Category: Bug of the Week

Greetings, BugFans,

When the BugLady started this little enterprise back in the summer of 2007, her main criteria for an episode were that she had taken a respectable picture of the bug, and that it had a good story to tell.  She doesn’t have any digital shots of a Milbert’s Tortoise at all, because she hasn’t seen one in at least 20 years (they were last recorded on the Riveredge Nature Center Butterfly count in 1998).  She may have an ancient color slide of one, but when she tries scanning slides, the results are always murky.  Thank goodness (once again) for bugguide.net.

Milbert’s Tortoiseshells (Aglais milberti.) are in the family Nymphalidae, the largest butterfly family.  A distinctive family trait is that their front pair of legs is hairy and much-reduced in size, which has earned them the nicknames “brush-footed” and “four-footed” butterflies (they get around just fine on their second and third pairs of legs).  Although some are very colorful, the upper wing surfaces of many family members are variations in orange and brown, and their underwing surfaces look like dried leaves (allowing them to disappear when they fold their wings https://bugguide.net/node/view/1730918/bgimage).

There are about 6,000 species of Nymphalids worldwide (only 209 in North America); for an introduction to the family, see http://www.biokids.umich.edu/critters/Nymphalidae/ (one of the BugLady’s favorite sources of information).

The spectacular Milbert’s Tortoiseshell https://bugguide.net/node/view/46852/bgimage https://bugguide.net/node/view/476935/bgimage, is also known as the Fire-rim Tortoiseshell (males and females look similar).  It’s pretty unmistakable (but at a very quick glance, might be mistaken in flight for a Red Admiral https://bugguide.net/node/view/1682166/bgimage).

MTs are found across North America, but their range skews north and they’re absent from the Southeast https://www.butterfliesandmoths.org/species/Aglais-milberti.  MT numbers are unpredictable from year to year, their distribution is described as “locally common,” and they like moist grasslands, roadsides, woods openings, the edges of wetlands, and higher elevations – anywhere nettle grows.

They are quick and alert.  Male MTs scan for flying females from perches in their territories, often sitting with their wings open.  Females deposit eggs in clusters on the undersides of leaves of nettle plants in the genus Urtica (she may lay as many as 900 but 150 is more likely) https://bugguide.net/node/view/1675002/bgimage.  The young caterpillars stay together, creating communal, silken nests and feeding within them, and older caterpillars https://bugguide.net/node/view/1367818/bgimage fold leaves around themselves.  They may form chrysalises gregariously, and, say Douglas and Douglas in Butterflies of the Great Lakes Region, and “when the butterflies emerge, their communal meconium stains surrounding areas red.”

There are at least two generations a year, maybe three.  Some of the final brood will overwinter as chrysalises https://bugguide.net/node/view/1459379/bgimage (“chrysalis” describes both the life stage and the exterior case), to emerge in early spring, but some fall butterflies will overwinter as adults in sheltered spots, often with a group of their confreres, flying on warm winter days and emerging, battered, even earlier in spring to heed the reproductive imperative.

The excellent Butterflies of Massachusetts website tells us that MTs are probably a species whose numbers increased as the European settlers cut the forests and established agricultural fields and pastures https://www.butterfliesofmassachusetts.net/milberts-tortoiseshell.htm They were given a boost, too, because the Europeans arrived with the common or stinging nettle (Urtica dioica), a food/medicine/fiber plant that loves disturbed soils and that quickly made itself at home in the New World, outcompeting the native nettle.  In 1899 Scudder described roadside nettles in Massachusetts as being black with MT caterpillars https://www.buglifecycle.com/?p=278.  Climate change could cause MTs to retreat to the more northern parts of their range.

Depending on the time of year, adults feed on sap drips, animal droppings, fermenting fruit or flower nectar.

MTs are “obligate dorsal baskers.”  Some insects can heat up their thorax by quivering their flight muscles in preparation for flight, but on cooler days, MTs have to warm their thorax by basking with open wings in order activate their wing muscles.

The MT is the only North American species in its much-fought-over genus (depending on the sources you look at, you can find them in three genera), but two non-native genus members have also been reported.  There are sporadic records along the East Coast of the very similar European Small Tortoiseshell https://www.ukbutterflies.co.uk/species.php?species=urticae, which ranges across Eurasia (there’s a great anecdote of a Small Tortoiseshell in Nova Scotia flying out of a box that had recently arrived from England).  The Peacock butterfly, a western European butterfly, arrived in Montreal in 1997 and is establishing a small population there https://www.ukbutterflies.co.uk/species.php?species=io.

Kate Redmond, The BugLady

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

Greetings, BugFans,

The BugLady has been hearing Pileated Woodpeckers recently – a few vocalizations here and there, and a bunch of territorial drumming.  Some owls have a very early courtship – Great-horned Owls are already incubating – and some hawks start early, too, building the pair bond with breathtaking aerial maneuvers.  But the BugLady is always surprised when Pileateds, the largest of our woodpeckers, begin announcing their intentions in mid-February.

This essay was originally written for the BogHaunter, the newsletter of the Friends of the Cedarburg Bog.  The Bog is a 2300 acre wetland in Ozaukee County in Southeastern Wisconsin.  Actually, it’s a wetland within a wetland within a wetland within….  Conifer and hardwood swamps surrounding a cattail marsh surrounding both an eyed, acid, floating-mat bog and a large, central, alkaline fen, the southernmost string/patterned bog (strangmoor) in North America, with alternating strings and flarks (not a typo, despite what Spellcheck says).  The Bog is the BugLady’s church and her shrink.  Adjacent to the Bog is the Cedarburg Beechwoods State Natural Area.

The clamor of Cranes and Geese may define the Bog’s wetlands, but the Pileated Woodpecker speaks for its uplands.  Similar to a Flicker’s call, its big, whooping sounds have more depth and resonance https://www.allaboutbirds.org/guide/Pileated_Woodpecker/sounds.  It also communicates by drumming rapidly on a hollow tree with its bill, a sound that can be heard at some distance.  Both the males and females drum.

Seeing or hearing this Crow-sized woodpecker with its black and white, 30 inch wingspan, is often a matter of luck.  Found throughout much of the United States, in dry uplands and wet swamplands, it is a secretive bird of mature woodlots.  Signs of its woodworking efforts are seen more frequently than is the bird itself.

Its scientific name, Drycopus pileatus, defines it well.  The Greek “Drycopus” means “tree cleaver,” and the Latin “pileatus” means “capped” and refers to the bird’s red crest.  The pronunciation of its common name causes confusion for birders – some say “pie’-lee-a-ted” and others “pill’-ee-a ted” (we Midwesterners tend to use the latter), and both are OK.  Like its slightly larger southern relative the Ivory-billed Woodpecker, with whom it shares/shared the southern swamps, the Pileated was sometimes called the “Good God” or “Lord God” bird.

Pileated Woodpeckers are not migratory, and although they are somewhat more relaxed about it in winter, they are territorial year-round.  A serious dispute involves vocalizations and chasing and may escalate to striking at a rival with wings and bill.

The male courts by perched and aerial displays of his striking plumage patterns.  Pairs are monogamous, but the birds will find another partner if one dies.

For its nest, it needs mature trees.  The round hole it excavates for its eggs faces east or south and is three to four inches across, about 45 feet off the ground, in a trunk that is at least 15 to 20 inches in diameter.  The male does much of the nest excavation, digging down a foot or more into the trunk and clearing the accumulating wood chips by tossing them out of the entrance hole.  Once finished, the female lays four eggs, which are cushioned only by wood chips.  Both parents incubate the eggs and feed the young.  Because these are big birds, and two adults (plus young) would more than fill a nest hole, they also make separate roosting holes.

Other birds may try to usurp their nests in summer, and old nest holes provide housing for wood ducks, screech owls and a variety of cavity-nesting mammals, but Pileateds themselves rarely use a nest hole more than once.  They will also use man-made nest boxes.

In search of food they carve a deep rectangle, sometimes a foot long and several inches deep, into dead or dying tree trunks, giving new meaning to the phrase “let the chips fall where they may.” Carpenter ants are the main item on their menu; they pinpoint accurately the location of an ant nest, excavate a fresh crevice in the wood, extend a long tongue, and lick up the ants.  Sources say that songbirds like wrens and flycatchers often visit feeding holes to take advantage of insects uncovered by the woodpeckers.

Pileated Woodpeckers also eat beetle grubs and a variety of other small insects and some nuts and fruits (even poison ivy berries).  The BugLady has seen pictures of Pileated Woodpeckers at suet feeders (but not at hers), and as with all woodpecker species, if they’re checking out the siding of your house, you may have an ant problem.  They often feed on or near the ground, where they’re vulnerable to predation by mammals, including house cats.  Weasels, rat snakes, squirrels and grey foxes (our tree-climbing fox) are nest predators, and they are preyed on in the air by hawks, owls, and eagles!

Both hunting and logging took their toll on Pileated Woodpeckers, and their numbers plummeted in the 18^th and 19^th centuries.  In the 1800’s they were shot as trophies and for food, although John James Audubon and others had reported that they tasted like the worms and ants they eat and were “extremely unpalatable.”  The harvesting and fragmentation of mature forests not only removed the large dead trees that served as nest sites, it also broke up vast stands of trees into units too small to support a pair of woodpeckers.

But the birds adapted to life in smaller trees (even utility poles!), and both woodlands and woodpeckers are making a comeback.  Most importantly, they have become more tolerant of human neighbors.  Fifty years ago, Ozaukee County had a single breeding pair of Pileated Woodpeckers, recorded annually in the Cedarburg Beechwoods State Natural Area.  Although they are more common in the north, they are now seen all over the state, and they continue to move into southern Wisconsin.

[The BugLady took these shots through her patio door at her old house.  The same patio door she intended to wash each season so that she could take pictures through it……  See a nice slide show at https://www.allaboutbirds.org/guide/Pileated_Woodpecker/id.]

Fun facts about Pileated Woodpeckers:

• Thank you, Linnaeus.  Before Linnaeus standardized classification of living things in the mid-1700’s, the Pileated Woodpecker was known as the larger red-crested Wood-pecker,” Picus niger maximus capite rubro.
• In less than a second, they can drum from 11 to 30 times!
• Despite its impressive 30” wingspan, it weighs only a little more than a half-pound.
• According to the American Bird Conservancy (ABC), Woody the Woodpecker was inspired by cartoonist Walter Lantz’s encounter with a particularly persistent Acorn Woodpecker https://www.allaboutbirds.org/guide/Acorn_Woodpecker/overview, not a Pileated.  As Lantz developed Woody, he used a little poetic license and exaggerated the crest, and Woody ended up looking more like a hybrid.

Kate Redmond, The BugLady

Howdy, BugFans,

The BugLady found this velvety, deeply maroon caterpillar at the Land Trust’s CESA site on a fine June day.  It’s the larva of a Straight-toothed sallow moth (Eupsilia vinulenta) (probably) (full disclosure – the experts caution us that the only way to positively ID an Eupsilia caterpillar is by rearing it to an adult).

Sallows are a group of Owlet moths (family Noctuidae) that are pretty hardy – depending on the latitude, moths may be active all winter, or overwintering adults may emerge from hibernation, fly around, and visit maple sugaring operations on balmy winter days when the temperature climbs above freezing (For a scenic side trip, see “Insects attracted to Maple Sap: Observations from Prince Edward Island, Canada” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3088023/).  One source reported seeing the moths searching for warmer shelters on sub-freezing nights, shelters they locate using their antennae.

In Caterpillars of Eastern North America, David Wagner notes that sallows readily come to sugar baits (Eupsilia species “gather by the hundreds at beer or sugar or other baits”).  He recommends to us Holland’s description of baiting moths, and the BugLady is grateful to the Alberta Lepidopterists Guild for posting it http://www.albertalepguild.ca/wp-content/uploads/2015/03/Moth_Sugaring.pdf.  They just don’t write science like that anymore.

The Moth Book by W.J. Holland was published in 1904, and with 48 (XLVIII) plates crammed with images, it was for decades the moth Bible (the down side was that moths are pictured like the pinned specimens that they are, with their wings spread, rather than perched naturally).  By 1926, it had joined five other books in a set called The Nature Library, and the set that the BugLady grew up with her nose in probably belonged to her Mom.

Kirk Mona, in his Twin Cities Naturalist blog found an alternate name for the Straight-toothed sallow – he says “The name the Satellite comes from the little spots that seem to orbit like satellites around the larger spot on the fore wings. What a cool name! It is much cooler than “Straight-toothed Sallow.” https://bugguide.net/node/view/1000248/bgimage.

Adults are variable in color, from pale https://bugguide.net/node/view/1051398/bgimage to brown, to rust https://bugguide.net/node/view/1008427/bgimage.  They mate in late winter and early spring; here are the eggs – https://bugguide.net/node/view/1220586/bgimage.  Adults nectar on early tree flowers like red maple.

Caterpillars https://bugguide.net/node/view/38981/bgimage are somewhat generalist feeders, found on the leaves of an assortment of shrubs and trees like box elder, oak, cherry and maple.  Wagner says that younger larvae are “new-leaf specialists that fashion crude leaf shelters in young leaves,” and they may use the abandoned shelters made by other caterpillars.  According to Owlet Caterpillars of Eastern North America, older caterpillars are found on the in leaf litter on the ground and may feed on low-growing plants or on plant material (like old flowers and catkins) that’s fallen off of trees.

On another front, Monarch butterflies are starting to reach our southern borders.  Here’s info about the status of Monarch populations in 2021: https://www.npr.org/2021/02/26/971650046/climate-change-deforestation-threaten-monarch-butterfly-migration?utm_source=npr_newsletter&utm_medium=email&utm_content=20210226&utm_term=5204798&utm_campaign=news&utm_id=2548916&orgid=675.  And here’s an animated 2021 Monarch migration map: https://maps.journeynorth.org/map/?map=monarch-adult-spring&year=2021

Go outside – look for moths (and listen for owls, too)!

Kate Redmond, The BugLady

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

Greetings, BugFans,

It’s time again to celebrate the bugs that fly under the radar – bugs that are neither famous nor infamous and that live alongside of us, about whom not much has been written.  All three of these species, coincidentally, have their flight periods in the first half of the summer.

CURRANT TIP BORER

This beetle is a poster child for insects that are barely visible online, although unlike many, it has picked up a common name along the way.

The Currant tip borer (Psenocerus supernotatus) is a not-very-long-horned member of the long-horned beetle family Cerambycidae.  The long-horned (long-antennaed) beetles are divided, uneasily and depending on whose book you read, into 10 subfamilies, and the Currant tip borer’s subfamily, Lamiinae, the Flat-faced Longhorns, includes about 20,000 of the 30,000 species of Cerambycid worldwide.  There are 5,000 species in the New World, but only 250 of them occur in North America.

This little beetle (about 1/3”) can be found in early summer, east of a line from Manitoba to Texas.  Its larvae feed within the dead branches of a variety of woody plants, and it’s been found on oak, Virginia creeper, poison ivy, sumac, catalpa, and mulberry as well as currant and gooseberry.  Considering its name, the BugLady was expecting to find a bunch of Extension Bulletins telling us how to protect our gooseberries and currants, but she found none.

Mr. R. P. Dow, writing in the Bulletin of the Brooklyn Entomological Society in 1916, recounts how he found some Currant tip borer larvae in sumac pith.  First to hatch were two males that, after exploring their surroundings, began to fight by a specific spot on the twig.  Two days later, a female emerged from that spot.  He wrote, “It is evident that some sense organ revealed the female to the males not less than 36 hours before her emergence from the unmarked wood.”

One source writes that the adults look ant-like.  Hmmm – the BugLady doesn’t see it

https://bugguide.net/node/view/162589/bgimage.

SULPHUR-WINGED GRASSHOPPER

The BugLady automatically surveys butterflies and dragonflies as she walks – it’s like breathing.  From mid-summer on, she sees Clouded Sulphurs over the grasslands (bugguide.net informs the BugLady’s spellcheck that “both spellings of “sulphur” or “sulfur” are seen frequently. The first prevalent in older works, with the second becoming more common in recent decades”).  With black-bordered, lemon-yellow wings, the butterflies are almost unmistakable (this is a remarkable shot, and not just because it shows the black edges on the upper surface of the wings https://bugguide.net/node/view/1452733/bgimage.  Sulphurs perch with their wings closed, so the black border is seldom photographed).

Almost unmistakable – the Sulphur-winged grasshopper (Arphia sulphurea) always makes her do a double-take https://bugguide.net/node/view/640715/bgimage.  Members of the genus Arphia are found across North America; they’re in the Short-horned grasshopper family Acrididae and in the Band-winged grasshopper subfamily Oedipodinae, some of which are pretty fancy https://bugguide.net/node/view/1673548/bgpage and https://bugguide.net/node/view/1298160/bgimage, and https://bugguide.net/node/view/238831/bgimage.

Most of the grasshoppers that the BugLady researches have extensive rap sheets due to their fondness for plants that grow in ag-lands and pastures, but she could find no wanted posters for the Sulphur-winged grasshopper, alias the Yellow-winged/Spring yellow-winged grasshopper.

Sulphur-winged grasshoppers are found in grasslands, edges, and sometimes in open woodlands east of that Manitoba-to-Texas line, and north just into Canada.  They feed primarily on grasses, with a few wildflowers thrown in for good measure, and unlike many grasshoppers, they don’t eat any animal material.  Bugguide.net tells us that both males and females “crepitate” – make snapping/crackling/popping sounds with their wings – during courtship displays.  Adults can be seen starting in early spring and are gone by mid-summer.

They overwinter as late-stage nymphs (and they have the best nymphs ever! https://bugguide.net/node/view/1593959/bgimage and https://bugguide.net/node/view/510468/bgimage).

WHITE-SPOTTED/THREE-SPOTTED HORSEFLY

In early summer, the BugLady spied this impressive male horsefly eyeing her from a lily pad (male, because its huge eyes meet in the middle – all the better to see you with…..).  Horse flies and deer flies are in the family Tabanidae.  For “Horse fly 101,” see https://uwm.edu/field-station/horsefly/.  Many species are also called Greenhead flies https://bugguide.net/node/view/327405/bgimage (visit the Atlantic coast in summer to get the full Greenhead experience), and many have spectacular, Technicolor eyes that make them the darlings of macro photographers https://bugguide.net/node/view/953808/bgimage, https://bugguide.net/node/view/601725/bgimage, https://bugguide.net/node/view/1510950, https://bugguide.net/node/view/1794820/bgimage, https://bugguide.net/node/view/775055/bgimage, https://bugguide.net/node/view/1263543/bgimage, https://bugguide.net/node/view/241452 (sorry – they’re just so cool).

They’re the flies we love to hate.  In “The Tabanidae of Minnesota” (1930), author Cornelius B. Philip anthropomorphizes, “After feeding to satisfaction, the fly may withdraw and make new stabs, apparently for the pure love of it…….”

The Three-spotted horse fly (Tabanus trimaculatus) is one of about 100 genus members in North America, and it will not surprise southern BugFans to read that the genus is most diverse in the their neck of the US.  According to bugguide.net, tabanus was “a name used by the Romans for a kind of biting fly.”

Horse flies lay their eggs in clumps https://bugguide.net/node/view/863583/bgimage on vegetation, in damp areas.  When the eggs hatch, the tiny, carnivorous larvae https://bugguide.net/node/view/864099/bgimage drop to the ground or into a “semiaquatic habitat” and burrow into the soft soil, where they find small invertebrates to eat.  They’re eaten, in turn, by nematodes and mud-probing birds, and they’re parasitized by sand wasps, tachinid flies, and chalcid wasps.  Here’s an interesting shot of a ladybug larva grazing on horse/deer fly eggs https://bugguide.net/node/view/193565/bgimage, and a shot of an older, generic Tabanid larva https://bugguide.net/node/view/854957.

TSHFs are fairly early-season horse flies that seem to prefer woodsy settings – researchers in the Minnesota study found that “the larvae outnumber by far any other species taken but the adults seem to have retiring habits in Minnesota.”

From what the BugLady could find, the TSHF is not a notorious scourge of man or beast.  Yes, female horse flies need the protein from a blood meal in order to produce eggs, but both females and males also feed on nectar.  In a study to discover which species of horse flies were most annoying to deer in Oklahoma, four species made up 95% of the horse fly attacks, and although the TSHF was abundant, it was not seen feeding on deer.

Kate Redmond, The BugLady

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

Howdy, BugFans,

Sawflies appear infrequently in these pages, the most recently a year ago, in the person of the spectacular Elm sawfly (https://uwm.edu/field-station/elm-sawfly/).  The sawflies that the BugLady typically sees (recognizes) are usually the wasp mimics that looks like this https://bugguide.net/node/view/26145.  About sawflies in general, much has been written, but the information often peters out as you zero in on species.  A little taxonomy first – they are in the sawfly-horntail-wasp-bee-hornet-yellowjacket-ant order Hymenoptera.  Sawflies are filed in a group called Symphyta, which is divided into 14 families and 8,000 species worldwide, and 1,245 species in 13 families in North America.

Sawflies are usually described as “primitive wasps,” but where a wasp has, well, a “wasp waist,” the connection between a sawfly’s thorax and abdomen is thick.  The “saw” refers to the serrated ovipositor that the female uses to incise leaves or bark so she can lay her eggs (but she doesn’t sting with it) https://bugguide.net/node/view/619563/bgimage.

Eggs are laid in groups called rafts or pods.  They start out tucked inconspicuously inside a slit in a plant, but the egg grows along with the developing larva, and the eggs may bulge from their hiding places by the time they hatch.  In general, the larvae feed on leaves; often feeding in groups, and they have some very cool synchronized alarm displays https://bugguide.net/node/view/1278507/bgimage.  Sawflies tend to be very specific about the host plants for their eggs, and a number are agricultural/silvicultural/horticultural pests.  The sluggish adults feed on pollen and nectar, and sometimes at sap seeps.

Sawfly larvae are easily mistaken for moth or butterfly caterpillars.  The secret handshake?  Count the feet https://bugguide.net/node/view/1279016/bgimage.  Like the adults, larval Lepidoptera have three pairs of (real) legs on the thorax, and they also have two to five pairs of hook-tipped prolegs spaced along the abdomen that support and anchor it. Many sawfly larvae have prolegs, too, but those that do, have six or more pairs of them.

There’s usually only one generation a year, with immature sawflies spending the winter on the ground as a pre-pupa in a cocoon or as a pupa in a pupal case, finally finishing their development in spring or early summer.  The adults live a week or so.  Some species are parthenogenic (meaning “virgin birth”), with females producing only female offspring, and no males in sight.

The Thick-clubbed sawfly (Abia inflata) is in the family Cimbicidae, a small family with about 12 species in four genera in North America and more elsewhere.  Cimbicids have noticeably clubbed antennae and tend to be bumble bee mimics.  Depending on the genus, the larvae feed (alone) on elm, cherry, or honeysuckle, and they often curl up on the undersides of leaves where they’re hard to spot (https://bugguide.net/node/view/1801346/bgimage – or not https://bugguide.net/node/view/371247/bgimage).

Abia like honeysuckle.  The Thick-clubbed sawfly is also called the American Honeysuckle sawfly, but the name also belongs to an American Honeysuckle sawfly that is a native species in the western US, and a non-native sawfly called the Honeysuckle sawfly is making itself at home on the East Coast, all of them in the genus Abia.  Abia inflata is found in the eastern part of the continent.

Females deposit eggs, only one or two at a time, in honeysuckle leaf edges, and the larvae eat the tender parts of the leaves between the main veins.  The speckled larvae may grow to 1 ¼” when mature.  Here are some life stages – note the cute little springtails by the curled up larva https://bugguide.net/node/view/410428.  Since they feed alone, they defend themselves by “reflex bleeding” rather than displays, oozing an offensive liquid from their joints that they sequester from chemicals in the leaves.

Abia inflata feeds on native honeysuckles, but grad student Loren Elizabeth Shewhart of Wright State University wondered if the species might be a potential biological control of the invasive Amur and other non-native honeysuckles that are taking over our landscapes.  In a series of experiments in which she fed whole and damaged leaves of native and exotic honeysuckles to Abia inflata and three other sawfly species, she determined (among other things) that Abia inflata will eat exotics and will mature and even thrive in laboratory settings, but it’s seldom found on Amur honeysuckle in the field.

Why damaged leaves?  Honeysuckle leaves that have been torn or chewed may produce more defensive chemicals than whole leaves; damaged leaves look “grazed” and give off aromatics, both of which attract predators and parasites.  Anyway, Shewhart speculates that Abia inflata simply doesn’t recognize the Amur honeysuckle as a potential host plant (yet), and this coupled with its preference for native species may cause natives to decline further as the exotics thrive in the absence of their natural grazers.

This is the big question in the control of any invasive plant – how long will it take for the native herbivores to figure out that all those new plants are a giant smorgasbord?

Thanks to Honorary BugFan PJ for identifying this sawfly.  It does take a village.

Kate Redmond, The BugLady

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

Greetings, BugFans,

The BugLady thought it was time to give this episode from 2008 a make-over – many new words and pictures.

Mayflies, order Ephemeroptera (which means “short-lived wings”) are a large and complicated group, and because the BugLady has not learned the secret mayfly handshake yet, what follows is general information about the Order Ephemeroptera.  Mayflies are not related to house flies (order Diptera).  They’re considered to have some primitive insect characteristics, and fossil evidence tells us that they’ve been around since the Carboniferous Age (354 to 290 million years ago).  Sources list 611 species in 21 families in North America (you can see physical differences in some of the mayflies pictured) and 3,350 worldwide.

Mayflies, aka lakeflies, willowflies, fishflies (though there’s a fishfly in the unrelated order Neuroptera), or shadflies (like shadbush flowers, they’re conspicuous in spring when the shad fish are spawning) have an interesting life cycle.  Immature mayflies (naiads) are aquatic, growing up in (mostly) well-oxygenated, unpolluted streams and rivers, though there are species that favor shallow, still water.  Adults are usually found at the edges of their natal wetlands.  Depending on their family, naiads live under rocks, on the stream bottom, in tunnels, or on decaying submerged vegetation, at specific depths, and within specific ranges of dissolved oxygen.  They are classified by their modes of locomotion as clingers, burrowers, sprawlers, crawlers, climbers, and swimmers, and one source calls them “microhabitat specialists.”

Most insects spend a disproportionate part of their lives as immatures, but mayflies take that to an extreme.  Depending on water temperature and water quality, the egg stage can last as long as a year and the immature (naiad) stage for three years.  Most adults live for three days, tops.

Although mayflies are most conspicuous in spring, some species are present in fall.  Like cicadas, they practice what the BugLady calls the “Normandy Beach strategy of reproduction” – if you throw enough soldiers onto the beach, some will reach the beachhead (or, in the case of the mayfly, live long enough to mate).  At their appointed time, mayflies emerge from the water, often at dawn or dusk, by the googol (more about that in a sec).  Males form dense, dancing clouds in the calm air (they are fragile) above the water.  Females fly in and pair up, and copulation is brief.  Males may dance again the next day.

Female mayflies lay 500 to 3000 eggs, singly or in batches or all at once, placing them onto/under the water’s surface while in flight or from a perch on a rock, and some species crawl underwater to oviposit.  The eggs sink to the bottom and go with the flow.  Naiads are aquatic, living under water, feeding on algae and on tiny bits of organic debris delivered by the current (adults do not have functional mouthparts and do not feed – “ephemeral”).  As they grow, naiads go through as many as two dozen molts (four times the number of molts that most insects with incomplete metamorphosis undertake).

Although they have external gills along the sides of their abdomen (the gills of species that live in still water are larger), naiads can usually absorb sufficient oxygen through their exoskeleton in well-oxygenated waters.  They use their gills to keep the water moving over their body, and this mini-current also delivers food.  Gills are used in low-oxygen situations.

When it’s time to emerge as adults, they have an unusual penultimate step.  The naiad swims to the surface or floats up on an air bubble (one source said that the naiad empties its abdomen of digested food, replaces it with air, and “becomes” the air bubble!).  It swims to shore and molts into a smoky-winged, not-quite-reproductively-mature subadult phase called a “sub-imago” or “dun.”  A few minutes to a few hours later, it molts again into the final, clear-winged adult stage called the “imago.”  The imago has longer “tails” for increased stability in flight and longer legs to grasp its mate.  For photos of molting sequence, see http://www.troutnut.com/article/10/pictures-of-mayfly-dun-molting-to-spinner.  Mayflies are the only insect that molts after reaching the winged, adult stage.

What can you mistake them for?  Because they both fold their wings above their abdomen, adults might be confused with caddisflies, which also have aquatic immatures, but the wing shape is different https://bugguide.net/node/view/1922281/bgimage.  Mayfly naiads are similar to stonefly naiads https://bugguide.net/node/view/517329, but mayflies almost always have three “tails.”  Stoneflies have two tails, and a stonefly’s gills are on its thorax.

And the Human-Mayfly Intersection?

First, as eggs, naiads and adults, mayflies are important strands of food webs in and around the water.  Eggs and naiads are a favorite food for other aquatic insects, snails, crayfish, leeches, and fish, and adults are eaten by birds, bats, dragonflies, spiders, frogs, and shrews.  Since mayflies are relished by trout, fly fisherpeople (and bait manufacturers) go to a good deal of effort to keep track of what’s emerging and to tie flies that “match the hatch.”

Second, mayflies are sensitive to changes in water quality and are indicators of clean water.  Like many other insects, their numbers are declining, most notably due to water pollution.

Finally, those dramatic, synchronized emergences of zillions of adults are cause for some lakeside and river communities to call in the snowplows in summer as the mayflies’ slippery bodies impair visibility and cover roads and bridge surfaces.  Mayflies are totally harmless but some people are allergic to large quantities of mayfly bits.  See pictures at https://www.accuweather.com/en/weather-news/mayflies-swarm-lake-erie-as-summer-kicks-off/762324 and radar at https://www.michiganradio.org/post/massive-mayfly-swarm-seen-leaving-lake-erie-weather-radar (and what an amazing shot of a mass of newly-emerged mayflies on the water’s surface!).

Nice biography and pictures here https://www.earthlife.net/insects/ephemer.html, and another bio and postage stamp at https://projects.ncsu.edu/cals/course/ent425/library/compendium/ephemeroptera.html.

For a survey of mayfly families, see https://dep.wv.gov/WWE/getinvolved/sos/Pages/Ephemeroptera.aspx.

The BugLady has no experience with this site and is not endorsing it, but she was tickled to find some mayfly wear: https://www.cafepress.com/mayflynews.

Kate Redmond, The Bug Lady

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

Howdy, BugFans,

The BugLady will always associate this wasp with the pandemic.  In early summer, she got an email from a BugFan who, because she was working from home (and maybe looking out the window a little bit??), noticed that the track of one her sliding windows had been stuffed with grass.  What was going on?  The BugLady sent her some info on Grass-carrying wasps and wished that she would see one someday).

Fast-forward to the Water Hemlock Wildflower Watch (of recent BOTW fame).  As she worked her way through the pictures she took on those outings, the BugLady suspected that the fuzzy, little Hymenopteran that she saw was, indeed, a Grass-carrying wasp.  Here are some nicer pictures: https://bugguide.net/node/view/1412306/bgimage, and https://bugguide.net/node/view/1592431/bgimage.

Grass-carrying wasps are, small, benign members of the wasp family Sphecidae, the Thread-waisted wasps (“thread-waisted” because their abdomen is connected to the thorax by a thin stalk called a “petiole”).  Some Sphecids are spectacular in size, shape, and color  https://bugguide.net/node/view/819298/bgpage, https://bugguide.net/node/view/1856936/bgpage, https://bugguide.net/node/view/68796/bgpage, https://bugguide.net/node/view/1572229/bgimage (all of these wasps have been featured in their own BOTWs).

Sphecids are solitary wasps; most make a nest in the ground that they provision with paralyzed invertebrates for their offspring.  The adults are pollinators that sip nectar from flowers (one article said that Sphecids prefer white flowers), drink some of the juices of the prey they collect, visit deposits of aphid honeydew, or even take advantage of hummingbird feeders https://bugguide.net/node/view/1401700/bgimage.

Counterintuitively, the Mexican grass-carrying wasp (Isodontia mexicana) is the most widespread (https://bugguide.net/node/view/34920/data) of the six genus members that occur in North America.  Bugguide.net lists a pretty reliable (but unofficial) field mark for the MGCW – a brown spot near the base of the petiole, and through the Joys of Photoshop, the BugLady was able to see it on her wasp https://bugguide.net/node/view/817656/bgimage.  Besides North America, they’ve also made their way to the UK, to Europe as far east as Crimea, and to Midway Atoll.  Not surprising considering their secretive nesting habits.

They’re found in gardens, grasslands and woodland edges, and when they’re not taking advantage of man-made “bee hotels” https://bugguide.net/node/view/1706561/bgimage and window ledges, they nest in crevices and cavities in wood, in hollow plant stems https://bugguide.net/node/view/231614, and in tunnels made by other animals (which they clean out before they add their own nest materials).  Unlike many Sphecids, MGCWs mostly nest above the ground.

Females gather blades of grass and stuff them into a nest site to form a lining (picture a ¾” wasp trailing a long piece of grass through the air https://bugguide.net/node/view/1560148/bgimage).  At the start of the process, she backs down the tube pulling the grass in behind her.  When she’s satisfied with the accommodations, she hunts for adult tree crickets https://bugguide.net/node/view/1163068, https://bugguide.net/node/view/453661/bgimage, and sometimes katydids, which she paralyzes and stows in the nest.  She lays an egg near her immobilized prey, and a stalk often contains a series of grass/tree cricket/egg units.  She finishes by stuffing the entry of her construction with a tuft of grass that some authors describe as “broom-like.”  Curiously, as the sequence of chambers lengthens, the offspring in the later cells (closer to the door) tend to be males.

There are two generations; the larvae https://bugguide.net/node/view/231618 of the first generation develop quickly – three to four weeks from egg to adult – emerging in mid-summer.  The second generation overwinters as a pupa, in diapause (suspended animation).

Despite their hiding places, the egg chambers are found by a few species of parasitic fly, and if the fly larva doesn’t kill the wasp larva outright (or starve it by appropriating its food supply), researchers O’Neill, et al found that “sharing” its food cache with fly maggots can have a “sublethal effect” on the wasp – less food results in a smaller adult wasp that may be less fit.

Several sources noted that most of the prey in a MGCW nest are adult, female tree crickets, and while this kind of gender bias is uncommon in insects as a whole, it’s common within the Sphecidae.  Researchers Ercit, Martinez-Novoa, and Gwynne took a look at this prey bias, and here are some of their observations.

• It would make more sense if males were most frequently captured, because their courtship behaviors put them at risk, out in the open.
•  “Females carrying more eggs https://bugguide.net/node/view/998532/bgimage were significantly more likely to be caught by wasps, regardless of their body size and jumping leg mass.”
• “In laboratory experiments, the number of mature ovarian eggs had a negative effect on jump distance.”

They noted that females also take risks in courtship and while ovipositing that make them more conspicuous; that females may simply be easier to catch (they’re often larger than males, especially when carrying eggs); and that some predators may have a preference for female prey because gravid females offer an added nutritional boost.

A few years ago, the BugLady purchased some iron bird silhouettes (“lawn fawns,” in her family’s vernacular) from a company called Houzz, which sells indoor and outdoor decor.  Houzz has lawn fawns galore, but they also have an on-line magazine, and in it, the BugLady found a detailed account of the MGCW https://www.houzz.com/magazine/meet-the-grass-carrying-wasp-a-gentle-pollinator-of-summer-flowers-stsetivw-vs~58817932.

Hats off, too, to the Master Gardeners of Northern Virginia for a good, well-illustrated write-up https://mgnv.org/2020/04/29/whats-that-dried-grass-doing-in-my-window-track/.

After the recent BOTW about coyotes, BugFan Tim sent this link to a video that is part of the pandemic-inspired virtual programming created by Milwaukee’s Urban Ecology Center https://www.youtube.com/watch?v=9KoNyFk6oIg&feature=youtu.be.  Enjoy.

Kate Redmond, The BugLady

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

Howdy, BugFans,

In mid-summer, water hemlock bloomed lushly in the swamps at the north end of the Bog.

A note about water hemlock (Cicuta maculata), a wetland plant that looks like Queen Anne’s lace on steroids. It’s related to the plant that killed Socrates but is in a different genus, and it’s probably the most poisonous plant in the Western hemisphere – to taste, not to touch. It can kill you within 20 minutes of eating it. Cicutoxin is a central nervous system stimulant that causes severe seizures and respiratory paralysis. Some books say that the root “smells edible” (insert BugLady eye roll here), and some people have mistaken it for the root of the edible Wild parsnip (which looks completely different to the BugLady, has yellow flowers, and grows in uplands instead of wetlands). All parts are poison (the insects are unaffected), especially the stem and root. The seeds, the least-poisonous part of the plant, look like fennel, anise, and dill seeds, and other members of the carrot family – wild food browsers beware. Despite its toxicity, small amounts of the plant were used medicinally by Native Americans, and they employed violent purges to treat accidental ingestion.

Anyway, the plants were hopping for about two weeks. Here are some of the insects that the BugLady saw – the stars of most of them are not hitched to water hemlock, it’s just that there was a ton of it in bloom and not much of anything else.

BI-COLORED PYRAUSTA – An eye-catching, day-flying moth in the Crambid/snout moth family with a wingspan of just under ¾”. It inhabits the eastern US from Texas, and its host plants are probably mints (lots of gaps in its biography). Pyrausta is Greek for “a winged insect that lives in fire.”

CARROT WASP – or Gasteruption. What a cool little wasp, with its high-arced abdomen! Bugguide.net says that “Gasteruption have a characteristic hovering flight with the swollen metatibiae hanging down so that the insect resembles a helicopter carrying a large load on a cable.” Since the BugLady has seen a helicopter carrying a large load on a cable, she will look at it with different eyes next summer. Adults are found on flowers, but their larvae are carnivores, living within the nests of cavity-dwelling, solitary bees and feeding on their larvae.

ICHNEUMON WASP, AROTES – Another classy wasp! Bugguide.net describes Arotes as “A group of boldly-patterned, medium-sized ichneumons.” The larvae of Ichneumons are mostly parasites of immature invertebrates; Arotes favors beetles – members of the metallic wood-boring, the long-horned, the false darkling, and the tumbling flower beetle families, all of which are found under bark.

PEACHTREE BORER MOTH – Each summer, hummingbird clearwing moths dance around the BugLady, mocking her camera. The Peachtree borer is from the other clearwing moth family Sesiidae, many of which are wasp-mimics (note the scale-free and therefore clear portions of the wings). Lots of internet Wanted Posters on the Peachtree borer because of the damage done by its larvae as they tunnel around within the roots and lower trunk of commercial peach, plum, and cherry trees. They are sexually dimorphic (two forms), with the more colorful female https://bugguide.net/node/view/981311/bgimage, and the equally-spectacular male https://bugguide.net/node/view/815698/bgimage.

PHANTOM CRANE FLY – The BugLady usually sees these exquisite little flies drifting in and out of the shadows at the edges of wetlands (their larvae live in the mud https://bugguide.net/node/view/1927371/bgimage). She was surprised to see this one sprawled on flower clusters (umbels). Some sources say that the adults don’t eat much, but others say that they feed on nectar.

WHITE-STRIPED BLACK MOTH – Sometimes when she’s leading a field trip, the BugLady asks people what they would name the plants and animals we see. This little moth is a no-brainer. According to Sogaard, in Moths and Caterpillars of the North Woods, Black-striped white moths have very sensitive “bat-detectors,” structures that are superfluous in a day-flying species. This suggests that the day-flying habit is relatively recently acquired.

SWEAT BEE – There are three species of sweat bee in the genus Augochloropsis – this is probably the Metallic epaulleted [sic]-sweat bee (A. metallica). Sweat bees are important native pollinators that visit a wide variety of flowers, and sometimes also eat honeydew from aphids. Female Augochloropsis dig a tunnel straight down into the earth and then make a lateral tunnel off of it. There they make cells for their eggs and provision them with pollen and nectar.

RED-SHOULDERED PINE BEETLES are members of the Long-horned beetle family Cerambycidae, whose larvae are often wood borers. Red-shouldered pine beetle larvae live in dead and decaying pine, hemlock, and fir, where their excavations help get the decomposition ball rolling.

BANDED HAIRSTREAK – Small, drab (unless newly-minted https://bugguide.net/node/view/803024/bgimage) butterflies – the BugLady searched for picture of one with its wings open, but she couldn’t find one. This is a butterfly of fields, edges, and open woodlands; males perch on vegetation to check their territory for females and for rivals (who they chase vigorously). It is suspected that ants may care for the caterpillars https://bugguide.net/node/view/803004/bgimage, as they do for some species of Azure caterpillars.

GRAY COMMA – Adults don’t visit flowers much; they get their nutrients from sap flows on damaged trees. In the Bog, gooseberries are the host plants for its spiny caterpillar https://bugguide.net/node/view/937966/bgimage. Like other “anglewings,” the Gray Comma overwinters as an adult, in a sheltered nook called a hibernaculum. The “comma” on the underside of its wings is more “V-shaped” https://bugguide.net/node/view/964668/bgimage.

ROBBER FLY LAPHRIA – Not all the insects on the water hemlock were plant feeders. This is Laphria sacrator (probably), a fairly common fly of woodlands in the eastern half of the country. Robber flies in the genus Laphria are called the Bee-like/Bee-mimic robber flies. Several kinds of robber flies surveyed the water hemlocks, looking for flying insects, including smaller robber flies, to tackle in mid-air. Size is no object.

GNAMPTOPELTA OBSIDIANATOR – The BugLady saw a few species of insects that were new to her, and this is one of them. For years, she’s been taunted by Thyreodon atricolor (https://bugguide.net/node/view/1688339/bgimage), a spectacular Ichneumon wasp that cruises through the underbrush slowly and without stopping to have its picture made. Gnamptopelta obsidianator https://bugguide.net/node/view/1803663/bgimage is its double. An expert on bugguide.net says that “I also have a feeling most of the Gnamptopelta images in the guide are misidentified Thyreodon.” Both species have been called Spider wasp mimics, too, though the BugLady is not sure what the advantage is, other than the fact that ichneumons are (relatively) docile and spider wasps have no qualms about stinging.

As if its scientific name weren’t enough of a mouthful, the BugLady found an equally tongue-twisting common name for Gnamptopelta obsidianator – the “Bent-shielded Besieger Wasp,” a translation of its scientific name. It is thought that adults may feed on nectar, but it lays its eggs on the caterpillars, especially those found on wild grapes (scroll down https://www.marylandbiodiversity.com/viewSpecies.php?species=12769).

Also seen were a click beetle, a tumbling flower beetle, several wasps and yellowjackets, a bald-faced hornet, a grass-carrying wasp (of future BOTW fame), other species of sweat bees, a daddy longlegs, a small spider, ants, a Summer Spring Azure butterfly, several species of syrphid flies, tephritid, tachinid, flesh, soldier, and green bottle flies, a dangling spider egg case, several species of Ichneumon wasps, and a White-faced Meadowhawk taking a rest.

Kate Redmond, The BugLady

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

Greetings, BugFans,

The story of this fly (whose name is considerably longer than the fly itself) demonstrates why the BugLady loves BOTW.  Could she dig up a lot of details about how this little beauty lives its life?  She could not.  But she found two interesting side stories about it.

As always, our first episode of the New Year is vocabulary-rich.

Procecidochares atra is a true fruit fly in the family Tephritidae – not one of those red-eyed, flying lab rats that circle your bowl of grapes in summer, or that escape from confinement and live in labs in perpetuity.  Those are more properly called Pomace or Vinegar flies, family Drosophilidae.  Because of the simplicity of their DNA and the ease in raising them, some Drosophila are extraordinarily well-studied and experimented on.

Fun Drosophila Fact: according to Wikipedia, if a female Drosophila melanogaster sees a female larva of an endoparasitic wasp, she will start laying her eggs on rotting fruit or some other alcoholic substrate.  Why?  Because her offspring will imbibe it, and wasps have a low tolerance for alcohol.

But we digress.

Tephritid flies are also called Picture-winged flies and Peacock flies, but those names are more properly applied to other tiny flies.  Those fancy wing patterns are used both in courtship and in defense (more about that in a sec).  Wikipedia says that the females use their telescopic ovipositors to insert their eggs in living plant material.  The larvae of most species are vegetarians, they feed on plant tissue that the eggs are deposited in, or like the genus Procecidochares, they make a gall https://bugguide.net/node/view/443421/bgimage and feed, and finally pupate inside it https://bugguide.net/node/view/857057/bgimage.  Some family members are food specialists while others enjoy a more varied menu; some are agricultural pests, and others help to control agricultural pests.  Adults feed blamelessly on nectar, pollen, honeydew, and decaying vegetation.

There are about 15 species in the genus Procecidochares in North America, all of which are gall-makers on goldenrods, and Procecidochares atra (no common name), found from the Atlantic to the Great Plains, is one of the larger and more common species (here’s a better picture https://bugguide.net/node/view/838430/bgimage).  Procecidochares atra has been recorded on three species of goldenrod.

Interesting Side Story Number 1 (and vocabulary challenge):

Most, but not all, genus members are univoltine (one generation per year), but Procecidochares atra is bivoltine (two generations).  The spring generation forms a stem gall near the base of an emerging goldenrod, and that gall is polythalamous (containing multiple larvae, as many as 21).  Galls of the late-summer generation are formed above mid-stem, often on the buds https://bugguide.net/node/view/1426536/bgimage, and are monothalamous (each houses a single larva).  The galls are leafy rosettes.  The photographer of this gall https://bugguide.net/node/view/1436982/bgimage bagged it to see what kind of fly would emerge and got wasps instead – the wasps had probably parasitized the larva of the gall-making fly (unless they were inquilines).  It’s probable that the adults overwinter and lay eggs as goldenrod starts to grow in spring.

But, as author Isaac Asimov once wrote, “The most exciting phrase to hear in science, the one that heralds new discoveries, is not ‘Eureka!’ but, ‘That’s funny….'”  Researchers Phillips and Smith studied Procecidochares atra, noting the seasonal and structural differences in its gall making habits and identifying two new host species, Canada goldenrod and horseweed (Erigeron canadensis).  To complicate things even more, the late summer gall they found on horseweed was a stem gall located inches from the ground, not a bud gall.

What’s going on?  The researchers suspected that they might be dealing with what is called a “cryptic species,” a described species that’s actually made up of several distinct species that don’t interbreed but that look (to us) identical.  This would explain the differences in hosts and seasons and gall formation.  Although (using the tools available in the 1990’s) they were “unable to differentiate this specimen [on Erigeron] morphologically from other specimens of Procecidochares atra,” they didn’t rule out the potential for two or more cryptic species, separating the spring, fall, and Erigeron gall makers.  And, of course, they noted that there needed to be a “systematic revision of the genus.”

Interesting side story Number 2:

Yes, males use their patterned wings like semaphore flags in courtship, to signal to females, but tephritids also use them in defense.  In its write-up about the family Tephritidae, bugguide.net says

• “Some spp. mimic jumping spiders. The wing-waving apparently deters the approach of jumping spiders, important predators of the flies. 
• ‘Spider predation has been intense enough to mold the evolution of prey characteristics: predation by salticids (jumping spiders) has shaped the morphology and behavior of some tephritid flies. Their wing markings resemble the pattern of the legs of jumping spiders; the flies also wave their wings in a fashion that appears to mimic the agonistic behavior of salticids – making them ‘proverbial sheep in wolf’s clothing.’”

Researchers Greene, Orsak, and Whitman studied a tephritid in a different genus, Zonosemata (https://bugguide.net/node/view/836289/bgimage) and wrote.  “When disturbed, these flies hold their wings perpendicular to the body and wave them up and down; this resembles the agonistic leg-waving behavior typical of the jumping spider.  Zonosemata flies initiate this display when stalked by jumping spiders, causing the spiders to display back and retreat.”

A New York Times article about the study elaborates “These spiders use this aggressive behavior to warn other members of their species to stay out of their territory.

 

When the fly flaps its wings, it fools the spider into thinking it has entered the territory of another spider. As Mr. Greene put it, the fly is sending the counterfeit message ‘’I am a mean jumping spider, so come no closer.’”

For the long version (if you haven’t used up your free NYT reads for the month) see https://www.nytimes.com/1987/04/28/science/fly-mimics-attakcing-spider-to-save-its-skin.html.

A jumping spider may back away from the encounter, but the subterfuge doesn’t work on other predators, even on non-jumping spiders.  The team speculated that even though this behavior hasn’t been observed a lot, it may be more common that we think.

Confession – the BugLady has a bit of trouble seeing a spider in the fly, but if she were ¼” long, it would probably be easier.

Kate Redmond, The BugLady

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

Greetings, BugFans,

Between Christmas and New Year’s Day, it’s all reruns.  Please enjoy this slightly updated episode about a pretty little garden scourge, along with a year-end sermonette. .

This is the story of The Little Beetle That Could, of a half-inch beetle that’s much too good at what it does.  So good, in fact, that it’s on Cooperative Extension Most Wanted Posters across the US, and its emigration to foreign countries was no cause for celebration (but it did inspire some great postage stamps and educational/propaganda posters – scroll through http://www.potatobeetle.org/memorabilia.html).

One source says that the Colorado potato beetle (aka the Potato bug) (Leptinotarsa decemlineata) (“ten lines”) is among the 10 insects that everyone should know.  Gardeners from California through Central America to Florida to Nova Scotia to British Columbia certainly know it – it’s said to make itself at home in more than 3 million square miles of North America (that’s about one-third of the land mass) and close to 2.5 million square miles  of Europe and Asia. 

At the end of a BOTW about the dogbane leaf beetle (August, 2010) the BugLady threw in this “by the way” paragraph about the dogbane beetle’s infamous Chrysomelid leaf beetle relative, the CPB:

“The Colorado Potato beetle’s is an amazing story of a home-grown pest.  A native leaf beetle, its “pre-settlement” range was restricted to the Upper Missouri River Basin (alternate sources place its origins in the Rocky Mountains and/or south of the Rio Grande), where it fed unobtrusively on a few members of the Potato family like buffalo bur, ground cherry, and nightshade, in harmony with its environment.  Wherever it started, it was enough of a presence in Colorado by the mid-1860’s that the state’s name was attached to it.  When the settlers pushed West, bringing their kitchen gardens, they planted “Irish potatoes” (potatoes are native to the Andes and had been brought to the Old World a few centuries earlier, had conquered Europe, had come back across the Atlantic to New England in the 1700’s, and then headed West by wagon train).  The CPB adopted potatoes, and with its food source increasing logarithmically, it left the Plains and headed East in 1854, hop-scotching from garden plot to garden plot and arriving on the Atlantic shore twenty years later, a “reverse pioneer.”  That CPB’s had quietly switched their main host plant to potatoes was noticed when the first CPB outbreak occurred in 1859, about 100 miles west of Omaha.

Both the adults and the larvae feed on the leaves of plants in the potato family, and the people who measure these things tell us that during its entire larval life, a CPB may eat about 6 square inches of leaves, but that an adult can put away 1.5 square inches of leaves daily.  The larvae feed in groups, compounding the destruction.

No BOTW is complete without a vocabulary challenge – the humpbacked CPB larvae/grubs are cyphosomatic – their dorsal and ventral surfaces are decidedly not parallel.

CPBs are in “survival mode” 24/7.  They lay a lot of eggs on the undersides of potato leaves (as many as 800 in a lifetime), and multiple encounters with multiple partners result in lots of genetic diversity.  They grow fast, have several generations per year, and overwinter in the soil as adults so they can come out swinging when the sun warms the earth in spring.  Adults, including gravid females, may move from field to field, so all of their eggs are not in the same basket.  Add to these external/behavioral attributes the CPBs’ enviable ability to develop an inheritable resistance to almost any of the chemicals we’ve thrown at them (possibly because they’ve “practiced” by rendering harmless the naturally occurring toxic glycoalkaloids of their host plants), and you’ve truly got a force to be reckoned with.

CPBs and their eggs and larvae have a number of natural predators including some species of ladybugs, stinkbugs, and ground beetles, and CPB larvae that hatch first may cannibalize the nearby unhatched eggs of their siblings.  Home and organic gardeners can control them by hand-picking the adults, larvae, and eggs, by mulching or row covering, and by removing related weeds that feed spring adults, but our reactions to their presence have typically been chemical.

The BugLady doesn’t work for Cooperative Extension (any more) and she tries not to get embroiled in debates about pest control measures, but she’s weighing in on this one.  In a nutshell, the BugLady doesn’t like “collateral damage.”  The neonicotinoid insecticides (nicotine-like neurotoxins) that have been successful against CPBs and other agricultural pests since the mid-‘90’s (some CPBs, though, are beginning to show resistance to “neo-nics”).  Neonicotinoids have been implicated in Colony Collapse Disorder in bees – the chemicals spread throughout the treated plants, appearing in pollen and other plant parts, and they are transported back to the hive.  They disturb the central nervous system, disorienting homeward bound bees.

They also make bees (wild and domestic, solitary and colonial) more susceptible to lethal fungal and viral infections, and less dramatically, it was recently discovered that exposure to “neo-nics” causes an “insomnia” in honeybees that simply causes them to run out of steam due to sleep loss.  Thirty-five per cent of agricultural crops rely on pollinators, honey bees and native bees alike.  This group of pesticides is also bad for butterfly caterpillars, including Monarchs, and for a variety of native pollinators.

No one can blame farmers for wanting a single product that is effective across the board, and heaven knows we all want to be able to afford to eat, but the complete answer to “How much does it cost?” may take years to calculate.  This is not Either-Or; not Potatoes vs. Butterflies.  Bees are one of the canaries in our mineshaft.  Generalized pesticides kill indiscriminately, randomly lopping off strands of food webs, and that is fundamentally unsustainable.  The result will be an oversimplified world where imbalances favor outbreaks of the pests whose predators perished in the chemical or bacterial barrage, and who then require more chemicals.  And then there’s the domino effect, in which fewer insects means fewer insect-eaters, including birds, bats, spiders, and the BugLady’s beloved dragonflies and more.  A very different world.

The real questions are “Why would we think that we can eliminate organisms, disrupt eons-old connections, and lower biodiversity, and still expect the subtle systems that keep us alive and healthy to keep functioning?”  What can we do about it?

If you shake the tree of BugFans, an awful lot of scientists and educators would fall out.  So, folks, how about it?  In an era where people have drifted pretty far from the natural world, how do we bridge this “disconnect” between our actions and their ecological effects?  How do we educate people about keeping our life-support healthy?

For some great pictures, check the always-excellent University of Florida Entomology and Nematology Department’s Featured Creatures: http://entnemdept.ufl.edu/creatures/veg/leaf/potato_beetles.htm.

Meanwhile, do you want fries with that?

 

Kate Redmond, The BugLady

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