Tag: bug of the week

Bug o’the Week – Tobacco Budworm

Bug o’the Week
by Kate Redmond

Tobacco Budworm

Greetings, BugFans,

The BugLady photographed this handsome moth on her back porch rail last summer, and she was temporarily mystified when she identified it as a Tobacco budworm moth, because the nearest tobacco farm is probably more than 100 miles west of her.  Then she found an alternative common name – the Geranium budworm – and since she is the Geranium Queen, it made more sense (and it explained the frass on the bookshelves).

There are lots of moths that aren’t big enough or bad enough or beautiful enough to have been studied enough.  This isn’t one of them.  It gets University Extension Agents riled up throughout tobacco and cotton-growing areas in the southern half of its range.

Tobacco budworms (Chloridea virescens) (before 2013 they were Heliothis virescens) are native moths in the Owlet moth family Noctuidae.  They’re considered an eastern and southwestern species, but they’ve been spotted in Canada, across the vast majority of the lower 48 plus the Caribbean, and sporadically south of the Rio Grande.  They produce five or six broods annually in the South, but generally just one or two in the North, and they are too tender to overwinter here.  Moths seen in the northern parts of the US in the second half of summer may have overwintered in a greenhouse or a sheltered patio or in a potted plant that was brought inside in fall, or they may have drifted north from the southern part of their range. 

Adults have a wingspread of about one-to one-and-a-half inches and are somewhat variable in color.  Virescens means “being or becoming green” and while some are greenish https://bugguide.net/node/view/662023/bgimage, many Tobacco budworm moths are tan https://bugguide.net/node/view/1440535/bgimage.  The caterpillars’ color is also variable and, as David Wagner says in Caterpillars of Eastern North America, “Somehow the larvae end up matching the color of their foodplant.  The caterpillars found on red geraniums are shades of pink, those on ground cherry yellow, and so on.”  https://bugguide.net/node/view/1735907/bgimage (pink flowers make pink frass https://bugguide.net/node/view/32268/bgimage), https://bugguide.net/node/view/899588/bgimage, https://bugguide.net/node/view/36749/bgimage.   

The first generation of larvae chew deeply into buds (scroll down https://extension.umn.edu/yard-and-garden-insects/tobacco-budworms) and the later broods feed on the flowers and seeds.  They prefer the reproductive tissues, but they’ll also eat leaves, leaf petioles and even stems, and the later generations cause the most damage to plants.  No picky eaters here – these are generalist feeders!  They especially like tobacco and cotton, but they eat other agricultural crops like soybeans, flax, squash, tomato, peanuts, peppers, lettuce, and alfalfa and other clovers,.  Garden flowers like roses, geraniums, morning glory, petunias, nicotiana, chrysanthemums, marigolds, snapdragons, zinnias, and verbenas are on the menu, and, as the bulletins say, so are “weeds” like beardtongue, cranesbill/wild geranium, dock, lupine, passion flower, ground cherry, and more (“weeds” – so judgy).  They’re not considered a pest here in God’s Country.     

They are eaten by a variety of insects and spiders, but where some of their predators are concerned, the caterpillars seem to have Super Powers.  According to Wikipedia, if a parasitic wasp named Cardiochiles nigripes approaches a caterpillar with the intention of laying an egg on it, a fluid oozes from the caterpillar’s pores “that causes C. nigriceps to become agitated and groom themselves, allowing the budworm to escape. C. nigriceps also avoid budworms painted with this exudate. It is hypothesized that this exudate may function by overloading the wasp’s sensory receptors.”  The tachinid fly Winthemia rufopicta may be successful at laying eggs on the exterior of a tobacco budworm caterpillar, “but upon hatching and trying to penetrate its host, the caterpillars react by biting, crushing, puncturing, or trying to eat the parasitoid eggs.  This kills off many of the maggots” (Wikipedia).  Plus (says Wagner) “My colleague Scott Smedley and his students recently discovered that the caterpillars manage to transfer the glandular defensive secretions of their foodplants onto their own setae [hairs], and in doing so accrue chemical protection from ants and other natural enemies.”

They court with pheromones – she releases chemicals (perfumes) into the air, but she will not produce them unless she has been in contact with a potential host plant, and a place to lay her eggs is assured.  He reads her signals with receptors on his antennae and responds, and when she picks up his signal, she stops producing hers.  Males court with pheromones produced by glands in structures called hair pencils, which pop out of their abdomen.  The chemicals he produces are “twofers” – they send a “back-off” message to other males, and a “come hither” message to females.  If she approves of his scent, it’s “game on.”  The odor has both a stimulating and tranquilizing effect on her. 

She lays her eggs https://bugguide.net/node/view/699644/bgimage (usually 300 to 500 of them, but as many as 1,500) on buds, blossoms and leaves in the upper parts of plants.  Research suggests that she picks as a host the same species of plant that she grew up on.  The larvae hatch and, if they’re not already there, head for the tips of the plant.  Larvae grow faster at warmer temperatures, and when they are mature, they pupate a few inches under the soil https://bugguide.net/node/view/587565/bgimage. 

Two big photo references – one to Wisconsin moths https://www.butterflyidentification.org/moths-by-state-listing.php?reach=Wisconsin, and the other a giant collection of caterpillar pictures by wildlife photographer Tom Murray (Wisconsin shares many moth species with New York) https://pbase.com/tmurray74/moth_caterpillars.

Kate Redmond, The BugLady

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

Bug o’the Week – Cylapus tenuicornis Plant Bug

Bug o’the Week
by Kate Redmond

Cylapus tenuicornis Plant Bug

Howdy, BugFans,

One day last August, the BugLady pulled her mail out of her mailbox and saw this little bug sitting on a newspaper, and she managed to take a few shots of it with her purse camera before it departed.  She had never seen it before, but its gestalt reminded her of the (unrelated) Japanese barklice https://bugguide.net/node/view/296617/bgimage that she once encountered in southern Ohio, and of the (related) Clouded plant bugs she’s photographed locally https://bugguide.net/node/view/950344.  If BOTW had an “Obscure (but Cute) Insects” category (and many BugFans might argue that it already does), this bug would be right at home there.

When she is researching these anonymous insects, the BugLady starts with the species, and if information is thin on the ground, she backs up to genus, and then maybe backs up even farther, to tribe or subfamily or family.  And so it was for Cylapus tenuicornis (no common name).

So – from the top – moving from the most general to the most specific classification:

Cylapus tenuicornis is in the True Bug order Hemiptera (110,000 species known worldwide out of an estimated total of 200,000, with 2,000 in North America).  Hemipterans have piercing-sucking mouthparts that most apply to plants, but there are some carnivores and blood suckers in the bunch.  

It’s in the large and diverse Plant bug/Leaf bug/Grass bug/Jumping tree bug family Miridae (11,000 known species with many more awaiting names and descriptions).  Most Mirids are small (under ½”), soft-bodied, and inconspicuous, except when they are being pests of agricultural crops.  Most are plant feeders – some are generalist feeders, and some target specific plants.  Females use their sharp ovipositor to cut slits in plants and deposit eggs.   

According to the Plant Bug Planetary Biodiversity Inventory at the University of New South Wales (the BugLady sometimes goes far afield for information), “Many lineages are strongly myrmecomorphic [ant-shaped] although the nature of their associations with ants are still not well understood.” https://bugguide.net/node/view/1047082/bgimage, https://bugguide.net/node/view/1299663/bgimage, https://bugguide.net/node/view/15814/bgimage.    

Another step down – they’re in the largely subtropical/tropical subfamily Cylapinae (500 species), which researchers seem to agree is an understudied group that’s probably due for some taxonomic wrangling.  Cylapines are hard to study (or even to collect) because they mostly live in leaf litter and in bark crevices and are hard to spot and pretty speedy.  Cool thing about the Cylapinae is the fact that “Bugs in this group tend to forage actively on fungus covered rotten logs in humid tropical forests.” (Wikipedia).  More about that in a sec.  

And down another step – there are 12 species in the genus Cylapus, but only one lives in North America.  It’s a Neotropical genus (found in the New World tropics, from Central America and the Caribbean, south).  They are diurnal (out and about in the daytime).  

Whew!  Finally! 

Cylapus tenuicornis is at home in eastern North America https://bugguide.net/node/view/40769/data.  They’re about a fourth of an inch long, “bug-eyed,” with long antennae.  Here’s what they look like when they’re not sitting on the Ozaukee Press: https://www.marylandbiodiversity.com/view/19791

One question that the BugLady always asks about her subjects is “What do they eat?”  And for this, we have to go back up to the subfamily.  Among the people who study the Cylapinae there’s a fair amount of discussion about their menu.  Remember – these bugs are typically seen on/under bark/leaf litter and on rotting logs in association with fungi.  There’s been speculation that some are predators (though long legs and antennae aren’t good adaptations for chasing prey under tree bark), but a subfamily member with the awesome name of Fulvius imbecilis has been reported as preying on the larvae of small beetles and flies and assorted other invertebrates that they find under bark and in certain fungi.

But there has long been a suspicion that some species feed on specific fungi, an unusual preference among the Hemiptera.  In lab experiments, Cylapus tenuicornis probed in the crevices of the fungi and underlying bark, and nymphs of two South American species mature within fungi.  Some Cylapinae were eventually seen eating fungi, but researchers investigated to make sure that the bugs were eating fungi rather than eating bugs that were eating fungi.  In this case, “investigate” meant catching some of them (no mean trick) and dissecting them to see if they had fungal materials in their guts.  Some did, and in amounts that indicate direct feeding.  

Lots of mysteries out there!  YAY!

Kate Redmond, The BugLady

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

Bug o’the Week – Burrowing Wolf Spider

Bug o’the Week
by Kate Redmond

Burrowing Wolf Spider

Greetings, BugFans,

One afternoon in late June as the BugLady was walking along the cordwalk at Kohler-Andrae State Park, she noticed a few half-inch-ish holes in the sand, holes that had more “structure” than the ones she makes with her walking stick, and larger than those made by solitary wasps.  She took a couple of throwaway shots and was very surprised when she put one up on the monitor and noticed eyes and legs!  She photographed more holes on subsequent trips, but their openings were unoccupied.  The cordwalk goes over both dunes with loose sand, and areas with low vegetation and a somewhat more organic soil.  The holes were in the loose sand.

She asked BugFan Mike if it might be a wolf spider called the Burrowing Wolf Spider (Geolycosa missouriensis).  He said that was a possibility and urged her (as always) to be conservative in her spider IDs, especially considering the quality of the picture.  Amen, Mike!

Wolf spiders (family Lycosidae) (lycosa is Greek for “wolf”) are common, hairy, nocturnal, ground-dwelling hunters with very good eyesight.  Most species of wolf spider do not spin trap webs. 

[Quick Detour: nowadays, we use the name “tarantula” to refer to a group of non-Lycosid, palm-sized, hairy, tropical spiders https://bugguide.net/node/view/289856/bgimage.  The BugLady’s 4th grade teacher told a story of being in basic training in California and digging foxholes that bisected tarantula borrows, which she thought was pretty cool (she doesn’t remember much else of 4th grade).  Anyway, the original tarantula is a southern European/Italian wolf spider.  Legend had it that if one bites you, you‘re doomed to dance a dance called the tarantella.  The BugLady assumes that when they saw the big hairy spiders, those settlers from the Old Country applied the name of a scary spider that they already knew about.  And in fact, a number of other groups of large spiders have been called tarantulas, too].

Wolf spiders in the genus Geolycosa are called the Burrowing wolf spiders (geo means “earth”).  They live in vertical burrows, and they are habitat specialists, preferring loose, sandy soil that makes digging easier.  Of the 75 species in the genus worldwide, 18 live in North America north of the Rio Grande.  They have strong legs and (short spider anatomy review, here) two strong chelicerae (jaws) that are used as pincers and that are tipped with fangs.  A pair of palps, which look like a short leg on each side of the chelicerae, are used to manipulate food https://keys.lucidcentral.org/keys/mites/ismite/html/a10h_Mouthparts.html. 

Burrowing wolf spiders are generally Stay-at-Homes – the spiderlings don’t scatter far from the maternal burrow.  They initiate their own lair when they’re very small, enlarging it as they grow, rarely straying more than an inch or so away from it, and retreating into it when alarmed.  Populations remain fairly restricted. 

They are tied to one spot, with fixed pools of prey and of potential mates, but the trade-off is an absence of Flying Monkeys. They can dodge predators and avoid desiccation within a relatively stable, climate-controlled tunnel.  In early fall, though, when a young spider’s fancy turn to love, he abandons that security and sets off in search of romance.  They mate in late summer, but the gravid female doesn’t make an egg sac until the next spring.  She displays maternal care – carrying around first her egg sac, and later her young https://bugguide.net/node/view/114423/bgimage (and not eating them).  Spiderlings hatch in early summer, overwinter as immature spiders in their first year, and become adults in late summer of their second year.

Gratuitous vocabulary word(s) of the day: some Geolycosa species are “turricolous” (they live in areas that have some leaf litter, and they create little turrets or lips made of debris, sand, and silk around the opening of the tunnel https://bugguide.net/node/view/912651/bgimage), and others are “aturricolous” (they don’t). 

Bracing itself within the tunnel with its legs, the spider uses its fangs to loosen the sand, and if the sand is not moist enough on its own, it uses silk to compact the sand into a pellet.  It uses its chelicerae and palps to move the pellet to the opening of the burrow, and it disposes of the pellet by flicking it away (sometimes a foot away) with its forelegs – unless it’s going to use it to build a turret.  Burrowing wolf spiders reinforce the upper section of their lair by covering the walls with a few layers of silk.  Summer burrows are less than a foot long, but winter burrows may be more than five feet deep.  Researchers who studied Geolycosa missouriensis noted that a spider excavating an average burrow removed 918 sand pellets. 

Larry Weber, in Spiders of the North Woods, says that if you stick a grass stem down an occupied Geolycosa missouriensis burrow, the spider will grab it and hang on, and you can dig out the entrance and see the spider.  Seriously, Larry?  All that work – 918 pellets – why would you?

They ambush their prey – lurking in the entryway and darting out to grab nocturnal invertebrates like crickets as they wander by.  They feed within, and the indigestible bits of prey fall to the end of the tunnel.  About the Geolycosa, the publication “The Insects and Arachnids of Canada, Part 17,” notes that when kept in captivity, “They should be individually caged because they are fierce predators, and cannibalism can soon reduce the culture to a single well-fed individual.”

So – who was in that burrow?  Here are a few possibilities.

A BURROWING WOLF SPIDER (Geolycosa missouriensis), aka the Missouri Earth Spider or the Missouri Wolf Spider, is found on sandy loam soils from Texas to Ontario and Saskatchewan https://bugguide.net/node/view/862935/bgimage.  Its leg-spread is around 1 ½”. 

The gravid female uses sand and silk to fashion a door for the tunnel in winter.  She will bring her egg case into the sun at the burrow opening on warm, spring days, and females can be found in their burrows carrying young on their back in early summer.  Sources are ambivalent about whether Geolycosa missouriensis makes turrets.  

GEOLYCOSA WRIGHTII (no common name) https://bugguide.net/node/view/1285635/bgimage.  It’s not as common, and its range is restricted to sand dunes and beaches from Indiana and Illinois north through the Western Great Lakes states and provinces.  Females protect their newly-hatched offspring by sealing themselves into the tunnel with their young for a few days, until they find their feet.  Geolycosa wrightii doesn’t make a turret. 

The BEACH WOLF SPIDER (Arctosa littoralis https://bugguide.net/node/view/771440/bgimage) also makes silk-lined tunnels, but unlike the Geolycosa, it hunts at night by chasing after prey on beaches and wetland banks, and shelters in tunnels or under driftwood in the day.  Entomologist Eric Eaton says that if you’re abroad on the beach at night, wearing a headlamp, “When the beam of the light hits a wolf spider, the animal’s eyes will glint a blueish-green shine…..and a female with young on her back looks like a diamond-studded stone.” 

Kate Redmond, The BugLady

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

Bug o’the Week – And Now for Something Different – Cattails

Bug o’the Week
by Kate Redmond

And Now for Something Different Cattails

 Howdy, BugFans,

This episode was adapted from an article that the BugLady wrote in 2007 for the BogHaunter, the newsletter of the Friends of the Cedarburg Bog.

Wanted: Colonists to settle in wide open spaces.  Must be adaptable, able to put down roots in submerged or soggy soil, and stand firm in the face of wind and waves, rodents and carp. Temporary accommodations only.

It turns out that cattails are ideal candidates for this not-so-attractive job description.  Their tall, strap-like leaves and conspicuous “wiener-on-a-stick” female flower and seed stalks emerge from standing water and from damp pond and stream edges.  The leaves’ slender shape is typical of “sun-catchers” in open spaces.  They are designed to bend without breaking via a series of internal veins or “struts” that divide the leaf’s interior into flexible cells.

But the infrastructure of a cattail marsh is as impressive as what appears above the waterline.  That mass of leaves is anchored by a dense, interlocking mat of rhizomes (a rhizome is an underground/underwater stem that puts out both shoots and roots).  Each fruiting plant may produce as many as 200,000 seeds called “nutlets” – this windborne fruit launches colonies, and seeds can sit in the seedbank for decades waiting for the right conditions to germinate.  Though a new plant doesn’t flower until its second summer, it develops, during its first year of life, a rhizome system that may span 10 feet in diameter and produce 100 shoots.  This botanical exuberance allows colonies to advance, like an amoeba, as much as 15 feet annually.  

Once a colony gets started, it spreads primarily by vegetative means, through the growth of the rhizomes.  Plants that sprout from the same rhizome are called clones; a dense cattail stand is an impossibly intricate interweaving of clones from many rhizomes, so crowded that there is no opportunity for its own seed to germinate.  Unless openings occur between the closely-packed cattails, there are few other large plants in the community.

But, what a cattail marsh may lack in plant diversity, it more than makes up for in animals.  Oxygen is added to the water during photosynthesis, and the forest of submerged stems is habitat for myriad aquatic critters.  Carp root at the rhizomes, breaking them up and aiding vegetative spread.  Other fish, including sunfish, spawn and shelter there.

Muskrat lifestyles are bound to cattails; the shoots and rhizomes are eaten, and the leaves and stalks are made into lodges.  These lodges, in turn, provide nest platforms for ducks and geese; and, by harvesting cattails, muskrats create open water for waterfowl.  Many marshland birds like rails, coots, bitterns, grebes, Marsh Wrens, and waterfowl find food, nesting material, nest sites, and cover in the cattail thickets.  Large flocks of blackbirds roost there and enrich the community with their droppings, and cattails are also used by frogs, beavers, painted turtles, and even moose. 

Insects?  Cattails attract a variety of moths, aphids, and caterpillars that feed on its rhizomes, leaves, sap, stem, and flower/seed spike, and their predators are attracted as well.  The female sac spider bends a leaf around herself to form a pyramid-shaped box.  Inside, she lays eggs and guards them there until she dies; her carcass provides her young with their first meal.  In winter, the cigar-like seed heads host the pupating caterpillars (birds pecking at seed heads are looking for this protein); the stalk is home to a variety of beetles, and the rhizomes conceal the larvae of cattail mosquitoes.

Common or Broad-leaved (Typha latifolia) grows on the damp soil and shallow standing water by a pond’s edge.  It is less tolerant of pollution but is found in a wider range of soil acidity.  Its base is fan-shaped, and the male and female flowers touch.  Narrow-leaved cattail (T. angustifolia), which may have come from Europe in the 1800’s) can grow in deeper, more polluted water, and prefers more alkaline locations.  Its base is cylindrical, its leaves narrower, and there is bare stem between the male and female flowers.  The two species grow side-by-side, and they hybridize, and both the Narrow-leaved and the hybrid can out-compete the Broad-leaved cattail. 

If cattails are community builders, cattail marshes are communities in transition.  They generally grow with land on one side and open water on the other, and their decomposing vegetation makes soil (the take-home – every lake is a dying lake), readying the marsh for eventual colonization by plants with dryer preferences.  As the land encroaches, cattails move farther out into the wetland.  Wetlands are among the most productive ecosystems in the world, rivaling tropical rainforests in their production of biomass (biomass is the measurement of the weight or volume of biological material produced in an area). For more information about wetland issues, visit the website of the Wisconsin Wetlands Association at www.wisconsinwetlands.org.

Are cattails good for anything?  The BugLady once read that wars were fought over wetlands, and cattails are certainly worth fighting for!  Some part of the plant is edible 12 months of the year, from the starchy rhizome (cooked like potatoes or pounded into flour) to the pollen (a flour substitute) – one report says that an acre of cattails could produce almost 6500 pounds of cattail flour.  Both the rhizomes and flower heads were used medicinally.

American Indians wove the leaves into mats, baskets, and walls, used the fluff for diapers (the settlers stuffed quilts with it and caned chairs with the leaves).  A jelly that was made by pounding the rhizome was used to seal leaky boats.  Today, research suggests that the food value of cattails approaches that of corn and rice.  Quikrete users please note – a mixture of cattail seeds, ash, and lime sets up harder than marble.

So, if the wildlife likes it, what’s the problem?  As one researcher said, narrow-leaved cattail can be beneficial to a wetland community “in limited quantities.”  Broad-leaved cattails form dense stands, but there are breaks in the stands where other vegetation can grow and open water can be found.  Narrow-leaved cattail crowds out native vegetation by forming impenetrable monocultures, and monocultures reduce food sources and don’t support a very diverse array of wildlife. 

On the up-side, cattails keep pond edges from eroding (while it’s eating the pond).

The BugLady once worked at a Nature Center where thinning the cattails in a small pond by the Education building was an annual task.  Here’s what she learned: when you pull on cattails, they pull back.

Kate Redmond, The BugLady

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

Bug o’the Week – Northern Two-striped Walkingstick – a Snowbird Special

Bug o’the Week
by Kate Redmond

Northern Two-striped Walkingstick a Snowbird Special

Howdy, BugFans,

In the recent episode about Saddleback caterpillars, the BugLady mentioned that she (rightly or wrongly) associates the South with a larger number of plants and animals that sting, bite, itch, poison, stab, spray, and spit (sorry, folks).  Here’s another one.

First of all, we’re not talking about the svelte Northern Walkingstick that graces our landscapes here in God’s Country (https://bugguide.net/node/view/2219691/bgimage).  The order Phasmida (aka the order Phasmatodea or Phasmatoptera) contains five walkingstick/stick insect families in North America (“Phasma” means phantom or spirit).  Northern Walkingsticks are in the family Diapheromeridae, and Northern Two-striped Walkingsticks are in the Striped Walkingstick family Pseudophasmatidae.

Thank You, BugFan Joe, for sending pictures from the Deep South and for submitting them to bugguide.net for a species ID.  Here’s what the expert at bugguide said, “The taxonomy of this genus needs to be worked out, but I would lean on these being ferruginea. True A. buprestoides [the Southern Two-striped Walkingstick (STSW)] is supposed to be mostly restricted to Florida and extreme southern GA and AL, and is supposed to have the dorsal stripe much more distinct. But better to leave at genus level for now.”  Our knowledge of the lifestyles of the two species has some gaps in it, but they seem to operate similarly.

Anisomorpha means “unequal form,” and the BugLady guesses that refers to the size difference between males and females.  There are four species in this New World genus – two north of Mexico – and (like the Saddleback caterpillar) they are famous/notorious for their chemical defense system. 

So – the Northern Two-Striped Walkingstick (Anisomorpha ferruginea) (probably) (ferruginea means “rust-colored”).  Like many odd-looking critters, it has amassed a bunch of common and regional names – Prairie Alligator, Musk Mare (she’s a Musk Mare; he’s a Musk Stallion), Western Two stripe, Witch’s Horse, Devil’s Darning Needle (dragonflies are given that nickname, too), Witch’s Hose, Stick Bug, Spitting Devil, Devil Rider, and even Scorpion.  The names come from its appearance, from its defense strategy, and/or from the piggyback habits of the male (she does not carry her young on her back like a loon or opossum or wolf spider). 

NTSWs are found from South Carolina to Alabama, through Texas and Oklahoma, plus Illinois; there are Florida records of NTSWs, but nymphs of the NTSW and the STSW are pretty hard to tell apart (adults can be, too), so those records are considered a little iffy.  Females are chunky, tan/brown/rust, and about 2 ½” to 3” long, not counting the antennae, and males are about 1 ½” long.  NTSWs have straighter, slimmer legs than STSWs, and STSWs are a little larger, come in three color morphs, and (often) have more distinctive stripes (https://bugguide.net/node/view/1767787/bgimage).  Insects’ legs (and wings) are attached to the thorax, and in aid of their twiggy disguise, the walkingsticks’ extra-long thorax allows their legs to be spaced out along its length.  Many, but not all, species are wingless. 

They graze on leaves at night, and they seem to be fond of members of the oak family, but not exclusively.  One source said that when numerous, they can damage/defoliate shrubs; one said that they don’t do significant damage; and the Missouri Department of Conservation Field Guide says (rather optimistically) that “Musk mares help to limit the growth of vegetation. Over time, they help develop vigorous strains of plants that are least hindered by their leaf chomping.”

Some birds, reptiles, mice, ants, and spiders may be discouraged by their chemical assaults, but not all of them, and their eggs are eaten on the forest floor. 

They spend the winter – sometimes two winters – as eggs.  Our Northern Walkingstick drops her eggs carelessly from the treetops, the NTSW deposits them into bark crevices or onto the ground, tucked into leaf litter, and the STSW digs little holes for them.  They hatch and the nymphs feed, mostly unnoticed, until they mature in fall and gather in open areas or on buildings or tree bark https://bugguide.net/node/view/74303/bgimage.  Mating can last from several days to several weeks (and they’re probably monogamous), but the male continues to ride piggyback after his reproductive duties are done.  It has been suggested that the arrangement serves both of them because two sets of eyes looking for predators are better than one. 

They protect themselves with a musky, milky, irritating chemical (anisomorphal) that they produce and spray as a fine mist from a pair of glands in the thorax, just behind the head.  They spray with amazing accuracy – they aim for your eyes, and they can project the spray at least a foot.  They have the ability to spray from the moment they break out of the egg. 

What does it feel like?  According to the Texas Entomology website, “The first account of A. buprestoides’ effect on humans was apparently by Stewart (1937), who wrote about an incident in Texas: ‘The victim was observing a pair of Anisomorpha buprestoides …. with his face within two feet of the insects, when he received the discharge in his left eye …. The pain in his left eye was immediately excruciating; being reported to be as severe as if it had been caused by molten lead. Quick, thorough drenching with cool water allayed the burning agony to a dull aching pain. The pain eased considerably within the course of a few hours. Upon awakening the next morning the entire cornea was almost a brilliant scarlet in color and the eye was so sensitive to light and pressure for the next forty-eight hours that the patient was incapacitated for work. Vision was impaired for about five days.’ (Thomas 2003).”  Inhaling the chemical is unpleasant, too. 

The late, great entomologist Thomas Eisner noted that the STSW “is the source of one of the most noxious defensive secretions known to be produced by an insect.”  He prodded and pinched them in the lab and reported that it didn’t take much hassling for the STSW to react, that the insect could activate one or both glands, and that it could direct the spray precisely at the probe that poked it.  The sight of a bird closer than eight inches away caused an STSW to spray without waiting for the bird to touch it, but the walkingstick did not react to a waving bundle of feathers or colored cloth.  Eisner wrote, “The insect is obviously programmed not to waste its secretion by being unduly ‘trigger happy.’”  Some mammals simply outlast the STSW, waiting until it has sprayed about five times and its reservoir is empty (it takes a week or two to generate enough spray to refill a reservoir); a few test rats simply got used to the spray and ate the walkingsticks; and STSWs have been found in bear scat.   

About anisomorphal Eisner said that “Anisomorphal is also produced by a mint plant, in which the compound is sealed within tiny capsules embedded in the leaf tissue.  The capsules are designed to rupture and release their repellent contents when herbivores bite into the leaves.”

Admire these guys from afar – or wear safety glasses!

Kate Redmond, The BugLady

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

Bug o’the Week – Bugs in the News XIII

Bug o’the Week
by Kate Redmond

Bugs in the News XIII

Howdy, BugFans,

The BugLady’s “newspaper clippings” file runneth over, so here are a few articles for you to peruse.  Please note that most come from the excellent Smithsonian daily e-newsletter, which is not only free (though a donation is always appreciated), but there’s no pay wall.  The newsletter includes articles about current discoveries, archaeology, history, insects, birds and mammals, oceans, etc.

THE BUGLADY KNOWS that she’s preaching to the choir, here – not to the folks who say “Fewer bugs?  That’s great!”  Anyone who likes to eat, who likes birds (and dragonflies!), and who appreciates our natural communities and ecosystems should be a fan of insects and other “bugs” and should be concerned about their diminishing populations https://theconversation.com/climate-change-triggering-global-collapse-in-insect-numbers-stressed-farmland-shows-63-decline-new-research-170738?fbclid=IwAR1etZiZaYH2Athk7nF-jYweC1CCo_C3OJTy2z5x5SH5wmSSIsMMJyvDp7Y

IN A RELATED VEIN – https://www.smithsonianmag.com/smart-news/toxic-pesticides-are-driving-us-insect-apocalypse-study-warns-180972839/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=20190807-daily-responsive&spMailingID=40375121&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=1580649837&spReportId=MTU4MDY0OTgzNwS2.

ALGORITHMS ARE EVERYWHERE.  Recipes are algorithms (“an algorithm is a finite set of instructions carried out in a specific order to perform a particular task.” Or solve a mathematical computation). Social media relies on algorithms to feed you content.  Now it turns out that even bees have algorithms https://www.smithsonianmag.com/smart-news/stingless-bees-build-spiral-honeycombs-grow-crystals-180975405/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=editorial&spMailingID=48505790&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2501713426&spReportId=MjUwMTcxMzQyNgS2.  

ONE MEASUREMENT that the BugLady has always used to gauge insect numbers is the flurry of bugs around the porch light at night.  Biographies of many insects, especially of moths, note whether they are attracted to light or not.  Scientists are figuring out what’s really happening (nice videos, too) https://www.smithsonianmag.com/smart-news/why-are-flying-insects-attracted-to-lights-scientists-may-finally-have-an-answer-180983704/?utm_source=smithsonian-daily&utm_medium=email&utm_campaign=editorial&spMailingID=49392239&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2640113033&spReportId=MjY0MDExMzAzMwS2.

WE JUMP IN LAKE MICHIGAN on January 1 (well, some of us do) (but not the BugLady); Cordova, Alaska has an Ice Worm Festival.  Whatever gets you through the winter.  Supposedly, cold-blooded critters don’t do so well when temperatures get below about 40 degrees (warm-blooded animals use part of their daily energy/food budget to maintain a core heat, but cold-blooded animals are at the mercy of the ambient temperature).  Ice worms have a couple of tricks up their sleeves.  https://www.smithsonianmag.com/travel/this-eight-day-festival-celebrates-one-of-alaskas-weirdest-worms-180983711/?utm_source=smithsonian-daily&utm_medium=email&utm_campaign=editorial&spMailingID=49392239&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2640113033&spReportId=MjY0MDExMzAzMwS2. 

Alas – we’ve just missed this year’s festival https://www.icewormfestival.com/, but it’s not too early to start planning for 2025.  

MONARCH WINGS – Life is Physics! – https://www.smithsonianmag.com/smart-news/monarch-butterflies-signature-white-spots-may-help-them-fly-180982418/

IN THE “ALWAYS-TASTEFUL” CATEGORY: years ago, a colleague of the BugLady’s husband asked if mice pee.  Her husband knew that if he said yes, the man was going to go home and empty the cupboards and sterilize everything.  So he said “No, the liquid is included in the mouse poop.”  Do insects pee?  Many don’t, and “peeing” isn’t exactly the right name for it because they don’t have a separate exit just for liquids.  Insects have structures (OK – Malpighian tubules) that collect liquid waste (uric acid and ammonia) and deposit it in the hind gut.  Terrestrial insects need to conserve water, so they reabsorb usable liquids from the hind gut and the rest gets mixed with the digestive wastes and excreted (“just like mice….”) (aquatic insects are constantly excreting liquid to keep from getting waterlogged). 

But – insects that suck sap have a different challenge.  Sap contains sugar in very small concentrations, so plant juice feeders have to take in a lot of liquid (about 300 times their body weight daily) in order to get enough calories, and it comes out under pressure.  Excess fluid abounds. How do they handle it?  https://www.smithsonianmag.com/smart-news/these-tiny-bugs-urinate-by-flinging-droplets-of-pee-180981720/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=editorial&spMailingID=48042798&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2420130861&spReportId=MjQyMDEzMDg2MQS2.

FINALLY – in the “Better Late than Never” category – the BugLady posted an episode about caddisflies last week, and today BugFan Steve sent this great video of a stream-dwelling caddis fly building a case https://www.youtube.com/watch?v=Z3BHrzDHoYo.

The groundhog did not see its shadow.  The way the BugLady learned it, if he sees his shadow, there are six more weeks of winter, and if he doesn’t, there’s a month and a half until spring (and insects).  

Kate Redmond, The BugLady

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

Bug o’the Week – Caddisfly revisited

Bug o’the Week
by Kate Redmond

Caddisfly revisited

Greetings, BugFans,

The BugLady is suffering from the February Doldrums in January – this is a massaged version of a BOTW that was originally posted in 2009, with some new words and new pictures.

“What’s in a name?  A rose by any other name would smell as sweet.”  What indeed?  The BugLady will get back to that.

Caddisflies, in the Order Trichoptera (“hairy wings”), are famous for the cases built for protection by their soft-bodied larvae (the only natural “armor” they possess is located on their head, thorax and legs) and for the larvae’s ability to produce silk thread via a silk gland in their lower lip.  They use silk to “glue” materials together to construct the case, to net some food, and to modify the case before they pupate.

Caddisfly larvae live in both running and still water; in fact, according to Elsie Klots in The New Fieldbook of Freshwater Life, they are one of four orders of insects that “have become almost wholly aquatic during their immature life.”  The larvae of one European species live in wet moss, and the larvae of another, called the Land Caddisfly (Enoicyla pusilla), are terrestrial, but they still make cases out of materials they find in the leaf litter where they live.  Female Land Caddisflies are wingless.

Many of the pond dwellers cut and assemble small bits of vegetation into portable homes.  Some “homes” are thin tubes, some get glued together “the long way,” and some resemble Lincoln-log-like chimneys made of mini-twigs, sedges or cattails custom-trimmed by the larva.  In streams or rivers, where staying in one place is a challenge, the larvae use heavier building materials like tiny pieces of gravel, or they spin a net that they glue onto a rock or into a crevice.  Unlike turtles, whose shell and body are joined, caddisflies can leave their case of sticks or stones.  Naked – deprived of their homes – they look like little wet caterpillars (to whom they are not-so-distantly related). 

Cases are open at both ends, to facilitate oxygen circulation, and in very still water, the larvae must be more active in order to make up for the lack of a current.  Caddisfly larvae are so specific about their choices of building materials that they can be classified down to family and sometimes genus, by the structure of their shelter.

The caddisflies, also called sedge-flies and rail-flies (and “fish food”), are a big order, with more than 15,000 species worldwide.  North America boasts around 1,500 species of Tri-cops (as they are known familiarly), and not surprisingly for such a large group, their larvae indulge in a wide variety of feeding methods.  There are predators and scavengers.  There are “shredders” that perform the valuable service of turning big pieces of vegetation into little ones, thereby setting the table for even smaller organisms.  Some net-spinners are “collectors” that let the current deliver their meals (bits of organic material) “carry-out” (some net-spinners can produce a sound by rubbing a front leg against the underside of their head).  Finally, there are “scrapers,” grazing on algae and other tiny organic particles stuck to underwater surfaces.  As adults, with mouthparts that are described as “sponge like,” they ingest only liquids, and many species don’t feed as adults.

Adult caddisflies resemble slim, very long-antennaed moths; they tent their wings above their abdomens (making them look triangular from the rear), and their wings are covered with tiny hairs.  Females of some species actually climb under water to lay their eggs, protected from getting soaked by a thin layer of air trapped in that dense covering of hairs.  According to Eaton and Kaufman in the Field Guide to Insects of North America, fly-tiers (or tie-flyers) work hard to replicate caddisflies with their lures.  Exceptionally sensitive to pollution, the presence of caddisflies signals good water quality.  And, with a little luck, trout. 

Once, when the BugLady gave a presentation about Pond Life to third graders, a child asked where the caddisfly got its name.  The BugLady did not know, but she loves to research the etymology of entomology, so she promised to find out, and here is what she discovered.  Back in the days of the first Queen Elizabeth (when Romeo and Juliet were obsessing about names) (and in the midst of the Little Ice Age – fascinating – look it up), itinerant peddlers roamed the world.  Those who sold ribbons, threads and yarns were called “Cadice-men” after “cadaz/caddis/caddice” – words that had come to refer to worsted yarn.  Cadice-men displayed their wares by attaching samples of threads and yarns to their coats.  In his wonderful A Guide to Common Freshwater Invertebrates of North America, J. Reese Voshell, Jr. says that the larva’s ability to glue pieces of material together to make its case was reminiscent of how a Cadice-man covered his jacket with pieces of textile.  Alternatively, it may refer to the fringe on the adults’ wings.  Was the person who named caddisflies, like the BugLady, a bug-loving history-geek?

If you search online, you can find jewelry made out of caddisfly cases – entrepreneurs supply caddisfly larvae with a variety of bling, and the larvae incorporate it into their cases. 

Kate Redmond, The BugLady

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

Bug o’the Week – Cereal bug

Bug o’the Week
by Kate Redmond

Cereal bug

Greetings, BugFans,

The BugLady loves finding an insect she’s never seen before.  When she saw it walking along a cordwalk (boardwalk on sand) in the dunes at Kohler-Andrae State Park, she knew that this guy/gal was in the stink bug family (Pentatomidae), but it’s more spindle-shaped and lacks the “shoulder pads” of a generic stink bug https://bugguide.net/node/view/2125170/bgpage (younger BugFans may have to Google “shoulder pads”).

It turned out to be a stink bug in the large subfamily Pentatominae and in the very small tribe Aeliini, which has only 37 species worldwide.  There are 8 species in the tribe in North America (in two genera), and this is the only species in its genus here.  The BugLady borrowed the name “Cereal bug” from one of the European species because she couldn’t find a common name for it.

Cereal bugs (Aelia americana) have an odd, patchwork range (based on pictures submitted by bugguide members https://bugguide.net/node/view/668478/data) that lies mostly west of the Mississippi – from British Columbia to Arizona to Alabama to Michigan, and within their range, they’re not very common.   

They feed by day on the ripening seeds of grasses, including agricultural crops like wheat, barley, and rye (https://bugguide.net/node/view/2241245/bgimage).  The BugLady found some brief write-ups about them from grain-producing areas of the upper Great Plains into Canada, but they’re not common enough to be a nuisance here.  Like other Hemipterans, they insert their beak into the plant, pump in some digestive juices, and suck out the softened tissue.     

Eggs are laid in late spring and early summer, and the nymphs reach maturity by fall and overwinter as adults.

[In the “Eternal Job Security” category that is insect taxonomy, the BugLady found a paper titled “Opening Pandora’s box: molecular phylogeny of the stink bugs (Hemiptera: Heteroptera: Pentatomidae) reveals great incongruences in the current classification.”  It reminded her of a quote she found years ago when she was writing about a moth, “The genus Haploa …… has furnished a great deal of amusement to classificationists.”  Presumably, the Hemiptera taxonomists are similarly amused.]  

Along with grasses, they have been collected from apple trees in orchards, and according to a paper published by the Michigan Entomological Society, adults have been found overwintering in grass clumps and under mullein leaves. 

Some genus members are considered pests in the Middle East and around the Mediterranean, though, and the BugLady found a lot more information about a closely-related-and-very-similar-looking European species called (wonderfully) the Bishop’s mitre (Aelia acuminata) than she did about our domestic species, but she suspects that the two are up to some of the same tricks. 

The Bishop’s mitre (a mitre/miter is a bishop’s peaked, ceremonial hat) is found feeding on grasses in dry meadows and damaging cereal crops across Europe, North Africa, and northern Asia, and the britishbugs.org website added that they may be found in sand dunes, too.  One British site said that the bugs resemble a grass seed (https://www.britishbugs.org.uk/heteroptera/Pentatomidae/aelia_acuminata.html).  They winter in grain fields, in leaf litter and other sheltered spots, and they migrate to wheat fields in spring when the wheat shoots appear (they’re good flyers).  Before the seeds are formed, they feed on juices from the stems of young plants.  After harvest, they move to wild grasses.    

Studies have shown that they enter diapause/dormancy/developmental arrest when the weather gets too hot in summer and go into hibernation when the weather gets too cold in fall.  The increasing day lengths of spring stimulate egg-laying, but if there’s a cold snap, females will stop ovipositing. 

Aelia americana was named by a British entomologist named William Sweetland (W.S.) Dallas (1824 – 1890).  He published a book in 1857 called Elements of Entomology: An Outline of the Natural History and Classification of British Insects which is still in print today and about which the folks at Amazon say “This book is an essential resource for amateur and professional entomologists alike.  This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it.” 

Kate Redmond, The BugLady

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

Bug o’the Week – Moths – Four Very Short Stories

Bug o’the Week
by Kate Redmond

Moths – Four Very Short Stories

Greetings, BugFans,

Everybody likes butterflies (the BugLady would not like to meet the person who dislikes butterflies).  But, in the order Lepidoptera, butterflies are just the tip of the iceberg – the heavy lifting is done by moths.  There are in the neighborhood of 180,000 species of Lepidoptera worldwide (“10% of the total described species of living organisms,” says Wikipedia), and about nine-tenths of them are moths.  Only around 700 of North America’s 12,000 species of Lepidoptera are butterflies.

Moths often languish in the BugLady’s picture files because: A) They can be tough to identify; and B) Most are not notorious enough to have drawn much attention to themselves, so their biographies are hard to find and are more like short stories.

Three of today’s four moths are in the family Geometridae – the “earth-measurers” or “loopers” – so-named for the gait of their caterpillars, the inchworms.  They are slim, well-camouflaged caterpillars with long abdominal segments, but with fewer and reduced abdominal prolegs (the fleshy, unjointed “helper” legs – the six real legs are on the thorax).  Having one set of prolegs toward the front of the abdomen and one set at the rear leaves them with no visible means of support in the middle, so they “inch” – move their front end forward and then hike the rear end up to follow it, measuring the earth as they go.  

About the Geometrids, Wagner, in Caterpillars of Eastern North America, says “Whether measured in terms of abundance or biomass, loopers are among the most important forest lepidopterans in Eastern North America.  They are an especially important component of the spring caterpillar fauna of deciduous forests, where they are a staple in the diets of many forest-nesting birds.” 

The NORTHERN PETROPHORA MOTH(Petrophora subaequaria)

The BugLady found this pretty moth in May at a small, acid bog that she frequents.  The Northern Petrophora moth is a Northeastern moth that is close to the west edge of its range in Wisconsin.  Caterpillars https://bugguide.net/node/view/1503546/bgimage are abroad throughout summer and are oligophagous (they feed on a variety of related plants) – look for them on ferns, including bracken fern.  The caterpillars have been described as “strong jumpers.”  

The COMMON METARRANTHIS (Metarranthis hypochraria)

The caterpillars feed in early summer on a number of trees and shrubs, especially in the genus Prunus (cherries, apples, and plums) and are stick mimics, but mature caterpillars are hard to find.  Wagner speculates that they may move down from the leaves onto the trunk or into the litter by day.  He also says that (of course) “the taxonomy of the group is in need of review.”  Many adults in this genus fly during the day and they often perch on the ground, cryptic against the fallen leaves.     

The THREE-SPOTTED FILLIP (Heterophleps triguttaria)

The BugLady found this small (3/4” wingspan), distinctly-marked moth at the same bog as the Petrophora moth.  It’s found throughout the spring and summer in wet woodlands and marshes from Colorado to Ontario to Quebec to North Carolina, and according to the “Moths of North Carolina” page on the NC Parks website, the majority of its other genus members live in India and China. 

It’s monophagous – it had long been thought that the caterpillar host plant was maple, but caterpillars that were fed maple leaves in the lab wouldn’t eat them, and it turned out that the caterpillars host is Clearweed, a kind of nettle. 

So – what is a “fillip?”  There are several, very diverse meanings, but an archaic one seems to fit in this context, “a movement made by bending the last joint of the finger against the thumb and suddenly releasing it; a flick of the finger.”  “To propel a small object with a flick of the finger.”  “Fillip is considered a phonetic imitation of the sharp release of a curled-up finger aimed to strike something.”  And it turns out that, according to the NC Parks website, “When disturbed the larvae form a tight coil and are known to hurl their frass pellets.”  

And the MORBID OWLET (Chytolita morbidalis) 

The Morbid Owlet is in the family Erebidae and the subfamily Herminiinae, the litter moths, some of whose caterpillars feed on live leaves, while others feed on algae, lichens, fungi, dung, decomposing vegetation or insects, organic stuff they find around animal nests.  Wagner describes them as lethargic caterpillars that avoid the light and that play dead when bothered.  Bugguide.net says that “morbidalis” comes from “morbus,” meaning “disease” and probably refers to the “sickly pale color” of the moth.  The “snout” protruding from the head is formed by the “labial palps,” which have a sensory function in feeding.

Morbid Owlet caterpillars eat dead leaves (they’re detritivores) and low vegetation like dandelions.  Wagner says that “they flatten the rear of the body in a manner that suggests a false head.”

Using her Peterson Field Guide to the Moths of Northeastern North America, the BugLady originally ID’d this moth as a Stone-winged Owlet Moth (Chytolita petrealis), but when she Googled it, it kept coming up as the Morbid Owlet (Chytolita morbidalis).  It appears that a recent taxonomic review of the genus (done after her moth book was published) lists Chytolita petrealis as a synonym of Chytolita morbidalis – basically, same species – and now the only member of its genus north of the Rio Grande.  The Stone-winged Owlet Moth form is said to be smaller and darker than the Morbid Owlet form.  Bugguide.net, whose account must also have been written before the review, lists the habitat of the Morbid Owlet as “deciduous woods and edges; generally drier or less boggy habitat than Chytolita petrealis.”   

Not so fast, says the North Carolina Parks Chytolita petrealis page.  “Chytolita petrealis is currently treated by some authorities to be a synonym of morbidalis, following determination that the type of petrealis was a morbidalis. Prior to that realization, however, the name petrealis had been applied to a distinct and much rarer species in the Southeast. The authors who sunk petrealis did not realize this so our petrealis has no name at the moment. To make things more complicated, there is another undescribed thing like it from the mountains (2-3 specimens known) whereas the petrealis that has been most widely recognized is present primarily in the Coastal Plain.”  And, it goes on to say “The majority of our records come from swamp and floodplain forests, forested shorelines, as well as peatlands and other wet forests.” 

The BugLady found it in that same acid bog as the Petrophora and the Fillip moths.  

Fun Fact about the Northern Petrophora Moth:

The species was described by 19th century British entomologist Francis Walker.  He published like crazy, shared his knowledge generously, and was respected by many of his peers.  Between 1848 and 1873, he worked at the monumental task of cataloging the insects in the collection of the British Museum, a task for which he was paid one shilling for each new species he determined and one pound for each new genus (and where he ended up describing 16,000 species).  Alas, he turned out to be a little careless/enthusiastic, sometimes assigning multiple different scientific names to specimens of the same species.  One source said that he was no worse than many other entomologists of his day – imagine doing a job like that without the kinds of communication, magnifying, and imaging tools we have today – but the huge scale he was working on multiplied his errors. 

After his death, an unsigned obituary began “More than twenty years too late for his scientific reputation, and after having done an amount of injury almost inconceivable in its immensity, Francis Walker has passed from among us.” 

Brutal!

Kate Redmond, The BugLady

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

Bug o’the Week – Saddleback Caterpillar – A Snowbird Special

Bug o’the Week
by Kate Redmond

Bug o’the Week Saddleback Caterpillar A Snowbird Special

Greetings, BugFans,

Today’s bug, the extraordinary-looking and aptly-named Saddle-backed caterpillar, is the 5th in our on-going Snowbird Special series about bugs you might see if you decide to tear yourself away from God’s Country in the winter.  The BugLady doesn’t know why one might consider that – except she’s posting this before dark because there’s a massive storm that’s raining all over her, accompanied by 20-plus mph north winds, and is delivering many inches of snow inland.  She suspects that the power will fail eventually.

Thanks to BugFan Tom in the Deep South for his pictures of this amazing caterpillar.

The Slug caterpillar family Limnacodidae has appeared in these pages before https://uwm.edu/field-station/bug-of-the-week/slug-moths-tale-two-parts/.  Limnacodidae means “snail/slug-form” and refers to its caterpillars, some of which look like space aliens, while others are limpet-shaped.  They have suckers instead of abdominal prolegs https://bugguide.net/node/view/225763/bgimage (prolegs are fleshy, unjointed “legs” that act as anchors, gripping the surface while the true legs (on the thorax) and the muscles in the body work to move it along).  Slug caterpillars exude a lubricant (not slime, like snails and slugs, but a type of liquid silk) that allows them to contact the substrate more completely and to glide/undulate through life.  Some have a smooth exterior, some are bristly, and some, like the Saddleback caterpillar, have fleshy horns decorated with hollow, stinging spines and hairs that will get your attention if you encounter one (more about that in a sec). 

Slug moths tend to be dark, sturdy, and hairy, with wide wings.  They can’t hear and they don’t feed, and they generally live for little longer than a week.  They often perch with the tip of their abdomen raised, though other kinds of moths do that, too.   

The BugLady always thinks of members of this family as belonging to the Deep South (because they have more “sting-y” things down there), but the range of the Saddle-backed caterpillar extends from Massachusetts to Florida to Texas (and points south) to Kansas, and through parts of Illinois (the BugLady saw a few maps that showed the species in far southern Wisconsin).  A number of species of Limnacodids are native to Wisconsin, including:

the Spiny oak slug https://bugguide.net/node/view/2212985/bgimage,

the Crowned slug moth https://bugguide.net/node/view/1938355/bgimage,

and the less-fancy but still lovely Shagreened slug moth https://bugguide.net/node/view/1859138/bgimage, and Skiff moth https://bugguide.net/node/view/446465/bgimage.     

Without further ado, the SADDLEBACK CATERPILLAR (Acharia stimulea).  

Adults fly in June and July in the northern parts of their range and pretty much all year Down South.  The eggs – so transparent that the tiny larvae may be seen inside https://bugguide.net/node/view/2003668/bgimage – are deposited at night in clumps of 30 to 50 on the undersides of the leaves of host plants. 

It’s not hard to find a host plant, because Saddleback Caterpillars eat the leaves of a pretty wide variety of trees, shrubs, wildflowers, grasses, garden plants and horticultural plantings.  Their only stipulation is that the leaves be smooth, not pubescent (hairy) – the rough texture of hairier leaves interferes with their ability to adhere and to move.   

Like other species of slug moths, Saddle-back caterpillars are, initially, gregarious leaf skeletonizers, nibbling at the tender surface of the underside side of a leaf and eschewing the tough leaf veins https://bugguide.net/node/view/954559/bgimage.  As they grow, they take on the whole leaf and eventually become more solitary.  Caterpillars take four or five months to mature (here’s a pretty cool shot of one that just molted https://bugguide.net/node/view/1570339/bgimage). 

About the sharp bits: 

The long, hollow spines contain a “hemolytic and vesicating venom” (a red-blood-cell-destroying and blister-raising venom) and will break away from the caterpillar and embed in whatever bumped/grabbed them (removing the spines gently and immediately with tape is highly recommended, followed by an ice pack) (and maybe an adult beverage).  Are the spines effective? 

Wagner, in Caterpillars of Eastern North America, says that, due to its size and quantity of its stinging spines, “The sting of the Saddleback Caterpillar may be the most potent of any North American caterpillar.” 

One contributor to bugguide.net wrote that “I grabbed a dead looking leaf off my small incubating Rose of Sharon in the evening. After that I don’t remember much. It was horrifying being stung by this well equipped little creature from another planet.”

A Virginia Extension Agent likened it to “getting hit by a jellyfish.”

The spines, which are part of the caterpillars’ redundant defense system, give pause to most vertebrate and invertebrate predators.  The venom can trigger intense pain, hives, migraines, GI issues, asthma, and even anaphylactic shock.  Yet they are vulnerable to tiny parasitic wasps that slip in between the spines and inject eggs into the caterpillar’s body.  The wasp larvae consume the inside of the caterpillar and then crawl outside to pupate in cocoons that look like tiny swabs https://bugguide.net/node/view/79421/bgimage.  And Tom photographed one in the clutches of the awesome nymph of a Giant Strong-nosed stink bug

They spend the winter as pre-pupae, and as they’re preparing to pupate, they intentionally expel fluids and frass from their bodies and shrink by about half.  The result is that the spines are more “concentrated” on their body surface than before.  They also release calcium oxalate (that’s the stuff that makes skunk cabbage poisonous), which forms crystals in the fabric of the cocoon and hardens it.  Spines may also be woven into the silk of the cocoon, too, and scattered around it.  Despite this, there’s still predation on the pupae.   

The Bottom Line: The moth is stunning https://bugguide.net/node/view/752824/bgimage, (and almost no one is sensitive to its hairs).  The caterpillars are cute as a button when they’re kittens https://bugguide.net/node/view/2225127/bgimage and are beautiful when they’re mature (about ¾” long).  The striking pattern of older caterpillars is thought to be aposematic (warning) coloration.  Plus, older caterpillars have a startle reaction that puts their spines at the ready.  Plus, their adhesive abilities mean that if you do bump one, it won’t just drop to the ground, encounter over – it will stick to its spot.  Plus, from the rear, their markings make a scary face https://bugguide.net/node/view/693213/bgimage.  Take the hint (and maybe don’t go barefoot, and maybe don’t grab ahold of a leaf without checking its underside). 

Special Treat – a Spun glass slug https://bugguide.net/node/view/2211409/bgimage (very young), and older https://bugguide.net/node/view/1480728/bgimage, https://bugguide.net/node/view/990165/bgimage, https://bugguide.net/node/view/9412/bgimage.

Special Thanks to the awesome folks at the University of Wisconsin Milwaukee who format the episodes and archive them on the Field Station website (and make them look good!).

Kate Redmond, The BugLady

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

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