, and frogs, snakes, and other small animals cross from upland to lowland there.  With Sandhill Cranes providing a sound track, the BugLady shared the road with a wolf spider, a six-spotted fishing spider and some small (but colorful) millipedes.

Millipedes, a.k.a rain worms, are fascinating critters – the BugLady wrote about them in the early days of BOTW (April, 2008) – see http://uwm.edu/field-station/millepede/ for Millipedes 101).  They seem to be in need of a good PR campaign, so here are the basics.  They don’t bite.  They’re not slimy.  Most of them are not carnivores.  Most of them shun living plants and feed on rotting organic material (many practice coprophagy, though).  They don’t give us diseases.  They don’t want to come inside for the winter.  If your home experiences a Biblical scourge of millipedes (which are humidity-seekers) it could be a First Alert that your plumbing needs a look.  See – all good!  Yet, many millipede hits on-line are exterminators (you don’t need one, because your house is way too dry for millipede comfort and will kill them all by itself.  Caulk the cracks to keep them out).

Millipedes are under the umbrella of the great phylum Arthropoda; along with centipedes and a few others, they’re in the subphylum Myriapoda (from “myrias,” the ancient Greek word for 10,000).  They’re in the class Diplopoda (for taxonomic comparisons, Insecta and Arachnida are also classes).  When you say “diplopod,” you’re also speaking Greek (“diplos” means “double,” and “pous” means “foot”).  Millipedes (Latin for “thousand feet”) have two legs on each sideof most segments (centipedes, also pictured here, have one on each side; for centipede info, see http://uwm.edu/field-station/house-centipede/).  No actual 1000-leggers have been found, and the present record belongs to an individual with 750 legs.  However many legs they have (and they have far more than any of the rest of us), those legs are short, and millipedes don’t disperse far or fast without help.

According to bugguide.net, there are 12,000 described species of diplopods worldwide, divided into two sub-classes, 16 orders, and 145 families, but there may be 70,000 more species out there waiting to be described!!  North America has just under 1,000 species in 52 families; bugguide.net illustrates members of 10 orders, including a few non-native species that have made it to our shores.  They speculate that there could be hundreds of undescribed species in North America.

Millipedes come in a surprising variety of sizes, shapes and colors – from millipedes that could be mistaken for pillbugs http://bugguide.net/node/view/1194436/bgpage to the world’s leggiest (California) – http://www.bbc.com/news/science-environment-20319140, to http://bugguide.net/node/view/595215/bgimage, and http://bugguide.net/node/view/320292/bgimage, and http://bugguide.net/node/view/1341190/bgpage, and http://bugguide.net/node/view/258352/bgimage, and http://bugguide.net/node/view/782904/bgimage.  Some are bioluminescent, and there’s even a species in South America that has moss growing on it https://commons.wikimedia.org/wiki/File:Psammodesmus_bryophorus.jpg. The longest US millipede is about 6 ¼” (also California, where they seem to be serious about their millipedes.).  For more eye candy, click your way through the orders and families at http://bugguide.net/node/view/37/bgpage.

They’ve been around for a long time – one of the first groups of animals to adapt to life on land 400 million years ago (in the days when oxygen levels were higher than they are now and therefore arthropods grew bigger – six-foot long millipedes).  Millipedes, whose exoskeleton lacks a protective, waxy cuticle, like to stay undercover where the humidity is high – in leaf litter, rotting wood, and soil.  Powered by all those legs, most are good diggers, though some very large and very small species don’t tunnel.

 

Millipedes are, figuratively speaking, exactly what one of their common names claims they are – “thousand-legged worms.”  They are cylindrical (except when they’re flat), many-legged, worm-ish critters.  Most have chewing mouthparts, simple eyes, and sensory organs on their antennae that help them detect light levels and possibly humidity.  An enlarged segment behind the head is called the collum.  Air passes through pores near the legs on each side of the body on its way into the tracheal system, and a millipede’s heart is as long as its body.  Their legs are seven-jointed, and males have longer legs than females.

An alarmed millipede tends to roll up in a tight disc, curling hard shell around soft legs.  Many also make bad-smelling or irritating defensive chemicals (including cyanide) (lemurs tease millipedes into expressing those chemicals and then rub the liquid on their fur to discourage mosquitoes).  Some chemical defense is less passive – a few tropical millipedes can spray chemicals about 20 inches.  Wash your hands, don’t rub your eyes.

In spring, a young millipede’s fancy turns to love.  For most species, courtship is minimal.  He may walk along her back to get her in the mood (different strokes), he uses modified legs toward the front of his abdomen to hold her as he inserts a spermatophore (sperm packet) into the operative opening, and they often embrace for a while afterward.  She lays her eggs (a few hundred to a few thousand) in an underground nest she shapes from excreted dirt, and in some species, she dies soon afterwards.  The young have six legs when they hatch and add more each time they molt http://bugguide.net/node/view/168292.  They grow and leave the nest, feeding on plant material and on the microorganisms their guts require to digest plant fibers.  They may take a few years to mature and may live a few more years after that.

What ecosystem services do millipedes perform?  As detritivores, they assist in the natural recycling process by making big pieces of organic material into smaller ones (for use by even smaller organisms).  They are an important determiner of soil composition, and in areas where earthworms are scarce, they may fill the earthworm’s niche, capable of creating, according to a scientist named F. H. Colville, two tons of fertilizer per acre per year.

The BugLady has photographed a variety of millipedes in her neighborhood, but no one has ever accused her of being a Myriapodologist, so the following identities are “approximate.”

She has a color slide, but not a digital image, of Wisconsin’s largest species (up to 4”), the millipede formerly known as Spirobolus marginatus, now reclassified as part of the Narceus americanus–annularis species complex http://bugguide.net/node/view/832866/bgimage.  It’s in the order Spirobolida and family Spirobolidae.  She finds it around fallen logs on leafy forest floors.  Interesting Narceus fact: the female lays a single egg in a cup formed from regurgitated food (bugguide.net).  See http://www.hiltonpond.org/ThisWeek030522.html for some nifty pictures.

The dark, curled-up millipede is Cylindroiulus caeruleocinctus (probably), in the order Julida and family Julidae.  The experts say that North American members of the family Julidae all originated in Europe.

The cute little guy semi-coiled on the leaf is a tough one.  The BugLady thinks it’s in the order Julida and the family Parajulidae, and possibly in the genus Ptyoiulus, but she wouldn’t bet the farm on it.  These are native millipedes and bugguide says that Parajulidae is the dominant millipede family in North America, from Canada to Guatemala.  You can really see the dome-shaped collum right behind the head.  Some millipedes burrow by pushing the tough collum down through the soil.

The very colorful millipede (burnished burgundy with purple bands) that shared the road with the BugLady looks like another Parajulid.

OK – the BugLady staged the shot of the millipede lying semi-curled on the green leaf with its feet up; it was on a stony parking lot and she thought it would be easier to photograph on a leaf.  It’s a Flat-backed millipede in the order Polydesmida (the largest order of millipedes, all chemically defended), a Pleuroloma flavipes (“flavipes” means “yellow foot”), in the family Xystodesmidae (unless it’s Apheloria virginiensis).  There are about 300 known species in the family, and a third of them live in the Appalachian Mountains (low mobility and geographic isolation make for some interesting species-rich regions).  They are famous for “swarms,” which are sometimes migratory.

The small, pinkish millipede with square plates in its back is another Flat-backed millipede, but this one is a foreigner.  The Greenhouse/ Hothouse/Short-flange millipede (Oxidus gracilis) hails from Asia but is well-established here.  It is in the order Polydesmida and the family Paradoxosomatidae.  It’s in reproductive mode all year.

Why did the millipede cross the road?  More precisely, why do they congregate on the BugLady’s front porch, and in her basement and garage?  They assemble and move around in response to heavy rain and to cooling temperatures (the seal on the BugLady’s garage door is not millipede-proof, and scores came in out of the cold last fall).  Reportedly, train tracks can become slippery with flattened millipedes.

Interesting millipede facts:

• Some of the larger species are sold as pets;
• Millipedes have been used in rituals, in folk medicine to treat fevers, hemorrhoids, wounds, and earache, among others, and to make poison-tipped arrows, but they are not part of many cuisines.

Kate Redmond, The BugLady

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

Howdy, BugFans,

This bug is so exquisite that it’s hard to remember that it’s an aphid.  It’s the winged phase; non-winged individuals are, depending on the species, blob-shaped, sesame seed-shaped, or spidery-looking insects seen en masse, sucking juices from the tender parts of plants http://bugguide.net/node/view/638959/bgimage.  Species of aphids are often associated with specific host plants.

The BugLady is going to go way out on a limb here, where taxonomists fear to tread, (she’s so far out that she can’t even see the tree trunk) and guess that this might be in the genus Euceraphis, and she’s going to pretend that the species is papyrifericola (to see just how far out, note that the expert at bugguide.net says “Tree aphids are not my strongest area, but I have collected off Betulaceae [birch] enough to know that what I think might be Euceraphis often turns out to be Calaphis when seen mounted on slides. I have little experience with them in the field, and cannot confidently recognize the genera from photos…… So, my recommendation is to not put a genus name on many of them in any confident way.”).

But, for the sake of argument, Euceraphis will open a door onto the tree aphids.  The family Aphidae has about 4,700 species (so far), many of which are not major plant pests.  Tree aphids are in the subfamily Calaphidinae (a bunch of deciduous tree feeders) and Euceraphis is in the tribe Calaphidini (mainly birch/alder-feeders, and there were birches nearby) (quick aside – Google offered to find for the BugLady some words that rhyme with Calaphidini, and the BugLady couldn’t resist, but they turned out to be words like “eeny,” “teeny,” “weany,” “meany,” and “beany”).  There are lots of hits for “tree aphid,” but most sites lump them, discussing generic aphid lifestyles, symptoms of their presence, and bug control, rather than who’s who.

Generic aphid lifestyle: Aphids are poised to take over the world.  Their reproductive strategy involves legions of females that move around on plants, popping out female young (already nymphs – they skip the egg stage) parthenogenetically (with no male “input”).  These clones mature quickly and soon produce their own young.  This is why naturalists joke that a female aphid who starts at the bottom of a stem is a great, great grandmother by the time she reaches the top (one species of rose aphid has been clocked at up to 15 generations per growing season).  Aphids are designed to cash in quickly on the nutritious new spring growth.

Aphids are generally wingless until an overcrowded plant/deteriorating plant quality signals them to produce winged forms that can migrate to nearby vegetation.  They have no “search image” – finding their host species is a matter of chance – so they often wind up on non-host plants accidentally.  They are all female until, at the appointed time of the year for each species (usually fall), females will produce winged male and female nymphs.  Romance ensues, and so does genetic diversity.  Females subsequently lay eggs that overwinter and produce more females in spring, and the beat goes on.

Symptoms: They suck juices from leaf veins, buds, and new twigs.  A healthy tree can shrug off the usual level of feeding, but a large infestation can cause brown/curled/wilted leaves and dieback of new shoots and even kill a plant, especially if aphid numbers are high for several years.  Excess sap flows out the other end of the bug; it’s sugary, and other insects congregate to feed on the “honeydew” that falls on leaves.  Humans are less enthusiastic about the sticky, hard-to-remove-once-it’s-dried stuff on their cars and patio furniture.  And honeydew is a great growth medium for an unsightly “sooty mold” that grows on the leaves.  With honeydew as a pay-off, some kinds of ants “farm” the nymphs of many kinds of aphids, but not those of Euceraphis.

This individual looks a bit fuzzy.  Many adult Calaphidini are initially a lovely, pale green, but, says the Report by the State Entomologist of Minnesota to the Governor, Volume 17 (1919), “Some of the species [of Calaphidini], at least, are further characterized by wax glands on the body, legs, and antennae, which secrete an abundant, white waxy substance in tufts or bands that give them a very peculiar appearance and may serve as protection against some of their enemies” http://bugguide.net/node/view/638961/bgimage.

Members of the genus Euceraphis have divvied up the birch species and do not poach, even when a tree and its aphid are relocated to a different country.  Euceraphis is notable among the tree aphids because all adults, not just a dispersal generation, are winged.  According to one source, Euceraphis stops reproducing in mid-summer as leaves mature, and then resumes in fall as sugars in the leaves are being broken down and sent to the roots.

Tree aphids are kept in check by birds, crab spiders, a variety of insect predators like lacewings, syrphid fly larvae, and ladybugs (both adults and larvae).  Several small wasps parasitize them, and they are subject to (vocabulary word of the day) entomopathogenic (“bad for insects”) fungi.

And what about Euceraphis papyrifericola?  Large for an aphid at just under three-eighths of an inch, it specializes in paper birch (Betula papyrifera), though it’s unusual because it may sip on gray birch and, when in Rome, on a European alder.

Kate Redmond, The BugLady

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

Greetings, BugFans,

A funny thing happened on the way to this BOTW.  The BugLady spent the morning on-line, trying to discover the identities of a few moths.  Suddenly, a screen popped up (and a voice came from her speakers) saying that this was a Microsoft Alert!!!  That her Internet was Blocked (it sure was – frozen solid, had to turn the computer off, and the screen came back when she restarted), that her Credit Card Info was At Risk, and Also her Photos (Yikes!!!), etc., and please call an 877 number immediately.  Yeah, right.  She always tries to practice safe surfing, but her tech guru, BugFan Becca, told her that internet evildoers sometimes plant their little bombs on obscure sites because the security there may be lax compared to bigger sites.  No surprise, if you call them back, they’ll be happy to take your credit card number in exchange for fixing the problem.  The BugLady was also assured that no bad stuff will travel with this post.

So – microlepidoptera are, as you’d expect, a big group of small moths.  It’s not exactly a scientific classification; there’s no single structure or life style that definitively says micro or macro.  To some extent, it’s a grouping that’s determined by the size of the moth; there are some families that include both macro and micro species, and the families of the micros tend to be more primitive than those of the macros.  As Wikipedia says, “Plans to stabilize the term have usually proven inadequate.” The group is very diverse and includes a bunch of day-flying species, and the biographies of many have not been written.  Remember – of the 18,000 or so species of Lepidopterans in North America, more than 11,000 are moths. Here are three (and a half) of them.

SYNCOPACMA NIGRELLA (no common name) is on the BugLady’s “porch bug” list; it showed up on a fine evening in late August.  It belongs to the Twirler moth family Gelechiidae, a large family with about 4,500 species globally (650 in North America). The family contains species that are agricultural pests and species that are biological controls of agricultural pests.

Syncopacma nigrella one of about five species in its genus in North America; this species is mostly found in the eastern US, but it also occurs in California, Wyoming, and Washington.  It’s about a half-inch long, and the slim, fringed wings are typical of the family.

Gelechiid larvae often feed under cover, on the insides of their host plants – Syncopacma nigrella prefers lupines (of which the BugLady has none).

We have met Crambid moths/Grass moths/Crambid snout moths (family Crambidae) before, in the form of the orange mint moth, the white-spotted sable moth, and the eastern grass veneer moth.  Crambids have wingspreads of ½” to 1 ¼” and have tympanal organs (ears) on their abdomens and hairy mouthparts that extend forward (and that put the “snout” in “snout moth”) (the hairs are sensory and give the moth information about its surroundings).  According to bugguide.net, the larvae are stem borers, root feeders, leaf tiers, and leaf miners, and the larvae of one group is only found in the nests of arboreal ants!  Adults of some species seek nectar on flowers and probably do a little pollinating.

The BugLady gets a kick out of the subtle patterns and silvery accents that are sported by some grass veneers, and by the way they sit, wings rolled up instead of folded over their backs.  The grass veneers are said to be twig mimics.

The VAGABOND CRAMBUS (Agriphila vulgivagellus) is also called the Vagabond sod webworm, which gives us a clue to what the larvae do for a living.  The species can be seen in late summer and early fall around grasslands and gardens, from the Atlantic coast to the Great Plains and north into Canada.

Adults are found perched in the grass by day, and are crepuscular (dawn/dusk) and nocturnal flyers. They fly over the grass-tops in September, sometimes in large numbers, drinking dew from the blades, and females lay eggs (60 per day for two weeks) by dropping them into the grass as they fly.  The larvae feed on a variety of grasses and grains.  They overwinter as immature larvae that awaken in spring and feed on grasses from a webbed tube they construct on the ground.  The vagabond sod webworm has a single generation per year and is not considered as serious a pest as other species of sod webworms because the grass blades they eat in fall and in spring are growing fast.

JULIA’S DICYMOLOMIA (Dicymolomia julianalis) led the BugLady on a merry chase through moth books and websites.  She found this lovely creature (and another species to be named later) on composites in early summer.  It is also in the Crambid family and is also found over the eastern side of North America.  The moth could perch on the BugLady’s thumbnail with plenty of room to spare.

The larval menu is diverse and includes cattails, the primary host, but also Opuntia cacti, a few composites, and the egg clusters of evergreen bagworms.  Eggs are inserted into cattail heads in mid-summer, and the larvae feed on fresh and then dried flower parts and on the seeds, digging deeper into the cattail head as they get older (a little lump on an otherwise-smooth cattail shows where they are feeding). The larvae spin silk through their chambers to hold the cattail head together and keep the seeds from scattering.  Half-grown larvae overwinter in the cattail head, and they also pupate there in early summer.

And the half-moth?

The BugLady chased these beautiful rust and silver moths around the Riveredge prairie, and when she put her pictures up on the screen, she (eventually) noticed some variation in pattern that hadn’t registered out in the field (and this is why her field identification skills are going south – she can sit and stare, with a book in her hand, at insects on a screen, and they don’t fly away (except, see paragraph one)).  She realized that one species (which turned out to be Julia’s Dicymolomia) had silver “suspenders” across the top of its wings, and the other had a horizontal silver band across the wings, about a quarter of the way south of the head.  Same patch of prairie, same time of day, same time of year, same composites.

Still looking – being careful of obscure moth sites – if it’s not a Dicymolomia, it might be a Chalcoela.  If anyone else would like to play, try http://bugguide.net/node/view/39603/bgpage and http://bugguide.net/node/view/29597/bgpage.  And maybe an adult beverage.

Kate Redmond, The BugLady

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

Howdy BugFans,

Spring is coming, and home gardeners have had a gleam in their eyes ever since the first seed catalog landed in the mailbox.  Sheaves of asparagus shiver on beds of ice in grocery stores, and foragers are anxious for those first stalks of “volunteer” asparagus to peek up along the roadsides.  They’re not the only ones who are waiting.

Asparagus beetles, in the leaf beetle family (Chrysomelidae), are asparagus specialists.  They’re lovely little beetles, and two species grace our area, the asparagus/common asparagus beetle (Criocerus asparagi) and the spotted/12-spotted asparagus beetle (Crioceris duodecimpunctata) (yes – Latin for “12-dotted”).  The common is, well, more common.  We tend to talk about them generically, but there are some important distinctions.

Both beetles are aliens – Eurasian natives that arrived here in the second half of the 19^th century and now occupy anyplace in North America where asparagus is grown.  The common asparagus beetle has even made its way to Hawaii.  The two species don’t look much alike – the 12-spotted asparagus beetle can be mistaken for a ladybug at a quick glance (one source points out that they even have spots on their “kneecaps”), and the spotting on the common asparagus beetle is variable.

The “what” and the “when” of their feeding makes the common asparagus beetle the less welcome of the two.  Both chew on asparagus spears, which can cause stunting and other cosmetic damage that make the asparagus unmarketable (and consumers don’t enjoy picking up a spear with a bunch of eggs glued to it or a smear of frass (bug poop) on it, either) http://bugguide.net/node/view/16283/bgimage.

Both species overwinter as adults in hollow asparagus stems, or under leaf litter, garden debris, or loose bark – that way, when the sun warms the soil and the asparagus spears poke their heads up in spring, the beetles are already in the neighborhood.  The common asparagus beetle is the first to wake up, and it also feeds on the lacy leaves, which can defoliate and weaken the plant, a perennial (no leaves = no photosynthesis = no food storage) and can make it susceptible to fungal infections.  Its larvae also eat the spears and leaves.

After some fun in the sun, http://bugguide.net/node/view/17260/bgimage the common asparagus beetle lays its eggs in rows of 3 to 8 on the new spears, leaves or flower buds http://bugguide.net/node/view/1109490.  There’s not much of a courtship, but she may parry his moves by turning her abdomen aside or by kicking.  To protect their genetic investment, males guard females after mating, remaining piggyback during ovipositing.  Female Chrysomelids have the ability to favor the sperm of a suitor by keeping eggs fertilized by a male if they like the cut of his jib and ejecting the sperm of previous males.  The young hatch within a week and start feeding http://bugguide.net/node/view/170240.  There may be two generations of common asparagus beetles each summer here in God’s Country, and up to five generations a year where the growing season is longer.

The 12-spotted gets out of the gate a little later in spring, and it also eats the spears and leaves, but its larvae concentrate on the fruits and don’t damage the plant (not a problem unless you raise asparagus for seed, and most growers don’t – they’re in it for the vegetable and they cultivate higher-yield, (seedless) male plants).  It lays one egg at a time on the leaves; the larvae hatch, head for the fruits, and burrow inside.  There are two generations per year, and they generally finish their life cycle by mid-summer.  The larvae of both species pupate in cocoons in the soil.

What eats asparagus beetles?  Ladybugs, ground beetles, wasps, flies, predaceous stinkbugs, dragon and damselflies, damsel bugs, lacewings, and a variety of birds including farmyard fowl.  Its most efficient predator seems to be a small, blue-black wasp, Tetrastichus asparagi, that is a parasitoid of the beetle larvae and that must develop a taste for them, because as an adult, it eats the egg masses.  One study in Massachusetts showed the wasp demolishing a hefty 50% of beetle eggs in an area and then parasitizing half of the remaining eggs.  It uses its antennae and/or ovipositor to detect hosts that are already parasitized and doesn’t waste its time on them, and it targets only the common asparagus beetle (alas for the 12-spotted; a different species in the wasp’s genus goes after them).

What does an asparagus beetle do when it’s alarmed?  Common asparagus beetles have several arrows in their quivers.  They may scoot over and hide on the other side of the stalk, may do the classic Chrysomelid drop to the ground, or may resort to secretions from defensive glands.  The 12-spotted beetles escape by flight.  Both species use stridulation – making noise by rubbing two body parts together (in the case of asparagus beetles, a part of the abdominal exoskeleton rubs against teeth on the hard wing covers), both to scare predators and to communicate with other beetles.

Kate Redmond, The BugLady

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

Salutations, BugFans,

What follows is a major overhaul of a BOTW from May, 2008.  New pictures, new facts.  Remember what the naturalists at Riveredge tell the kids – “Scientists don’t say ‘EEiiiooouuuwwww!’  Scientists say “Oooohhhhh, how interesting!’”

Let us pause for a moment to salute that classic movie, “The African Queen.”  People may not recall the characters’ names or whether he stopped drinking or she started drinking or whether the boat went over Victoria Falls or even who won WWI, but they always remember the leech scene.

Continue reading “Bug o’the Week – Leeches, revisited”

Howdy, BugFans,

The star of today’s show is one of several stink bugs that the BugLady photographed during the Stink Bug Summer of 2016.  A pair of stink bugs was featured a few months ago, one a carnivore, and the other an herbivore.  The herbivore, the Twice-stabbed stink bug, includes a few agricultural crops on its menu but is not generally considered a big pest.  The star of today’s show is an herbivore that on the Most Wanted lists of Extension agencies everywhere.

Stink bugs are a long-time favorite of the BugLady.  They belong to the family Pentatomidae, which is in the Order Hemiptera, and they have the mouthparts to prove it – a sharp-tipped tubular “beak” that allows them to pierce their prey, inject a tissue-tenderizing chemical saliva, and then suck out the resulting goop.  They are solid, no-nonsense bugs whose name is well-deserved, being endowed (at the other end) with glands that manufacture chemicals which, when sprayed, make their predators think again (alas, not all are deterred).  They come in a rainbow of colors and even the nymphs are pretty.

Continue reading “Bug o’the Week – Brown Stink Bug”

Salutations, BugFans,

The BugLady never met a water lily she didn’t admire, and as she takes (inevitably-over-exposed) pictures of the flowers, she always looks to see who’s visiting the plant.  In 2013, while she was photographing the magnificent water lily planthopper (Megamelus davisi), she also found an adult, larva and pupa of some sort of Chrysomelid (leaf beetle) on the water lily leaves, and later a pupa with a cluster fly perched on it (with no evil intent – cluster flies are nectar-feeders).  That same year, the BugLady wrote an article about a beetle in the genus Donacia, also in the family Chrysomelidae, also called the Water lily leaf beetle.

Chrysomelidae is a very large, diverse family of beetles that are vegetarians both as larvae (roots, stems, leaves) and as adults (leaves, flower parts).  They often target specific plants and are named after them.  Some are agricultural pests and some are biological controls of pest species.  There are some 1,900 species of Chrysomelids in North America and 35,000 species worldwide, and there may be an equal number awaiting discovery.

So, one day, the BugLady Googled “Chrysomelid, water lily.”  Ain’t the internet grand!  The Water lily leaf beetle du jour turns out to be Galerucella nymphaeae, formerly known as Pyrrhalta nymphaeae.  It’s found throughout North America, wherever its host plants grow, and in northern Europe.  Evans, in Beetles of Eastern North America, describes its range as “Europe; widely established in North America.”

It feeds primarily on water lilies (Nuphar and Nymphaea) and smartweeds (Polygonium); each of the two distinct plant families presents unique feeding challenges, and it has been suggested that there are two, specialized races of WLLBs, with slightly different sizes, colors and jaw widths.  A study in which larvae were mixed and matched with either food plant showed that not all host plants are created equal – beetles preferred, grew faster on, and had higher survival rates on their natal plants.  Selection is reinforced by the fact that they mate and lay eggs there.

The BugLady’s first (stray) thought, when she saw the pupa on the water lily leaf, was, “Hmm – wonder how that got there.”  Her second thought was, “Well, Duh (head smack), it hatched there!”  And, her third thought was, “pretty safe spot to grow up.”  Alas, not so.  The beetles’ feeding – they chew little holes and trenches into the top surface of the leaf – hastens the decay of the leaf and makes it, like a boat with holes, less buoyant.  A leaf that’s just one- quarter eaten can become unusable, and they may literally eat their island out from under themselves.  This happens sooner rather than later if there are several larvae present, and the only escape is trekking to an adjacent leaf.

Female WLLBs lay their eggs above the water, a few per leaf, and they prefer to oviposit on younger leaves because these leaves allow optimal weight gain for their offspring.  The eggs hatch about a week later, and the clock is ticking.  Since the average leaf lasts less than a month and a larva needs more time than that to mature, emigration is a given; no matter what the population density, and the larvae start spreading to different leaves at a young age.  Grazing/defoliation causes some kinds of plants to produce more leaves, but this isn’t true of water lilies.

There are probably two generations per year, with the second overwintering as adults.

Adults are listed as “semiaquatic,” they’re found on leaves around the edges of shallow wetlands.  How do they get around?  Researcher Haripirya Mukundarajan, who studied the physics of the beetles’ movement over the water, calls it “waterskiing.”  The WLLB lifts its middle pair of legs, raises its elytra (wing covers), angles its body upwards, and uses its flying wings to scoot along the surface film at a half-meter per second (500 km/hour in human terms).  It’s reminiscent of a diving duck running across the water in order to gain lift, but the beetle has no intention of taking to the air.  The beetles, says Ms. Mukundarajan “move so fast that they interact with the ripples generated by their own motion, which increases drag and causes a bumpy ride.  It’s as if surface tension acts as a pogo stick that the beetle is jumping on.”  According to the study, the beetles’ strong wings “allow them to produce a lot of lift while counteracting drag from the surface. And their legs are covered with tiny hairs that repel water while a claw at the tip is hydrophilic [water-loving], allowing them to pin themselves to the surface of the water.  This structure is critical for the beetle to maintain its level exactly on the water surface.”  See the video at https://www.newscientist.com/article/2079427-the-secret-of-beetles-that-waterski-so-fast-they-vanish/.  Practical applications?  According to the article, “understanding the motion of the beetles could help us develop robots that move across water quickly. Many current designs are based on water striders, which move more slowly.”

The WLLB comes from a distinguished lineage.  According to bugguide.net, the “beetles have been raised in the lab on Purple Loosestrife (Lythrum salicaria),” and two European Galerucella (“Cella”) beetles, Galerucella pusilla and Galerucella calmariensis, are presently being raised for release on purple loose strife on these shores.

And then there’s water chestnut, an invasive aquatic plant in Northeastern North America whose seed pod you do not want to encounter while barefoot https://nas.er.usgs.gov/queries/greatlakes/FactSheet.aspx?SpeciesID=263&Potential=N&Type=0.  The WLLB has been suggested as a control for Water chestnut.  In a study to determine whether Galerucella birmanica, a related beetle from Asia, should be introduced to control water chestnut, the native beetle acted as a testing surrogate.  Turned out that Galerucella nymphaeae larvae were eaten with gusto by backswimmers and by a ladybug called the spotted or the pink spotted (but not the pink–spotted) lady beetle, preventing larval populations from rising to the levels needed for biocontrol.  It didn’t help that while larval Galerucella nymphaeae will feed naturally on water chestnut, their survival rate there is very low.  Water chestnut leaves are small and get eaten faster, which results in more frequent leaf-switching, which results in more larval drownings.  Also, adults reared as larvae on the exotic water chestnut reverted to native plants when given a chance.  Back to the drawing board (but, the BugLady is heartened that these experiments were carried out, rather than simply importing the Asian species and throwing it out into the field to see what would happen, like we did in the bad old days).

A European study painted a picture of coots, swimming among the water lily leaves, picking the beetles/pupae/larvae off of the leaves.

Kate Redmond, The BugLady
Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Salutations, BugFans,

Caddisflies are famous for having soft-bodied, aquatic larvae that, depending on their species and habitat, use plant materials or teeny stones to construct portable cases that may be “log-cabin,” tube, or snail shell-shaped http://bugguide.net/node/view/258710/bgpage (caddisflies that live in strong currents may spin nets instead).  For “glue,” they use silk that they produce in a gland in their “lower lip.”  Some people “farm” caddisfly larvae, giving them bits of semiprecious stones and metals to build with and then making jewelry from the shed cases (you can Google it).

In the early days of modern taxonomy, caddisflies (now order Trichoptera) were listed with dragonflies, stoneflies, mayflies, dobsonflies (hellgrammites), lacewings, and more, in the order Neuroptera, but caddisflies were split off 200 years ago.  Their larvae look caterpillar-ish and the adults are often mistaken for moths, so it’s not surprising that caddisflies are closely related to the Lepidopterans.

Continue reading “Bug o’the Week – Giant Casemaker Caddisfly”

Greetings, BugFans,

No – not March yet, but it will be some day.  Actually, the BugLady had to wait until the end of October to find this March fly (Bibio slossonae) (probably).  She was walking in her favorite wetland on a cool, fall day and assumed that the flies around her were midges (famous for their cold-weather flights) until, as she photographed a grouse locust, along came a March fly, and sat down beside her.

Continue reading “Bug o’the Week – March Fly”